우리나라 한중콘크리트 적용기간의 변화에 관한 고찰

한민철,김경민,신동안,윤기원,한천구 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

In this paper. variations of the period of cold weather concrete in Korea are discussed based on the climate data of Korean Meteorological Adminstration(KMA). Determination of the period of cold weather concrete with the region is done by following Korean Concrete Institute(KCD, American Concrete Institute(ACD and AIJ(Architectural Institute of Japan(AIJ) specification. Present study is compared with previous study done by the authors. Period of cold weather concrete is found to increase with high altitude and in-land and mountain area. Period of cold weather concrete by present study is shorted compared with that of previous study by about 3~6 days regardless of applied specification. Especially. the period of cold weather concrete at southern region near sea is reduced remarkably compared with that of previous study. This is due the rise of mean air temperature by global warming. In the scope of present study, period of cold weather concrete is provided with table and map diagram.

슈미트햄머의 반발도 및 초음파속도에 미치는 결합재의 영향

한민철,이백수,윤기원,최영화,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This paper reports the influence of kinds of cement and replacing ratio of fly ash(FA) and blast furnace slag powder(BS) on estimation of compressive strength by non-destructive test. According to the results, the compressive strength, the rebound value of schmidt hammer and ultrasonic pulse velocity show the higher value in order of AMC, UHC and OPC. In concrete replaced with mineral admixture, they are lower at early age, but higher at the age of 91 days compared with plain concrete. As the influence of the kinds of cement, estimated compressive strength by Schmidt hammer is almost same in the case of UHC, but much lower at the same rebound value in the case of AMC, in comparison with OPC. But the influence of mineral admixture is very insignificant. Compressive strength estimated by ultrasonic pulse velocity method shows the higher value by 10MPa, 12.5MPa in the case of UHC and AMC respectively compared with OPC, and the influence of mineral admixture on ultrasonic pulse velocity is insignificant.

Antioxidant Activity and Whitening Effect of Lindera erythrocarpa Extract

Min ?Chul Kang,Ryeo Kyeoung Ko,Ju-Yeop Lee,Haeng-Bum Kim,Bong-Seok Kim,Jong-Heon Han,Seong-Hyun An,Gi-Ok Kim 한국생물공학회 2008 한국생물공학회 학술대회 Vol.2008 No.10

형질전환 제초제저항성 벼 밀양 204호의 농업적 특성

정응기,이기환,원용재,박향미,전남수,최준호,구연충,한창덕,은무영,김태산,남민희 Plant molecular biology and biotechnology research 2005 Plant molecular biology and biotechnology research Vol.2005 No.

This study was conducted to investigated the major characteristics of genetically modified rice of "Milyang 204" originated from Dongjinbyeo compared to a non-transgenic rice varieties Dongjinbyeo and Junambyeo. Basta resistant transgenic rice lines carrying bar gene produced by the Yeongnam Agricultural Research Institute were evaluated for their agronomic characters. The transgenic Japonica rice of "Milyang 204" showed inferior phenotypic traits compared to a non-transgenic rice variety Dongjinbyeo and Junambyeo. On the basis of UPOV (Union Internationale Pour la Protaection des Obtentions Vegetables) and NSMO(National Seed Management Office) the transgenic "Milyang 204" showed difference in some traits out of some agronomic traits, such as leaf color, angle of flag leaf, number of spikelets, culm length, white core and white belly compared to the nontransgenic varieties rice.

회수수에 당류계 안정화제를 처리한 시멘트 모르터의 특성

金虎林,우종완,한민철,류현기,한천구 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

In this paper, fundamental properties of cement mortar using recycled water with stabilizing agent are discussed in order to investigate the applicability of recycled water. Stabilizing agent content, solid contents and open time are varied in this paper. For fresh mortar properties, highest fluidity with 0.15% of stabilizing agent was observed and air content was increased with an increase in stabilizing agent contents. Solid contents and open time of recycled water had nothing to do with fluidity and air content loss. Little difference in setting time was found with the presence of stabilizing agent and without, while it was accelerated with an increase in open time and solid content. For strength properties, the highest strength value was observed at 0.15% of stabilizing agent. An increase in solid contents resulted in an enhancement of strength, while strength decreased with an increase in open time and elapse of age. Drying shrinkage exhibited a reduction with an increase in stabilizing agent contents and open time. From the present paper, the combination of 0.15% of sacharic based stabilizing agent, 3% of solid content and 1day of open time is found to be an optimal condition to perform effectively.

