29,763 research outputs found
Common Psittacine Behavioral Problems
The 1980\u27s saw a dramatic increase in the popularity of pet psittacine birds in the U.S. Owners of psittacines revealed that many had misconceptions as to what kind of a pet their bird would be. Even though some owners do research about their pets before obtaining them, most are poorly informed about normal behavior. A practicing veterinarian should be prepared to answer questions regarding psittacine behavioral problems. The intent of this paper is to discuss the causes, management, and prevention of such problems
To Duckweeds (\u3cem\u3eLandoltia punctata\u3c/em\u3e), Nanoparticulate Copper Oxide is More Inhibitory than the Soluble Copper in the Bulk Solution
CuO nanoparticles (CuO-NP) were synthesized in a hydrogen diffusion flame. Particle size and morphology were characterized using scanning mobility particle sizing, Brunauer–Emmett–Teller analysis, dynamic light scattering, and transmission electron microscopy. The solubility of CuO-NP varied with both pH and presence of other ions. CuO-NP and comparable doses of soluble Cu were applied to duckweeds, Landoltia punctata. Growth was inhibited 50% by either 0.6 mg L−1 soluble copper or by 1.0 mg L−1 CuO-NP that released only 0.16 mg L−1 soluble Cu into growth medium. A significant decrease of chlorophyll was observed in plants stressed by 1.0 mg L−1 CuO-NP, but not in the comparable 0.2 mg L−1 soluble Cu treatment. The Cu content of fronds exposed to CuO-NP is four times higher than in fronds exposed to an equivalent dose of soluble copper, and this is enough to explain the inhibitory effects on growth and chlorophyll content
Exact strip postbuckling analysis of composite plates under compression and shear
Stiffened wing and fuselage panels often have a postbuckling reserve of strength, enabling them to carry loads far in excess of their critical buckling loads. Therefore allowing for postbuckling in design can reduce their weight, hence reducing fuel consumption and environmental impact. The present paper extends the postbuckling analysis in the exact strip software VICONOPT to more accurately reflect the skewed mode shapes arising from shear load and anisotropy. Such mode shapes are represented by a series of sinusoidal responses with different half-wavelengths which are coupled together using Lagrangian multipliers to enforce the boundary conditions. In postbuckling analysis the in-plane deflections involve responses with additional half-wavelengths which are absent from the out-of-plane deflection series. Numerical results are presented and compared with finite element analysis for validation. The present analysis gives close results compared to the finite element and finite strip methods and saves computational time significantly
Exactness of the Fock space representation of the q-commutation relations
We show that for all q in the interval (-1,1), the Fock representation of the
q-commutation relations can be unitarily embedded into the Fock representation
of the extended Cuntz algebra. In particular, this implies that the C*-algebra
generated by the Fock representation of the q-commutation relations is exact.
An immediate consequence is that the q-Gaussian von Neumann algebra is weakly
exact for all q in the interval (-1,1).Comment: 20 page
Phase Diagram of the Spin-One Heisenberg System with Dimerization and Frustration
We use the density matrix renormalization group method to study the ground
state properties of an antiferromagnetic spin- chain with a next-nearest
neighbor exchange and an alternation of the nearest neighbor
exchanges. We find a line running from a gapless point at upto an almost gapless point at such that
the open chain ground state is -fold degenerate below the line and is unique
above it. A disorder line runs from to about
. To the left of this line, the peak in the structure factor
is at , while to the right of the line, it is at less than .Comment: 11 pages, plain TeX, 3 figures available on reques
Left-Right Asymmetry of Weak Interaction Mass of Polarized Fermions in Flight
The left-right polarization-dependent asymmetry of the weak interaction mass
is investigated. Based on the Standard Model, the calculation shows that the
weak interaction mass of left-handed polarized fermions is always greater than
that of right-handed polarized fermions in flight with the same velocity in any
inertial frame. The asymmetry of the weak interaction mass might be very
important to the investigation of neutrino mass and would have an important
significance for understanding the parity nonconservation in weak interactions.Comment: 8 pages, 2 figures, corrected calculatio
Quantitative micro-elastography: imaging of tissue elasticity using compression optical coherence elastography
Probing the mechanical properties of tissue on the microscale could aid in the identification of diseased tissues that are inadequately detected using palpation or current clinical imaging modalities, with potential to guide medical procedures such as the excision of breast tumours. Compression optical coherence elastography (OCE) maps tissue strain with microscale spatial resolution and can delineate microstructural features within breast tissues. However, without a measure of the locally applied stress, strain provides only a qualitative indication of mechanical properties. To overcome this limitation, we present quantitative micro-elastography, which combines compression OCE with a compliant stress sensor to image tissue elasticity. The sensor consists of a layer of translucent silicone with well-characterized stress-strain behaviour. The measured strain in the sensor is used to estimate the two-dimensional stress distribution applied to the sample surface. Elasticity is determined by dividing the stress by the strain in the sample. We show that quantification of elasticity can improve the ability of compression OCE to distinguish between tissues, thereby extending the potential for inter-sample comparison and longitudinal studies of tissue elasticity. We validate the technique using tissue-mimicking phantoms and demonstrate the ability to map elasticity of freshly excised malignant and benign human breast tissues.Kelsey M. Kennedy, Lixin Chin, Robert A. McLaughlin, Bruce Latham, Christobel M. Saunders, David D. Sampson and Brendan F. Kenned
Hadron Spectrum in QCD with Valence Wilson Fermions and Dynamical Staggered Fermions at $6/g^2=5.6
We present an analysis of hadronic spectroscopy for Wilson valence quarks
with dynamical staggered fermions at lattice coupling at
sea quark mass and 0.025, and of Wilson valence quarks in quenched
approximation at and 5.95, both on lattices. We
make comparisons with our previous results with dynamical staggered fermions at
the same parameter values but on lattices doubled in the temporal
direction.Comment: 32 page
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