Integrability of the quantum KdV equation at c = -2

We present a simple a direct proof of the complete integrability of the quantum KdV equation at $c=-2$, with an explicit description of all the conservation laws.Comment: 9 page

Interacting two helical edge modes in quantum spin Hall systems

We study theoretically the two interacting one-dimensional helical modes at the edges of the quantum spin Hall systems. A new type of inter-edge correlated liquid (IECL) without the spin gap is found. This liquid shows the diverging density wave (DW) and superconductivity (SC) correlations much stronger than those of the spinfull electrons. Possible experimental observations are also discussed

Gate-controlled one-dimensional channel on the topological surface

We investigate the formation of the one-dimensional channels on the topological surface under the gate electrode. The energy dispersion of these channels is almost linear in the momentum with the velocity sensitively depending on the strength of the gate voltage. The energy is also restricted to be positive or negative depending on the strength of the gate voltage. Consequently, the local density of states near the gated region has an asymmetric structure with respect to zero energy. In the presence of the electron-electron interaction, the correlation effect can be tuned by the gate voltage. We also suggest a tunneling experiment to verify the presence of these bound states.Comment: 5 pages, 4 figure

Toward the classification of the realistic free fermionic models

The realistic free fermionic models have had remarkable success in providing plausible explanations for various properties of the Standard Model which include the natural appearance of three generations, the explanation of the heavy top quark mass and the qualitative structure of the fermion mass spectrum in general, the stability of the proton and more. These intriguing achievements makes evident the need to understand the general space of these models. While the number of possibilities is large, general patterns can be extracted. In this paper I present a detailed discussion on the construction of the realistic free fermionic models with the aim of providing some insight into the basic structures and building blocks that enter the construction. The role of free phases in the determination of the phenomenology of the models is discussed in detail. I discuss the connection between the free phases and mirror symmetry in (2,2) models and the corresponding symmetries in the case of the (2,0) models. The importance of the free phases in determining the effective low energy phenomenology is illustrated in several examples. The classification of the models in terms of boundary condition selection rules, real world-sheet fermion pairings, exotic matter states and the hidden sector is discussed.Comment: 43 pages. Standard Late

Online Learning: Exploring the Landscape

The Policy and Planning Council of the Metropolitan Educational Research Consortium (MERC) at Virginia Commonwealth University (VCU) rightfully identified online learning as an area ripe for study. This report summarizes findings from both phases of the research is the first report of the study that was ultimately commissioned. After a brief review of the literature, this report includes a description of the survey research portion of the study as well as findings from the statewide survey that was undertaken and then phase 2, which consisted of case studies of four Virginia school divisions. The report concludes with a brief summary of the findings and some policy and research recommendations

Local Electronic Correlation at the Two-Particle Level

Electronic correlated systems are often well described by dynamical mean field theory (DMFT). While DMFT studies have mainly focused hitherto on one-particle properties, valuable information is also enclosed into local two-particle Green's functions and vertices. They represent the main ingredient to compute momentum-dependent response functions at the DMFT level and to treat non-local spatial correlations at all length scales by means of diagrammatic extensions of DMFT. The aim of this paper is to present a DMFT analysis of the local reducible and irreducible two-particle vertex functions for the Hubbard model in the context of an unified diagrammatic formalism. An interpretation of the observed frequency structures is also given in terms of perturbation theory, of the comparison with the atomic limit, and of the mapping onto the attractive Hubbard model.Comment: 29 pages, 26 Figures. Accepted for publication in Phys. Rev.

Conceptual mechanization studies for a horizon definition spacecraft attitude control subsystem, phase A, part II, 10 October 1966 - 29 May 1967

Attitude control subsystem for spin stabilized spacecraft for mapping earths infrared horizon radiance profiles in 15 micron carbon dioxide absorption ban

BIOREFINERIES USING AGRICULTURAL RESIDUE FEEDSTOCK IN THE GREAT PLAINS

Rising prices and uncertain supplies of petroleum, together with environmental concerns regarding fossil fuel combustion, has enhanced interest in biobased products and fuels. The work reported here analyzes the feasibility of a multi-product biorefinery using wheat straw as feedstock that produces ethanol, electricity, and cellulose nanofibers. The nanofibers (nanowhiskers) would be used as reinforcements in a biobased nanocomposite material that could substitute for fiberglass in many applications. The analysis indicates that, at 2005 prices and costs, the biorefinery would be marginally profitable. Anticipated advances in bioprocessing technology would enhance profitability. The facility would also make a substantial contribution to the biorefinery site area economy, as a high percentage of operating expenses would be payments to local entities. The growth of a biobased industry could have major economic development implications for the Great Plains/Midwest region.biomass, biomaterials, ethanol, wheat straw, cellulose nanowhiskers (CNW), economic development, Resource /Energy Economics and Policy,