Use of infrared spectroscopy for controlling protein concentration in lacrimal fluid and diagnosing corneal diseases

It was shown that changes in the absorption band intensities of peptide groups in infrared spectra of proteins contained in lacrimal fluid can be used for controlling their concentrations and diagnosing corneal diseases.     

On time-periodic solutions of a quasilinear wave equation

Existence and regularization theorems are obtained for generalized solutions of a quasilinear wave equation with variable coefficients and homogeneous Dirichlet boundary conditions. The nonlinear term either exhibits a power growth or satisfies a nonresonance condition.     

Calculations of the thermodynamic properties of dimethylsulfoxide-water solutions on the basis of the cluster solvation model

The thermodynamic functions of dimethylsulfoxide mixtures with water were analyzed over the whole composition range using the cluster solvation model taking into account the distribution of clusters over solvation numbers. The equations of the model were shown to correctly describe the concentration dependences of saturated vapor pressure and excess enthalpy and volume on the assumption of dimethylsulfoxide hydration. The hydration numbers of dimethylsulfoxide and the variance of the distribution of hydrates over stoichiometric numbers were shown to increase as the temperature decreased.     

Assessment of the Accuracy of Estimating Adsorption Parameters of Organic Substances from Differential Capacitance Curves: Monte-Carlo Simulation of the Random-Error Effect in Capacitance Measurements

Monte-Carlo method is used for elucidating the effect of a random normally distributed error of capacitance measurements on estimated adsorption parameters of organic substances on an ideally polarizable electrode. Within the model of two parallel capacitors and a Frumkin isotherm with preset adsorption parameters, initial differential capacitance vs. potential dependences are calculated for ten organic-substance concentrations. Then, a random normally distributed error is introduced at every point in these dependences. For estimating the adsorption parameters, 100 series of dependences thus obtained are processed by a nonlinear regression analysis technique. Histograms of distributions of found parameters are plotted. The accuracy of the parameter calculation is assessed for 5 and 10% errors of capacitance measurements.     

Calorimetric study of the interaction of oxygen with Pd-black and Pd/Al2O3

The kinetics of molecular hydrogen oxidation by palladium(II) has been studied under homogeneous conditions, excluding Pd-black formation. The rate constants for PdCl_i(H₂O)_4–i complexes for i=0, 1, 2, 3 and 4 are 0.12±0.003; 3.4±0.4; 5.2±0.3; 2.34±0.07 and 0 M^–1s^–1, respectively.

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, Pd-, H₂ (II). PdCl_i(H₂O)_4–i 0,12±0,003; 3,4±0,4; 5,2±0,3; 2,34±0,07 0 ^{–1 –1}, .

     

Ultrafast structural and isomerization dynamics in the Rydberg-exited quadricyclane: norbornadiene system

The quadricyclane-norbornadiene system is an important model for the isomerization dynamics between highly strained molecules. In a breakthrough observation for a polyatomic molecular system of that complexity, we follow the photoionization from Rydberg states in the time-domain to derive a measure for the time-dependent structural dynamics and the time-evolving structural dispersion even while the molecule is crossing electronic surfaces. The photoexcitation to the 3s and 3p Rydberg states deposits significant amounts of energy into vibrational motions. We observe the formation and evolution of the vibrational wavepacket on the Rydberg surface and the internal conversion from the 3p Rydberg states to the 3s state. In that state, quadricyclane isomerizes to norbornadiene with a time constant of τ(2) = 136(45) fs. The lifetime of the 3p Rydberg state in quadricyclane is τ(1) = 320(31) and the lifetime of the 3s Rydberg state in norbornadiene is τ(3) = 394(32).     

Formation of W/HfO2/Si gate structures using in situ magnetron sputtering and rapid thermal annealing

The W(150 nm)/HfO₂(5 nm)/Si(100) structures prepared in a single vacuum cycle by rf magnetron sputtering were subjected to rapid thermal annealing in argon. It is found that at an annealing temperature of 950°C, the tungsten oxide WO _x phase and the hafnium silicate HfSi _x O _y phase grow at the W/HfO₂ and HfO₂/Si(100) interfaces, respectively. Herewith, the total thickness of the oxide layeris 30% larger than that of the initial HfO₂ film. In addition, a decrease in the specific capacitance in accumulation C _max and in the dielectric constant k (from 27 to 23) is observed. At an annealing temperature of 980°C, intensive interaction between tungsten and HfO₂ takes place, causing the formation of a compositionally inhomogeneous Hf _x Si _y W _z O oxide layer and further decrease in C _max. It is shown that a considerable reduction in the leakage currents occurs in the W/HfO₂/X/Si(100) structures, where X is a nitride barrier layer.