Do correlations create an energy gap in electronic bilayers? Critical analysis of different approaches

This paper investigates the effect of correlations in electronic bilayers on the longitudinal collective mode structure. We employ the dielectric permeability constructed by means of the classical theory of moments. It is shown that the neglection of damping processes overestimates the role of correlations. We conclude that the correct account of damping processes leads to an absence of an energy gap.Comment: 4 page

Consecutive Aqueous Extractions of Wet-milled Corn Germ Cake

Corn germ cake is an abundant and inexpensive residue of corn germ pressing. The permanent increase of corn processing – due to the recent growing demand for bioethanol – has resulted in a surplus of this by-product, making it unmarketable as feed. Our goal was to find an alternative way to utilize this by-product. We could successfully extract 86 % of the polysaccharide content of the squeezed germ by using only hot distilled water and 1 % dilute sulphuric acid consecutively. The 14.7 % oil content of the squeezed germ was concentrated to 46.25 % in the remaining solid fraction, which is high enough to be pressed. (Oil content of less than 20 % can only be extracted with organic solvents, which is not attractive for food safety and environmental reasons.) The sterol concentration of this oil was 8200 mg kg-1, which is significantly more than the sterol concentration of commercial germ oils (4500 mg kg-1)

Driven transverse shear waves in a strongly coupled dusty plasma

The linear dispersion properties of transverse shear waves in a strongly coupled dusty plasma are experimentally studied by exciting them in a controlled manner with a variable frequency external source. The dusty plasma is maintained in the strongly coupled fluid regime with (1 < Gamma << Gamma_c) where Gamma is the Coulomb coupling parameter and Gamma_c is the crystallization limit. A dispersion relation for the transverse waves is experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to show good agreement with viscoelastic theoretical results.Comment: The manuscripts contains five pages and 6 figure

I Still Can Dream

https://digitalcommons.library.umaine.edu/mmb-vp/4228/thumbnail.jp

My Bajadere

https://digitalcommons.library.umaine.edu/mmb-vp/4798/thumbnail.jp

A theory of the infinite horizon LQ-problem for composite systems of PDEs with boundary control

We study the infinite horizon Linear-Quadratic problem and the associated algebraic Riccati equations for systems with unbounded control actions. The operator-theoretic context is motivated by composite systems of Partial Differential Equations (PDE) with boundary or point control. Specific focus is placed on systems of coupled hyperbolic/parabolic PDE with an overall `predominant' hyperbolic character, such as, e.g., some models for thermoelastic or fluid-structure interactions. While unbounded control actions lead to Riccati equations with unbounded (operator) coefficients, unlike the parabolic case solvability of these equations becomes a major issue, owing to the lack of sufficient regularity of the solutions to the composite dynamics. In the present case, even the more general theory appealing to estimates of the singularity displayed by the kernel which occurs in the integral representation of the solution to the control system fails. A novel framework which embodies possible hyperbolic components of the dynamics has been introduced by the authors in 2005, and a full theory of the LQ-problem on a finite time horizon has been developed. The present paper provides the infinite time horizon theory, culminating in well-posedness of the corresponding (algebraic) Riccati equations. New technical challenges are encountered and new tools are needed, especially in order to pinpoint the differentiability of the optimal solution. The theory is illustrated by means of a boundary control problem arising in thermoelasticity.Comment: 50 pages, submitte