State Of OD Research Articles

A study of engineering and electricity properties of cement mortar added with recycled materials and piezoelectric powders

Due to increasing global energy saving, carbon reduction, environmental considerations, and the environmental change resulting from the greenhouse effect, and because Taiwan is located on the plate junction, where earthquakes frequently occur, and because there is an abundance of rainfall during typhoon season, which often cause natural disasters, it is necessary to enhance the disaster prevention of buildings. This study uses recycled materials (fly ash, ground granulated blast furnace slag (GGBFS), and waste Liquid Crystal Display (LCD) glass powder) and Pd-Zr-Ti piezoelectric (PZT) to enhance intelligent functions of original substrates. The volumetric method is used for the design. The control group uses recycled materials to replace cement [0%, 10%, 20%, and 30%]. The PZT group uses a PZT powder to replace 5% of fine aggregates to make cement mortar to test the correlation between engineering and electricity properties of flow, compressive strength, water absorption, ultrasonic pulse velocity (UPV) and resistivity (electricity at 50V and 100V). The mechanical and electrical effects of cement mortar of various groups are discussed to determine the correlation between impedance characteristics and mechanical behavior of cement mortar in different electrical field environments and aqueous states, to build an engineering-electricity relation database for recycled materials and PZT, and to determine the relationships between various variables. A pozzolanic reaction occurs in GGBFS after 7days. A 30% GGBFS replacement (32.9MPa) has the maximum compressive strength. A 20% waste LCD glass powder replacement (31.8MPa) can fill up finer pores and accelerate hydration. The addition of GGBFS and waste LCD glass powder reduces water absorption and internal porosity. Water absorption increases when fly ash is replaced. The resistivity at 50V is higher than resistivity at 100V in an electrical field environment. Specifically, in a high voltage environment, the resistivity generated during the delivery process is reduced. Because the voltage increase improves conductivity inside the specimen, the resistivity is reduced. The resistivity increases in correlation with compressive strength in the SSD state of fly ash and GGBFS. The resistivity decreases when the compressive strength increases in the OD state. The resistivity increases when the waste LCD glass powder is replaced in SSD and OD states.

Reaction dynamics of O(¹D) + HCOOD/DCOOH investigated with time-resolved Fourier-transform infrared emission spectroscopy.

We investigated the reaction dynamics of O((1)D) towards hydrogen atoms of two types in HCOOH. The reaction was initiated on irradiation of a flowing mixture of O3 and HCOOD or DCOOH at 248 nm. The relative vibration-rotational populations of OH and OD (1 ≦ v ≦ 4, J ≤ 15) states were determined from time-resolved IR emission recorded with a step-scan Fourier-transform spectrometer. In the reaction of O((1)D) + HCOOD, the rotational distribution of product OH is nearly Boltzmann, whereas that of OD is bimodal. The product ratio [OH]/[OD] is 0.16 ± 0.05. In the reaction of O((1)D) + DCOOH, the rotational distribution of product OH is bimodal, but the observed OD lines are too weak to provide reliable intensities. The three observed OH/OD channels agree with three major channels of production predicted with quantum-chemical calculations. In the case of O((1)D) + HCOOD, two intermediates HOC(O)OD and HC(O)OOD are produced in the initial C-H and O-D insertion, respectively. The former undergoes further decomposition of the newly formed OH or the original OD, whereas the latter produces OD via direct decomposition. Decomposition of HOC(O)OD produced OH and OD with similar vibrational excitation, indicating efficient intramolecular vibrational relaxation, IVR. Decomposition of HC(O)OOD produced OD with greater rotational excitation. The predicted [OH]/[OD] ratio is 0.20 for O((1)D) + HCOOD and 4.08 for O((1)D) + DCOOH; the former agrees satisfactorily with experiments. We also observed the v3 emission from the product CO2. This emission band is deconvoluted into two components corresponding to internal energies E = 317 and 96 kJ mol(-1) of CO2, predicted to be produced via direct dehydration of HOC(O)OH and secondary decomposition of HC(O)O that was produced via decomposition of HC(O)OOH, respectively.

