Shaping of molecular weight distribution by iterative learning probability density function control strategies

A mathematical model is developed for the molecular weight distribution (MWD) of free-radical styrene polymerization in a simulated semi-batch reactor system. The generation function technique and moment method are employed to establish the MWD model in the form of Schultz-Zimmdistribution. Both static and dynamic models are described in detail. In order to achieve the closed-loop MWD shaping by output probability density function (PDF) control, the dynamic MWD model is further developed by a linear B-spline approximation. Based on the general form of the B-spline MWD model, iterative learning PDF control strategies have been investigated in order to improve the MWD control performance. Discussions on the simulation studies show the advantages and limitations of the methodology

Phase-locking at low-level of quanta

We discuss phase-locking phenomena at low-level of quanta for parametrically driven nonlinear Kerr resonator (PDNR) in strong quantum regime. Oscillatory mode of PDNR is created in the process of a degenerate down-conversion of photons under interaction with a train of external Gaussian pulses. We calculate the Wigner functions of cavity mode showing two-fold symmetry in phase space and analyse formation of phase-locked states in the regular as well as the quantum chaotic regime.Comment: 6 pages, 4 figure

Neutron star matter in the quark-meson coupling model in strong magnetic fields

The effects of strong magnetic fields on neutron star matter are investigated in the quark-meson coupling (QMC) model. The QMC model describes a nuclear many-body system as nonoverlapping MIT bags in which quarks interact through self-consistent exchange of scalar and vector mesons in the mean-field approximation. The results of the QMC model are compared with those obtained in a relativistic mean-field (RMF) model. It is found that quantitative differences exist between the QMC and RMF models, while qualitative trends of the magnetic field effects on the equation of state and composition of neutron star matter are very similar.Comment: 16 pages, 4 figure

Novel polymorphic microsatellites from Guppy (Poecilia reticulata) and their utility in swordtails (Xiphophorus helleri)

Ten microsatellites were isolated from a genomic DNA library generated from guppy (Poecilia reticulata; Poecilidae) enriched for CA-repeats. All of the 10 microsatellites were polymorphic in guppy with an average allele number of 4.9/locus ranging from 2 to 14. All 10-primer pairs amplified specific products in green swordtail (Xiphophorus helleri) and 9 of the 10 microsatellites displayed polymorphism (average allele number: 4.1/locus with a scope between 2 and 8). Size range of alleles at most loci were similar between the two fish species. These microsatellites could be applied to breeding programs performed on these two species and possibly other poecilids and to genetic and ecological studies

Detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs

Describes the process of detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs

Production and decay of the neutral top-pion in high energy e+e−e^{+}e^{-} colliders

We study the production and decay of the neutral top-pion $\pi_{t}^{0}$ predicted by topcolor-assisted technicolor(TC2) theory. Our results show that, except the dominant decay modes $b\bar{b}$, $\bar{t}c$ and $gg$, the $\pi_{t}^{0}$ can also decay into $\gamma\gamma$ and $Z \gamma$ modes. It can be significantly produced at high energy $e^{+}e^{-}$ collider(LC) experiments via the processes $e^{+}e^{-}\to \pi_{t}^{0}\gamma$ and $e^{+}e^{-}\to Z\pi_{t}^{0}$. We further calculate the production cross sections of the processes $e^{+}e^{-}\to\gamma\pi_{t}^{0}\to\gamma\bar{t}c$ and $e^{+}e^{-}\to Z\pi_{t}^{0}\to Z\bar{t}c$. We find that the signatures of the neutral top-pion $\pi_{t}^{0}$ can be detected via these processes.Comment: Latex file, 13 Pages, 6 eps figures. to be published in Phys.Rev.

A new problem with cross-species amplification of microsatellites: Generation of non-homologous products

Microsatellites have been widely used in studies on population genetics, ecology and evolutionary biology. However, microsatellites are not always available for the species to be studied and their isolation could be time-consuming. In order to save time and effort researchers often rely on cross-species amplification. We revealed a new problem of microsatellite cross-species amplification in addition to size homoplasy by analyzing the sequences of electromorphs from seven catfish species belonging to three different families (Clariidae, Heteropneustidae and Pimelodidae). A total of 50 different electromorphs were amplified from the seven catfish species by using primers for 4 microsatellite loci isolated from the species Clarias batrachus. Two hundred and forty PCR-products representing all 50 electromorphs were sequenced and analyzed. Primers for two loci amplified specific products from orthologous loci in all species tested, whereas primers for the other two loci produced specific and polymorphic bands from some non-orthologous loci, even in closely related non-source species. Size homoplasy within the source species was not obvious, whereas extensive size homoplasy across species were detected at three loci, but not at the fourth one. These data suggest that amplification of products from non-orthologous loci and appearance of size homoplasy by cross-amplification are locus dependent, and do not reflect phylogenetic relationship. Amplification of non-orthologous loci and appearance of size homoplasy will lead to obvious complications in phylogenetic interference, population genetic and evolutionary studies. Therefore, we propose that sequence analysis of cross-amplification products should be conducted prior to application of cross-species amplification of microsatellites