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Man is the measure of all things: of things that are, that they are; of things that are not, that they are not. Protagoras In 'The Age of the World [...]

The dynamic behavior of the hydrolysis reaction of Si(OCH3)(sub 4) under neutral, basic and acidic conditions was investigated at the atomic level with short time intervals using a novel tight-binding quantum chemical molecular dynamics program 'Colors'. The simulation results of this study clearly indicate that a flank-side attack mechanism is favored for the hydrolysis process, and pentacoordinate silicon intermediates were easy pathways for the displacement of -OCH3 by -OH on silicon.

The activation of hydrogen peroxide in a titanosilicate catalyst is studied using density functional theory (DFT) calculations. It was found that, it is possible to form the hydrated peroxotitanosilicate complex, which contains a (Ti)-O-O-(Si) peroxo-moiety oxidizing agent.

A study was conducted to analyze the adsorption states of ammonia on both the Bronsted and Lewis acid sites of V2O5(010) surface. Periodic boundary first-principles density functional computations were utilized to carry out the analysis. Results indicated that ammonia adsorbs on the Lewis sites with different coverages. Stability under high coverage was low because of the steric repulsion determined from the coadsorbed ammonia molecules.

Periodic boundary models and the density functional computations were used in studying the molecular and dissociative adsorption of a water molecule on the V2O5(010) surface. The calculations were done using CASTEP and DSolid computer programs. Results indicate that the adsorption of water molecule on the V2O5(010) surface occurs favorably while dissociation hardly occurs due to Coulombic repulsion of the lattice oxygens around the exposed vanadium center to the approaching oxygen of the hydroxyl species. It has also been observed that the vanadyl oxygen is the most favorable site for adsorption and dissociation.

The molecular dynamics (MD) of a chemical vapor deposition process on the zeolite ZSM-5(010) surface has been studied by using the MOMODY simulation code. Si(OH)4 molecules were placed on the zeolite surface and the MD simulation was carried out for 12 ps. The atomic motions were calculated using the Verlet algorithm while the electrostatic interactions were determined through the Ewald method. It has been observed that H2O molecules form and evaporate on the surface. The formation of Si-O-Si bonds at the surface was also noticed, indicating crystal growth on the surface of ZSM-5(010).

A study was conducted to analyze hydrogen adsorption on the V2O5(010) surface using density functional computations. Results indicated that the use of a periodic approach eliminates artifacts of the cluster technique. In addition, findings confirmed the effectiveness of using the density functional theory in examining the geometric, electronic and catalytic characteristics of transition metal oxide catalysts.

A periodic density functional study was conducted to analyze the oxidation and stabilization of unreconstructed hydrogen and fluorine-terminated Si(100) surfaces. The oxidation of the Si(100) surface for H and F-terminated surfaces were analyzed to determine possible mechanisms of oxidation. Two types of experimental situations were carried out, namely, the generation of the Si-O-H bond and the production of Si-O-Si.

The molecular dynamics approach and computer graphics methods were employed to examine the atomistic structural characteristics of Pd clusters on the MgO(001) surface. The two methodologies were used in the estimation of the numerical features of the surface atomic rows, the in-plane symmetric configurations, the height deviation of the layer and the lattice length between near neighboring rows. In addition, this investigation determined the dependency and the interdependence of the results. A comparison between the results on the lattice spaces and experimental and other theoretical findings was performed.

Blood clots that block coronary arteries and cause a heart attack have a different appearance than clots that cause unstable angina. This could reflect differences in composition and could explain why thrombolytic drugs - drugs that break up clots - are effective in heart attacks but not in unstable angina. Angioscopy was performed within eight hours after symptoms began in 16 patients diagnosed with heart attack, and within 48 hours after symptoms began in 15 patients with unstable angina. Angioscopy involves the insertion of a catheter into the heart that allows doctors to see the inside of the coronary arteries. Blood clots were observed in all but two patients - one in each group. However, the clots in the arteries of most of the angina patients were grayish-white, whereas the clots in the arteries of all of the heart attack patients were red.

A hybrid tight-binding quantum chemical molecular dynamics method was adopted to study the atomistic behavior of the phosphoric ester molecule on the nascent Fe surface under boundary lubrication conditions. Phosphoric ester was shown to interact with the nascent Fe surface forming both covalent and ionic bonds and it was found that friction influences the formation and dissociation of covalent bonds.

The strained methylenecycloalkanes, often undergo ring-opening reactions promoted by single-site metallocene-based complexes, and they are effectively utilized in . The selectivity of insertion and ring-opening site is dependent on the combination of both the substrates and the catalysts.