451 research outputs found
Relativistic Meson Spectroscopy and In-Medium Effects
We extend our earlier model of mesons using relativistic
quasipotential (QP) wave equations to include open-flavor states and running
quark-gluon coupling effects. Global fits to meson spectra are achieved with
rms deviations from experiment of 43-50 MeV. We examine in-medium effects
through their influence on the confining interaction and predict the confining
strength at which the masses of certain mesons fall below the threshold of
their dominant decay channel.Comment: 12 Pages, 2 Postscript figures (appended at the end with
instructions, available also from [email protected]
Computerized Scanning Auger Microprobe
An Auger spectrometer has been automated using a microcomputer. Fundamental considerations in the design and choice of the computerized system are presented and should be of general interest. The spectrometer was a Physical Electronics Ind. model 545 scanning Auger microprobe. The microcomputer chosen was a Southwest Technical Products 6809 computer system. Hardware details are discussed with emphasis on the four computer-spectrometer interface boards. These boards are (1) Auger energy control board, which sets the Auger detection energy with its 16 bit digital-to-analog converter (DAC); (2) read Auger signal board, which reads the Auger signal intensity with its 12 bit analog-to-digital converter; (3) multipurpose DAC board, which uses two pairs of 8 bit DAC\u27s to position the excitation beam and display the data in memory on a CRT monitor, and (4) timing and relay control board, which selects various instruments and power supplies as required during the fully automated depth profiling sputter sequences. Organizational details of the control, analysis, and output software are discussed. The operation of the main Auger control program is emphasized along with its menu driven options, which provide great versatility to the operator. Examples are shown of the various data output modes, which include displays on the CRT monitor and plots from the multicolor digital plotter. © 1985, American Vacuum Society. All rights reserved
Intermingled basins in coupled Lorenz systems
We consider a system of two identical linearly coupled Lorenz oscillators,
presenting synchro- nization of chaotic motion for a specified range of the
coupling strength. We verify the existence of global synchronization and
antisynchronization attractors with intermingled basins of attraction, such
that the basin of one attractor is riddled with holes belonging to the basin of
the other attractor and vice versa. We investigated this phenomenon by
verifying the fulfillment of the mathematical requirements for intermingled
basins, and also obtained scaling laws that characterize quantitatively the
riddling of both basins for this system
Lagrangian tracers on a surface flow: the role of time correlations
Finite time correlations of the velocity in a surface flow are found to be
important for the formation of clusters of Lagrangian tracers. The degree of
clustering characterized by the Lyapunov spectrum of the flow is numerically
shown to be in qualitative agreement with the predictions for the white-in-time
compressible Kraichnan flow, but to deviate quantitatively. For intermediate
values of compressibility the clustering is surprisingly weakened by time
correlations.Comment: 4 pages, 5 figures, to be published in PR
Clustering in mixing flows
We calculate the Lyapunov exponents for particles suspended in a random
three-dimensional flow, concentrating on the limit where the viscous damping
rate is small compared to the inverse correlation time. In this limit Lyapunov
exponents are obtained as a power series in epsilon, a dimensionless measure of
the particle inertia. Although the perturbation generates an asymptotic series,
we obtain accurate results from a Pade-Borel summation. Our results prove that
particles suspended in an incompressible random mixing flow can show pronounced
clustering when the Stokes number is large and we characterise two distinct
clustering effects which occur in that limit.Comment: 5 pages, 1 figur
Effective Swarm Parameters And Transport Coefficients In CO2 Laser Mixtures
A pulsed electron swarm technique has been used to obtain effective attachment and ionization cross-sections as well as electron drift velocities in mixtures of CO2 laser interest. In binary CO2:N 2 mixtures, below a reduced electric field of E/N=60*10 -17 V cm2, attachment was the principal ion production process. (N is the total gas number density.) The reduced attachment coefficients measured were small and in excellent agreement with numerical predictions. In ternary mixtures of He:CO2:N2, positive ion formation described by Townsend\u27s first ionisation coefficient played a more important role over the same range of E/N. The reduced coefficient for total ion formation was measured and found to be in good agreement with numerical calculations. Electron drift velocities in both the binary and ternary mixtures were determined using a time-of-flight technique. Overall agreement with previous experimental and numerical results was good
The Determinants Of Human Wellbeing In Professional Activities
The article discusses the issue of person's attitude towards success in his professional activities, which are the value of human labor and his wellbeing in professioanl activity. Personal attitude and substantial components of socio-psychological factors of attitude development provides the field of welfare of the employee. It focuses on the implementation of efficient technologies of formation attitude towards success in the process of training and retraining. The object of the research was the OJSC Evrazruda candidate pool members studying at the Evraz Siberia Regional Staff Training Center, as well as a group of experts (engineer, metallurgists). The techniques of V. K. Gerbachevsky, V. V. Stolin, S. R. Panteleyev, H. J. Eysenck, M. Rokeach, N. M. Peysakhov and J. Rotter were used in the research. The study showed the interconnection of a person's attitude with the dominant features of the component structure of motivational, volitional and self-consciousness factors. They are the determinants of wellbeing and quality of life in professional activity
On the Aggregation of Inertial Particles in Random Flows
We describe a criterion for particles suspended in a randomly moving fluid to
aggregate. Aggregation occurs when the expectation value of a random variable
is negative. This random variable evolves under a stochastic differential
equation. We analyse this equation in detail in the limit where the correlation
time of the velocity field of the fluid is very short, such that the stochastic
differential equation is a Langevin equation.Comment: 16 pages, 2 figure
- …