• Title/Summary/Keyword: rates

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A simple method for estimating the major nuclide fractional fission rates within light water and advanced gas cooled reactors

  • Mills, R.W.;Slingsby, B.M.;Coleman, J.;Collins, R.;Holt, G.;Metelko, C.;Schnellbach, Y.
    • Nuclear Engineering and Technology
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    • v.52 no.9
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    • pp.2130-2137
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    • 2020
  • The standard method for calculating anti-neutrino emissions from a reactor involves knowing the fractional fission rates for the most important fissioning nuclides in the reactor. To calculate these rates requires detailed reactor physics calculations based upon the reactor design, fuel design, burnup dependent fuel composition, location of specific fuel assemblies in the core and detailed operational data from the reactor. This has only been published for a few reactors during specific time periods, whereas to be of practical use for anti-neutrino reactor monitoring it is necessary to be able to predict these on the publicly available information from any reactor, especially if using these data to subtract the anti-neutrino signal from other reactors to identify an undeclared reactor and monitor its operation. This paper proposes a method to estimate the fission fractions for a specific reactor based upon publicly available information and provides a database based upon a series of spent fuel inventory calculations using the FISPIN10 code and its associated data libraries.

Web Accessibility Evaluation of Korean Museum Websites (국내 미술관 사이트의 웹 접근성 평가)

  • Yun, Eun Young;Lee, Hwa Sei
    • Journal of Korea Multimedia Society
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    • v.19 no.10
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    • pp.1816-1828
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    • 2016
  • Museums have recently been expanding their roles as education providers to use websites to provide a variety of information and services including educational programs. In order to better perform their roles as education providers, it is important for museums to commit themselves to making their websites accessible and easy for everyone to use, in compliance with web accessibility. 20 of museum websites were chosen to study the state of web accessibility of domestic museum websites, and were evaluated by using an automated web accessibility evaluation tool called the K-WAH 4.4. And then, we analyze the compliance rates of web accessibility based on 6 Requirements in the KWCAG 2.1. As a Result, only two museums satisfy the compliance rates on 6 Requirements and national & public museums are higher than private museums in compliance rates. So, to improve web accessibility, we comply with accessibility guidelines and design web contents. After witch we should improve web accessibility by modifying insufficient requirements immediately through periodical evaluations.

Review on the Pertinent Discount Rate for the Public Investment Project (공공투자사업(公共投資事業)의 적정(適正) 할인율(割引率) 검토(檢討)에 관(關)한 연구(硏究))

  • Park, Jae Keun;Lim, Jae Hwan
    • Korean Journal of Agricultural Science
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    • v.30 no.1
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    • pp.89-101
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    • 2003
  • For the pre-feasibility study and project evaluation, the discount rate or cutoff rate should be given by the government authority. To get the Benefit/Cost Ratio, NPV(Net Present Value) and IRR(Internal Rate of Return) of the public investment projects, the pertinent and realistic discount rate should be determined to be suitable to the present time period. The cut-off rates in Korea were equivalent to 15% in 1970's, 10% in 1980's and 8% in 1990's. The prevailing rate of discount as 8% is considered not to be suitable for the 2000's public project appraisal considering the present interest rates on deposit and national bonds. To determine the socio-economic feasibility of the public projects, the IRR should be bigger than the present cutoff rate. When we still use the high old rate of discount, the analytical results of project appraisal will show always economically unfeasible. Therefore the new rate of discount suitable for present time should be determined by the government. The public projects to be implemented in 2000 year onward are recommended to be adapted 5% of cutoff rate for the project appraisal and evaluation according to the results of reviewing the tendency of discount rates and market rates of interest in Korea.

