• Title/Summary/Keyword: energy sources

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A Formal Guidance for Handling Different Uncertainty Sources Employed in the Level 2 PSA

  • Ahn Kwang-Il;Yang Joon-Eon;Ha Jae-Joo
    • Nuclear Engineering and Technology
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    • v.36 no.1
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    • pp.83-103
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    • 2004
  • The methodological framework of the Level 2 PSA appears to be currently standardized in a formalized fashion, but there have been different opinions on the way the sources of uncertainty are characterized and treated. This is primarily because the Level 2 PSA deals with complex phenomenological processes that are deterministic in nature rather than random processes, and there are no probabilistic models characterizing them clearly. As a result, the probabilistic quantification of the Level 2 PSA CET / APET is often subjected to two sources of uncertainty: (a) incomplete modeling of accident pathways or different predictions for the behavior of phenomenological events and (b) expert-to-expert variation in estimating the occurrence probability of phenomenological events. While a clear definition of the two sources of uncertainty involved in the Level 2 PSA makes it possible to treat an uncertainty in a consistent manner, careless application of these different sources of uncertainty may produce different conclusions in the decision-making process. The primary purpose of this paper is to characterize typical sources of uncertainty that would often be addressed in the Level 2 PSA and to provide a formal guidance for quantifying their impacts on the PSA Level 2 risk results. An additional purpose of this paper is to give a formal approach on how to combine random uncertainties addressed in the Level 1 PSA with subjectivistic uncertainties addressed in the Level 2 PSA.

Study on the Performance of Fuel Cell Driven Compound Source Heat Pump System to a Large Community Building (대형 Community 건물의 연료전지 구동 복합열원 하이브리드 히트펌프 시스템 성능에 관한 해석적 연구)

  • Jeong, Dong-Hwa;Byun, Jae-Ki;Choi, Young-Don;Cho, Sung-Hwan
    • New & Renewable Energy
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    • v.4 no.3
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    • pp.23-35
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    • 2008
  • In the present study, performances of fuel cell driven compound source hybrid heat pump system applied to a large community building are simulated. Among several renewable energy sources, ground, river, sea, and waste water sources are chosen as available alternative energies. The performance and energy cost are varied with the hybrid heat pump sources. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. Th system is driven by fuel cell system instead of the late-night electricity due to the advantages of the low energy cost and waste heat with high temperature.

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A method of Shaped Sound Focusing Using Multiple Monopole Sources: Hollow Cylinder shape (다수의 단극 음원들을 이용한 속이 빈 실린더 형상의 응향 위치 에너지 집적공간 형성방법)

  • Park, Jin-Young;Kim, Yang-Hann
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.537-540
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    • 2005
  • Shaped Sound Focusing is defined as the generation of acoustically bright zone with a certain shape in space using multiple sources. The acoustically bright zone is a spatially focused region with relatively high acoustic potential energy level. In view of the energy transfer, acoustic focusing using multiple sources is essential because acoustic energy is very small to use other type of energy. It can be done by taking optimization techniques which can be acoustic brigtness control and acoustic contrast control. But it has not been frequently concerned about several cases, so the case of hollow cylinder shaped sound focusing is adapted and there wi11 be arguments about available control variables and spatially controllable region in this case.

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Effect of Energy Sources (Glucose, Pyruvate and Lactate) Added to Dulbecco's Modified Eagle Medium (DMEM) on the Mouse 2-cell Embryo Development (Glutamine 함유 배양액에 첨가한 에너지원이 마우스의 배 발달에 미치는 영향)

