• Title/Summary/Keyword: Site Constants

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Conformity Enhancement of Methane Generation Model for In-Service Landfill Site (운영 중인 매립장에서의 메탄가스 발생 모델의 정합도 향상)

  • Chun, Seung-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.1
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    • pp.213-223
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    • 2016
  • The validity of landfill gas models is an important problem considering that they are frequently used for landfill-site-related policy making and energy recovery planning. In this study, the Monte Carlo method was applied to an landfill gas generation model in order to enhance conformity. Results show that the relative mean deviation between measured data and modeled results (MD) decreased from 19.8% to 11.7% after applying the uncertainty range of Intergovernmental Panel on Climate Change (IPCC) to the methane-generation potential and reaction constants. Additionally, when let reaction constant adjust derived errors from all other modeling components, such as model logic, gauging waste, and measured methane data, MD decreased to 6.6% and the disparity in total methane generation quantity to 2.1%.

Polarization Mode Coupling Constants in Solid-State Lasers

  • Park, Jong-Dae;Cho, Chang-Ho
    • The Journal of Natural Sciences
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    • v.17 no.1
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    • pp.31-37
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    • 2006
  • We have found that the polarization mode coupling between the orthogonally linearly polarized dual mode laser results from the anisotropy of dipole moments. Rate equation analysis demonstrated that high anisotropy in dipole moment components can give rise to law intrinsic mode coupling constants while isotropic dipole moment components give high intrinsic mode coupling constant. The populations at active ion sites are shown to self-organize the populations such that laser mode gain is constant adove threshold while the gain contributions from the each site adjust themselves with pump power.

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Excitation Energy Transfer Rate Constants in meso-meso Linked Zn(II) Porphyrin Arrays with Energy Accepting 5,15-Bisphenylethynylated Zn(II) Porphyrin

  • Ko, Da-Mee;Kim, Hee-Young;Park, Jin-Hee;Kim, Dong-Ho;Sim, Eun-Ji
    • Bulletin of the Korean Chemical Society
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    • v.26 no.10
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    • pp.1505-1511
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    • 2005
  • The excitation energy transfer process occurring in energy donor-acceptor linked porphyrin array system is theoretically simulated using the on-the-fly filtered propagator path integral method. The compound consists of an energy donating meso-meso linked Zn(II) porphyrin array and an energy accepting 5,15-bisphenylethynylated Zn(II) porphyrin, in which the donor array and the acceptor are linked via a 1,4-phenylene spacer. Real-time path integral simulations provide time-evolution of the site population and the excitation energy transfer rate constants are determined. Simulations and experiments show an excellent agreement indicating that the path integration is a useful tool to investigate the energy transfer dynamics in molecular assemblies.

Sorption of Pd on illite, MX-80 bentonite and shale in Na-Ca-Cl solutions

  • Goguen, Jared;Walker, Andrew;Racette, Joshua;Riddoch, Justin;Nagasaki, Shinya
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.894-900
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    • 2021
  • This paper examines sorption of Pd(II) onto illite, MX-80 bentonite, and Queenston shale in Na-Ca-Cl solutions of varying ionic strength (IS) from 0.01 to 6.0 mol/L (M) and pHc ranging from 3 to 9 under atmospheric conditions. A 2-site protolysis non-electrostatic surface complexation and cation exchange model was applied to the Pd sorption onto illite and MX-80 using PHREEQC, and the model results were compared to the experimental ones obtained in this work. Surface complexation and cation exchange constants were estimated for both illite and MX-80 through the optimization process to bring the predicted distribution coefficients from the model into alignment with the experimentally derived values. These optimized surface complexation constants were compared to existing linear free energy relationships (LFER).

Crystallographic Effects of Larger Indium Ion Substitution in NiFe2-xInxO4 (x = 0, 0.2, 0.5, and 1.0) System

