THEORETICAL INVESTIGATION OF UNSTEADY DIFFUSION WITH RECOMBINATION IN A TERNARY MIXTURE OF DIATOMIC MOLECULES, DISSOCIATED ATOMS, AND AN INERT GAS

Unsteady diffusion with recombination in ternary mixture of diatomic molecules, dissociated atoms, and an inert ga

The DaVinci Center For Community Progress: Making The Community More Liveable

There are many innovations, projects, and programs which can make a community more liveable. The elements that they have in common are 1) the vision of the founder (or co-founders), 2) a dedicated connection to the community and populations in which the innovation or project is located, 3) the necessary social skills and contacts of the founder(s) and other key people involved in the innovation, 4) hard work, and 5) funding sources that continue over time to keep the services (or project) going, as well as to add services as needs change. The DaVinci Center for Community Progress, in Providence, RI, is an excellent example of how to make a community more liveable for diverse populations for whom it has provided services since it opened its doors in 1972. The DaVinci Center is a multi-purpose facility based on the settlement house model in regard to many of the services it offers. It differs from the settlement house model in that the DaVinci Center staff does not live at the Center. The Center was co-founded by John DeLuca who has also served as its longtime Executive Director. The content for this article was gathered, in part, through a lengthy, structured interview both authors conducted with John at the Center, a review of written materials produced by the Center, and information provided on the Center’s website

High stability amplifier

An electrical RF signal amplifier for providing high temperature stability and RF isolation and comprised of an integrated circuit voltage regulator, a single transistor, and an integrated circuit operational amplifier mounted on a circuit board such that passive circuit elements are located on side of the circuit board while the active circuit elements are located on the other side is described. The active circuit elements are embedded in a common heat sink so that a common temperature reference is provided for changes in ambient temperature. The single transistor and operational amplifier are connected together to form a feedback amplifier powered from the voltage regulator with transistor implementing primarily the desired signal gain while the operational amplifier implements signal isolation. Further RF isolation is provided by the voltage regulator which inhibits cross-talk from other like amplifiers powered from a common power supply. Input and output terminals consisting of coaxial connectors are located on the sides of a housing in which all the circuit components and heat sink are located

The Wilson loop from a Dyson equation

The Dyson equation proposed for planar temporal Wilson loops in the context of supersymmetric gauge theories is critically analysed thereby exhibiting its ingredients and approximations involved. We reveal its limitations and identify its range of applicability in non-supersymmetric gauge theories. In particular, we show that this equation is applicable only to strongly asymmetric planar Wilson loops (consisting of a long and a short pair of loop segments) and as a consequence the Wilsonian potential can be extracted only up to intermediate distances. By this equation the Wilson loop is exclusively determined by the gluon propagator. We solve the Dyson equation in Coulomb gauge for the temporal Wilson loop with the instantaneous part of the gluon propagator and for the spatial Wilson loop with the static gluon propagator obtained in the Hamiltonian approach to continuum Yang-Mills theory and on the lattice. In both cases we find a linearly rising color potential.Comment: 12 pages, 7 figure

Two-Point Functions of Coulomb Gauge Yang-Mills Theory

The functional approach to Coulomb gauge Yang-Mills theory is considered within the standard, second order, formalism. The Dyson-Schwinger equations and Slavnov-Taylor identities concerning the two-point functions are derived explicitly and one-loop perturbative results are presented.Comment: 12 pages, no figure

Local order parameters for use in driving homogeneous ice nucleation with all-atom models of water

We present a local order parameter based on the standard Steinhardt-Ten Wolde approach that is capable both of tracking and of driving homogeneous ice nucleation in simulations of all-atom models of water. We demonstrate that it is capable of forcing the growth of ice nuclei in supercooled liquid water simulated using the TIP4P/2005 model using overbiassed umbrella sampling Monte Carlo simulations. However, even with such an order parameter, the dynamics of ice growth in deeply supercooled liquid water in all-atom models of water are shown to be very slow, and so the computation of free energy landscapes and nucleation rates remains extremely challenging.Comment: This version incorporates the minor changes made to the paper following peer revie

Phase behavior of empirical potentials of titanium dioxide

In recent years, several relatively similar empirical models of titanium dioxide have been proposed as reparameterisations of the potential of Matsui and Akaogi, with the Buckingham interaction replaced by a Lennard-Jones interaction. However, because of the steepness of the repulsive region of the Lennard-Jones potential, such reparameterised models result in rather different mechanical and thermodynamic properties compared to the original potential. Here, we use free-energy calculations based on the Einstein crystal method to compute the phase diagram of both the Matsui-Akaogi potential and one of its Lennard-Jones-based reparameterisations. Both potentials are able to support a large number of distinct crystalline polymorphs of titanium dioxide that have been observed in experiment, but the regions of thermodynamic stability of the individual phases are significantly different from one another. Moreover, neither potential results in phase behaviour that is fully consistent with the available experimental evidence.No external funders

Influence of Soil-Residual Fomesafen and Dicamba Tank-Mixtures on the Frequency of PPO-Resistant Waterhemp

The present experiment quantified the selection for PPO-resistant waterhemp following a soil-residual application of fomesafen applied alone (1.32, 13.2, and 132g ai ha-1) and in combination with dicamba (0.77, 7.7, 77 g ai ha-1), respectively. The logistic rate structure aimed to simulate the degradation of herbicide in the soil, with the highest rate being one third of a full use rate. Tissue samples were taken from the first 20 emerging waterhemp plants in each treatment, including the non-treated control, and genotyped using an allele specific TaqMan assay to detect the codon deletion responsible for PPO resistance in waterhemp. Results indicated that applications of fomesafen alone at 132 g ai ha-1 increased the frequency of PPO resistance in the emerging population, with 90% of the sample population having resistance compared to 25% of population in the untreated control. The addition of dicamba to fomesafen reduced the frequency of resistant waterhemp to 70% of the population. While this research demonstrates that the addition of dicamba may not fully reduce the selection for PPO-resistant biotypes, fomesafen and dicamba applied together at the highest rate provided considerable residual control of the resistant waterhemp. Therefore, these results further emphasize the importance of proactive herbicide resistance management by employing full use rates of soil-residual herbicides and the combination of multiple herbicide modes of action