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An experimental study on cooling characteristics of mist impinging jet on a flat plate (평판에 분사된 분무충돌제트의 냉각특성에 대한 실험적 연구)

  • Jun, Sang-Uk;Chung, Won-Seok;Lee, Joon-Sik
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.528-533
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    • 2001
  • An experimental study is carried out to investigate the effects of air and water mass flow rates on cooling characteristics of mist impinging jet on a flat plate. Experiments are conducted with air mass flow rates from 0.0 to 3.0 g/s, and water mass flow rates from 5.0 to 20.0 g/s. An air-atomizing nozzle is used for the purpose of controlling air and water mass flow rates. In this study, a new test section is designed to obtain local heat transfer coefficient distributions. Heat transfer characteristics of the mist impinging jet are explained with the aid of flow visualization. Surface temperature and heat transfer coefficient distributions become more uniform as air mass flow rate increases, and that the increases in water flow rate mainly enhance cooling performance. Air mass flow rate weakly influences averaged heat transfer coefficient when water mass flow rate is low, but averaged heat transfer coefficient increases remarkably as air mass flow rate in case of high water mass flow rate.

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Antagonistic activity of Streptomyces halstedii and S. violaceusniger In pepper anthracnose fungus Colletotrichum gloeosporioides

  • Park, Dae-Yong;Lim, Tae-Heon;Byeongjin Cha
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.96.2-97
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    • 2003
  • More than 1200 microorganisms were isolated from soil samples collected from various sources and localities. Among the isolates, 2 actinomyces (TH-04 and BA313) and 1 Bacillus sp. (CJ3) were selected as antagonists to pepper anthracnose fungus Colletotrichum gloeosporioides. These 3 isolates inhibitied mycelial growth of C gloeosporioides and the inhibition rates were over 70% on PDA. When the isolates were co-cultured with conidia of C. gloeosporioides in potato dextrose broth, conidial germination was severely inhibited and the inhibition rates of TH-04, BA313, and CJ3 at 24 hours were 75%, 72%, and 68%, respectively. The inhibition rates at n hours incubation were not much different from the rates at 24 hours. To check the activity on the plant, each isolate was mixed with equal volume of conidial suspension of C. gloeosporioides and wound-inoculated on green pepper fruit. After 6 days, the anthracnose lesions on the fruits inoculated with the mixture were much smaller than the lesions caused by the C. gloeosporioides itself. The lesion areas of TH-04 or BA313 treated pepper were less than 30% of the check. TH-04 and BA313 also showed antagonistic activity to Phytophthora spp. and Botrytis cinerea. By scanning electron microscopy and fatty acid analyses (MIDI), TH-04 and BA313 were identified to Streptomyces halstedii and S. violaceusniger, repectively.

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Species-specific biomass drives macroalgal benthic primary production on temperate rocky reefs

  • Spector, Michael;Edwards, Matthew S.
    • ALGAE
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    • v.35 no.3
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    • pp.237-252
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    • 2020
  • Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m-2 d-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

Larval Growth of Cloeon dipterum(Ephemeroptera: Baetidae) in Different Temperature Conditions (서로 다른 온도 조건에서 연못하루살이(Cloeon dipterum: 꼬마하루살이과, 하루살이목) 유충의 성장)

  • Hwang Jeong Mi;Lee Sung Jin;Bae Yeon Jae
    • Korean Journal of Environmental Biology
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    • v.23 no.2 s.58
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    • pp.114-119
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    • 2005
  • Larval survivorships, growth rates, developmental rates, and emergence rates of Cloeon dipterum were studied under four constant temperatures $(10^{\circ}C,\; 15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C)$ in the laboratory. Larval mortalities were relatively higher during the initial one-week period, but those tend to be stabilized as the experiments proceed. Judging from the growth and develop-mental rates, estimated optimal temperature for larval growth and development lies between $20^{\circ}C\;and\;25^{\circ}C$. Estimated larval period for emergence is less than 100 days.