Dynamics of the reactions of O(1D) with CD3OH and CH3OD studied with time-resolved Fourier-transform IR spectroscopy

We investigated the reactivity of O((1)D) towards two types of hydrogen atoms in CH(3)OH. The reaction was initiated on irradiation of a flowing mixture of O(3) and CD(3)OH or CH(3)OD at 248 nm. Relative vibration-rotational populations of OH and OD (1 ≤ v ≤ 4) states were determined from their infrared emission recorded with a step-scan time-resolved Fourier-transform spectrometer. In O((1)D) + CD(3)OH, the rotational distribution of OD is nearly Boltzmann, whereas that of OH is bimodal; the product ratio [OH]/[OD] is 1.56 ± 0.36. In O((1)D) + CH(3)OD, the rotational distribution of OH is nearly Boltzmann, whereas that of OD is bimodal; the product ratio [OH]/[OD] is 0.59 ± 0.14. Quantum-chemical calculations of the potential energy and microcanonical rate coefficients of various channels indicate that the abstraction channels are unimportant and O((1)D) inserts into the C-H and O-H bonds of CH(3)OH to form HOCH(2)OH and CH(3)OOH, respectively. The observed three channels of OH are consistent with those produced via decomposition of the newly formed OH or the original OH moiety in HOCH(2)OH or decomposition of CH(3)OOH. The former decomposition channel of HOCH(2)OH produces vibrationally more excited OH because of incomplete intramolecular vibrational relaxation, and decomposition of CH(3)COOH produces OH with greater rotational excitation, likely due to a large torque angle during dissociation. The predicted [OH]/[OD] ratios are 1.31 and 0.61 for O((1)D) + CD(3)OH and CH(3)OD, respectively, at collision energy of 26 kJ mol(-1), in satisfactory agreement with the experimental results. These predicted product ratios vary weakly with collision energy.

Ab initio calculation of (2+1) resonance enhanced multiphoton ionization spectra and lifetimes of the (D,3)Σ−2 states of OH and OD

High-level ab initio potential-energy curves and transition dipole moments for the OH X 2Pi, 2 2Pi, 1 2Sigma-, D 2Sigma-, 3 2Sigma-, A 2Sigma+, B 2Sigma+, 1 2Delta, 1 4Sigma-, and 1 4Pi states are computed. The results are used to estimate the (2+1) resonance enhanced multiphoton ionization spectrum for the (D,3)2Sigma-(upsilon')<--2hnuX 2Piupsilon") transitions, which are compared with experiments by Greenslade et al. [see M. E. Greenslade, M. I. Lester, D. C. Radenovic, J. A. van Roij, and D. H. Parker, J. Chem. Phys. 123, 074309 (2005), preceeding paper]. We use the discrete variable representation-absorbing boundary condition method to incorporate the effect of the dissociative intermediate 1 2Sigma- state. We obtain qualitative agreement with experiment for the line strengths. Radiative and predissociative decay rates of the Rydberg (D,3)2Sigma- states of OH and OD were computed, including spin-orbit coupling effects and the effect of spin-electronic and gyroscopic coupling. We show that the lifetime of the Rydberg 2Sigma- states for rotationally cold molecules is limited mainly by predissociation caused by spin-orbit coupling.

On the energy dependence of the Zeeman and hyperfine parameters in the state of OH and OD

Abstract We report quantum beat studies of the energy dependence of the Zeeman parameters in the A 2 Σ + state of OH and OD, and the nuclear hyperfine parameters of OD( A 2 Σ + ). In contrast to previous work, we find that the sign and magnitude of the anisotropic g-factor gl for υ′=0 is consistent with that expected from Curl’s relationship. However, at higher energies gl changes sign, a result we attribute to interaction with the repulsive 1 4 Π state, which is known to lead to predissociation at higher energies. The magnetic and electric quadrupole hyperfine constants were determined for OD( A 2 Σ + ,υ ′ =0–3) , and the constants for υ′=2,3 are reported here for the first time. The derived values are consistent with previous experimental results and available ab initio calculations.

