조강 및 포조란시멘트 의결경화촉진이 콘크리트 강도에 미치는 영향에 관한 연구

전현우 한국농공학회 1972 한국농공학회논문집 Vol.14 No.3

시멘트의결경화촉진(疑結硬化促進)으로 콘크리트의 초기압축강도(初期壓縮强度)를 얻음으로서 한중(寒中)콘크리트 공사시(工事時) 동해(冬害)를 예방(豫防)하고 보다 안전(安全)하게 구조물(構造物)을 축조(築造)하는데 도움을 얻고자 일반(一般) 포트랜드시멘트(TYPE I) 조강(早强)시멘트(TYPE II) 및 포조란시멘트를 사용(使用)하여 본시험(本試驗)을 실시(實施)한 것이다. 이상(以上)의 결과(結果)를 요약(要約)하면 다음과 같다. 1. 보통(普通)포트랜드시멘트(TYPE I) 보다 조강(早强)시멘트(TYPE II)가 초기강도(初期强度)가 높았고, 2. 조강(早强)시멘트로 만든 콘크리트 초기강도(初期强度)의 증진(增進)으로 공기(工期)를 최대한(最大限)으로 단축(短縮)시킬수 있어 한중(寒中)콘크리트 공사시공(工事施工)에 적합(適合)하겠다. 3. 조강(早强) 및 포조란은 높은 분말도(粉末度)로 외기(外氣)에 대(對)한 풍화작용(風化作用)이 촉진(促進)될 우려(憂慮)가 있으므로 저장기간(貯藏期間)이 짧아야 하겠다. 4. 국내(國內)에서 생산(生産)되는 포조란시멘트가 조강현상(早强現象)을 나타냄으로 이에 대(對)한 시험(試驗)이 계속 필요(必要)하겠다. 이상(以上)의 결과(結果)는 공사현장(工事現場)에서 유효하게 적용(適用)될 것으로 믿는다. This study was carried out to search for an effect on strengths of a pozzolan and a high-early strength cements due to accelerating the initial setting and a rate of strength development at early age, and to obtain the effects applicable for structural construction works safety in the cold winter weather. The results of the study were as follows: 1. The early strength of high-early strength cement was higher than an ordinary portland cement(Type I). 2. High-early strength cement had a characteristic suitable for construction works in the cold weather due to the rate of acceleration of the eary strength. 3. When using pozzolan cements, a weight proportion should be considered in mix design since the pozzolan cement has a lower specific gravity than other portland cements. 4. It was desirable for the pozzolan cement to shorten the storage period since particles of the pozzolan cement was so fine that it was likely to weathering.

2P-374 Biosynthesis β-amino acid using ELP-fused ω-transaminase.

전현우,윤상한,( Sharad Sarak ),( Mahesh Patil ),유소정,윤형돈 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

Market Myopia - The Research about Response of Stock Price of R&D Investment Disclosure

전현우,정용화 한국상업교육학회 2009 상업교육연구 Vol.23 No.4

This paper investigates the market's response about long-term investment disclosure after separating the stock market before and after Financial crisis and analyse to focus on market myopia. First, we studied the end of the year settlement firm among the manufacturing industry that were made during the period 1993 to 2002 where the firm was listed on KRX. As a result, in market myopia, the hypothesis that R&D announcement happens negative move of stock price is rejected. R&D announcement of stock market is regarded as the positive signal which will produce the increasing of corporate income. Second, We divided the data into two samples by starting from Financial crisis. The first sample consists of the firm during 1993 to 1997, and the second sample consists of the firm during 1998 to 2002. Also we redivided each samples into three samples by own ratio.As a result, market myopia didn't exist before Financial crisis, but it existed after Financial crisis. As mentioned above, Investors don't think that any invest bring high expected cash flow to them because market circumstance is changed and uncertainty increase. Exactly, this implies the occurrence of the Market Myopia.

[전기인의 맛집] 경주를 닮은 곳, 고두반

전현우 대한전기협회 2016 전기저널 Vol.- No.477

공기청정기의 현장적용평가를 통한 의료기관 내 공기오염물질 저감효율 파악

전현우,손종렬,최정숙,정백영,김주혁 한국퍼실리티매니지먼트학회 2019 한국퍼실리티매니지먼트학회지 Vol.14 No.2

According to a recent report on indoor air quality map conducted by the Ministry of Environment (2016-2017), the importance of indoor air quality in hospitals has emerged, with total airborne bacteria (82.3% and 149 cases) showing the highest number of facilities exceeding maintenance standards by contaminant. In particular, interest in the hospital environment is increasing as it is the living space of patients who are mostly vulnerable to pollutants. This study introduced an air purifier with decontamination function within the hospital facility, and the site application evaluation of the air purification system is given as a table of contents. The measurement items for the site application evaluation are fine dust, gross airborne bacteria, fungi, temperature and humidity, and the measuring equipment for each item is grimm dust spectrometer (model 1.108), Mars-100, and HOBO MX 1101. In the case of fine dust, the variation of fine dust can be seen through the measurement of the mining equation, and in the case of floating microorganisms (total airborne bacteria, bear Pangi) the impact method specified in the indoor air quality process test standards was collected, cultivated and quantified. Data were collected for conversion to CFU by counting after incubation of bioaerosol in case of temperature and humidity. The reduction efficiency is presented by comparing data before and after operation of the air purifier

우폐하에 위치한 심막낭종 459 -1예 보고-

전현우,심성보,사영조,박재길,이선희 대한흉부외과학회 2007 Journal of Chest Surgery (J Chest Surg) Vol.40 No.6

심막낭종은 매우 드문 종격동 양성종양으로 대부분 우측 심장횡경막각에서 발생한다. 그러나 흉곽 내의 다른 부위에서도 드물게 발생할 수 있으며, 이런 경우 종격동에서 기원하는 다른 낭종 질환과의 감별진단에 주의를 기울여야 한다. 본 증례는 비전형적인 병소인 폐하부에 위치한 심막낭종을 비데오 흉강경을 이용하여 낭종제거술을 시행하고 문헌고찰과 함께 보고하는 바이다.

