• 제목/요약/키워드: Time elapse

검색결과 157건 처리시간 0.029초

희생양극재의 매입에 의한 콘크리트 중의 전기방식 효과 (Effects of the Protection for Rebars by Embeded Sacrificial Anode in Concrete)

  • 김성수;김홍삼;김종필
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
    • /
    • pp.1207-1212
    • /
    • 2001
  • Reinforced concrete has defects in durability due to carbonation, freezing and thawing, and penetration of chloride ions with elapse of time in spite of super structure. Especially steel corrosion in concrete due to penetration of chloride ions has result in a severe decline in service life. The principal purpose of this study is to estimate effects of sacrificial anode cathodic system, one of the electrochemical methods in order to control of steel corrosion in concrete. There are chloride content in concrete in cracked and non cracked specimen with cathodic protection. To investigate the effect of sacrificial anode cathodic protection, potential-decay with current density, corrosion ratio, etc. are measured. We have the excellent effect for control steel corrosion adaption sacrificial anode cathodic system.

  • PDF

미니멀리즘을 통한 현대실내공간의 한국성 표현에 관한 연구 (A Study on the expression Korea Characteristics of Contemporary Interior Space by Minimalism)

  • 이창윤;오인욱
    • 한국실내디자인학회논문집
    • /
    • 제20호
    • /
    • pp.33-39
    • /
    • 1999
  • Nowadays minimalism has influence on Korean Architecture and Interior Architecture at the turning of new generatiov. Minimalism is a plural phenomenon that has developed from Modernism to Contemporary but there is the tendency to define minimalism within Architecture and Art. Also it is a fact that there are many disordered minimal aspects in Architecture. This study is started from accurate understanding the mistakes in the field of Interior Architecture, that are brought by the elapse of time, and analogizing the circumstances of Interior Architecture in the field of Architecture. Especially the purpose of this study is to grasp the relation between the minimal characteristics of Korean traditional Architecture and the stagnancy of Korean Architecture. Under the assumption that the characteristics of minimalism exist in Korean tradition, this study contents the characteristics of minimalism in western modernism to analyze the contemporary Korean Architecture and interior Architecture that the assumption is appled to.

  • PDF

콘크리트의 블리딩에 미치는 혼화제의 영향 (Influence of Chemical Admixture on Bleeding of Concrete)

  • 김은호;황인성;손유신;김규용;한천구
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.339-342
    • /
    • 2003
  • This study is intended to investigate the influence of chemical admixture on bleeding of concrete. According to the results, the amount of bleeding with elapse of time does not make much difference in the case of naphthalene type water reducing agent(RN), Naphthalene type high performance water reducing agent(HN) and Melamine type high performance water reducing agent(HM), but it is largest in the case of Polycarbonic acid type high performance water reducing agent(HP). Bleeding speed also is highest in the case of HP in comparison with other chemical admixture. This prove that high performance water reducing agent like HP has little effect on fluidity of concrete, but influences the amount of bleeding more greatly, instead. As properties of hardened concrete, compressive strength makes no difference in the case of RN, HN and HM, but on the other hand, it increases in the case of HP due to a decrease of air content and the large amount of bleeding.

  • PDF

선박용 디젤엔진 과급기 로터 접합체의 부식특성에 미치는 비틀림응력의 영향 (Effects of Torsional Stress on the Corrosion Characteristics in the Rotor Assembly of Marine Diesel Engine Supercharger)

  • 조상근;공유식;김영대
    • 동력기계공학회지
    • /
    • 제9권1호
    • /
    • pp.50-56
    • /
    • 2005
  • The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded torsional stress. The surface corrosion pattern of SCM440 area was showed global corrosion and narrow pitting, that was cause by galvanic corrosion between friction welded IN713LC and SCM440. But corrosion does not proceeded from IN713LC area. Initially, the average relative electrode potential and corrosion current were decreased suddenly, by and large, it was stabilized gradually tend to decreasing with the elapse of the immersion time. The corrosion rate was decreased by increasing the load stress, but 200 MPa specimen was showed most large value.

  • PDF

TLC와 컬러화상처리를 이용한 자동차 실내 환기유동의 온도장 측정 (Temperature Field Measurement of Ventilation Flow in a Vehicle Interior)

  • 윤정환;이상준;김기원
    • 한국자동차공학회논문집
    • /
    • 제5권1호
    • /
    • pp.120-128
    • /
    • 1997
  • The variations of the temperature field in a passenger compartment were measured by using a HSI true color image processing system and TLC(Thermochromic Liquid Crystal) solution. This temperature measurement technique was proved to be useful for analyzing the ventilation flow. The flow field in the passenger compartment was visualized using a particle streak method with pulsed laser light sheet. The temperature field and flow field in the passenger copartment were affected significantly by the ventilation mode. The panel-vent mode heating had shorter elapse time to reach a uniform temperature than the foot-vent mode under the same ventilation condition and nonuniformity inside the passenger compartment could be minimized effectively by using the bilevel heating mode. The temperature increase rate in the rear passenger compartment was iower than the front compartment, especially in the vicinity of the rear seat occupants' knee level.

  • PDF

The Rotational Speed measurement of three-phase Induction Motor by use of delivering unbalanced input from PWM Inverter

  • Okauchi, Shouji;Aoshima, Nobuharu
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
    • /
    • pp.413-418
    • /
    • 1998
  • We often use induction motor in the hard environment including vibration and high ambient temperature, or in maintenance free operation, because induction motor has durable and simple structure. However, when we use it as servo actuator or accurate speed control motor, we have to equip sensor such as encoder and tachogenerator with the motor control system. And generally those sensor's abilities against bad environment are less than the induction motor itself, So if we can remove these sensors from the system, it'll have more environmental resistance, and the cost will also be reduced. Actually this removal has been achieved in limited field. However, that needs complex calculations and a certain elapse time for data processing. In our study, we intended to estimate the rotational speed from the motor current instead of speed sensor, easily and rapidly in comparison to former methods.