High-resolution inner-shell photoabsorption of the OH and OD free radicals

The O 1s photoabsorption (ion-yield) spectra of OH (2Πi,v″=0) and OD (2Πi,v″=0) radicals have been studied in the gas phase for the first time. Spectroscopic parameters for the O 1s→π excited Σ+2 state of OH and OD, observed at ∼525.8 eV, have been obtained from a Franck–Condon analysis comparing the spectra of both molecules. The lifetime width of this state has been measured as Γ=147±11 meV and Γ=156±7 meV for OH and OD, respectively. Excellent quantitative agreement is found between the experimental spectroscopic parameters re, ωe, and T0, measured in this work for the Σ+2 state and recent theoretical results obtained for OH by high-level ab initio calculations. The spectroscopic parameters predicted by the equivalent-core model are close to the experimental values within a few percent. This model therefore provides an accurate description of the lowest-lying excitation process in both OH and OD molecules.

Low temperature vibrational relaxation of OD in the A2Σ, state

The vibrational relaxation of the A 2Σ state of OD has been studied in the low translational temperature environment of an argon free-jet (Ttrans near 5 K). Using laser induced fluorescence (LIF), the absolute vibrational relaxation rate coefficients were measured for OD A2Σ (ν′) to be 7.1 ± 2.6 × 10−11, 5.9 ± 1.4 × 10−11, and 2.7 ± 1.1 × 10−11 cm3 s−1 for the ν = 3, 2 and 1 states, respectively. State-to-state relaxation rate coefficients were also obtained for the ν= 1, Ń = 1 level going to ν= 0, Ń levels in the A2Σ manifold. The rotational relaxation rate coefficient for ν= 1, Ń= 1 in the A state of OD was found to be 9.6 ± 1.0 × 10−11cm3s−1. These values are consistent with values measured for OH A2Σ, and the total loss rates are near the capture rate coefficient value. The vibrational relaxation rate coefficients kν appear to be governed by the vibrational energy of the molecule rather then by interaction with nearby dissociative states such as the a4Σ state. The relative Einstein A factors for the A2σ (ν = 3) state of OD were determined and compared with the available calculated value.

Product-State-Resolved Study of the O- + D2 Reaction: Anomalous Vibrational-State Distributions at Low Collision Energies

We present a product vibration-state-resolved study of the reaction O[sup [minus]] + D[sub 2] [yields] OD[sup [minus]] + D over the collision energy range from 0.25 to 1.20 eV. At the upper end of this range, the OD[sup [minus]] products are primarily scattered forward, with substantial vibrational excitation. At 0.37 eV and below, the products show both forward and backward scattered contributions, primarily in the [nu][prime] = 1 state of OD[sup [minus]]. We argue that this anomalous behavior is inconsistent with statistical partitioning of energy in a long-lived complex and discuss these results in the context of theory and experiment on the isoelectronic F + H[sub 2] system. 24 refs., 5 figs.

State-selected photodissociation of D2O

The effect of selective vibrational preparation of the parent on its absorption cross section and on the vibrational distribution of the photofragments is studied in D2O. Rovibrationally excited D2O molecules are prepared in the | 03 〉− state by infrared excitation and photolyzed via the A(1B1) state by 193 nm photons. The OD fragments are detected by laser-induced fluorescence. The ≈ 1 eV vibrational excitation of D2O results in a five orders of magnitude increase in the absorption cross section and its subsequent photolysis yields OD with (v = 1)/(v = 0) = 0.39±0.07. The significant population of both vibrational states of OD may help in testing quantitative agreement between experiment and future theoretical studies of state-selected photodissociation.