Applying System Dynamics Model to Estimate the Effects of Healthy City Policies on Reducing Social Cost (시스템다이내믹스 기법을 이용한 건강도시화 정책의 사회적비용 절감효과 분석)

  • Kim, Eun Jung;Kim, Young-Pyo
    • Korean System Dynamics Review
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    • v.13 no.3
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    • pp.23-46
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    • 2012
  • The purpose of this paper is to estimate effects of healthy city policies on reducing social costs. The analyses were dune at the cities, counties, and communities levels in 2009, and covered Seoul Metropolitan Area(SMA). For estimation of reducing social costs, it developed a system dynamics(SD) model that analyzed causal relationships between physical inactivity rates, the number of deaths, medical expenses, and total social costs. Simulation period of SD was from 2009 to 2030. Three alternatives were proposed with combinations of length of bike lanes, number of bus routes, crime rates, self-reported good health status rates, and obesity rates. The total estimated cost of physical inactivities from 2009 to 2030 was 31.9 trillion won from the future forecast without policies. As a result of simulations with three alternatives, there were economic benefit approximately from 119.7 billion won to 1.16 trillion won. This study contributed to better understanding the economic benefits of healthy cities that were associated with design of built environment and physical activity. It also emphasized the importance of healthy cities planning as one of national welfare polices.

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Studies on Maturation In Vitro of Rat Follicular Oocytes and Fertilizatin in Vitro of Cumulus-Removed and Intact Oocytes after Maturation

  • Kim, C.K.;Chung, Y.C.;Park, J.W.;Yoon, J.T.;Kim, H.T.
    • Korean Journal of Animal Reproduction
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    • v.12 no.2
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    • pp.120-124
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    • 1988
  • Rat oocyte-cumulus complexes were cultured in verious media in order to induce maturation division in vitro. When the complexes were cultured in mKRB containing estrous rat serum (ERS) and FCS of 5% instead of BSA higher proportions(83.3 and 86.7%) of oocytes matured to metaphase II in 20h compared to control(75%) and t도 maturation rates in mKRB plus FCS were generally higher than those in mKRB plus ERS. Fertilization and early cleavage rates in vitro of the intact oocytes matured in mKRB containing BSA and FCS were generally higher than those of cumulus-removed oocytes and these rates were higher in mKRB containing 5% FCS than those in mKRB containing BSA. These results indicate that maturation rate in vitro was greatly increased by the addition of FCS instead of BSA to mKRB solution and the presence of cumulus cells around oocytes prior to sperm insemintion may be responsible for the increase of in vitro fertilization and early cleavage rates.

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Effect of Co-Culture Mouse Fetal Fibroblast Cell on In Vitro Development of Blastomeres Separated from Mouse Preimplantation Embryos (생쥐 태아 Fibroblast 세포와 공동배양이 초기 생쥐배 분할구의 체외 발생능에 미치는 영향)

  • 김진호;정병헌;이훈택;정길생
    • Korean Journal of Animal Reproduction
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    • v.16 no.4
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    • pp.341-346
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    • 1993
  • The development of isolated blastomeres from mammalian preimplantation embryos has been basically studied for the multiplication of embryos from superior animals. Therefore, this study was investigated the effect of co-culture with mouse fetal fibroblast cells(MFFC) on in vitro development of blastomeres from mouse preimplantation embryos. Mature female ICR mice were treated with hormone to induce superovulation and embryos were collected at each 2, 4, and 8-cell stage. Then, after removing zona pellucida with protease, blastomeres were isolated by micropipetting, or reconstituted with different stage blastomere, and incubated for 72 hrs either in T6 or TCM199 or on the monolayer of MFFC, which was prepared with fibroblast cells from 14∼14 day mouse fetus. After incubation, we examined their development rates every day and the nuclei numbers of each blastocyst by Hoechst-33342 staining. In the development rates of blastomeres, there were no significant differences between media but the higher rateswere found in the monolayer of MFFC, regardless of reconsititution. In addition, blastomeres cultured with MFFC had slightly greater number of nuclei than those cultured in single media. Generally, the higher development rates of blastomeres were found from earlier stage embryos than the later ones, regardless of culture conditions. Reconsitituted blastomeres had more nuclei but did not show the higher development rates, compared to the single blastomeres. Taken together, our results suggest that co-culture with MFFC have a beneficial effect on the in vitro development of blastomeres from mouse embryos.

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