Investigation of interaction femtosecond laser pulses with skin and eyes mathematical model

We present a mathematical model of linear and nonlinear processes that takes place under the action of femtosecond laser radiation on the cutaneous covering. The study is carried out and the analytical solution of the set of equations describing the dynamics of the electron and atomic subsystems and investigated the processes of linear and nonlinear interaction of femtosecond laser pulses in the vitreous of the human eye, revealed the dependence of the pulse duration on the retina of the duration of the input pulse and found the value of the radiation power density, in which there is a self-focusing is obtained. The results of the work can be used to determine the maximum acceptable energy, generated by femtosecond laser systems, and to develop Russian laser safety standards for femtosecond laser systems

La expectativa de jubilación como un estrés psicológico que afecta la edad biológica en las persona de la Federación de Rusa

The method of age-related samples is used. Biological age is estimated using a formula including indicators of metabolism, cardiovascular, respiratory, equilibrium systems, and psychological health questionnaire data. The biological age, proper biological age, and relative aging index have been researched. Examinees were adults of 26 - 88 years old, divided into 9 age groups. We’ve founded two types of psychological stress affecting a person’s biological age: stress caused by the expectation of retirement and stress on the retirement. Upon the results of the study, it’s stated that in Russia the biological age of a person is associated with a calendar inverted U-shaped dependence. The peak of relative aging happens on the pre-retirement and post-retirement ages. In women, biological aging begins to intensify in the period of 51-60 years, in men in 46-50 years, in women it stops in the period of 66-70 years, and in men only after 71 years. The maximum of biological consenescence in women occurs immediately after retirement (56-60 years), and in men at the age of the expectation of retirement (56-60 years). Based on the achieved data, it can be concluded that psychological stress caused by the expectation of retirement exists, it’s more severe in men than in women.Se utiliza el método de muestras relacionadas con la edad. La edad biológica se estima utilizando una fórmula que incluye indicadores de metabolismo, cardiovasculares, respiratorios, sistemas de equilibrio y datos de cuestionarios de salud psicológica. Se ha investigado la edad biológica, la edad biológica adecuada y el índice de envejecimiento relativo. Los examinados eran adultos de 26 a 88 años, divididos en 9 grupos de edad. Hemos fundado dos tipos de estrés psicológico que afectan la edad biológica de una persona: el estrés causado por la expectativa de jubilación y el estrés en la jubilación. Sobre los resultados del estudio, se afirma que en Rusia la edad biológica de una persona está asociada con una dependencia de calendario en forma de U invertida. El pico del envejecimiento relativo ocurre en las edades previas y posteriores a la jubilación. En las mujeres, el envejecimiento biológico comienza a intensificarse en el período de 51-60 años, en los hombres en 46-50 años, en las mujeres se detiene en el período de 66-70 años, y en los hombres solo después de 71 años. El máximo de consenso biológico en las mujeres ocurre inmediatamente después de la jubilación (56-60 años) y en los hombres a la edad de la expectativa de jubilación (56-60 años). Con base en los datos obtenidos, se puede concluir que el estrés psicológico causado por la expectativa de jubilación existe, es más severo en los hombres que en las mujeres

Precision determination of band offsets in strained InGaAs/GaAs quantum wells by C-V-profiling and Schroedinger-Poisson self-consistent simulation

The results of measurements and numerical simulation of charge carrier distribution and energy states in strained quantum wells In_xGa_{1-x}As/GaAs (0.06 < x < 0.29) by C-V-profiling are presented. Precise values of conduction band offsets for these pseudomorphic QWs have been obtained by means of self-consistent solution of Schroedinger and Poisson equations and following fitting to experimental data. For the conduction band offsets in strained In_xGa_{1-x}As/GaAs - QWs the expression DE_C(x) = 0.814x - 0.21x^2 has been obtained.Comment: 9 pages, 12 figures, RevTeX

Peculiar Features of the Velocity Field of OB Associations and the Spiral Structure of the Galaxy

Some of the peculiar features of the periodic velocity-field structure for OB associations can be explained by using the model of Roberts and Hausman (1984), in which the behavior of a system of dense clouds is considered in a perturbed potential. The absence of statistically significant variations in the azimuthal velocity across the Carina arm, probably, results from its sharp increase behind the shock front, which is easily blurred by distance errors. The existence of a shock wave in the spiral arms and, at the same time, the virtually free motion of OB associations in epicycles can be reconciled in the model of particle clouds with a mean free path of 0.2-2 kpc. The velocity field of OB associations exhibits two appreciable nonrandom deviations from an ideal spiral pattern: a 0.5-kpc displacement of the Cygnus- and Carina-arm fragments from one another and a weakening of the Perseus arm in quadrant III. However, the identified fragments of the Carina, Cygnus, and Perseus arms do not belong to any of the known types of spurs.Comment: 14 pages, 3 postscript figures, to be published in Astronomy Letter

Investigation of interaction femtosecond laser pulses with skin and eyes mathematical model

We present a mathematical model of linear and nonlinear processes that takes place under the action of femtosecond laser radiation on the cutaneous covering. The study is carried out and the analytical solution of the set of equations describing the dynamics of the electron and atomic subsystems and investigated the processes of linear and nonlinear interaction of femtosecond laser pulses in the vitreous of the human eye, revealed the dependence of the pulse duration on the retina of the duration of the input pulse and found the value of the radiation power density, in which there is a self-focusing is obtained. The results of the work can be used to determine the maximum acceptable energy, generated by femtosecond laser systems, and to develop Russian laser safety standards for femtosecond laser systems