• 제목/요약/키워드: EC2-94

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Comparison between ACI 318-05 and Eurocode 2 (EC2-94) in flexural concrete design

  • Hawileh, Rami A.;Malhas, Faris A.;Rahman, Adeeb
    • Structural Engineering and Mechanics
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    • 제32권6호
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    • pp.705-724
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    • 2009
  • The two major widely used building design code documents of reinforced concrete structures are the ACI 318-05 and Eurocode for the Design of Concrete Structures EC2. Therefore, a thorough comparative analysis of the provisions of these codes is required to confirm their validity and identify discrepancies in either code. In this context, provisions of flexural computations would be particularly attractive for detailed comparison. The provisions of safety concepts, design assumptions, cross-sectional moment capacity, ductility, minimum and maximum reinforcement ratios, and load safety factors of both the ACI 318-05 and EC2 is conducted with parametric analysis. In order to conduct the comparison successfully, the parameters and procedures of EC2 were reformatted and defined in terms of those of ACI 318-05. This paper concluded that although the adopted rationale and methodology of computing the design strength is significantly different between the two codes, the overall EC2 flexural provisions are slightly more conservative with a little of practical difference than those of ACI 318-05. In addition, for the limit of maximum reinforcement ratio, EC2 assures higher sectional ductility than ACI 318-05. Overall, EC2 provisions provide a higher safety factor than those of ACI 318-05 for low values of Live/Dead load ratios. As the ratio increases the difference between the two codes decreases and becomes almost negligible for ratios higher than 4.

West electric '94를 다녀와서

  • 김용삼
    • 전기의세계
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    • 제43권5호
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    • pp.53-55
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    • 1994
  • 미국에서 발간되는 전기잡지인 EC & M(Electrical Construction and Maintenance)사에서 후원하는 전기기자재 전시회가 금년에는 2월 8일에서 10일까지 샌프란시스코 Moscon convention 센터에서 개최되었다. EC&M 잡지를 수년간 구독하는 입장에서 미국의 전기기자재 전시회는 어떤 방식으로 개최되고 출품되는 품목은 무엇이고 또 전시회와 동시에 열리는 세미나는 어떤 내용을 갖고 어떻게 진행되는지 여러가지 궁금하여 참관하였는데 상당히 유익하였기에 전시회 내용을 소개하고 이와같은 전시회 참관요령을 안내하고자 한다.

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벼 건답직파(乾畓直播)에 있어서 효과적(效果的)인 잡초방제(雜草防除) (Effective Weed Control in Direct-Seeded Rice under Dry Fields)

  • 박태선;박재읍;류갑희;이인룡;이한규;이정운
    • 한국잡초학회지
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    • 제15권2호
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    • pp.99-104
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    • 1995
  • 벼 건답직파(乾畓直播)논에서 효과적(效果的)인 잡초방제(雜草防除)를 위한 경엽처리용(莖葉處理用) 제초제(除草劑)의 선발시험(選拔試驗)과 효과적(效果的)인 방제체계시험(防除體系試驗)을 실시(實施)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 경엽처리용(莖葉處理用) 제초제(除草劑)인 cyhalofop/bentazone EW와 cyhalofop/pendimethalin EC는 90% 이상(以上)의 방제효과(防除效果)를 보였다. 2. cyhalofop/bentazone EW 등 공시약제(供試藥劑) 모두 약해(藥害)는 발생(發生)치 않았으며 수확량(收穫量)은 cyhalofop/bentazone EW와 cyhalofop/pendimethalin EC는 10a당(當) 620kg 이상(以上)을 보였으나 cyhalofop/cinosulfuron WP와 cyhalofop/azimsulfuron은 10a당(當) 각각(各各) 510kg과 576kg으로 나타나 다소(多少) 차이(差異)를 보였다. 3. 제초제(除草劑) 체계처리효과(體系處理效果)에는 파종후(播種後) 15일(日)에 pendi pronil EC를 처리(處理)한 다음 담수후(湛水後) 5일(日)에 pyrazosufuron molinate GR를 체계처리(體系處理)한 구(區)에서 94%의 높은 잡초방제(雜草防除)를 보였다. 4. 담수시기별(湛水時期別) 잡초발생량(雜草發生量)은 파종후(播種後) 25일(日) 담수구(湛水區)는 파종후(播種後) 35일(日) 담수구(湛水區)에 비(比)해 일년생잡초(一年生雜草) 발생량(發生量)이 25% 적었고 방제효과(防除效果)도 94%로 높았다. 5. 담수시기(湛水時期)를 달리 하여 pendi pronil EC와 pyrazosulfuron molinate GR를 체계처리(體系處理)한 결과(結果) 파종후(播種後) 25일(日) 담수구(湛水區)는 94%의 높은 방제가(防除價)를 보였다.