시멘트의 분말도 변화에 따른 시멘트 모르터의 역학적 특성

文學龍,김경민,전충근,윤기원,양성환,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

This study discusses the influence of fineness of cement on mechanical properties of cement mortar. According to the result, compressive strength increases in order of C>B>OPC>A and C>B>A>OPC at mixture proportion of 1:1 and 1:3 respectively. An increase of compressive strength by increase of fineness of cement is because internal structure of concrete grows dense by an increase of hydration reaction. As for curing condition, compressive strength is higher in standard curing than in air curing at mixture proportion of 1:1 and 1:3. There is not any tendency of strength development with age and fineness of cement by 91days. Length change by drying shrinkage increases in order of C>B>OPC>A at mixture proportion of 1:1 and 1:3 due to an increase of water content by variation of W/C.

술후 진통을 위해 투여한 Ketorolac이 혈액응고 기능에 미치는 영향 : 혈전탄성묘사도를 이용한 평가 A Thromboelastographic Evaluation

최인범,고성훈,김동찬,한영진,최훈,민기철 대한마취과학회 2002 Korean Journal of Anesthesiology Vol.43 No.6

Background: Thromboelastography (TEG) has recently become popular for assessment of whole blood coagulation in the operating room. Ketorolac, a potent injectable nonsteroidal anti-inflammatory drug (NSAID), is commonly used for postoperative analgesia. NSAID inhibit plated aggregation in coagulation process. This study was designed to determine whether ketorolac used for postoperative analgesia can affect hemostatic function using a TEG. Methods: Seventy-four female patients, ASA physical status 1 or 2, scheduled for an elective gynecologic surgery were randomly allocated into one of four groups (Group 1: n=10, control without patient-controlled analgesia (PCA); Group 2: n=21, PCA with morphine 60 mg; Group 3: n=20, PCA with morphine 30 mg + ketorolac 90 mg; Group 4: n=23, PCA with ketorolac 180 mg). Blood samples were obtained for TEG analysis preoperatively and 24, 48 and 72 h after surgery. Cumulative drug dosage, visual analog pain scale, satisfaction degree and side effects were measured at 24, 48 and 72 h after surgery. Results: There were no significant differenced in TGE parameters among the four groups at each time. There were no significant differenced in visual analog pain scales and satisfaction degree among the three groups using PCA for postoperative analgesia. Among the three groups using PCA for postoperative analgesia, Group 2 experienced more side effects. Conclusions: Ketorolac does not affect hemostatic function for 3 days after surgery when administrated as a PCA drug. (Korean J Anesthesiol 2002; 43: 755~762)

주물공장 근로자에서 발생한 국한성 석면폐증 1예

김태우,고동희,김민기,유승원,류향우,한정희,정순희 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

배경: 주물공장 근로자에서 발생한 석면폐증의 작업 관련성을 평가하고 그 증례를 보고하고자 한다. 증례: 30년간 주물공장에서 근무한 환자로 인후통, 기침, 노란 가래가 있어 검사한 결과 결핵이 의심되어 치료 하였으며, 치료 중 석면폐증으로 진단되었다. 작업 관련성 평가를 위해 실시한 폐 조직의 조직학적 검사에서 1 cm^(2)당 3개의 석면소체가 발견되었고, 투과전자현미경으로 분석한 석면 함유량은 23.26x10^(6) fibers/g이었다. 결론: 작업환경조사, 폐 조직의 석면 분석 등을 통해 작업 관련성이 높다고 판단하였다. Background: Foundry workers are known to be exposed to silica and have an increased risk of Silicosis. There are also reports that state these foundry workers were associated with asbestos-related change in the X-ray results of the lungs. This report discusses a case of localized asbestosis developed in a foundry worker who worked in 12 Korean foundries. Case report: A 49-year-o1d man who worked at molding and melting for 30 years, Presented with sore throat, cough and yellow sputum for 1 month. From physical and clinical examination, Pulmonary tuberculosis was highly suspicious; therefore, he was medicated for 6 months. After tuberculosis medication, the radiological finding was reactivation of tuberculosis, and an asbestos body was detected at a trans-bronchial lung biopsy. During an operation, operators found multiple palpable masses and bullae 10calized in the right upper lobe (RUL) and performed right upper lobectomy and right middle lobe wedge resection. Using hematoxylin-eosin stain and iron stain, we could detect asbestos bodies by light microscopy. We analyzed the asbestos fiber burden in dry lung tissue by transmission electron microscopy with energy dispersive X-ray spectrometer (TEM-EDX). The fiber type was chrysotile and the fiber burden was 23.26 x 10^(6) fiber/g dry lung. Discussion: This case study of a foundry worker with localized asbestosis is uncommon in Korea. We found an occupational relationship between the foundry worker and localized asbestosis through various investigative techniques such as measurements taken at his working environment, clinical, radiological and pathological examination of the foundry worker and mineralogical examination of the asbestos fiber.

