1,252,953 research outputs found
Survival and Longevity of \u3ci\u3eOtiorhynchus Ligustici\u3c/i\u3e (Coleoptera: Curculionidae) in Alfalfa Hay Bales in Eastern Ontario
The alfalfa snout beetle, Otiorhynchus ligustici, a pest of European origin, has recently spread into mainland Ontario. A two-year study showed that dispersing adults incorporated into bales of alfalfa during harvest can survive therein for up to 46 days of storage in a mow. Furthermore, they can remain fertile for most of this period. This has important implications with respect to the shipment of hay from infested areas
Magnetic Oscillations in the Nambu - Jona-Lasinio model
The phase structure of a simple Nambu-Jona-Lasinio model has been
investigated at non-zero values of and H, where H is an external magnetic
field and is the chemical potential. On this basis magnetic oscillations
effects were considered. It was shown that there are standard (periodic) van
Alphen-de Haas magnetic oscillations of some thermodynamical quantities,
including magnetization, pressure and particle density in the NJL system.
Besides, we have found non-standard, i.e. non-periodic, magnetic oscillations,
since the frequency of oscillations is a H-dependent quantity. Finally, there
arises an oscillating behaviour not only for thermodynamical quantities, but
also for a dynamical quantity like the quark mass. The possibility for magnetic
oscillations of some physical quantities inside neutron stars is discussed.Comment: RevTeX, 12 pages; Talk given by K.G. Klimenko at the International
Workshop on Hadron Physics, 10-15 September 1999, Coimbra, Portuga
Isostatic compression process converts polyaromatics into structural material
Isostatic compression process compacts certain powdered aromatic polymers into homogeneous materials that can be machined to form useful components, such as bearings. It provides for complete removal of air in the interstitial spaces surrounding the granules of the powdered polymer before the powder is subjected to isostatic compression
Diquarks in the color--flavor locked phase of dense quark matter
Diquark excitations of dense quark matter are considered in the framework of
the Nambu -- Jona-Lasinio model with three types of massless quarks in the
presense of a quark number chemical potential . We investigate the
effective action of meson- and diquark fields at sufficiently high values of
, where the color--flavor locked (CFL) phase is realized, and prove the
existence of NG-bosons in the sector of pseudoscalar diquarks. In the sector of
scalar diquarks an additional NG-boson is found, corresponding to the
spontaneous breaking of the U(1) baryon symmetry in the CFL phase. Finally,
the existence of massive scalar and pseudoscalar diquark excitations is
demonstrated.Comment: 10 pages, 2 figures; version accepted for publication in PR
Evidence for a first order transition in a plaquette 3d Ising-like action
We investigate a 3d Ising action which corresponds to a a class of models
defined by Savvidy and Wegner, originally intended as discrete versions of
string theories on cubic lattices. These models have vanishing bare surface
tension and the couplings are tuned in such a way that the action depends only
on the angles of the discrete surface, i.e. on the way the surface is embedded
in . Hence the name gonihedric by which they are known. We show that
the model displays a rather clear first order phase transition in the limit
where self-avoidance is neglected and the action becomes a plaquette one. This
transition persists for small values of the self avoidance coupling, but it
turns to second order when this latter parameter is further increased. These
results exclude the use of this type of action as models of gonihedric random
surfaces, at least in the limit where self avoidance is neglected.Comment: 4 pages Latex text, 4 postscript figure
All fiber polarization insensitive detection for spectrometer based optical coherence tomography using optical switch
Polarization dependent image artifacts are common in optical coherence tomography imaging. Polarization insensitive detection scheme for swept source based optical coherence tomography systems is well established but is yet to be demonstrated for all fiber spectrometer-based Fourier domain optical coherence tomography systems. In this work, we present an all fiber polarization insensitive detection scheme for spectrometer based optical coherence tomography systems. Images from chicken breast muscle tissue were acquired to demonstrate the effectiveness of this scheme for the conventional Fourier domain optical coherence tomography system
- …