Digital Commons Network^™

Effects Of Surfaces On Dynamic Percolation, H. K. Janssen, B. Schaub, Beate Schmittmann

Beate Schmittmann

The general epidemic process, which is a stochastic multiparticle process belonging to the universality class of dynamic percolation, is studied in a semi-infinite geometry. Critical exponents characterizing the fractal properties are calculated to O(ε) (ε=6-d, where d is the spatial dimension) with use of renormalization-group techniques.

Modified Broyden’S Method For Accelerating Convergence In Self-Consistent Calculations, Duane D. Johnson

Duane D. Johnson

A modification to Broyden’s method for obtaining stable and computationally efficient convergence in self-consistent calculations is developed and discussed. The method incorporates the advantages of two schemes proposed by Srivastava and by Vanderbilt and Louie without any increase in complexity. Its improvement over their methods is discussed. The present method is compared with two other widely used convergence methods, simple mixing and Anderson’s method, for the case of the disordered binary alloy Ni0.35Fe0.65 on the verge of a magnetic instability and is shown to be much improved in stability and rate of convergence.

The Effect Of Solvent Type On The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes, Mark Anderson, Daniel Blackwood, Thomas Richmond, Stanley Pons

Mark R. Anderson

The infrared spectrum of CO adsorbed on a platinum electrode from several solvents was investigated. In N-methylformamide, acetonitrile, and 1,2-dichloroethane, the infrared band attributed to linearly bonded CO had experimental Stark tuning rates of 20 cm−1/V, 22 cm−1/V, and 19 cm−1/V, respectively. For each of these solvents, the potential dependence of the band position was found to be linear for the entire potential range investigated. When methanol was the solvent, the plot of the band position versus potential had three distinctly linear portions, each with a different value for the slope. The behavior is explained in terms of the ability …

The Behavior Of The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes From Non-Aqueous Solvents, Mark Anderson, Daniel Blackwood, Stanley Pons

Mark R. Anderson

Electrochemical oxidation of vanadium hexacarbonyl anion, V(Co)6 in aprotic solvents results in formation of the V(0) complex which decomposes to form CO in high concentrations next to the electrode surface. As a result, CO is more rapidly adsorbed on the surface than by conventional methods. Surface reflection infrared spectroscopy shows that the potential dependent frequency shift for the infrared active bands due to CO adsorbed on platinum is 19 cm−1/V in 1,2-dichloroethane and 22 cm−1/V in acetonitrile, which are considerably less than the 30 cm−1/V observed in aqueous systems.

Potential Energy Surfaces For The Reaction Si (Silicon) + H2o (Water), Shogo Sakai, Mark S. Gordon, Kenneth D. Jordan

Mark S. Gordon

The potential energy surfaces for the reactions of silicon atom (ID and 3P) with the water molecule were calculated by ab initio self-consistent field (SCF) methods. The transition states for the insertion of silicon atom into the D--H bond of water were also calculated by the multiconfigurational SCF method. It is found that the crossing point of the singlet and triplet surfaces along the insertion reaction paths is near the transition state for the triplet rearrangement from the Si:OH2 complex to HSiOH. The potential energy surfaces for the 1,2-hydrogen migration HSiOH- H2Si0 in the singlet and triplet states and the …

Polymer Science In Romania I: "Petru Poni" Institute Of Macromolecular Chemistry, Iasi, Romania, Otto Vogl, Cristofor I. Simionescu, Ioan I. Negulescu

Otto Vogl

No abstract provided.

U.S.-Japan Seminar: "Synthesis, Properties And Reactions Of Specialty Polymers", Otto Vogl, Hiroshi Sumitomo

Otto Vogl

No abstract provided.

Systems Of Functional Differential Equations With Asymptotically Constant Solutions, William F. Trench, T. Kusano

William F. Trench

No abstract provided.

Vandafil Advanced Blend, Vandafil Advance

vandafil advance

Surface-Enhanced Raman Study: Effect Of Ph And Electrode Potential On The Interfacial Behavior Of Some Substituted Pyridines, Mark Anderson, Daniel Evans

Mark R. Anderson

The surface-enhanced Raman spectra (SERS) provide information about the extent of protonation of the species adsorbed at the silver/aqueous solution interface. The compounds investigated were 4-pyridylcarbinol (1), 4-acetylpyridine (2), 3-pyridinecarboxaldehyde (3), isonicotinic acid (4), isonicotinamide (5), 4-benzoylpyridine (6), 4-(aminomethyl)pyridine (7) and 4-aminopyridine (8). For 1, the fraction of the adsorbed species which was protonated at -0.20 V vs. SCE varied with pH in a manner indicating stronger adsorption of the neutral than the cationic form. The fraction protonated increased at more negative potentials. Similar results were obtained with 3. For all compounds but 4, bands due to the unprotonated species …

31st International Congress Of Pure And Applied Chemistry, Sofia, Bulgaria,1987, Otto Vogl, Ivan Shopov, Ivan Panayotov

Otto Vogl

No abstract provided.