GPS 와 대기오염측정망 자료를 이용한 PM10 개인노출 추정 및 평가

전현우,황윤형,이기영 한국환경보건학회 2022 한국환경보건학회 학술대회 자료집 Vol.2022 No.5

培養한 人體口腔 上皮細胞의 成長에 미치는 Epidermal Growth Factor의 影響

全鉉禹,朴鍾琇,李永卓,李仁洙,朴周鴻,曹永俊,高光三 中央醫學社 1988 中央醫學 Vol.53 No.4

Single Incision Thoracoscopic Left Lower Lobe Superior Segmentectomy for Non-Small Cell Lung Cancer

전현우,최수환,현관용,왕영필 대한흉부외과학회 2014 Journal of Chest Surgery (J Chest Surg) Vol.47 No.2

Lobectomy with mediastinal node dissection has been standard treatment for non-small cell lung cancer (NSCLC). Nowadays, video-assisted thoracoscopic surgery (VATS) is gaining acceptance as an alternative treatment option, given the quality-of-life benefits that it confers. For the VATS procedure, most surgeons create two or three ports with a utility incision of 3 to 5 cm. However, with acquired skill and instrumentation advances, single-incision thoracoscopic surgery has emerged over time. Here, we report the case of an 86-year-old female with NSCLC treated by single-incision segmentectomy.

혼화제인 염화칼슘이 콘크리트 강도에 미치는 영향에 관한 연구

전현우,임종국,Jun, Hyun-Woo,Lim, Chong-Kook 한국농공학회 1971 한국농공학회논문집 Vol.13 No.4

한중(寒中)콘크리트 시공(施工)에 염화(鹽化)칼슘사용(使用)은 콘크리트의 초기강도(初期强度)를 최대한(最大限)으로 높여 동해(凍害)를 방지(防止)함과 경제적(經濟的인 구조물(構造物)을 만들고자 하는데 목적(目的)이 있으며 시험결과(試驗結果)로서 그의 범위(範圍)를 요약(要約)하면 다음과 같다. 1. 염화(鹽化)칼슘을 시멘트중량비(重量比) 1.5%를 TYPE I TYPE II에 혼합(混合)하면 초기강도(初期强度)를 최대한(最大限)으로 증진(增進)할 수 있고 구조물(構造物)의 안전(安全)을 위(爲)해서 1.5%내외(內外)가 적합(適合)하겠다. 2. 염화(鹽化)칼슘을 혼합(混合)하여 동결(凍結)의 위험(危險)을 방지(防止)하기 위한 콘크리트를 만들자면 w/c비(比)를 50% 내외(內外)로 정(定)해야 만이 한중(寒中)에 안전(安全)하겠다. 3. 포조란 초기강도(初期强度)는 떨어지나 후기강도(後期强度)가 점차(漸次)로 상승(上昇)한다. 4. 콘크리트의 초기강도(初期强度)의 증진(增進)으로 양생기간(養生期間)을 최대한(最大限)으로 단축(短縮)시킬 수 있으므로 콘크리트 구조물(構造物)의 끝손질을 조기(早期)에 실시(實施)해야 한다. 염화(鹽化)칼슘의 혼입(混入)은 시멘트응결(凝結)을 촉진(促進)시킬 수 있어 한중(寒中)에 있어서 동해(凍害)를 방지(防止)하고 공기(工期)를 최대한(最大限)으로 단축(短縮)시킬 목적(目的)으로 공사시공(工事施工) 현장(現場)에서는 유효히 사용(使用)될것으로 사료(思料)된다. In many cold weather concrete constructison jobs calcium chloride $CaCl_2$ can be used safely as an accelerating admixture. For producing satisfactory concrete during cold weather calcium chloride is used to develop the level of strength required in a shorter period by obtaining higher early strength, the resulting in crease in heat of hydration. In this paper, to get adequated data and information of the effect on strength of concrete in using calcium chloride as an accelerating admixture, Portland cement (Type I), High-early-strength cement(Type II) and Pozzolans cement with certain 1.5 percentage of calcium chloride by weight of the cement were tested. As the result of this experiment, followings were founded: 1. At the 1.5 percent of calcium chloride cement ratio, the early strength was accelerated to the highest level, and some 1.5 percent of calcium chloride cement ratio was suitable for the stabilization of the concrete structures. 2. For Some 50 percent of Water Cement ratio was suitable, making good Concrete in the Cold weather by admixture of Calicum Chloide. 3. The concrete of Pozzorans cement in early strength was weak but that in later rised by degree. 4. As abtaining higher early strength the curing period can be reduced, but the finishing work should be done as early as possible.