Dissociation dynamics of H2O(D2O) following photoexcitation at the Lyman-α wavelength (121.6 nm)

The technique of H(D) atom photofragment translation spectroscopy has been used to investigate the collision free photodissociation of jet cooled H2O(D2O) molecules following excitation to their B̃(1A1) excited state at 121.6 nm. The resolution of the total kinetic energy release spectrum obtained with this technique, allows assignment of the eigenvalues for the individual rotational quantum states and an estimation of the respective quantum state population distributions for the nascent OH(X 2Π) and OH(A 2Σ+) photofragments (and their deuterated analogs). This provides us the first experimental observations of high angular momentum states of OD(X). Analysis of the quantum state population distribution show both the ground (X 2Π) and electronically excited (A 2Σ+) OH(OD) fragments to be formed with little vibrational excitation but with highly inverted rotational distributions. Spectral simulation enables estimation of relative branching ratios for these two dissociation channels, and for the three-body fragmentation yielding ground state atoms. The observed energy disposal has been rationalized by considering the motion of a wavepacket launched on the B̃ state surface at a geometry corresponding to the ground state equilibrium configuration. Electronically excited OH(OD) fragments result from that fraction of the photoexcited molecules that dissociate on the B̃ state surface; their rotational excitation results from the marked angular anisotropy of the B̃ state surface. Ground state OH(OD) fragments can arise as a result of radiationless transfer to the lower Ã(1B1) or X̃(1A1) surfaces. The wavepacket calculations show that B̃■X̃ transfer via the conical intersection linking these two surfaces leads to the most highly rotationally excited OH(OD) fragments. These calculations also show that the contribution made by B̃■Ã radiationless transfer to the overall rotational distribution in the ground state OH(OD) fragments scales with the amount of a-axis rotational excitation in the photoexcited molecules: The detailed form of the OH(OD) product state population distribution is thus predicted to be temperature dependent.

The OH and OD laser: Collision-induced energy transfer pumping

Detailed studies of the relative intensities of pure rotational lasing in the v=0, 1, 2, 3 states of OH(2Π1/2) and the v=0, 1, 2, states of OD(2Π1/2) are presented. Differences in the laser patterns of these two molecules, such as variation in intensity maxima for specific J levels and double pulsed lasing phenomena, are explained on the basis of a computer simulation model incorporating R→T and V→R energy transfer mechanisms. The probability of collisionally induced R→T transitions is assumed to be given by exponential gap model in which the rotational parameter is evaluated by information theory (sum rule) approximations. The V →R relaxation is described in a two step process: first, the change of oscillator vibrational energy directly into oscillator rotational energy, and second, the absorption or removal of the energy defect (mismatch) by collisional R→T processes. The appropriate parameters for this transfer mechanism are also calculated with sum rule assumptions for the two molecules. The temporal evolution of nascent populations relaxing by the mechanisms lead directly to population inversions which corroborate in specific detail the lasing patterns observed experimentally.

Energy transfer in A 2Σ+ OH. II. Vibrational

Vibrational energy transfer within the A 2Σ+ state of OH and OD has been studied. A frequency doubled tunable dye laser excites individual N′, J′ levels in v′=1 or 2, and the intensities of rotationally resolved fluorescence emitted in the presence of collision partners (He, Ar, H2, D2, and N2) furnished state-to-state transfer rates. It is found that the transfer rates are strongly dependent on initial rotational level (decreasing as Ni increases), that the final rotational state distributions are near thermal but hot, that isoenergetic transfer is small, and that the magnitudes for transfer 1→0, 2→1, and 2→0 are all similar. The rates themselves are large; for example, with N2, k1→0 (Ni=3) =1.7×10−10 cm3 sec−1. The results, taken together, are supportive of a long-lived collision in which anisotropic attractive forces are of importance in the dynamics of the entrance channel.

Relative transition probabilities in the A-X system of OD

As in a previous study on the OH molecule, branching ratios for emission from v′ = 0, 1 and 2 of the A 2Σ + state of OD have been measured using frequency-doubled, tunable dye laser excitation. The six independent ratios so obtained are used to assess calculations incorporating an electronic transition moment varying linearly with internuclear distance, a form judged superior from the OH work. Calculations of the rotational dependence of the transition probabilities in OD, and comments on some recent OH investigations are included.