Polymer Science In Czechoslovakia Ii: Universities In The Czech Socialist Republic, Otto Vogl, Jaroslav Kralicek, Miroslav Schatz, Petr Vondracek

Otto Vogl

No abstract provided.

Relative Energies Of Silaethylene And Methylsilylene, Roger S. Grev, Gustavo E. Scuseria, Andrew C. Scheiner, Henry F. Schaefer Iii, Mark S. Gordon

Mark S. Gordon

The energy difference between silaethylene (H2Si=CH2) and methylsilylene (SiHMe) has been determined with ab initio quantum chemical techniques. Large basis sets and a variety of methods for the inclusion of electron correlation effects have been employed. In direct contrast to the recent theoretical and experimental results of Shin, Irikura, Beauchamp, and Goddard, which suggested silaethylene was 10 kcaljmol more stable than methylsilylene, we find the energy difference to be nearer 4 kcal/mol.

Slip, Twinning, And Fracture At A Grain Boundary In The L12 Ordered Structure—Aς = 9 Tilt Boundary, Alexander H. King, M. H. Yoo

Alexander H. King

The role of interaction between slip dislocations and a Σ = 9 tilt boundary in localized microplastic deformation, cleavage, or intergranular fracture in the Li2 ordered structure has been analyzed by using the anisotropic elasticity theory of dislocations and fracture. Screw superpartials cross slip easily at the boundary onto the (1$\overline 1$1) and the (001) planes at low and high temperatures, respectively. Transmission of primary slip dislocations onto the conjugate slip system occurs with a certain degree of difficulty, which is eased by localized disordering. When the transmission is impeded, cleavage fracture on the ($\overline 1$11) plane is predicted to …

Iupac “Macro 87” In Merseburg (Gdr) Linking Tradition And Future In Polymer Science, Otto Vogl, Burkart Philipp

Otto Vogl

No abstract provided.

Gas-Phase And Computational Studies Of Pentacoordinate Silicon, Robert Damrauer, Larry W. Burggraf, Larry P. Davis, Mark S. Gordon

Mark S. Gordon

We have demonstrated that a wide variety of pentacoordinate silicon anions (siliconates) should be stable and can be prepared by combining the predictive powers of MNDO and ab initio computational methods and the flowing afterglow (FA) experimental technique. MNDO has been used to compute the anion affinities of 91 siliconates; all but five of these are predicted to be stable with respect to the loss of an anion. Twenty-four siliconates, most of them previously unreported, have been prepared and studied in the FA. The MNDO predictions were, in general, consistent with the experimental results and with trends previously reported by …

Constraints On Left-Right-Symmetric Models From Neutron Decay, As Carnoy, J Deutsch, Br Holstein

Barry R Holstein

The implications for left-right-symmetric models of recent neutron-β-decay asymmetry and lifetime measurements are analyzed. The significance of forthcoming high-precision lifetime measurements is stressed.

Surface-Enhanced Raman Study Of The Effect Of Electrode Potential And Solution Ph Upon The Interfacial Behavior Of 4-Pyridinecarboxaldehyde, Mark Anderson, Dennis Evans

Mark R. Anderson

Surface-enhanced Raman scattering (SERS) spectra were obtained at a silver electrode in aqueous solutions at potentials from -0.2 to -0.6 V vs SCE and pH 1-7. The forms of 4-pyridinecarboxaldehyde that are adsorbed parallel those present in solution. In particular, the fraction of adsorbed species that is protonated at -0.2 V varies with pH in a manner almost identical with the fraction that is protonated in bulk solution. The protonated compound exists almost completely in the hydrated form (gem-diol) in the interface just as it does in solution. At a given pH, the fraction protonated on the surface increases as …

The Effect Of Solvent Type On The Infrared Spectrum Of Carbon Monoxide Adsorbed On A Platinum Electrode, Stanley Pons, Mark Anderson, Daniel Blackwood

Mark R. Anderson

No abstract is currently available.

A Comprehensive Method To Characterize Mixed Conduction Electrolytes, Michael P. Setter, J. Bruce Wagner Jr.

