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Izuru Takewaki - One of the best experts on this subject based on the ideXlab platform.
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Critical earthquake input Energy to connected building structures using impulse input
Earthquakes and Structures, 2015Co-Authors: Yoshiyuki Fukumoto, Izuru TakewakiAbstract:A frequency-domain method is developed for evaluating the earthquake input Energy to two building structures connected by viscous dampers. It is shown that the earthquake input energies to respective building structures and viscous connecting dampers can be defined as works done by the boundary forces between the subsystems on their corresponding displacements. It is demonstrated that the proposed Energy Transfer Function is very useful for clear understanding of dependence of Energy consumption ratios in respective buildings and connecting viscous dampers on their properties. It can be shown that the area of the Energy Transfer Function for the total system is constant regardless of natural period and damping ratio because the constant Fourier amplitude of the input acceleration, relating directly the area of the Energy Transfer Function to the input Energy, indicates the Dirac delta Function and only an initial velocity (kinetic Energy) is given in this case. Owing to the constant area property of the Energy Transfer Functions, the total input Energy to the overall system including both buildings and connecting viscous dampers is approximately constant regardless of the quantity of connecting viscous dampers. This property leads to an advantageous feature that, if the Energy consumption in the connecting viscous dampers increases, the input energies to the buildings can be reduced drastically. For the worst case analysis, critical excitation problems with respect to the impulse interval for double impulse (simplification of pulse-type impulsive ground motion) and multiple impulses (simplification of long-duration ground motion) are considered and their solutions are provided.
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Critical double impulse input and bound of earthquake input Energy to building structure
Frontiers in Built Environment, 2015Co-Authors: Kotaro Kojima, Kohei Fujita, Izuru TakewakiAbstract:A theory of earthquake input Energy to building structures under single impulse is useful for disclosing the property of Energy Transfer Function. This property shows that the area of the Energy Transfer Function is constant irrespective of natural period and damping of building structures. However single impulse may be unrealistic from a certain viewpoint because the frequency characteristic of input cannot be expressed by this input. In order to resolve such issue, a double impulse is introduced in this paper. The frequency characteristic of the Fourier amplitude of the double impulse is found in an explicit manner and a critical excitation problem is formulated with an interval of two impulses as a variable. The solution to that critical excitation problem is derived. An upper bound of the earthquake input Energy is then derived by taking full advantage of the property of the Energy Transfer Function that the area of the Energy Transfer Function is constant. The relation of the double impulse to the corresponding one-cycle sinusoidal wave as a representative of near-fault pulse-type waves is also investigated.
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critical excitation for earthquake Energy input in structure pile soil system
Critical Excitation Methods in Earthquake Engineering (Second edition), 2013Co-Authors: Izuru TakewakiAbstract:This chapter discusses a new method in the frequency domain for the computation of earthquake input energies both to a structure–pile system and a structure only. In investigating the Energy flow in the structure–pile system, many difficulties arise resulting from the dynamic interaction between the pile and the surrounding soil. It can be shown that the formulation of the earthquake input Energy in the frequency domain is effective for deriving the earthquake input Energy both to a structure–pile system and a structure only. An efficient continuum model consisting of a dynamic Winkler-type soil element and a pile is used to express the dynamic behavior of the structure–pile system accurately. The formulation of the earthquake input Energy in the frequency domain is appropriate for introducing the frequency-dependent vibration property of the surface ground. It is demonstrated that the present formulation is effective for various input levels and ground properties. The Energy input mechanism in the building structure–pile system can be well described by the newly introduced Energy Transfer Function. The chapter introduces a new concept called the input Energy densities at various underground levels, which is used to disclose the Energy input mechanism in the building structure–pile system.
