• Title/Summary/Keyword: recycling coefficient

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Neutron Spectrum Effects on TRU Recycling in Pb-Bi Cooled Fast Reactor Core

  • Kim Yong Nam;Kim Jong Kyung;Park Won Seok
    • Nuclear Engineering and Technology
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    • v.35 no.4
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    • pp.336-346
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    • 2003
  • This study is intended to evaluate the dependency of TRU recycling characteristics on the neutron spectrum shift in a Pb-Bi cooled core. Considering two Pb-Bi cooled cores with the soft and the hard spectrum, respectively, various characteristics of the recycled core are carefully examined and compared with each other. Assuming very simplified fuel cycle management with the homogeneous and single region fuel loading, the burnup calculations are performed until the recycled core reached to the (quasi-) equilibrium state. The mechanism of TRU recycling toward the equilibrium is analyzed in terms of burnup reactivity and the isotopic compositions of TRU fuel. In the comparative analyses, the difference in the recycling behavior between the two cores is clarified. In addition, the basic safety characteristics of the recycled core are also discussed in terms of the Doppler coefficient, the coolant loss reactivity coefficient, and the effective delayed neutron fraction.

Effect of Recycling on the Papermaking Properties of Wood Pulp Fibers (펄프섬유(纖維)의 제지특성(製紙特性)에 미치는 회수처리(回收處理)의 영향(影響))

  • Kim, Hyoung-Jin;Jo, Byoung-Muk
    • Journal of the Korean Wood Science and Technology
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    • v.21 no.1
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    • pp.21-38
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    • 1993
  • In order to investigate the influence of recycling, a laboratory method simulating the papermaking process was used for assessing the effects of recycling on fiber properties. Sw-BKP, Hw-BKP and BGP were disintegrated and beaten to about 42$^{\circ}$SR-44$^{\circ}$SR by a valley beater. After beating, these pulps were dewatered by centrifuge and dried at 90$^{\circ}C$ for 72hrs. This recycling process(sequence of wetting, defiberating, dewatering and drying) was repeated seven times. Physical, mechanical and optical properties of recycled pulps were evaluated by TAPPI Standards. Morphological changes occurred through recycling process was observed by SEM. Sheet density decreased with recycling. The largest drop in density occurred during the first recycling. The porosity values decreased with recycling. Mechanical properties such as tensile, burst strength and folding endurance, decreased with recycling. However tear strength of Sw-BKP and mixtured pulp increased at the first recycling. Optical properties such as brightness, opacity and light scattering coefficient, increased with recycling. However, brightness of mixtured pulp gradually decreased with recycling. Fibrillated outer layer of the fiber was gradually removed from the surface with recycling. As a result of recycling, crinkles on the fiber surface were found to be more folded.

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Evaluation of Kinetic Constant and Effect of Effluent Recycling in Wastewater Treatment from Fisheries Processing Plant using EMMC Process (EMMC공정을 이용한 수산물 가공공장 폐수처리에서 동력학적 인자 평가와 유출수반송의 영향)

  • Jeong, Byung-Gon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.1
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    • pp.1-8
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    • 2009
  • EMMC(Entrapped Mixed Microbial Cell) process which is a kind of active cell immobilizing method was applied to treat fisheries processing wastewater biologically. Kinetic constants were calculated for organic and nitrogen removal and effect of effluent recycling on system performance was evaluated also. Yield coefficient, Y showed relatively low value compared with Y value obtained from conventional activated sludge process. It means that EMMC process can reduce amount of excess sludge significantly compared with conventional activated sludge process. Endogenous respiration coefficient $k_e$ of EMMC process also showed relatively low value compared with that of conventional activated sludge process. Yield coefficient Y, endogenous respiration coefficient $k_e$ and half saturation constant $k_s$ obtained from EMMC process in terms of nitrification were compared with reported value from literature based on suspended growth nitrification system. The value of Y obtained from this study has no difference compared with values obtained from literature review and $k_e$ of this study was low but $k_s$ of this study was high compared than values obtained from suspended growth nitrification system. To evaluate the effect of internal recycling on system performance, system was operated with internal recycling ratio of 1.5Q, 2.0Q, 2.5Q and 3.0Q. increase of internal recycling ratio effect more greatly on improvement of denitrification efficiency than that of nitrification efficiency. Accordingly, optimization of internal recycling ratio has to be based on improvement of anoxic reactor performance.

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Convergence analysis of data-recycling LMS equalizer (데이터 재활용 LMS equalizer의 수렴성능 분석)

  • 김남용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.8
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    • pp.1905-1913
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    • 1996
  • The convergence characteristics of an LMS type Equalizer whose coefficient are multiple adapted in a symbol time period by recycling the received data are analyzed. The theoretical analysis shows that the data-recycling LMS technique can increase convergence speed by (B+1) times, where B is the number of recycled data. The results of the computer simulation demonstrate that the simulation results are in accordence with the theoretical analysis and the superiority of the equalizer algorithm.