Michael P. Setter

Determination of the electrical characteristics of an electrolyte is vitally important to the design of battery materials and sensors. A wide variety of parameters are available from both dc and ac measurements. Through the use of computer control and a custom multiplexor, we can perform dc polarization and ac impedance measurements on a sample, without replacing electrodes.

Bulking Control With Ozonation In A Nutrient Removal Activated Sludge System, Johannes Van Leeuwen

Johannes van Leeuwen

The control of sludge bulking by ozonation was studied on four parallel pilot-scale (100 l/d) biological nutrient removal systems. Bulking was caused by filamentous organisms which typically occur in nutrient removal systems, i.e. Type 0092, Tpye 0041 and Microthrix parvicella. Continuous dosing of ozone, at 1; 2 and 4g O3/kg mixed liquor suspended solids (MLSS).d resulted in a diluted sludge volume index of about 50 ml/g less than the unozonated control. Ozonation was more effective in the sludge cycle than directly into the aeration basin. Nitrification-denitrification was not affected, not even at dosages of 30 g O3/kg MLSS.d. Biological phosphate …

Remarks On A Semilinear Elliptic Equation On Rn, Yi Li

Yi Li

No abstract provided.

Analysis Of The Convergence History Of Fluid Flow Through Nozzles With Shocks, Mohammad Saleem, A Cheer, M Hafez, T Pulliam

Mohammad Saleem

"Convergence of iterative methods for the solution of the steady quasi-one-dimensional nozzle problem with shocks is considered. The finite-difference algorithms obtained from implicit schemes are used to approximate both the Euler and Navier-Stokes Equations. These algorithms are investigated for stability and convergence characteristics. The numerical methods are broken down into their matrix-vector components and then analyzed by examining a subset of the eigensystem using a method based on the Arnoldi process. The eigenvalues obtained by this method are accurate to within 5 digits for the largest ones and to within 2 digits for the ones smaller in magnitude compared the …

"The Infrared Spectra Of Carbon Monoxide Adsorbed On A Polycrystalline Platinum Electrode From Nonaqueous Solutions, Mark Anderson, Daniel Blackwood, Stanley Pons

Mark R. Anderson

No abstract is currently available.

Theoretical Studies Of Silabicyclobutanes And Silacyclobutenes, Cnsi4-Nh6 (N = 0-4), Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

The geometries of the silicon-substituted bicyclobutanes and cyclobutenes c.Si4-.H6 are predicted by using the 3-21G(d) basis set and SCF wave functions. Strain energies and heats of formation are predicted by using MP2/6-31G(d) energies in conjunction with the appropriate homodesmic reactions. Bent bond lengths are calculated by tracing the path of maximum electron density connecting two nuclei, with the 6-31 G(2d) basis set at the 3-21 G(d) structures.

Potentially Aromatic Metallocycles, Kim K. Baldridge, Mark S. Gordon

Mark S. Gordon

Ab initio molecular orbital theory is used to characterize a series of metal-substituted benzene and cyclopentadiene structures, with the heteroatom taken from the block in the periodic table bounded by groups IV-VI and periods 2-5. Structures are predicted with the 3-21G* basis set and SCF wave functions. The calculated bond lengths and bond angles are in general within 0.04 A and 2°, respectively, of the available experimental values. As a measure of the de localization stabilization, !::.£and t::..H0 values for the appropriate bond separation and superhomodesmic reactions are calculated with 3-21 G* Hartree-Fock energies for these compounds and some smaller …

Http://Jackedextreme.Com/Noticeably-Skin/, Sobre Esdruj

sobre esdruj

Theoretical Study Of The Decomposition Of Five-Coordinate Silicon Anions, Larry P. David, Larry W. Burggraf, Mark S. Gordon

Mark S. Gordon

We have performed a theoretical study of the decomposition of the five-coordinate silicon anions (siliconates) H3(CH3)SiOH- and (CH3) 4SiOH-. These ions can be formed from hydroxide ion attack on methylsilane or tetramethylsilane, respectively. Both MNDO and ab initio calculations show that removal of methane from the five-coordinate structure is likely, via a transfer of the proton from the OH group to an adjacent methyl substituent. This process we term anionic dissociative proton transfer, because the transition state is one in which the methyl group being removed is almost completely dissociated to methide ion before the proton transfer takes place. This …

Ab Initio Approach To The Deuteron In The Skyrme-Witten Model, Alec Schramm

Alec J Schramm

No abstract provided.

A Calculation Of The Deuteron As A Biskyrmion, Alec Schramm, Yossef Dothan, L. Beidenharn

Alec J Schramm

No abstract provided.