Comment on the quadrupole coupling constants in the A 2Σ+ states of OD and NO

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High field level crossing measurements of the A 2Σ+ state of OD

High field level crossing measurements have been performed on the v′=0 and the v′=1 levels of the A 2Σ+ state of OD using a tunable laser excitation source. The hyperfine constants were found to be b=109.73±0.10 MHz, c=25.73±0.25 MHz, and eqQ=0.22±0.03 MHz for v′=0 and b=111.15±0.10 MHz, c=24.40±0.25 MHz, and eqQ=0.05±0.04 MHz for v′=1. The measured values of the magnetic hyperfine constants are found to be within a few percent of the values obtained from an ab initio theoretical calculation.

Collision and quenching cross sections in the A 2Σ+ state of OH and OD

A pulsed dye laser has been used to excite OH and OD radicals to the A 2Σ+ state and the quenching and vibrational relaxation cross sections have been measured for several different buffer gasses. It was found that the quenching cross sections were reasonably constant within a given vibrational level and tended to increase at higher vibrational levels. The vibrational relaxation cross sections decreased for higher rotational states and were generally smaller for collisions in which V′ changes by two than for collisions where it changes by only one. Finally, the implications of these measurements to the detection of OH in the atmosphere are discussed.

Radiative and predissociative lifetimes of the V ′=0, 1, and 2 levels of the A 2Σ+ state of OH and OD

A direct measurement of the fluorescent decay rates of the V ′=0, 1, 2 vibrational levels of the A 2Σ+ state of OH and OD has been performed using pulsed laser excitation and at total gas pressures of less than 1 mTorr. The present experiment is the first in which lifetime measurements have been performed for individual rotational levels (N ′) of each of the three lowest vibrational states of both OH and OD and at pressures where both quenching and excitation transfer should be minimal. The radiative lifetime was found to increase slightly for the higher vibrational levels in agreement with a model of linear decrease of the transition moment with increasing internuclear separation. The measured radiative lifetimes, τV ′± (3σ), for OH were τ0=693±30 nsec, τ1=736±33 nsec and for OD were τ0 =691±27 nsec, τ1=712±30 nsec, τ2=736±39 nsec. The V ′=2 level of OH was found to be strongly predissociated with a predissociation lifetime of about 270±25 nsec at N ′=1. An analysis of the energies at which predissociation occurs leads to the conclusion that the repulsive 4Σ− state is responsible for all the observed predissociations for V ′?2 in both OH and OD.

Rotational and predissociation lifetimes of the A^2∑^+ state of OD*

The lifetime and predissociation probabilities of various rotational levels of the A2∑+ state of OD were measured. A strong predissociation at N′ = 35 was observed. This predissociation could be explained by the level crossing of the A2∑+ state with the repulsive 4∑− state which are mixed by a weak spin–orbit interaction.

The A2Σ +- X2Π i system of OD : Determination of molecular constants by the direct two-state fit approach

Accurate molecular constants for the low vibrational levels of the A 2Σ + and X 2Π i states of OD are reported for the first time. All available literature data are analyzed by the direct two-state fit approach. The problem of almost total correlation between the first-order spin-rotation coupling constant (γ) and the second-order centrifugal spin-orbit constant ( A D = 2 A J ) in 2Π states is discussed in detail. A new general procedure for the calculation of A D is described and gives results similar to the approximation proposed by Veseth. The molecular constants of OD are used to compute RKR potential energy curves and a set of J-dependent Franck-Condon factors for v′ ≤ 3, v″ ≤ 3 of the A 2Σ +- X 2Π i system.

Spin-orbit coupling and Λ-type doubling in the ground state of OD, X2Π : Comparison of experimental constants with ab initio calculations

Ab initio calculations of the electronic matrix elements, 〈 X 2 Π∥ L ̂ +∥A 2 Σ + 〉, 〈 X 2 Π∥ H ̂ SO ∥A 2 Σ + 〉 and 〈 X 2 Π∥ H ̂ SO ∥X 2 Π 〉 of the OD molecule are reported as a function of internuclear separation. Methods are developed to test the accuracy of these calculations by comparison with matrix elements determined from the Λ-doubling and spin-orbit coupling parameters from analysis of the OD A 2 Σ +-X 2 Π system. The agreement between the experimental and ab initio matrix elements is better than 1%.