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Instantaneous earthquake input Energy and sensitivity in base-isolated building
The Structural Design of Tall and Special Buildings, 2009Co-Authors: Kaoru Yamamoto, Kohei Fujita, Izuru TakewakiAbstract:The input Energy and Energy input rate to a base-isolated (BI) building during an earthquake are considered and formulated in the frequency domain. The frequency-domain approach for computation of input Energy and Energy input rate has different remarkable advantages compared with the conventional time-domain approach. It is demonstrated that the input Energy can be of a compact form via the frequency integration of the product between the input component (squared Fourier amplitude spectrum of acceleration) and the structural model component (so-called Energy Transfer Function). Furthermore, the Energy input rate can also be of a similar form via the frequency integration of the product between the instantaneous power spectrum and the Energy Transfer Function. With the help of this compact form, it is shown that the formulation in the frequency domain is essential for deriving arbitrary-order closed-form sensitivities of the input Energy and Energy input rate with respect to uncertain stiffness and damping coefficients in the BI storey. The closed-form sensitivity expressions provide us with information on the most unfavourable variation of the uncertain parameters that leads to the maximum input Energy and input rate. Copyright © 2009 John Wiley & Sons, Ltd.
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earthquake input Energy to tall and base isolated buildings in time and frequency dual domains
Structural Design of Tall and Special Buildings, 2009Co-Authors: Izuru Takewaki, Kohei FujitaAbstract:Earthquake input energies to tall and base-isolated buildings are examined by both time-domain and frequency-domain methods. Both methods support the validity of evaluating the earthquake input Energy each other. It is shown that both methods have different advantages and can compensate for each other. While the time-domain method has a long history and is applicable to nonlinear models as well, the frequency-domain method is characterized by the Energy Transfer Function and its equi-area property plays an important role in the discussion of the stability of earthquake input Energy. This equi-area property can be derived by the residue theorem only in a simple model. It is also demonstrated that this equi-area property in multi-degree-of-freedom models can be derived by the time-domain method for an idealized model of input motions with a constant Fourier amplitude spectrum. This idea is applied to tall and base-isolated buildings. The equi-area property of the Energy Transfer Function provides a stable characteristic on the input Energy as far as the total mass of the buildings is constant. Copyright © 2008 John Wiley & Sons, Ltd.
Dmitri Babikov - One of the best experts on this subject based on the ideXlab platform.
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate −500 ⩽ ΔE ⩽ +500 cm−1 the approximate method is rather accurate. The absolute valu...
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate -500 ≤ ΔE ≤ +500 cm(-1) the approximate method is rather accurate. The absolute values of stabilization cross sections for scattering resonances trapped behind the centrifugal threshold are a factor 2-to-3 smaller (compared to the explicit-rotation approach). This performance is acceptable and similar to the well-known sudden-rotation approximation in the time-independent inelastic scattering methods.
Alexander Teplukhin - One of the best experts on this subject based on the ideXlab platform.
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate −500 ⩽ ΔE ⩽ +500 cm−1 the approximate method is rather accurate. The absolute valu...
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate -500 ≤ ΔE ≤ +500 cm(-1) the approximate method is rather accurate. The absolute values of stabilization cross sections for scattering resonances trapped behind the centrifugal threshold are a factor 2-to-3 smaller (compared to the explicit-rotation approach). This performance is acceptable and similar to the well-known sudden-rotation approximation in the time-independent inelastic scattering methods.
Mikhail V Ivanov - One of the best experts on this subject based on the ideXlab platform.
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate −500 ⩽ ΔE ⩽ +500 cm−1 the approximate method is rather accurate. The absolute valu...
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frozen rotor approximation in the mixed quantum classical theory for collisional Energy Transfer application to ozone stabilization
Journal of Chemical Physics, 2013Co-Authors: Alexander Teplukhin, Mikhail V Ivanov, Dmitri BabikovAbstract:A frozen-rotor approximation is formulated for the mixed quantum/classical theory of collisional Energy Transfer and ro-vibrational Energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)]. Numerical tests are conducted to assess its efficiency and accuracy, compared to the original version of the method, where rotation of the molecule in space is treated explicitly and adiabatically. New approach is considerably faster and helps blocking the artificial ro-vibrational transitions at the pre- and post-collisional stages of the process. Although molecular orientation in space is fixed, the Energy exchange between rotational, vibrational, and translational digresses of freedom still occurs, allowing to compute ro-vibrational excitation and quenching. Behavior of the Energy Transfer Function through eight orders of magnitude range of values and in a broad range of ΔE is reproduced well. In the range of moderate -500 ≤ ΔE ≤ +500 cm(-1) the approximate method is rather accurate. The absolute values of stabilization cross sections for scattering resonances trapped behind the centrifugal threshold are a factor 2-to-3 smaller (compared to the explicit-rotation approach). This performance is acceptable and similar to the well-known sudden-rotation approximation in the time-independent inelastic scattering methods.