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Toxicological Studies on the Essential Oil of Eugenia caryophyllata Buds

  • Park, Hee-Juhn
    • Natural Product Sciences
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    • 제12권2호
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    • pp.94-100
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    • 2006
  • The essential oil (EC-oil) obtained from the buds of Eugenia caryophyllata (Myrtaceae) was examined for its free radical-scavenging activity, cytotoxicity, and in vivo toxicity. To find the xenobiotic properties of EC-oil, serum thiobarbituric acid reactive substances (TBARS) level and hepatic drug-metabolizing enzyme activities were measured. It was found that EC-oil displayed xenobiotic properties like bromobenzene. The cytotoxicities of eugenol and of the EC-oil were greatly attenuated by the sulfhydryl-containing N-acetyl-L-cysteine (NAC), suggesting that eugenol was susceptible to nucleophilic sulfhydryl. In addition, eugenol also showed potent free radical-scavenging activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Moreover, methyleugenol considerably exhibited less cytotoxicity and less potent free radical-scavenging activity than eugenol, and the cell viability of the methyleugenol was more increased with NAC treatment than the eugenol. These results indicate that the phenolic OH in eugenol may play a crucial role in both cytotoxicity and free radical-scavenging activity. The fashion on oxidative stress and hepatic drug-metabolizing enzyme activities of eugenol resembled those of bromobenznene.

차광 및 질소시비량이 상추내 질산염 함량에 미치는 영향 (Effect of Shading and Nitrogen Level on the Accumulation of $NO_3\;^-$ in Leaf of Lettuce(Lactuca Sativa. L.))

  • 이경자;강보구;김현주;민경범
    • 한국환경농학회지
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    • 제19권4호
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    • pp.294-299
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    • 2000
  • 차광 및 질소시비량이 상추의 엽내 $NO_3\;^-$ 축적에 미치는 영향을 구명하기 위하여 질소 시비량을 달리하여(100, 180, 200, 300, $400\;kg{\cdot}ha^{-1}$) 50% 차광 과 무차광 상태에서 상추를 재배하였다. 1. 시험전 토양에 비하여 시험후 토양에서 pH는 낮아진 반면 EC 및 $NO_3-N$ 함량은 높아졌다. 질소 시비량이 증가할수록 pH는 낮아지는 경향이며, EC 및 $No_3\;^-$ 함량은 높아지는 경향이었다. 또한, 시험후 토양에서 $NO_3-N$ 함량이 증가할 수록 EC가 높아졌다. 2. 질소시비량이 100, 180, 200, 300 그리고 $400kg{\cdot}ha^{-1}$에서 상추의 입모율은 각각 84, 78, 76, 72 및 74% 이었고, 생존율은 각각 94, 94, 90, 60 및 46%로서 질소시비량이 증가할수록 입모율 및 생존율이 감소하였다. 상추의 생산량은 무차광 재배에서 진단시비($180\;kg{\cdot}ha^{-1}$)에서 $45\;g{\cdot}$$^1$ 로서 가장 높았다. 3. 상추 엽중 $NO_3\;^-$ 함량은 질소시비량이 증가할수록 높아졌고 또한 무차광에 비하여 50% 차광에서 $2.8{\sim}4.1$배 높았으며, 엽위별로의 $NO_3\;^-$ 함량은 7엽기까지 증가하다가 8엽기부터 감소하였다. 4. NRA은 50% 차광보다 무차광에서 높게 나타났다.