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A Study on the Optimal Method of Eco-Friendly Recycling through the Comparative Analysis of the Quantitative Calculation and Scope of Recycling

  • Seung-jun WOO;Eun-gyu LEE;Chul-hyun NAM;Kang-hyuk LEE;Woo-Taeg KWON;Hee-Sang YU
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.3
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    • pp.1-11
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    • 2024
  • Purpose: The purpose of this study is to present an efficient emission reduction ratio of plastic to reduce carbon dioxide, the main cause of greenhouse gases. Research design, data and methodology: This study calculated the absolute value of carbon dioxide by setting an equation through the emission coefficient using the US EPA's WARM model. Results: In the recycling ratio of 70%, it was found that the energy recovery ratio was 15.6%, which was the energy recovery ratio without generating carbon dioxide. When carbon dioxide is generated by changing plastic waste emissions, optimal efficiency is achieved by reducing emissions by 10% to 30% of energy recovery ratio, 20% to 50% of energy recovery ratio, and 30% to 80% or more of energy recovery ratio. Conclusions: The recycling rate should be set at a minimum of 70%, so that a carbon dioxide-free energy recovery rate could be obtained during the recycling process, supporting an eco-friendly basis for environmental policies aimed at this rate. In addition, it was possible to suggest that it is essential to reduce emissions by at least 30% for eco-friendly recycling measures that can achieve both economic and environmental feasibility in the energy recovery process through incineration during recycling in Korea.

Properties of Alkali-activated Slag-Red Mud Soil Pavement Using Recycled Aggregate (순환골재를 사용한 알칼리활성화 슬래그-레드머드 흙포장재의 특성)

  • Kang, Suk-Pyo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.276-283
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    • 2016
  • Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. the development of alkali-activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. This study is to investigate the optimum water content, compressive strength, moisture absorption coefficient and efflorescence of alkali-activated slag-red mud soil pavement according to the recycling fine aggregate content. The results showed that the optimum water content, moisture absorption coefficient and efflorescence area of alkali-activated slag-red mud soil pavement increased but the compressive strength of that decreased as the recycled fine aggregate content increased.

Calculation of the Activity Coefficients of Ions in Weak Electrolyte Solutions (묽은 전해질용액에서 이온의 활동도계수 계산)

  • Lee, Man-Seung;Son, Seong Ho
    • Resources Recycling
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    • v.27 no.5
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    • pp.9-13
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    • 2018
  • The equilibrium constant of a chemical reaction is related to the standard Gibbs free energy change. Since equilibrium constant is defined as the ratio of the activities of the chemical species, it is necessary to consider the non-ideal behavior of the solutes as ionic strength of the solution increases. In this paper, the derivation of Debye-$H{\ddot{u}}ckel$ limiting law and its modification by which the activity coefficient of an ion can be calculated was explained. Moreover, the method to obtain the activity coefficient of an ion from the experimentally determined mean activity coefficients of an electrolyte was explained.

Dialysis in double-pass cross-flow rectangular membrane modules with external recycle for improved performance

  • Yeh, Ho-Ming
    • Membrane and Water Treatment
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    • v.2 no.2
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    • pp.75-89
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    • 2011
  • The predicting equations for mass transfer rate in cross-flow rectangular dialyzers with double flow and recycle, have been derived by mass balances. The recycling operation has two conflicting effects. One is the desirable effect of the increase in fluid velocity, resulting in an increased mass transfer coefficient. The other is the undesirable effect of the reduction in concentration difference due to remixing, resulting in decreased mass-transfer driving force. In contrast a single-pass device without recycling, considerable improvement in mass transfer is achieved if the cross-flow rectangular dialyzer of same size is operated with double pass and external recycling. It is concluded that recycle can enhance mass transfer, especially for larger reflux ratio.

Locational Characteristics of Recycling Industries (재생용 사업의 입지적 특성)

  • Han, Ju-Seong
    • Journal of the Korean association of regional geographers
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    • v.10 no.4
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    • pp.775-786
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    • 2004
  • Establishments of wholesale of recycling materials are located in the region where an amount of recyclable wastes generated as artery industry developed and the region of rather many population. And they are located not in underpopulated area as noxious facilities, but located in the non-residential area of many population regions in the whole country. Also, establishments of recycling of metal wastes and scrap, and non-metal wastes and scrap are mainly located in the peripheral region of metropolitan cities, regional centered cities, and adjacent regions of industrial area, because of high coefficient of localization, and agglomerated effects of production. The factor influencing the location of recycling industries is deeply connected with the location of wholesale of recycling materials, and thus, the transportation costs to carry recycling materials from supplied regions to plants are important but population is not so important.

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