Closed loop spray cooling apparatus

A closed loop apparatus for spraying coolant against the back of a radiation target is described. The coolant was circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material was disposed between the bubble and the surface of the liquid coolant which was below the bubble at a predetermined level. In a second embodiment, no inert gas was used, the bubble consisting of a vapor produced when the coolant was sprayed against the target

Kpi form factors and final state interactions in D+ --> K- pi+ pi+ decays

We present a model for the decay D+ --> K- pi+ pi+. The weak interaction part of this reaction is described using the effective weak Hamiltonian in the factorisation approach. Hadronic final state interactions are taken into account through the Kpi scalar and vector form factors fulfilling analyticity, unitarity and chiral symmetry constraints. The model has only two free parameters that are fixed from experimental branching ratios. We show that the modulus and phase of the S wave thus obtained agree nicely with experiment up to 1.55 GeV. We perform Monte Carlo simulations to compare the predicted Dalitz plot with experimental analyses. Allowing for a global phase difference between the S and P waves of -65 degrees, the Dalitz plot of the D+ --> K- pi+ pi+ decay, the Kpi invariant mass spectra and the total branching ratio due to S-wave interactions are well reproduced.Comment: 24 pages, 4 figures, REVTeX style. A discussion on the isospin 2 component has been included. Two references added. Published in Phys. Rev.

Novel phosphors for solid state lighting

Solid state white light emitting diode lighting devices outperform conventional light sources in terms of lifetime, durability, and lumens per watt. However, the capital contribution is still to high to encourage widespread adoption. Furthermore, the colour from today's devices is unsuitable for general room illumination and thus new phosphor materials are needed. This dissertation will examine the synthesis of inorganic nanoparticles and the possibility of using hybrid inorganic-organic frameworks in the search for new lighting phosphors. Nanoparticles of the oxide compound yttrium aluminium garnet were synthesized using an emulsion technique, though it was found that the high temperature processing needed for good optical properties was not compatible with maintaining nanosized particles. In terms of hybrid framework phosphors, several aspects of this new area have been explored. The mechanical and optical properties of a dense cerium oxalate formate hybrid framework compound have been investigated. Its strength was found to be nearly as great as some classical ceramic compounds, and clearly robust enough for device applications. While the photoluminescence of the cerium oxalate formate was not suitable for solid state lighting, the impressive mechanical properties evaluated are expected to be valid for a wide range of dense inorganic-organic frameworks. A novel approach to solid state lighting phosphors was introduced by using ligand-based photoluminescence in hybrid frameworks. Novel frameworks were prepared using 9,10-anthraquinone-2,3-dicarboxylic acid in combination with calcium, manganese, nickel, and zinc. These compounds show excellent photoluminescent emission for use in solid state lighting applications, although the luminescence is quenched at room temperature due to dynamic effects. The excitation, while reaching the blue part of the spectrum, falls just short of what is needed for use today's devices. To address these issues, a second class of novel framework compounds was prepared using 9-fluorenone-2,7-dicarboxylic acid in combination with calcium, strontium, barium, cadmium, and manganese. They are more rigid structures and show good luminescence at room temperature with a photoluminescent excitation spectrum extending further into the blue than the anthraquinones. Additionally, quantum yield in the calcium fluorenone is nearly double that of its parent ligand, suggesting that there is an enhancement in luminescent properties as a result its inclusion in a framework structure. An explanation for the differences in efficiency between seemingly similar compounds are drawn from their compositions, crystal structures, photoluminescence, and specific heat properties. Finally, some structural and chemical targets for future hybrid phosphor development are identified based on the relationships identified in this work.This work was supported by Mitsubishi Chemical Center for Advanced Material

K→ππK \to \pi \pi Decays with Domain Wall Fermions: Towards Physical Results

We are using domain wall fermions to study $K \to \pi \pi$ matrix elements by measuring $K \to \pi$ and $K \to 0$ matrix elements on the lattice and employing chiral perturbation theory to relate these to the desired physical result. The residual chiral symmetry breaking of domain wall fermions with a finite extent in the fifth dimension impacts these measurements. Using the Ward-Takahashi identities, we investigate residual chiral symmetry breaking effects for divergent quantities and study pathologies of the quenched approximation for small quark mass. We then discuss the $\Delta S = 1$ operator $O_2$, where chiral symmetry is vital for the subtraction of unphysical effects.Comment: 4 pages, 3 figures, Lattice 2000 (Hadronic Matrix Elements), RBC Collaboration, corrected equations 2 and