  • PDF

유화처리 바이오디젤이 도포된 콘크리트의 침투깊이 판정 (Evaluation of Penetration Depth of Emulsified Refined Bio Diesel Applied to the Concrete)

  • 백철;김태우;이재진;이동윤;한민철;한천구
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2017년도 추계 학술논문 발표대회
    • /
    • pp.17-18
    • /
    • 2017
  • This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

  • PDF

신장율 변화에 의한 폴리프로필렌 필름의 정전기 대전 특성 (Electrostatic Electrification Properties of Polypropylene Film due to Elongation Transition)

  • 이성일;김상현
    • 한국전기전자재료학회논문지
    • /
    • 제23권1호
    • /
    • pp.48-52
    • /
    • 2010
  • This paper examined the effects of specimen elongation on the electrostatic electrification voltages when polypropylene film specimens with 500%, 650% and 700% elongations were rotated at 1550 rpm. The results were as follows. The decease of electrification voltage was not measured according to the time elapse, in case of elongated specimens with 70% environment humidity. As +10 kV was applied to the specimens with 650% elongations, the electrostatic electrification voltages were increased by the effect of environment humidity (1.23~1,25 kV at 50~60% humidity, and 1,46 kV at 70% humidity). The voltages were decreased to 1.2 kV at 700% elongation. As -10 kV was applied to the specimens with 500%, 650% and 700% elongations, the electrostatic electrification voltages were negatively increased with the increase of environment humidity and the elongation of specimens.

Hadoop 상에서 MapReduce 응용프로그램 평가 (Performance Evaluation of MapReduce Application running on Hadoop)

  • 김준수;강윤희;박용범
    • 소프트웨어공학소사이어티 논문지
    • /
    • 제25권4호
    • /
    • pp.63-67
    • /
    • 2012
  • 다양한 분야에서 빠르게 대용량의 자료가 생성됨에 따라 이를 처리하기 위해 분산 프로그래밍 모델인 MapReduce의 활용이 도입되고 있다. 본 논문에서는 SUN Blade150에 Solaris와 Linux 환경의 클러스터 시스템을 구축한 뒤 해당 환경에서의 MapReduce 미들웨어인 Hadoop 에서 응용수행에 대한 평균 시간 및 표준 편차를 평가하여 Hadoop 기반 MapReduce 구현이 어떠한 클러스터 시스템에 의해 성능이 영향을 미치는지를 보인다.

  • PDF

저산소성 뇌손상의 자기공명영상 소견: 유병기간 및 예후와의 연관성 (MR Findings of Hypoxic Brain Damage: Relation to Time Elapse and Prognosis of Patients)

  • 서경진;강채훈;유동수;김상준
    • Investigative Magnetic Resonance Imaging
    • /
    • 제10권1호
    • /
    • pp.8-15
    • /
    • 2006
  • 목적 : 저산소성 뇌손상의 자기공명영상(MR) 소견을 유병기간 및 예후와 연관 지어 알아보고자 하였다. 대상 및 방법 : 임상적으로 저산소성 뇌손상으로 진단된 환자 18명의 19예의 MR을 대상으로 분석하였다. MR은 저산소증 발생 후 1일에서 20일(평균 8.6일)사이에 시행되었으며, 대상환자의 T1 및 T2 강조영상에서 비정상 고신호강도 병변의 위치, 뇌부종의 동반 유무 및 시간경과와 예후에 따른 병변의 양상을 분석하였다. 결과 : 전체 19예의 MR영상에서, T2 강조영상에서의 고신호강도 병변은 기저핵(15예, 78.9%), 뇌피질(13예, 68.4%), 뇌백질(9예, 47.4%), 시상(6예, 31.6%), 소뇌(4예, 21.1%), 뇌간(1예, 5.3%)의 순으로 관찰되었다. 뇌피질의 병변은 모든 경우 심부회색질에도 이상소견을 동반 하였으며 양측성, 미만성의 병변을 보였고, 뇌피질 대부분 또는 두정 후두엽에 국한되어 나타났다. 뇌피질 및 심부회색질의 T2 강조영상에서의 고신호는 급성기(6일이내)부터 아급성기(6일이후)에 걸쳐 1예를 제외한 전 예에서 다양한 정도로 있었다. 뇌간이나 소뇌의 침범은 비교적 드물었고 모두 뇌피질의 병변이 동반되어 관찰되었다. 뇌백질의 병변도 대부분 아급성기에 뇌피질과 심부회색질의 병변이 있을 때 발생했지만 양측성 분수경계역 뇌경색의 소견으로 단독 침범한 경우도 1예 있었다. T1 강조영상에서의 고신호강도 병변은 뇌피질 및 심부회색질에 주로 아급성기에 관찰되었으나, 급성기에도 일부 관찰되었다. 뇌부종은 11예에서 급성기, 아급성기에 걸쳐 관찰되었다. 의식이 회복된 환자의 MR에서 뇌피질의 침범이나 뇌부종의 빈도가 적었다. 결론 : 저산소성 뇌손상의 MR소견은 다양하지만, 거의 대부분 뇌피질과 심부 뇌회색질을 침범하는 양측성 미만성의 병변으로 나타났다. 뇌백질의 병변은 아급성기 이후에 주로 나타나나 급성기의 혹은 단독의 병변으로도 나타날 수 있다. 뇌피질의 침범정도가 경미하거나 뇌부종이 미약한 경우 예후가 좋았다.

  • PDF