A new tunneling path for reactions such as H+H_2→H_2+H

The standard tunneling path in transition state theory for reactions such as H+H_2→H_2+H has been the so‐called reaction path, namely the path of steepest ascent to the saddle point. This path is now known to give numerical results for the reaction probability which are in disagreement with the exact quantum mechanical ones by an order of magnitude at low tunneling energies. A new tunneling path corresponding to a line of vibrational endpoints is proposed. It is much shorter and is shown to give results in agreement with the quantum ones to within about a factor of two. A semiclassical basis for choosing this new path is given

Energy Frontier Research Center for Solid-State Lighting Science: Exploring New Materials Architectures and Light Emission Phenomena

The Energy Frontier Research Center (EFRC) for Solid-State Lighting Science (SSLS) is one of 46 EFRCs initiated in 2009 to conduct basic and use-inspired research relevant to energy technologies. The overarching theme of the SSLS EFRC is the exploration of energy conversion in tailored photonic structures. In this article we review highlights from the research of the SSLS EFRC. Major research themes include: studies of the materials properties and emission characteristics of III-nitride semiconductor nanowires; development of new phosphors and II−VI quantum dots for use as wavelength downconverters; fundamental understanding of competing radiative and nonradiative processes in current-generation, planar light-emitting diode architectures; understanding of the electrical, optical, and structural properties of defects in InGaN materials and heterostructures; exploring ways to enhance spontaneous emission through modification of the environment in which the emission takes place; and investigating routes such as stimulated emission that might outcompete nonradiative processes

Origin of Reaction-Induced Current in Pt/GaN Catalytic Nanodiodes

We have searched for chemicurrent generation in Pt/GaN nanodiodes during catalytic CO oxidation and observe a reaction-induced current that scales with reaction rate. But after considering (1) how the reaction-induced current depends on diode shunt resistance, (2) calculations of the Pt surface temperature rise during reaction, (3) direct experimental measurements of the Pt surface temperature rise during reaction, and (4) direct experimental measurements of the lateral temperature gradient during reaction, and thus the consequent thermoelectric current it produces, we conclude that the reaction-induced current is generated entirely from a thermoelectric voltage and is not true chemicurrent

A Fortran Computer Code Package For The Evaluation Of Gas-Phase, Multicomponent Transport Properties

This report documents a Fortran computer code package that is used for the evaluation of gas-phase multicomponent viscosities, thermal conductivities, diffusion coefficients, and thermal diffusion coefficients. The package is in two parts. The first is a preprocessor that computes polynomial fits to the temperature dependent parts of the pure species viscosities and binary diffusion coefficients. The coefficients of these fits are passed to a library of subroutines via a linking file. Then, any subroutine from this library may be called to return either pure species properties or multicomponent gas mixture properties. This package uses the chemical kinetics package CHEMKIN, and transport property subroutines are designed to be used in conjunction with the CHEMKIN subroutine library. This package supersedes a previously-written transport property code package in which we used certain mixture averaging rules to compute mixture properties rather than the full multicomponent formulation. 3..