• Title/Summary/Keyword: Energy contribution

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Hydrophilic Modification of Poly(ethylene oxide) by UV Irradiation

  • Koo, Gwang-Hoe;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.21 no.5
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    • pp.16-20
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    • 2009
  • Films of Poly(ethylene oxide), PEO, were modified to impart hydrophilicity via UV irradiation. The UV irradiation treatment produced new photo-oxidized groups of carbonyl and ether groups as indicated in ATR and ESCA analysis. It was found that water contact angle decreased from $15^{\circ}C$ to $10^{\circ}C$ and total surface energy of PEO increased from 54.2 mN/m to 76.6 mN/m with increasing UV energy, which was attributed to significant contribution of acid base interaction of the photo-oxidized PEO rather than nonpolar interaction originating from the dominant increase in Lewis acid parameter. The increased hydrophilicity and surface energy were also proved by the decreased water wetting time.

A study of Maintaining supply reliability of small isloated power systems using renewable energy (신재생 에너지원을 사용하는 특정 지역에서 공급 신뢰도 유지를 위한 연구)

  • Jung, Young-Kee;Lee, Dong-Woo;Moon, Seung-Il
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.608-609
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    • 2008
  • Photovoltaics and wind energy sources are being increased recognised as cost effective generation sources in small isolated power systems(SIPS) primarily supplied by costly diesel fuel. Deterministic and probabilistic techniques are combined using a system well-being approach to provide useful reliability indices for SIPS containing renewable energy. An evaluation of the contribution from photovoltaics and wind energy sources to SIPS reliability is presented. The practicality and effectiveness of the methodology is illustrated by a case study.

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Evaluation of Neutron Cross Sections for Eu-153, Gd-155 and Gd-157

  • Lee, Y. D.;J. H. Chang
    • Nuclear Engineering and Technology
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    • v.35 no.1
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    • pp.35-44
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    • 2003
  • The neutron induced nuclear data for Eu-153, Gd-155 and Cd-157 are calculated and evaluated in the high energy region. The evaluation procedure for deformed nuclei is setup by using Ecis-Empire codes. The energy dependent optical model potential parameters are searched based on the recent experimental data and applied up to 20 MeV. Optical model, full featured Hauser-Feshbach model and multistep direct and multistep compound model are used in the calculation. The direct-semidirect capture model and the direct coupled-channels contribution to discrete levels are introduced to improve the capture and inelastic scattering cross sections. The theoretically calculated cross sections are compared with the experimental data and the evaluated files. The model-calculated total and capture cross sections are in good agreement with the reference experimental data. The evaluated cross section results are compiled to ENDF-6 format and are expected to improve the ENDF/B-Vl.

Conformational Analysis of Sulfonylureas : Acetohexamide and Tolazamide (Sulfonylurea 유도체들의 구조분석 : Acetohexamide와 Tolazamide)

  • 정우태;강기롱;이성희
    • YAKHAK HOEJI
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    • v.39 no.3
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    • pp.329-336
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    • 1995
  • Conformational free energy calculations using an empirical potential function and a hydration shell model(program CONBIO) were carried out on hypoglycemic agent acetohexamide and tolazamide in the unhydrated and hydrated states. The initial geometry of sulfonylureas was obtained from X-ray crystallographieal data and homologous molecular fragments. In both states, the feasible conformations were obtained from the calculations of conformational energy, conformational entropy, and hydration free energy by varying all the torsion angles of the molecules. From the calculation results, it is known that the conformations] entropy is the major contribution to stabflize the low-free-energy conformations of two sulfonylureas in both states. But, in hydrated state, the hydration does not directly affect each conformations. The intramolecular hydrogen bonding of sulfonylurea hydrogen and 7-membered nitrogen appeared to the conformations of tolazamide in both states. It is thought that the hydrogen bonding decrease steric hindrance on the receptor binding direction. The substitution of alicyclic or N-heterocyclic ring than that of carbons chain of urea moiety may be properly interaction between sulfonylureas and the putative pancreatic receptor.

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Further Applications of Molecular Orbital Calculations for Solid HF According to Pseudolattic Method

  • Kim, Jin-Seog;No, Kyoung-Tai;Jhon, Mu-Shik
    • Bulletin of the Korean Chemical Society
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    • v.5 no.2
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    • pp.61-64
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    • 1984
  • The molecular orbital calculations for solid HF are performed by using the pseudolattice method considering the coulomb lattice sum. In order to obtain the reliable net atomic charges and lattice energy of one dimensional chains, the limited counting of interactions terms up to second neighbours for zig-zag chain and third neighbours for linear chain are sufficient in this calculation. In three dimensional solid HF, the contribution of interaction energy between non-hydrogen bonded neighbours to lattice energy is about 3.5% and the lattice energy of nonpolar structure is stablized by 2.05 kcal/mole compared with that of polar structure. And, this method is further tested and compared with the other methods.

Analysis of Radiation-Induced Cancer Mortality for Korean Using the BEIR V Method

  • Hwang, Won-Tae;Han, Moon-Hee;Kim, Eun-Han;Suh, Kyung-Suk;Gyuseong Cho
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11b
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    • pp.629-635
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    • 1996
  • The lifetime radiation-induced cancer mortality for Korean has been estimated for both single and continuous radiation exposure using the BEIR V method. In case of single exposure, a dominant cancer site for young and old ages was digestive and respiratory cancer, respectively. For Korean population, digestive cancer was the most dominant radiation-induced cancer site. In case of 1 mGy/yr continuous exposure from birth to death, the contribution of total radiation-induced cancer mortality was negligible as within 3% in comparison with total natural cancer mortality.