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강화도 지역에서 겨울철 $PM_{205}$의 화학적 성분 특성 (Characteristics of Chemical Species in $PM_{205}$ during the Winter in Kangwha)

  • 여현구
    • 한국대기환경학회지
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    • 제16권4호
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    • pp.309-316
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    • 2000
  • Chemical compositions of air pollutants with fine particles (<2.5 ${\mu}{\textrm}{m}$, PB2.5) were evaluated at background site. Kangwha. in Korea during the winter season. The data set was obtained for seventeed days with 24-hour sampling from December 11 to 16, 1996 and from January 9 to 1997. The chemical species have been measured {{{{ {SO }`_{4 } ^{2- } }}}}, {{{{ { NO}`_{3 } ^{- } }}}}, {{{{ { NH}`_{4 } ^{+ } }}}}. OC and EC in the particulate phase, NH3 HNO3, HCl and SO2 in the gas phase using the three stage filter pack method. Mean concentration ($\mu\textrm{g}$/m3) of this study were : 35.42 for PM2.5 8.78 for organic carbon (OC) 7.25 for nss {{{{ {SO }`_{4 } ^{2- } }}}}, 4.94 for {{{{ { NO}`_{3 } ^{- } }}}}, 3.58 for {{{{ { NH}`_{4 } ^{+ } }}}} and 1.48 for elemental carbon (EC) respectively. Contributive rates of major particulate components in PM2.5 were OC (25%) nss- {{{{ {SO }`_{4 } ^{2- } }}}}(20%) ,{{{{ { NO}`_{3 } ^{- } }}}}(14%) {{{{ { NH}`_{4 } ^{+ } }}}}(10%) and EC (4%) respectively and these components could be accounted for 73% of PM2.5 mass. Reactive forms of {{{{ { NH}`_{4 } ^{+ } }}}} were considered as NH4HO3 and NH4{{{{ {SO }`_{4 } ^{2- } }}}} during the sampling periods. {{{{ { NO}`_{3 } ^{- } }}}}/({{{{ { NO}`_{3 } ^{- } }}}} + HNO3) and {{{{ {SO }`_{4 } ^{2- } }}}}/({{{{ {SO }`_{4 } ^{2- } }}}} + SO2) were calculated 0.8 and 0.9 respectively. Most of these compounds might be formed in partiiculate phase in the air. Correlation coefficient between OC and EC was 0.866 which might have the same sources during the sampling periods,.

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QSAR방법을 이용한 CAHs와 Chlorophenol 유도체에 대한 $EC_{50}$값 예측 (Prediction of $EC_{50}$ of Photobacterium phosphoreum for CAHs and Chlorophenol Derivatives Using QSAR)

  • 이홍주;유승오;이정건;김병용;전억한
    • 한국미생물·생명공학회지
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    • 제27권1호
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    • pp.54-61
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    • 1999
  • Measurement of inhibition of bioluminescence in Photobacterium phosphoreum has been porposed as a sensitive and rapid procedure to monitor toxic substances. However, at first, $EC_{50}$ which shows degree of toxicity to each toxic substances must be calculated. QSAR (Quantitative Structure Activity Relationship) model can be used to estimate $EC_{50}$ to save time and endeavor. Moderately high correlation coefficients ($r^2{\geq}$ 0.97) were calculated from the linear correlation between $EC_{50}$ and molecular connectivity indices of CAHs (chlorinated aliphatic hydrocarbons)such as $^0X$, $^0X^V$, $^1X$, $^2X$ and $^3X^v_c$ and quadratic correlation between $EC_{50}$ and $^0X$, $^0X^V$, $^2X^V$, $^3X_c$, $^3X^V_c$ and P. It shows that the molecular connection indices in carbon structure is contributed to biological characters with linear relation and that in the other one with quadratic relation. The $EC_{50}$ of chlorophenol derivatives had quadratic relation with the value of octanol/water prtition coefficients ($r^2$=0.99) and linear and quadratic relation with the number of chlorine compound (($r^2{\geq}$0.94). This confirms the already known trend of increasing toxicity with increasing ability of a compound to diffuse through cell membrane and number of chlorine substitution.

