• Title/Summary/Keyword: macroscopic

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$^1H$ NMR Estimation of Multi-Redox potentials of Cytochrome $c_3$ from Desulfovibrio vulgaris Hildenborough

  • 박장수;강신원;최성낙
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.331-336
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    • 1995
  • The macroscopic and microscopic redox potentials of tetrahemoprotein, cytochrome c3 from Desulfovibrio vulgaris(Hildenborough) (DvH) were estimated from 1H NMR and differential pulse polarography(DPP). Five sets of NMR resonances were confirmed by a redox titration. They represent cytochrome c3 molecules in five macroscopic redox states. The electron transfer in cytochrome c3 involves four consecutive one-electron steps. The saturation transfer method was used to determine the chemical shifts of eight heme methyl resonances in five different oxidation states. Thirty two microscopic redox potentials were estimated. The results showed the presence of a strong positive interaction between a pair of particular hemes. Comparing the results with those of Desulfovibrio vulgaris Miyazaki F (DvMF), it was observed that the two proteins resemble each other in overall redox pattern, but there is small difference in the relative redox potentials of four hemes.

A Network Partition Approach for MFD-Based Urban Transportation Network Model

  • Xu, Haitao;Zhang, Weiguo;zhuo, Zuozhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4483-4501
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    • 2020
  • Recent findings identified the scatter and shape of MFD (macroscopic fundamental diagram) is heavily influenced by the spatial distribution of link density in a road network. This implies that the concept of MFD can be utilized to divide a heterogeneous road network with different degrees of congestion into multiple homogeneous subnetworks. Considering the actual traffic data is usually incomplete and inaccurate while most traffic partition algorithms rely on the completeness of the data, we proposed a three-step partitioned algorithm called Iso-MB (Isoperimetric algorithm - Merging - Boundary adjustment) permitting of incompletely input data in this paper. The proposed algorithm was implemented and verified in a simulated urban transportation network. The existence of well-defined MFD in each subnetwork was revealed and discussed and the selection of stop parameter in the isoperimetric algorithm was explained and dissected. The effectiveness of the approach to the missing input data was also demonstrated and elaborated.

Mass transfer in the filtration membrane covering from macroscale, multiscale to nanoscale

  • Lin, Wei;Li, Jian;Zhang, Yongbin
    • Membrane and Water Treatment
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    • v.13 no.4
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    • pp.167-172
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    • 2022
  • The analytical results are presented for the mass transfer in a cylindrical pore covering from the macroscale, multiscale to nanoscale owing to the variation of the inner diameter of the pore. When the thickness hbf of the physically adsorbed layer potentially fully formed on the pore wall is comparable to but less than the inner radius R0 of the pore, the multiscale flow occurs consisting of both the nanoscale non-continuum adsorbed layer flow and the macroscopic continuum liquid flow; When R0 ≤ hbf, the flow in the whole pore is essentially non-continuum; When R0 is far greater than hbf, the flow in the whole pore can be considered as macroscopic and continuum and the adsorbed layer effect is negligible.

A Constitutive Law for Porous Solids with Pressure-Sensitive Matrices and a Void Nucleation Model (평균수직응력에 민감한 모재를 가진 기공체의 구성식과 기공생성모델)

  • Jeong, Hyeon-Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.2 s.173
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    • pp.472-480
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    • 2000
  • A macroscopic yield criterion for porous solids with pressure-sensitive matrices modeled by Coulomb's yield criterion was obtained by generalizing Gurson's yield criterion with consideration of the hydrostatic yield stresses for a spherical thick-walled shell and by fitting the finite element results of a voided cube. The macroscopic yield criterion is valid for negative mean normal stresses as well as for positive mean normal stresses. From the yield criterion, a plastic potential function for the porous solids was derived either for plastic normality flow or for plastic non-normality flow of pressure- sensitive matrices. In addition, the elastic relation, an evolution equation of the plastic flow stress of the matrices and an evolution equation of the void volume fraction were presented to complete a set of constitutive relations. The set of constitutive relations was implemented into a finite element code ABAQUS to analyze the material behavior of rubber-toughened epoxies. The cavitation and the deformation behavior were analyzed around a crack tip under three-point bending and around notch tips under four-point bending. In the numerical analyses, the cavitation of rubber particles was considered via a stress-controlled nucleation model. The numerical results indicate that a reasonable cavitation zone can be obtained with void nucleation controlled by the macroscopic mean normal stress, and a plastic zone is smaller around a notch tip under compression than under tension. These numerical results agree well with corresponding experimental results on the cavitation and plastic zones.

A Macroscopic Framework for Internet Worm Containments (인터넷 웜 확산 억제를 위한 거시적 관점의 프레임워크)

  • Kim, Chol-Min;Kang, Suk-In;Lee, Seong-Uck;Hong, Man-Pyo
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.9
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    • pp.675-684
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    • 2009
  • Internet worm can cause a traffic problem through DDoS(Distributed Denial of Services) or other kind of attacks. In those manners, it can compromise the internet infrastructure. In addition to this, it can intrude to important server and expose personal information to attacker. However, current detection and response mechanisms to worm have many vulnerabilities, because they only use local characteristic of worm or can treat known worms. In this paper, we propose a new framework to detect unknown worms. It uses macroscopic characteristic of worm to detect unknown worm early. In proposed idea, we define the macroscopic behavior of worm, propose a worm detection method to detect worm flow directly in IP packet networks, and show the performance of our system with simulations. In IP based method, we implement the proposed system and measure the time overhead to execute our system. The measurement shows our system is not too heavy to normal host users.

Application case for phase III of UAM-LWR benchmark: Uncertainty propagation of thermal-hydraulic macroscopic parameters

  • Mesado, C.;Miro, R.;Verdu, G.
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1626-1637
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    • 2020
  • This work covers an important point of the benchmark released by the expert group on Uncertainty Analysis in Modeling of Light Water Reactors. This ambitious benchmark aims to determine the uncertainty in light water reactors systems and processes in all stages of calculation, with emphasis on multi-physics (coupled) and multi-scale simulations. The Gesellschaft für Anlagen und Reaktorsicherheit methodology is used to propagate the thermal-hydraulic uncertainty of macroscopic parameters through TRACE5.0p3/PARCSv3.0 coupled code. The main innovative points achieved in this work are i) a new thermal-hydraulic model is developed with a highly-accurate 3D core discretization plus an iterative process is presented to adjust the 3D bypass flow, ii) a control rod insertion occurrence -which data is obtained from a real PWR test- is used as a transient simulation, iii) two approaches are used for the propagation process: maximum response where the uncertainty and sensitivity analysis is performed for the maximum absolute response and index dependent where the uncertainty and sensitivity analysis is performed at each time step, and iv) RESTING MATLAB code is developed to automate the model generation process and, then, propagate the thermal-hydraulic uncertainty. The input uncertainty information is found in related literature or, if not found, defined based on expert judgment. This paper, first, presents the Gesellschaft für Anlagen und Reaktorsicherheit methodology to propagate the uncertainty in thermal-hydraulic macroscopic parameters and, then, shows the results when the methodology is applied to a PWR reactor.