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Direct observation of the Gouy phase shift in THz impulse ranging
(AIP Publishing, 2000-02-07)
Here we present a direct observation of the Gouy effect through THz impulse scattering from cylindrical and spherical targets. A pi/2 Gouy phase shift through a one-axis focus compared to the more common pi phase shift of ...
Single-mode waveguide propagation and reshaping of sub-ps terahertz pulses in sapphire fibers
(AIP Publishing, 2000-04-10)
Waveguide propagation of sub-ps terahertz pulses in single-crystal sapphire fibers is reported. An incident THz pulse of approximately 0.6 ps duration undergoes considerable reshaping due to the absorptive and dispersive ...
Characterization of alginate lyase from Pseudomonas syringae pv. Syringae
(American Society for Microbiology, 2000-11)
The gene encoding alginate lyase (algL) in Pseudomonas syringae pv. syringae was cloned, sequenced, and overexpressed in Escherichia coli. Alginate lyase activity was optimal when the pH was 7.0 and when assays were conducted ...
Electrical characterization of conducting polypyrrole by THz time-domain spectroscopy
(AIP Publishing, 2000-10-16)
Using an optoelectronic THz beam system for THz time-domain spectroscopy (THz TDS), we have measured the absorption and index of refraction of a conducting polypyrrole film from low frequencies to 2.5 THz. From these ...
Compactifying sufficiently regular covering spaces of compact 3-manifolds
(American Mathematical Society (AMS), 2000)
In this paper it is proven that if the group of covering translations of the covering space of a compact, connected, P²-irreducible 3-manifold corresponding to a non-trivial, finitely-generated subgroup of its fundamental ...
Cost of forward contracting hard red winter wheat
(Cambridge University Press, 2000-04)
Two methods were used to estimate the cost of forward contracting hard red winter wheat. One hundred days before delivery, the estimated cost of forward contracting ranged from six cents/bu. to eight cents/bu. Thus, further ...
Genetic diversity among Arthrobacter species collected across a heterogeneous series of terrestrial deep-subsurface sediments as determined on the basis of 16S rRNA and recA gene sequences
(American Society for Microbiology, 2000-08)
This study was undertaken in an effort to understand how the population structure of bacteria within terrestrial deep-subsurface environments correlates with the physical and chemical structure of their environment. ...
Plane curves with small linear orbits, I
(Association des Annales de l'Institut Fourier, 2000)
In this paper we compute the degree of the closure of the linear orbits of most curves with positive dimensional stabilizers. Our tool is a nonsingular variety dominating the orbit closure, which we construct by a blow-up ...
Plastic ribbon THz waveguides
(AIP Publishing, 2000-10-01)
We report an experimental and theoretical study of single mode, guided wave propagation in plastic ribbons. Using cylindrical THz optics, we obtain excellent quasioptic coupling between freely propagating THz waves and a ...
Consolidating rural school districts: Potential savings and effects on student achievement
(Cambridge University Press, 2000-12)
One frequently proposed policy is to consolidate rural school districts in order to save money by obtaining economies of size. The effects of school district size on both expenditures and standardized test scores are ...