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제주도 고산 PM10, PM2.5, PM1.0 중 OC와 EC의 계절별 변화 특성 (Seasonal Variations of OC and EC in PM10, PM2.5 and PM1.0 at Gosan Superstation on Jeju Island)

  • 임세희;이미혜;강경식
    • 한국대기환경학회지
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    • 제26권5호
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    • pp.567-580
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    • 2010
  • Organic carbon (OC) and elemental carbon (EC) concentrations were determined for $PM_{10}$, $PM_{2.5}$ and $PM_{1.0}$ aerosols particles collected at Gosan Superstation on Jeju Island from August 2007 to September 2008. Aerosols were collected on quartz filters for 24 hours and then OC and EC were analyzed by TOR/IMPROVED method. Mean concentrations of OC and EC were $4.66\;{\mu}g/m^3$ and $1.69\;{\mu}g/m^3$ for $PM_{10}$, $3.95\;{\mu}g/m^3$ and $1.69\;{\mu}g/m^3$ for $PM_{2.5}$, and $3.16\;{\mu}g/m^3$ and $1.42\;{\mu}g/m^3$ for $PM_{1.0}$, respectively. The concentrations of OC and EC comprised 16.4% and 6.0% of $PM_{10}$, 22.9% and 9.8% of $PM_{2.5}$, and 23.0% and 10.0% of $PM_{1.0}$. OC and EC showed a clear seasonal variation with the highest in winter and the lowest in summer. The correlations between the two were also the best during the winter ($R^2$=0.87, 0.94, and 0.95 for $PM_{10}$, $PM_{2.5}$ and $PM_{1.0}$). The ratio of OC/EC exhibited the maximum (7.24) during an Asian dust event due to an increase of OC, which was possibly derived from soil. The mass fraction of both OC and EC was the highest in fall. When OC and EC concentrations were highly elevated, EC1 (the first EC fraction determined at $550^{\circ}C$) and pyrolyzed OC (POC) were dominant subcomponents in winter and OC3 (the third OC fraction determined at $450^{\circ}C$) and POC in spring.

매실농축액의 에틸카바메이트 분석과 노출량 평가 (Determination of Ethyl Carbamate in Maesil Extract and Estimated Daily Intake)

  • 최보경;고은미
    • 한국식품조리과학회지
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    • 제31권2호
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    • pp.112-117
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    • 2015
  • The analytical method for ethyl carbamate (EC) in maesil (Prunus mume) extract was developed with deuterium-labeled ethyl carbamate as an internal standard. Samples were neutralized with an addition of 1 N sodium hydroxide solution, followed by a solid phase extraction with a Chem Elut cartridge. A standard curve exhibited a good linearity with correlation coefficient of 0.9991. The limit of detection (LOD) and limit of quantification (LOQ) were 2.91 ng/g and 8.83 ng/g, respectively. The recovery rate of EC ranged from 91.40% to 120.90%. The precision never exceeded 12.57% (intra-day) and 11.03% (inter-day). Samples were comprised of 24 home-made and 7 commercially-available maesil extracts. Eight home-made samples contained EC at levels between 3.39 and 75.76 ng/g. Three commercially-available samples had EC at levels between 11.67 and 20.16 ng/g. Average daily intakes of EC from maesil extracts for consumers were 0.23 g/kg of body weight. Based on a benchmark dose confidence limit ($BMDL_{10}$) of 0.25 mg/kg of body weight/day, the margin of exposure (MOE) of EC in maesil extract for consumers was 94,150, which is not of concern. Considering that a daily intake of maesil extract has been increasing, further studies on the formation of EC in maesil extract is needed.