  • Kim, Ju-Hwan;Park, Kee-Sang;Lee, Taek-Hoo;Chun, Sang-Sik;Song, Hai-Bum
    • Clinical and Experimental Reproductive Medicine
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    • v.27 no.1
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    • pp.1-7
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    • 2000
  • Objective: Mammalian embryos undergo changes of energy environment for transfer from oviduct to uterus. Also, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration (oviduct - glucose: 0.5 mM, pyruvate: 0.32 mM, lactate: 10.5 mM; uterus - goucose: 3.15 mM, pyruvate: 0.1mM, lactate: 5.87 mM, respectively). This study was conducted to examine the effect of these energy sources added in DMEM with glutamine on the mouse embryo development. Methods: There was used ICR female mouse. Two cell embryos of mouse are collected by method of 'flushing'. Flushing fluid was used Ham's F-10 added to 20% FBS. The collected 2 cell embryos were cultured in media such as Control (only DMEM), group A and B (DMEM supplemented with 0.5 mM and 3.15 mM glucose), and group C and D (DMEM supplemented with 0.1 mM and 0.32 mM pyruvate), and group E and F (DMEM supplemented with 5.87 mM and 10.5 mM lactate). All experimental media supplemented with 20% hFF, respectively. Pattern of embryo development was observed to interval at 24hr during 96hr. Results : The media with glutamine added glucose (group A: 51.0%; group B: 48.4%) was significantly (p<0.05) higher than other experimental group in development into the morula stage after 24 hr in culture, but not significantly different compared with control and the rate of development into the blastocyst was significantly (p<0.05) low in the both of pyruvate (group C: 7.9% group D: 6.8%) and lactate (group E: 7.1%, group F: 7.1%) treatment group after 48 hr in culture. Development into the blastocyst and hatched balstocyst after 72 hr in culture revealed similarly in control (81.9%) and glucose treatment group (group A: 83.3%, group B: 82.8%). However, development into the hatched and attached blastocyst after 96hr in culture revealed significantly (p<0.05) development in the glucose treatment group (group A: 82.3%, group B: 78.5%) than control (63.2%), and its of pyruvate (group C: 34.1%, group D: 34.1%) and lactate (group E: 25.9%, group F: 33.3%) treatment group were significantly (p<0.05) lower than control similar to previous observations. Conclusion : The glucose added to the DMEM with only glutamine, as energy source, was highly to the rate of development compared with control, but the other energy sources were not, synthetically. Above refer to, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration. Thus, further studies are will examine continuously to effects by interaction of different energy sources in the mouse embryo development, and these results will provide to foundation on the human embryo culture.

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Emission Estimation of Air Pollutants in Kimhae Area (김해시 대기오염물질 배출량 산정)

  • 박종길;김종필;김지형
    • Journal of Environmental Science International
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    • v.7 no.5
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    • pp.647-652
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    • 1998
  • This study is to find out the emission estimation in Kimhae area. For this purpose, the Kimhae statistical yearbook and data of waste facilities issued by Kimhae city and the report on energy census issued by the ministry of trade, industry and energy are used. Each item for the emission estimation is $SO_2$, CO, HC, Nox, TSP from point, line, area sources. The results were as follows; The air pollutants with the highest mont of emission from the emission sources is CO followed by Nox, $SO_2$, TSP, HC in descending order of magnitude. The emission consists of 66.15% of line, 24.65% of area and 9.20% of point sources at Kimhae.

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A Study on the Algorithm for Multi-Functional Protection Devices in Distribution Systems with New Energy Sources (신 에너지전원이 연계된 배전계통의 통합 보호기기의 알고리즘 개발에 관한 연구)

  • Yoon, Gi-Gab;Kang, Dae-Hoon;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2253-2260
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    • 2009
  • The typical distribution systems have the power flow from distribution substations (sources) to customers (load) only as one direction. However, in the case where new energy power sources are connected to distribution systems, the output variations of new energy sources to distribution systems, which is so called reverse power flow, may cause the bi-directional power flow. So, the reverse power flow has severe impacts on typical power system, for example power quality problems, protection coordination problems, and so on. Therefore, this paper proposes the algorithm for Multi-functional protection devices in distribution systems in the case where new energy sources are interconnected. The proposed algorithm is verified to show the effectiveness by simulating and experimenting the prototype systems.

Energy and Nutrient Digestibility in Four Sources of Distillers Dried Grains with Solubles Produced from Corn Grown within a Narrow Geographical Area and Fed to Growing Pigs

  • Stein, Hans H.;Connot, S.P.;Pedersen, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.1016-1025
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    • 2009
  • Two experiments were conducted to determine energy and nutrient digestibility in four sources of distillers dried grains with solubles (DDGS) produced from corn and fed to growing pigs. The objective was to test the hypothesis that energy and nutrient digestibility in DDGS does not vary if samples are procured from ethanol plants that use similar production technologies and use corn that is grown within a narrow geographical area. The four sources of DDGS that were used were procured from ethanol plants that were less than 10 yr old and located within 250 km of each other. In Exp. 1, five growing barrows (initial BW = 71.4 kg) that were fitted with a T-canula in the distal ileum were allotted to a 5${\times}$5 Latin square design and used to measure apparent (AID) and standardized (SID) ileal digestibility of AA in the four sources of DDGS. Results of this experiment showed that the SID of CP and all AA except Cys and Pro were greater (p<0.05) in two of the DDGS sources than in the other two sources. Exp. 2 was conducted to measure the concentration of DE and ME and the apparent total tract digestibility (ATTD) of energy, N, P, ether extract, NDF, and ADF in corn and in the same four sources of DDGS as used in Exp. 1. Five pigs (initial BW = 29.7 kg) that were placed in metabolism cages and allotted to a 5${\times}$5 Latin square design were used. Results of Exp. 2 showed that the average DE and ME in DDGS were 4,072 and 3,750 kcal/kg DM, respectively, which was less (p<0.01) than the DE and ME in corn (4,181 and 4,103 kcal/kg DM, respectively). The average ATTD for P in DDGS was 56.1%, which was greater (p<0.01) than the ATTD for P in corn (31.9%). The ATTD for ADF in DDGS was also greater (p<0.05) than in corn, but the ATTD for ether extract and NDF were greater (p<0.05) in corn than in DDGS. It is concluded that energy and nutrient digestibility vary among sources of DDGS even when the DDGS is procured from ethanol plants that use corn grown within a narrow geographical region. Thus, factors other than corn growing region are responsible for the variability of energy and nutrient digestibility in DDGS.