James A Miller - One of the best experts on this subject based on the ideXlab platform.
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third body collision efficiencies for combustion modeling hydrocarbons in atomic and diatomic baths
Proceedings of the Combustion Institute, 2015Co-Authors: Ahren W Jasper, Melania C Oana, James A MillerAbstract:Abstract The collisional Energy Transfer dynamics relevant to the unimolecular kinetics of linear, branched, and cyclic hydrocarbons, including both radicals and saturated and unsaturated molecules, in atomic and diatomic baths is studied via classical trajectories. A set of full-dimensional potential Energy surfaces (PESs) suitable for efficient trajectory simulations involving large hydrocarbons (C x H y ) colliding with any of seven baths (M = He, Ne, Ar, Kr, H 2 , N 2 , O 2 ) is validated against direct dynamics calculations for two small systems. The PESs are then used to calculate Lennard-Jones collision parameters, and a general rule for calculating these parameters based only on the number of carbon atoms and the bath gas is obtained. Next, the PESs are used to calculate low-order moments of the collisional Energy Transfer Function relevant to low-pressure-limit unimolecular kinetics for a total of 266 systems (38 unimolecular reactants in 7 baths), with a focus on the average angular momentum and total Energy Transferred in deactivating collisions. These moments are used to quantify the relative rotational and total collision efficiencies of the 7 baths for the various hydrocarbon reactants. Trends in the collision efficiencies with respect to the chemical structures of the hydrocarbon reactants are discussed.
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collision efficiency of water in the unimolecular reaction ch4 h2o ch3 h h2o one dimensional and two dimensional solutions of the low pressure limit master equation
Journal of Physical Chemistry A, 2013Co-Authors: Ahren W Jasper, James A Miller, Stephen J KlippensteinAbstract:The low-pressure-limit unimolecular decomposition of methane, CH4 (+M) ⇆ CH3 + H (+M), is characterized via low-order moments of the total Energy, E, and angular momentum, J, Transferred due to collisions. The low-order moments are calculated using ensembles of classical trajectories, with new direct dynamics results for M = H2O and new results for M = O2 compared with previous results for several typical atomic (M = He, Ne, Ar, Kr) and diatomic (M = H2 and N2) bath gases and one polyatomic bath gas, M = CH4. The calculated moments are used to parametrize three different models of the Energy Transfer Function, from which low-pressure-limit rate coefficients for dissociation, k0, are calculated. Both one-dimensional and two-dimensional collisional Energy Transfer models are considered. The collision efficiency for M = H2O relative to the other bath gases (defined as the ratio of low-pressure limit rate coefficients) is found to depend on temperature, with, e.g., k0(H2O)/k0(Ar) = 7 at 2000 K but only 3 at 3...
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solution of some one and two dimensional master equation models for thermal dissociation the dissociation of methane in the low pressure limit
Journal of Physical Chemistry A, 2002Co-Authors: James A Miller, Stephen J Klippenstein, Christophe RaffyAbstract:Using three formulations of the master equation (ME), we have investigated theoretically the dissociation of methane in the low-pressure limit. The three forms of the ME are as follows: (1) A one-dimensional model in which E, the total Energy, is the independent variable (the E model). (2) The two-dimensional strong-collision-in-J model of Smith and Gilbert (Int. J. Chem. Kinet. 1988, 20, 307−329) in which e, the Energy in the active degrees of freedom, and J, the total angular momentum quantum number, are the independent variables (the e,J model). (3) A two-dimensional variant of the e,J model in which E and J are the independent variables (the E,J model). The third form of the ME is the most physically realistic, and for this model we investigate the dependence of values of the Energy Transfer moments (〈ΔEd〉, −〈ΔE〉, and 〈ΔE2〉1/2) deduced from experiment on assumed forms of the Energy Transfer Function, P(E,E‘), and on temperature. All three moments increase as the temperature rises; −〈ΔE〉 increases fro...