Prime Quasientropy and Quasichaos

We construct a prime symmetry relation for integers that is equivalent to Goldbach's conjecture and show that numerical computations of this prime symmetry property strongly resemble a chaotic sequence. We define and examine the notions of global and local prime quasientropies. Finally, we employ the fact that the prime number sequence satisfies the property of deterministic randomness to consider its utility for the field of quantum computation.     

Siscom — a new library search system for mass spectra

SISCOM is a library search system for mass spectrometry which is based on a new method of coding spectra by selecting the most important peaks within homologous ion series, and on a multiple factor assessment of the result. Examples demonstrate the ability of the system to identify various compounds, even from mixtures or by reference spectra which differ from those measured. SISCOM is especially suitable for detecting structural similarities like common substructures, even in cases where no similarity can be recognized by visual comparison of patterns or by human interpretation of the spectrum.     

A computer system for measuring fast-scan lowresolution mass spectra

A microprocessor-based satellite computer system (MASDAT) controls a low-resolution, fast-scan mass spectrometer for the measurement of series of spectra. Special digitization hardware (logarithmic A/D converter) and software algorithms are necessary to achieve a dynamic range (ratio of highest to lowest intensity) of about 10⁵ in peak heights. Up to three MASDAT satellites can be connected to a host computer. Synchronized parallel programs in the host system communicate with the operator, calibrate the mass scale, print an interscan report, and store final spectra and, optionally, unreduced data on mass storage devices. Host software is described for a RSX11M and for a VAX/VMS operating system.     

Electron spin resonance and antiferromagnetic resonance of single crystals of yttrium doped with gadolinium

The nonlinear interaction of oscillation modes is investigated on the basis of Lagrangian formalism. Equations describing the changes of the bound mode amplitudes versus time, are obtained. It is shown that the energy transformation between different modes is of a periodic nature: if in the initial moment of time an appreciable part of the energy is contained, for example, in them-th mode, then after a period of timeTt (called a time of nonlinear interaction) the energy will be transformed to then-th mode. Expressions forT _t for cases with the interaction of two and three modes are obtained. As a particular case the process of nonlinear interaction of the electron “transverse” and “longitudinal” oscillations in the highfrequency hybrid resonance region of a “weakly” inhomogeneous plasma was investigated.     

On the Evolution of the Flow Field in a Spark Ignition Engine

The development of the turbulent flow field inside a spark ignition engine is examined by large-eddy simulation (LES), from the intake flow to the tumble break-down. Ten consecutive cold flow engine cycles on a coarse and twenty cycles on a fine grid are simulated and compared to experiments of the same engine. The turbulent subgrid scales are modeled by the standard Smagorinsky and by the recently developed Sigma model. A comparison of the intake flow is made against Particle Image Velocimetry (PIV) measurements along horizontal and vertical lines and to an LES simulation performed by the Darmstadt group. Furthermore, we show the first LES comparison to Magnetic Resonance Velocimetry (MRV conducted by Freudenhammer et al.) measurements, which provided the 3D flow field inside a full scale dummy of the entire upper cylinder head including the valve seat region, at a time which mimics inflow conditions of the corresponding engine. Our LES is in good qualitative and quantitative agreement with the simulation and the experiments, with the notable exception of the measured in-cylinder pressure, which is discussed in detail and compared to 0D simulations and simulations from other groups. A criterion is proposed for estimating the number of cycles needed in a simulation, if experimental data is available. We put emphasis on the flow in the valve seat region, where turbulence is generated, and discuss the formation of the large scale tumble motion, including a comparison of the radial velocity fields on rolled-up planes around the valve seat. Here, spots of high velocities were found in the under flow region, which cannot been seen by the ensemble averaged MRV measurement. Within the compression stroke, a 2D vortex center identification algorithm is applied on slices inside the combustion chamber, yielding a 3D visualization of the tumble vortex, which is found to have a “croissant-like” shape. The tumble vortex trajectory is plotted on the symmetry plane and compared to measurements. Finally, we consider a modified definition of the (turbulent) integral length scale that provided further insight to the tumble break-down process.