Coupling of Transport and Chemical Processes in Catalytic Combustion

Catalytic combustors have demonstrated the ability to operate efficiently over a much wider range of fuel air ratios than are imposed by the flammability limits of conventional combustors. Extensive commercial use however needs the following: (1) the design of a catalyst with low ignition temperature and high temperature stability, (2) reducing fatigue due to thermal stresses during transient operation, and (3) the development of mathematical models that can be used as design optimization tools to isolate promising operating ranges for the numerous operating parameters. The current program of research involves the development of a two dimensional transient catalytic combustion model and the development of a new catalyst with low temperature light-off and high temperature stablity characteristics

VISITOR PREFERENCES AND VALUES FOR WATER-BASED RECREATION: A CASE STUDY OF THE OCALA NATIONAL FOREST

We used the open-ended contingent valuation method to elicit willingnes to pay (WTP) for day visitors and extended visitors on the Ocala National Forest (ONF), Florida. A Tobit model specification was applied to account for the issues involved with censored WTP bids. The results reveal that visitors would pay more for improved recreational facilities at the ONF. In particular, our estimates show that visitors would pay $1 million for basic facilities,$1.9 million for moderate improvements, and $2.5 million for more improvements.contingent valuation, Tobit analysis, water-based recreation, Resource /Energy Economics and Policy, Q23, Q26,

Thermally induced magnetic relaxation in square artificial spin ice

The properties of natural and artificial assemblies of interacting elements, ranging from Quarks to Galaxies, are at the heart of Physics. The collective response and dynamics of such assemblies are dictated by the intrinsic dynamical properties of the building blocks, the nature of their interactions and topological constraints. Here we report on the relaxation dynamics of the magnetization of artificial assemblies of mesoscopic spins. In our model nano-magnetic system - square artificial spin ice - we are able to control the geometrical arrangement and interaction strength between the magnetically interacting building blocks by means of nano-lithography. Using time resolved magnetometry we show that the relaxation process can be described using the Kohlrausch law and that the extracted temperature dependent relaxation times of the assemblies follow the Vogel-Fulcher law. The results provide insight into the relaxation dynamics of mesoscopic nano-magnetic model systems, with adjustable energy and time scales, and demonstrates that these can serve as an ideal playground for the studies of collective dynamics and relaxations.Comment: 15 pages, 5 figure

Approximations of Sobolev norms in Carnot groups

This paper deals with a notion of Sobolev space $W^{1,p}$ introduced by J.Bourgain, H.Brezis and P.Mironescu by means of a seminorm involving local averages of finite differences. This seminorm was subsequently used by A.Ponce to obtain a Poincar\'e-type inequality. The main results that we present are a generalization of these two works to a non-Euclidean setting, namely that of Carnot groups. We show that the seminorm expressd in terms of the intrinsic distance is equivalent to the $L^p$ norm of the intrinsic gradient, and provide a Poincar\'e-type inequality on Carnot groups by means of a constructive approach which relies on one-dimensional estimates. Self-improving properties are also studied for some cases of interest

SSTRED: A data-processing and metadata-generating pipeline for CHROMIS and CRISP

We present a data pipeline for the newly installed SST/CHROMIS imaging spectrometer, as well as for the older SST/CRISP spectropolarimeter. The aim is to provide observers with a user-friendly data pipeline, that delivers science-ready data with the metadata needed for archival. We generalized the CRISPRED data pipeline for multiple instruments and added metadata according to recommendations worked out as part of the SOLARNET project. We made improvements to several steps in the pipeline, including the MOMFBD image restoration. A part of that is a new fork of the MOMFBD program called REDUX, with several new features that are needed in the new pipeline. The CRISPEX data viewer has been updated to accommodate data cubes stored in this format. The pipeline code, as well as REDUX and CRISPEX are all freely available through git repositories or web download. We derive expressions for combining statistics of individual frames into statistics for a set of frames. We define a new extension to the World Coordinate System, that allow us to specify cavity errors as distortions to the spectral coordinate.Comment: Draf