Utilization and evaluation of an indoxacarb-based granular bait (Advion) developed for the control of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae)

This research evaluated the new red imported fire ant (RIFA) bait Advionâ¢. Advion⢠contains the active ingredient indoxacarb which, following ingestion, must be metabolized into an N-decarbomethoxyllated metabolite known as JT333 in order to become acutely toxic. Laboratory experimentation was conducted to determine the most effective chemical form and concentration of indoxacarb, as well as the most appropriate grit size, for use in Advionâ¢. The results indicated that Advion⢠containing indoxacarb was more effective than Advion⢠containing JT333, that 0.10%, 0.06%, and 0.045% were the most effective concentrations of indoxacarb, and that standard sized grit (~2 mm) was more effective than small sized grit (<1 mm). Field experimentation was conducted to determine the most effective concentration and quantity of Advionâ¢, as well as the most effective placement of the bait, for obtaining maximum control of RIFA colonies via individual mound treatments. The results indicated that 10 g (2 Tbsp) of 0.045% Advion⢠placed around the mound in a circle with a radius of 0.5-3.0 m was the most effective manner in which to treat individual RIFA mounds. Field experimentation was also conducted to compare the effectiveness of label-rate broadcast treatment with Advion⢠to the effectiveness of both label-rate broadcast treatment with Amdroî and pre-baiting broadcast treatment with Advionâ¢. Both pre-baiting broadcast treatment and label-rate broadcast treatment with Advion⢠ultimately resulted in 98-99% RIFA colony mortality, which was significantly greater than the 87% colony mortality resulting from broadcast treatment with Amdroî. The 6.2 d LT90 for label-rate broadcast treatment with Advion⢠was nearly one half that of the LT90 for pre-baiting broadcast treatment. Laboratory experimentation was conducted to determine whether RIFA workers were capable of metabolizing indoxacarb into the toxic metabolite, and the results clearly indicated that they were. Finally, field experimentation was conducted to evaluate the effectiveness of label-rate broadcast treatment with Advion⢠at controlling multiple ant species. The results indicated that label-rate broadcast treatment with Advion⢠resulted in control of the RIFA and Pogonomyrmex barbatus for at least 7 wk, and Monomorium pharaonis and Dorymyrmex pyramicus for some period of time between 3 and 7 wk

Scalar resonances: scattering and production amplitudes

Scattering and production amplitudes involving scalar resonances are known, according to Watson's theorem, to share the same phase $\delta(s)$. We show that, at low energies, the production amplitude is fully determined by the combination of $\delta(s)$ with another phase $\omega(s)$, which describes intermediate two-meson propagation and is theoretically unambiguous. Our main result is a simple and almost model independent expression, which generalizes the usual $K$-matrix unitarization procedure and is suited to be used in analyses of production data involving scalar resonances.Comment: 10 pages, 4 figures. Minor changes, references added, version to appear in Phys. Rev.

Design of a low cost earth resources system

The author has identified the following significant results. Survey results indicated that users of remote sensing data in the Southeastern U.S. were increasingly turning to digital processing techniques. All the states surveyed have had some involvement in projects using digitally processed data. Even those states which do not yet have in-house capabilities for digital processing were extremely interested in and were planning to develop such capabilities

Computer processing of peach tree decline data

There are no author-identified significant results in this report

Formation of plasma around a small meteoroid: 1. Kinetic theory

This article is a companion to Dimant and Oppenheim [2017] https://doi.org/10.1002/2017JA023963.This paper calculates the spatial distribution of the plasma responsible for radar head echoes by applying the kinetic theory developed in the companion paper. This results in a set of analytic expressions for the plasma density as a function of distance from the meteoroid. It shows that at distances less than a collisional mean free path from the meteoroid surface, the plasma density drops in proportion to 1/R where R is the distance from the meteoroid center; and, at distances much longer than the mean‐free‐path behind the meteoroid, the density diminishes at a rate proportional to 1/R2. The results of this paper should be used for modeling and analysis of radar head echoes.This work was supported by NSF grant AGS-1244842. (AGS-1244842 - NSF