Optical Kerr type nonlinearity

The origin of the Kerr type nonlinearity of the medium as a result of the interaction between photons via the Dirac delta-potential is presented in the formalism adopted from the photon wave function approach. In the view of the result the optical soliton may be treated as a bound state (cluster) of many photons.Comment: Late

Using Phytotechnologies to Remediate Brownfields, Landfills, and Other Urban Areas

Urban areas requiring remedial work has prompted the use of phytotechnologies to improve water quality, soil health, and biodiversity, as well as to achieve sustainable social and economic goals. Phytotechnologies directly use plants to clean up contaminated groundwater, soil, and sediment. While woody and herbaceous crops are candidates for such remediation systems, trees within the genera Populus (poplars, cottonwoods, aspens) and Salix (willows) are ideal given their fast growth, extensive root systems, and elevated rates of photosynthesis and transpiration. The genetic diversity within these genera substantially increases the establishment and growth potential across heterogeneous sites. We have tested these trees for more than a decade across various sites and contaminants, which has resulted in developing phyto-recurrent selection, a method utilizing multiple testing cycles to evaluate, identify, and select favorable varieties with adequate genetic variation to guard against insect/disease outbreaks and changing edaphic conditions (especially those induced by contaminated soil and water) in the field. We will present information from our studies involving the selection and growth of trees performing well across variable site conditions (generalists) or sites with specific contaminant concerns (specialists) in order to enhance the success of phytotechnologies at brownfields, landfills, and other urban areas. This effort supports scientists and resource managers to acquire information that contributes to the deployment of systems that are ecologically and economically more sustainable versus traditional technologies, while the general public maintains environmental quality and protection of the natural resource base on which local and regional recreation, agriculture, and forestry depend

Composite Texture Synthesis

Many textures require complex models to describe their intricate structures. Their modeling can be simplified if they are considered composites of simpler subtextures. After an initial, unsupervised segmentation of the composite texture into the subtextures, it can be described at two levels. One is a label map texture, which captures the layout of the different subtextures. The other consists of the different subtextures. This scheme has to be refined to also include mutual influences between textures, mainly found near their boundaries. The proposed composite texture model also includes these. The paper describes an improved implementation of this idea. Whereas in a previous implementation subtextures and their interactions were synthesized sequentially, this paper proposes a parallel implementation, which yields results of higher qualit

Short Rotation Woody Crop Production Systems for Ecosystem Services and Phytotechnologies

While international efforts in the development of short rotation woody crops (SRWCs) have historically focused on the production of biomass for bioenergy, biofuels, and bioproducts, research and deployment over the past decade has expanded to include broader objectives of achieving multiple ecosystem services. In particular, silvicultural prescriptions developed for SRWCs have been refined to include woody crop production systems for environmental benefits such as carbon sequestration, water quality and quantity, and soil health. In addition, current systems have been expanded beyond traditional fiber production to other environmental technologies that incorporate SRWCs as vital components for phytotechnologies, urban afforestation, ecological restoration, and mine reclamation. In this Special Issue of the journal Forests, we explore the broad range of current research dedicated to our topic: International Short Rotation Woody Crop Production Systems for Ecosystem Services and Phytotechnologie

Biofuels, Bioenergy, and Bioproducts from Sustainable Agricultural and Forest Crops

This issue of BioEnergy Research highlights the Short Rotation Crops International Conference held in Bloomington, Minnesota in August 2008. This is the first special issue of BioEnergy Research, with several additional special issues planned in the next year, focused on the three U.S. Department of Energy Bioenergy Research Centers (Great Lakes Bioenergy Research Center, BioEnergy Science Center, and Joint BioEnergy Institute), and emerging technologies for biodiesel production. The purpose of these special issues is to highlight emerging research efforts in the areas of biomass, biofuels, and bioenergy. The Short Rotation Crops International Conference represented a unique opportunity for communication and interaction between researchers working on herbaceous and woody bioenergy feedstocks, one that we hope will continue to stimulate new interactions and creative solutions for bioenergy and bioproducts. We invite other groups to submit ideas for future special issues to one of the three co-Editors-in-Chief of BioEnergy Research