공명초음파분광법을 이용한 광컨넥터용 결합소자의 비파괴 검사

김성훈,조영재,백경윤,양순호,민한기,양인영 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

본 연구의 목적은 비파괴 평가방법인 공명초음파분광법(RUS)을 사용하여 세라믹제 페롤과 볼렌즈의 결함과 형상오차를 평가하는 것이다. RUS시스템은 스펙트럼에너라이저,파워 엠플리파이어,압전진동자센서와 지지프레임으로 구성되어진다. RUS 시스템에 의한 페롤과 볼렌즈의 비파괴평가를 위해 본 연구에서는 각 시험편에 대한 공진주파수를 측정하였으며,측정된 공진 주파수의 비교분석에 의해 결함의 유 · 무를 판별하였다. 그 결과 페롤의 경우,크랙을 갖는 페롤의 공진주파수 대역이 양품페롤의 공진 주파수 대역보다 고주파대역으로 이동함을 알 수 있었으며,볼렌즈의 경우,시험편 질량이 감소함에 따라 공진주파수 대역이 고주파 대역으로 이동함을 알 수 있었다. 또한 볼렌즈의 공진주파수가 측정되는 대역을 예측할 수 있는 파라메타인 β를 설정하여 그 결과를 고찰하였다. The objective of this paper is to evaluate the defect and shape error of a ceramic ferrule and ball lens by Resonant Ultrasound Spectroscopy(RUS) method. RUS system is consisted of spectrum analyzer, power amplifier, PZT sensor, and support frame. For nondestructive evaluate by using RUS system, first of all, we measured the natural frequency of each specimen, and we decided on the shape and size of flaw by measured natural ferquencies. And then, in the case of ferrule, natural frequency bandwidth of ferrule with crack was higher than acceptable ferrule. As mass of ball lens decreased, natural frequency bandwidth was shifting to high-frequency range. Thus, we discussed on the relationship between β and mass of ball lens, which β is parameter that we can predict measurable natural frequency bandwidth of ball lens.

Ethanosolv 전처리에 의한 보릿짚의 리그닌 제거

김영란(Youngran Kim),유안나(Anna Yu),정봉우(Bongwoo Chung),한민희(Min-hee Han),최기욱(Gi-wook Choi) 한국생물공학회 2009 KSBB Journal Vol.24 No.6

본 연구에서는 바이오 에탄올 생산을 위한 보릿짚의 전처리에 ethanosolv 방법을 적용하여 그 타당성을 조사 하였다. 리그닌제거율은 처리 온도와 시간에 따라 증가 하였으며 180℃, 200℃에서 거의 38%정도의 비슷한 제거율을 보였는데 비용절감 등의 부분을 감안할 때 80℃, 120 min가 적정조건이라는 결론을 얻었다. ethanosolv 전처리 효과를 증대시키기 위하여 2단계의 전처리 방법을 적용하였다. 볶은 후 ethanosolv 한 보릿짚의 경우 리그닌 제거율은 35%정도로 그렇지 않은 경우와 거의 유사하여 볶음이 리그닌제거율에 큰 영향을 미치지 않음을 확인 할 수 있었다. XRD분석을 통하여 전처리 시간과 온도가 증가할수록 결정성은 감소하였다. 볶은 후 ethanosolv 한 것과 ethanosolv 단독 처리한 보릿짚 사이의 결정성은 미소 하지만 물리적 변형을 한 단계 더 겪은 볶은 보릿짚이 전체적으로 낮게 나타났다. Lignocellulose represents a key sustainable source of biomass for transformation into biofuels and bio-based products. Unfortunately, lignocellulosic biomass is highly recalcitrant to biotransformation, both microbial and enzymatic, which limits its use and prevents. As a result, effective pretreatment strategies are necessary. The vast majority of pretreatment strategies have focused on achieving a reduction of lignin content. In this work, an ethanosolv pretreatment has been evaluated for extracting lignin from barley straw. 75% ethanol was used as a pretreatment solvent to extract lignin from barley straw. The influence on delignification of three independent variables are temperature, time, catalyst (1 M H₂SO₄) dose. The best pretreatment condition observed was 180℃, 120 min, 0.2% H₂SO₄ and delignification was 38%. A combined roasting and ethanosolv, 2-step pretreatment, was developed in order to improve the delignification. Roasting didn"t increase the delignification but reduced the pretreatment time. X-ray diffraction results indicated that these physical changes enhance the enzymatic digestibility in the ethanosolv treated barley straw. The cellulose in the pretreated barley straw becomes more crystalline without undergoing ethanosolv.