On the Coulomb-Sturmian matrix elements of the Coulomb Green's operator

The two-body Coulomb Hamiltonian, when calculated in Coulomb-Sturmian basis, has an infinite symmetric tridiagonal form, also known as Jacobi matrix form. This Jacobi matrix structure involves a continued fraction representation for the inverse of the Green's matrix. The continued fraction can be transformed to a ratio of two $_{2}F_{1}$ hypergeometric functions. From this result we find an exact analytic formula for the matrix elements of the Green's operator of the Coulomb Hamiltonian.Comment: 8 page

Proximity effects of high voltage electric power transmission lines on ornamental plant growth

The proximity effects of high voltage electric power transmission lines on Leyland Cypress (xCupressocyparis leylandii (Dallim. and A.B. Jacks.) Dallim) and Japanese Privet (Ligustrum japonicum Thunb.) growth were examined in a private nursery located in Sakarya, Turkey. Five transect were randomly chosen in both leylandii and privet lots in the nursery. In the summer of 2009, starting from under the power line 12 sampling point for every five meters away from the power line on each transaction was located. From these sampling points, five seedlings for each species were randomly chosen. From each sampling seedlings, five - seven leaves (for private) or spurs (for leylandii) were collected from lower-, middle- and upper-crown. For each sampling seedling diameter at breast height (dbh) were measured with a caliper. Within the laboratory, the projected surface area (SLA) of needles and leaves were determined using a leaf area meter. The relationship among measured seedling variables and the proximity to high voltage electric power transmission lines were evaluated using correlation. The effects of proximity to power-line on specific leaf area and seedling dbh were tested with an analysis of variance procedure (ANOVA). Tukey’s HSD test with alpha = 0.05 was performed to compare means. The result of the data revealed that the mean of seedling dbh at 55 m away from the power line was about 25% smaller than that of the seedlings underneath the power line. The data also showed that there was a gradual decrease at dbh value of the privet with the distance from the power line. Seedling mean dbh value at the 25th m sampling point was about 10% lower than that of the seedlings underneath the power line. At the 40th m sampling point this dbh value was about 17 and 8% lower than those of the seedlings underneath the power line and of the seedling at 25th m sampling point, respectively. Specific leaf area after the 30th m away from the power line has been decreasing. The SLA value at the 30th m is about 17% lower than that of the seedling underneath the power line.Key words: magnetic field, ornamental plant growth, power transmission line, Leyland Cypress, Japanese Privet

Ultrafine conducting fibers: metallization of poly(acrylonitrile-co-glycidyl methacrylate) nanofibers

Electrospun poly(glycidylmethacrylate) (PGMA) and poly(acrylonitrile-co-glycidyl methacrylate) (P(AN-GMA)) nanofibers were coated with monodisperse silver nanoparticles by using an electroless plating technique at ambient conditions. Oxirane groups on the surface of nanofibers were replaced with reducing agent, hydrazine. Surface modified nanofibers were allowed to react with ammonia solution of AgNO3. A redox reaction takes place and metallic silver nucleate on fibers surface. Parameters affecting the particle size were determined

Room-temperature larger-scale highly ordered nanorod imprints of ZnO film

Cataloged from PDF version of article.Room-temperature large-scale highly ordered nanorod-patterned ZnO films directly integrated on III-nitride light-emitting diodes (LEDs) are proposed and demonstrated via low-cost modified nanoimprinting, avoiding a high-temperature process. with a 600 nm pitch on top of a critical 200 nm thick Imprinting ZnO nanorods of 200 nm in diameter and 200 nm in height continuous ZnO wetting layer, the light output power of the resulting integrated ZnO-nanorod-film/semi-transparent metal/GaN/InGaN LED shows a two-fold enhancement (100% light extraction efficiency improvement) at the injection current of 150 mA, in comparison with the conventional LED without the imprint film. The increased optical output is well explained by the enhanced light scattering and outcoupling of the ZnOrod structures along with the wetting film, as verified by the numerical simulations. The wetting layer is found to be essential for better impedance matching. The current-voltage characteristics and electroluminescence measurements confirm that there is no noticeable change in the electrical or spectral properties of the final LEDs after ZnO-nanorod film integration. These results suggest that the low-cost high-quality large-scale ZnOnanorod imprints hold great promise for superior LED light extraction. ©2013 Optical Society of Americ

EfficientTempNet: Temporal Super-Resolution of Radar Rainfall

Rainfall data collected by various remote sensing instruments such as radars or satellites has different space-time resolutions. This study aims to improve the temporal resolution of radar rainfall products to help with more accurate climate change modeling and studies. In this direction, we introduce a solution based on EfficientNetV2, namely EfficientTempNet, to increase the temporal resolution of radar-based rainfall products from 10 minutes to 5 minutes. We tested EfficientRainNet over a dataset for the state of Iowa, US, and compared its performance to three different baselines to show that EfficientTempNet presents a viable option for better climate change monitoring.Comment: Published as a workshop paper at Tackling Climate Change with Machine Learning, ICLR 202

Sneutrino Dark Matter: Symmetry Protection and Cosmic Ray Anomalies

We present an R-parity conserving model of sneutrino dark matter within a Higgs-philic U(1)' extension of the minimal supersymmetric standard model. In this theory, the mu parameter and light Dirac neutrino masses are generated naturally upon the breaking of the U(1)' gauge symmetry. The leptonic and hadronic decays of sneutrinos in this model, taken to be the lightest and next-to-lightest superpartners, allow for a natural fit to the recent results reported by the PAMELA experiment.Comment: Revised to match the published version; 11 pages (2 column format), 1 table, 6 figures, to appear in PR

Shear Viscosity in a Perturbative Quark-Gluon-Plasma

Among the key features of hot and dense QCD matter produced in ultra-relativistic heavy-ion collisions at RHIC is its very low shear viscosity, indicative of the properties of a near-ideal fluid, and a large opacity demonstrated by jet energy loss measurements. In this work, we utilize a microscopic transport model based on the Boltzmann equation with quark and gluon degrees of freedom and cross sections calculated from perturbative Quantum Chromodynamics to simulate an ideal Quark-Gluon-Plasma in full thermal and chemical equilibrium. We then use the Kubo formalism to calculate the shear viscosity to entropy density ratio of the medium as a function of temperature and system composition. One of our key results is that the shear viscosity over entropy-density ratio $\eta/s$ becomes invariant to the chemical composition of the system when plotted as a function of energy-density instead of temperature.Comment: 11 pages, 8 figures: version #2 contains some revisions and added references to clarify relationship to previously published wor