Kinetic Path Summation, Multi--Sheeted Extension of Master Equation, and Evaluation of Ergodicity Coefficient

We study the Master equation with time--dependent coefficients, a linear kinetic equation for the Markov chains or for the monomolecular chemical kinetics. For the solution of this equation a path summation formula is proved. This formula represents the solution as a sum of solutions for simple kinetic schemes (kinetic paths), which are available in explicit analytical form. The relaxation rate is studied and a family of estimates for the relaxation time and the ergodicity coefficient is developed. To calculate the estimates we introduce the multi--sheeted extensions of the initial kinetics. This approach allows us to exploit the internal ("micro")structure of the extended kinetics without perturbation of the base kinetics.Comment: The final journal versio

Hyperspherical theory of anisotropic exciton

A new approach to the theory of anisotropic exciton based on Fock transformation, i.e., on a stereographic projection of the momentum to the unit 4-dimensional (4D) sphere, is developed. Hyperspherical functions are used as a basis of the perturbation theory. The binding energies, wave functions and oscillator strengths of elongated as well as flattened excitons are obtained numerically. It is shown that with an increase of the anisotropy degree the oscillator strengths are markedly redistributed between optically active and formerly inactive states, making the latter optically active. An approximate analytical solution of the anisotropic exciton problem taking into account the angular momentum conserving terms is obtained. This solution gives the binding energies of moderately anisotropic exciton with a good accuracy and provides a useful qualitative description of the energy level evolution.Comment: 23 pages, 8 figure

Experimental and Numerical Study of Low Temperature Methane Steam Reforming for Hydrogen Production

Low temperature methane steam reforming for hydrogen production, using experimental developed Ni/Al2O3 catalysts is studied both experimentally and numerically. The catalytic activity measurements were performed at a temperature range of 500–700 °C with steam to carbon ratio (S/C) of 2 and 3 under atmospheric pressure conditions. A mathematical analysis to evaluate the reaction feasibility at all different conditions that have been applied by using chemical equilibrium with applications (CEA) software and in addition, a mathematical model focused on the kinetics and the thermodynamics of the reforming reaction is introduced and applied using a commercial finite element analysis software (COMSOL Multiphysics 5.0). The experimental results were employed to validate the extracted simulation data based on the yields of the produced H2, CO2 and CO at different temperatures. A maximum hydrogen yield of 2.7 mol/mol-CH4 is achieved at 700 °C and S/C of 2 and 3. The stability of the 10%Ni/Al2O3 catalyst shows that the catalyst is prone to deactivation as supported by Thermogravimetric Analysis TGA results

Surgical treatment of spondylitis and diaphragm relaxation in patient less than 1 year old

Design Case report. Introduction The combination of severe post-infectious kyphosis and diaphragm relaxation is extremely rare in patient early than 1 year old. Its no publications concerning their simultaneous surgical treatment. Case description 7-Month-old girl had simultaneous spinal reconstruction with anterior and posterior instrumentation and plastic of diaphragm because of sequelae of non-granulenatous spondylitis complicated by severe kyphosis (54°) and diaphragm relaxation. Between 1.5 and 3 months of live she had several infections incl. pneumonia, enterocolitis, ENT infection. Anterior fusion was done by titanium mesh with auto-rib, posterior – by compressive rods based on low-profile hooks. The deformity was reduced till 20°. 2.5 years after initial surgery and 1 year after removal of posterior instrumentation the adequate level of diaphragm and minimal (4°) loss of kyphosis correction were identified. Conclusions The combination of spondylitis and diaphragm relaxation in early aged patient could be explained but it could not be confirmed as a sequelae of late-onset neonatal sepsis with a multi-focal lesions. The simultaneous surgery provided on the combined approaches (trans-thoracic and posterior) looks as optimal options in such combination of pathologies. In remains controversial how will the spine develop after so early reconstructive surgery, including in situ stable anterior fusion carried out by titanium mesh with auto-rib

Influence of vapors of volatile organic compounds on spectral shift of bending vibrations of freely suspended ferroelectric liquid-crystal films

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Serguei V. Yablonskii, Kazuyuki Nakano, Masanori Ozaki, and Katsumi Yoshino, Appl. Phys. Lett. 84, 3723 (2004) and may be found at https://doi.org/10.1063/1.1697630

Whisker's Directional Selectivity: Orientation Columns in the Barrel Field?

Using voltage-sensitive dye optical imaging methods, we visualized neural activity in the rat barrel cortex in response to the deflection of a single whisker in different directions. Obtained data indicates that fast movements of single whiskers in varying directions correlate with different patterns of activation in the somatosensory cortex. A functional map was created based on the voltage-sensitive dye optical signal. This supports prior research that vibrissae deflections cause responses in different cortical neurons within the barrel field according to the direction of the deflection. By analogy with the orientation columns in the visual cortex, directionally-biased single whisker responses to different directions of deflection could be a possible mechanism for the directional selectivity of this important sensory response

Reciprocal Relations Between Kinetic Curves

We study coupled irreversible processes. For linear or linearized kinetics with microreversibility, $\dot{x}=Kx$, the kinetic operator $K$ is symmetric in the entropic inner product. This form of Onsager's reciprocal relations implies that the shift in time, $\exp (Kt)$, is also a symmetric operator. This generates the reciprocity relations between the kinetic curves. For example, for the Master equation, if we start the process from the $i$th pure state and measure the probability $p_j(t)$ of the $j$th state ($j\neq i$), and, similarly, measure $p_i(t)$ for the process, which starts at the $j$th pure state, then the ratio of these two probabilities $p_j(t)/p_i(t)$ is constant in time and coincides with the ratio of the equilibrium probabilities. We study similar and more general reciprocal relations between the kinetic curves. The experimental evidence provided as an example is from the reversible water gas shift reaction over iron oxide catalyst. The experimental data are obtained using Temporal Analysis of Products (TAP) pulse-response studies. These offer excellent confirmation within the experimental error.Comment: 6 pages, 1 figure, the final versio

Optomechanical effect in ferroelectric liquid crystal freely suspended films

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Serguei V. Yablonskii, Kazuyuki Nakano, Masanori Ozaki, Mikhail V. Kozlovsky, and Katsumi Yoshino, Journal of Applied Physics 94, 5206 (2003) and may be found at https://doi.org/10.1063/1.1611637