A Study on Sources of Energy & Macronutrients from Korean Dishes by Area (지역에 따른 주요영양성분의 공급음식에 관한 연구(I) -에너지 및 3대 영양소를 중심으로-)

  • Lee, Haeng-Shin;Park, Mee-Ah;Kye, Seong-Hee;Moon, Hyun-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.11 no.4
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    • pp.431-438
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    • 1996
  • The dietary intake of nutritional elements by Koreans as determined by the Ministry of Health and Welfare's National Nutrition Survey have been reported for $1969{\sim}1993$. But these data were based on not dish but food. Therefore, the purpose of this study was to compare dish sources of energy and macronutrients (carbohydrate, fat, protein) in the diets of three area (large city, small city and rural). Dish sources were evaluated from two-day record obtained in the secondary analysis of the 1993 Korean National Nutrition Survey. The result, large city and small city had higher fat and protein intake than did rural. Otherwise, carbohydrate intake among rural was higher than those among large and small city (p<0.05). The primary dish source of energy and macronutrients was cooked rice for all area. The percentage of cooked rice in daily carbohydrate intake was 52.64% for nationwide, 48.40% for large city, 50.52% for small city, 61.79% for rural. The cumulative percent of top 10 dish sources to carbohydrate for large city, small city, rural were 78.02%, 81.16%, 85.69%, respectively. These was higher than cumulative percent of other macronutrients. The milk as good protein source ranked 3 for large city, 6 for small city, 22 for rural. The major dish sources to fat were cooked rice and pork that prepared by various cooking way. These results show that the major dish sources of energy and macronutrients were cooked rice based of Korea traditional consumption pattern. The most of nutrient intake consumed some dishes for all area. The dish consumption pattern was generally similar between large and small city. But rural was different from other area. Threfore, nutrition educations and interventions should be targeted to each area and should be attended with studies that comparision of dish sources to nutritional elements by specific age-sex groups.

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The role of nuclear energy in the correction of environmental pollution: Evidence from Pakistan

  • Mahmood, Nasir;Danish, Danish;Wang, Zhaohua;Zhang, Bin
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1327-1333
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    • 2020
  • The global warming phenomenon emerges from the issue of climate change, which attracts the attention of intellectuals towards clean energy sources from dirty energy sources. Among clean sources, nuclear energy is getting immense attention among policymakers. However, the role of nuclear energy in pollution emissions reduction has remained inconclusive and demand for further investigation. Therefore, the current study contributes to extend knowledge by investigating the nexus between nuclear energy, economic growth, and CO2 emissions in a developing country context such as Pakistan for the period between 1973 and 2017. The auto-regressive distributive lag model summarizes the nuclear energy has negative effect on environmental pollution as it releases carbon emission in the environment. Moreover, vector error correction Granger causality provides evidence for bidirectional causality between nuclear energy and carbon emissions. These interesting findings provide new insight, and policy guidelines provided based on these results.

A Performance Study on Silica Gel Adsorption Desalination System Utilizing Low Temperature Heat Sources (저온 활용을 위한 실리카겔 흡착식 담수화시스템의 성능연구)

  • Hyun, Jun-Ho;Israr, Farrukh;Lee, Yoon-Joon;Chun, Won-Gee
    • Journal of the Korean Solar Energy Society
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    • v.33 no.6
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    • pp.39-46
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    • 2013
  • This work introduces a simple one-reactor adsorption desalination system that harnesses low temperature heat sources (solar energy, waste heat), which has been experimentally studied to elicit the most suitable design parameters and operating conditions. The design process of the system was divided into three parts to reflect the operating principle of desalination technology with application of adsorption processes. First, the evaporator for the vaporization of saline water was designed, then the reactor for the adsorption and release of the steam, followed by the condenser for condensation of the fresh water. The specific water yield is measured experimentally with respect to the time while controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. The present system well demonstrates the applicability of silica gel in relation to adsorption technologies that utilize low temperature heat sources ranging from 60 to $80^{\circ}C$, such as solar energy and waste heat.