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Demand-based charging strategy for wireless rechargeable sensor networks

  • Dong, Ying;Wang, Yuhou;Li, Shiyuan;Cui, Mengyao;Wu, Hao
    • ETRI Journal
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    • v.41 no.3
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    • pp.326-336
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    • 2019
  • A wireless power transfer technique can solve the power capacity problem in wireless rechargeable sensor networks (WRSNs). The charging strategy is a wide-spread research problem. In this paper, we propose a demand-based charging strategy (DBCS) for WRSNs. We improved the charging programming in four ways: clustering method, selecting to-be-charged nodes, charging path, and charging schedule. First, we proposed a multipoint improved K-means (MIKmeans) clustering algorithm to balance the energy consumption, which can group nodes based on location, residual energy, and historical contribution. Second, the dynamic selection algorithm for charging nodes (DSACN) was proposed to select on-demand charging nodes. Third, we designed simulated annealing based on performance and efficiency (SABPE) to optimize the charging path for a mobile charging vehicle (MCV) and reduce the charging time. Last, we proposed the DBCS to enhance the efficiency of the MCV. Simulations reveal that the strategy can achieve better performance in terms of reducing the charging path, thus increasing communication effectiveness and residual energy utility.

Analysis of Exposure Pathways and the Relative Importance of Radionuclides to Radiation Exposure in the Case of a Severe Accident of a Nuclear Power Plant (원전 중대사고시 피폭경로 및 핵종의 방사선 피폭에 대한 상대적 중요도 해석)

  • Hwang, Won-Tae;Suh, Kyung-Suk;Kim, Eun-Han;Han, Moon-Hee;Kim, Byung-Woo
    • Journal of Radiation Protection and Research
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    • v.19 no.3
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    • pp.209-221
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    • 1994
  • In the case of a severe accident of a nuclear power plant, the whole body dose and the relative importance of the radionuclides during the lifetime of an exposed person were estimated for each exposure pathway with distances from the release point. The external exposure pathways due to immersion of radioactive cloud and deposition of radioactive materials on the ground, and the internal exposure pathways due to inhalation and ingestion of contaminated foodstuffs were considered. The effects due to the ingestion of contaminated foodstuffs were estimated considering the variation of radioactive concentration in the foodstuffs according to deposition time and elapsed time after deposition using a dynamic ingestion pathway model applicable to Korean environment, named 'KORFOOD'. As the results up to 80 km from the release point, the effects due to ingestion of contaminated foodstuffs showed the highest contribution to total exposure dose. The contribution of I isotopes was the highest in the case of the external dose due to immersion of radioactive cloud and internal dose due to inhalation. The contribution of Cs isotopes was highest in the case of the external dose due to deposition of radioactive materials on the ground. In the case of the internal dose due to ingestion of contaminated foodstuffs, Cs deposition in summer and Sr deposition in winter, respectively, were the most dominant radionuclide to whole body.

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Environmental Impact of Soil Washing Process Based on the CO2 Emissions and Energy Consumption (토양세척 공정의 환경영향 분석 - 이산화탄소 배출량 및 에너지 사용량을 중심으로)

  • Kim, Do-Hyung;Hwang, Bo-Ram;Her, Namguk;Jeong, Sangjo;Baek, Kitae
    • Korean Chemical Engineering Research
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    • v.52 no.1
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    • pp.119-125
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    • 2014
  • This study evaluated the environmental impacts of a soil washing (SW) process, especially, we compared the on-site and off-site remediation of TPH-contaminated soil using green and sustainable remediation (GSR) tool. To assess relative contribution of each stage on environmental footprints in the entire soil washing process, we classified the process into four major stages: site foundation (stage I), excavation (stage II), separation & washing (stage III), and wastewater treatment (stage IV). In on-site SW process, the relative contribution of $CO_2$ emissions and energy consumption were 87.1% and 80.4%, respectively in stage I, and in off-site SW process, the relative contribution of $CO_2$ emissions and energy consumption were 82.7% and 80.5%, respectively in stage II. In conclusion, the major factor contributing environmental impact in the SW process were consumable materials including steel and stainless steel for washing equipment in on-site treatment and fuel consumption for transportation of soil in off-site treatment.

Influences and International Political Implications of the Shale gas Revolution (셰일가스 혁명의 파급영향과 국제정치적 함의 - 에너지 안보를 중심으로 -)

  • Suh, Dong-Joo
    • Strategy21
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    • s.34
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    • pp.26-57
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    • 2014
  • Revolution of Shale gas literally brings about great changes in many spheres. In the past most academic research had been focused on the influence and innovative change in term of economic perspective. But nowadays we should more concern about the security approach and perspective as its status of the future's core energy resources. Revolution of Shale gas has an great influence on the reshaping of global and regional alliance order. There are many international political implications as follows. Contribution of energy hegemony with leading U.S.; Acting as strategic leverage on the reshaping international order; Deepening competition among major states on the construction of energy security and so on. We'd better make a good solution and systematic policies which are preparing for the Shale gas's revolution period including on the understanding about the change on the global energy structure and making a national policy agenda of energy security issues and so on. The thesis like 'to get the energy resources is to get the hegemonic power in the world' will persist. The same holds good of Shale gas case. To meet the revolution of shale gas era, we have important tasks as like making an opportunity to develope not only regional but also international prosperity.