  • Yoon, Sung-Hyun;Yoon, Chang-Sun;Kim, Byung-Ho
    • Journal of Magnetics
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    • v.10 no.1
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    • pp.23-27
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    • 2005
  • The crystallographic and magnetic properties of a series of substitutions in nickel ferrite where the Fe3+ is replaced with In3+ have been investigated using X-ray diffraction (XRD) and Mössbauer spectroscopy. Information on the exact crystalline structure, lattice parameters, bond lengths and bond angles were obtained by refining their XRD profiles by a Rietveld method. All the crystal structures were found to be cubic with the space group Fd/3m. The lattice constants increased with In3+ concentration. The expansion of the tetrahedron was outstanding, indicative of the tetrahedral (A) site preference of larger indium ion. The Mossbauer spectra showed two sets of sextuplet originating from ferric ions occupying the tetrahedral sites and the octahedral (B) sites under the Neel temperature TN. Regardless of the composition x, the electric quadrupole splitting was zero within the experimental error. At x = 0.2, the magnetic hyperfine fields increased slightly, which meant that the nonmagnetic indium ions occupied preferentially the A-site. At the same time, the intensity of the B-site sub-spectra decreased markedly at the elevated temperature, indicating that the occupation of the A site by indium induced a considerable perturbation on the B site.

Influence of Sample Number on the Estimation of Blasting Coefficients and Limit Scaled Distance (측정수가 발파계수와 허용환산거리의 산정에 미치는 영향)

  • 양형식;전양수;정지문
    • Journal of KSNVE
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    • v.8 no.5
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    • pp.814-820
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    • 1998
  • Vibration data from two blasting sites were analyzed to determine the sufficient sample number for blasting vibration estimation. Most important result is that much more than 30 sample data and succeeding measurement are necessary to estimate confident blasting vibration level and to determine limit scaled distance.

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Use of Probe Class for Estimating Java Class Area Size (자바 클래스 영역 크기 예측을 위한 탐침 클래스의 사용)

  • 양희재
    • Proceedings of the IEEK Conference
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    • 2003.11b
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    • pp.19-22
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    • 2003
  • Class area is a portion of memory where the constants, fields, and codes of the classes loaded into the Java virtual machine are kept. Knowing the site of the class area is very important especially for embedded Java system with limited memory resources. This paper induces a formula which makes it possible estimate the size of the area. The formula needs some constant values specific to target JVM implementation. We also show that these values can be found using some simple probe classes. An experimental result is included in this paper to confirm the correctness of our approach.

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Studies on the Adsorption Modeling of Cationic Heavy Metals(Pb, Cd) by the Surface Complexation Model (Surface Complexation Model을 이용한 양이온 중금속(Pb, Cd) 흡착반응의 모델화 연구)

  • 신용일;박상원
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.211-219
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    • 1999
  • Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(II) and Cd(II). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.

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Interfacial Properties of $\gamma-Alumina/KCI^{(ag)}$ Electrical Double Layer ($\gamma$-알루미나/KCl 수용액의 전기 이중층에서 계면 물성)

  • 홍영호;함영민;장윤호
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.678-684
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    • 1994
  • The surface of alumina is capable of acquiring a change when it is in an aqueous solution. This surface change will have a strong influence on the surrounding ions, particularly those of opposite change known as the counter ions. A site-binding model of the {{{{ gamma }}-alumina/KCl(aq) interface was used to calculated theoretical surface ionization constants and P.Z.C.(Point of zero change) of {{{{ gamma }}-alumina. This paper was carried out to investigate the effect of calcination temperature on the acidic and electrical properties of pure {{{{ gamma }}-alumina prepared by the precipitation method from the Al(NO3)3.9H2O and NH4OH. From the experimental data it was shown that {{{{ gamma }}-alumina have a mainly Br nsted acid site. However, the acidity of {{{{ gamma }}-alumina decreased with increasing calcination temperature at strength Ho +9.3. The surface charge density of {{{{ gamma }}-alumina was increased with electrolyte ionic strength and calcination temperature.

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고온공기주입시 지중온도에 의한 ISR의 변화

  • 박기호;박민호;이의신;신항식
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.91-94
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    • 2003
  • A field pilot-scale demonstration of an enhanced SVE using hot air injection and extraction was conducted to remove diesel range compounds from subsurface soils at a site in J-city, Korea. The objective of demonstration was to evaluate field ISR by intrinsic microorganism after an application study of hot air-SVE technology and to calculate each first-order kinetic with soil temperature. TPH concentration of contaminated soil at the site was approximately 2, 000~11, 000 mg/kg (average 6, 900 mg/kg) with depths greater than 5 m bgs. The 1st-order reaction rate constants, k were 0.0438(@about5$0^{\circ}C$), 0.0564(@4$0^{\circ}C$), and 0.0685(@33$^{\circ}C$) d-1 respectively.

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