3,491 research outputs found
Effect of various levels of dietary whole cottonseed on blood parameters and performance of Awassi lambs under heat stress
This study was carried out to determine the effect of whole cottonseed (WCS) supplementation on finishing performance and blood parameters of Awassi lambs under heat stress. The compositions of diets for the various treatments were i) control: concentrate without WCS plus 15% wheat straw; ii) 8.5% WCS, 76.5% concentrate and 15% wheat straw; and iii) 17% WCS, 68% concentrate plus 15% wheat straw. Twenty seven male Awassi lambs (4 - 5 months old) were allotted to three dietary treatments in equal numbers for each diet in a completely randomized design. Following 15 days of diet adaptation, lambs were fed the experimental diets ad libitum for 56 days. According to the finishing trial, average daily gain (ADG), feed intake (FI), dry matter intake (DMI), feed efficiency and water consumption were not affected by the inclusion of WCS. Only numerical increment of daily gain, FI and DMI was observed in the 8.5% WCS group. Supplementation of WCS did not affect blood glucose, urea, total protein, albumin and potassium levels, but blood cholesterol level was increased. Changes in scrotal circumference were observed with supplementation of 17% WCS. As a result, WCS can replace concentrate up to 8.5% of diet without negative effects on finishing performance of Awassi lambs under heat stress conditions.Keywords: Sheep, finishing, efficiency, gain, oil see
The effect of supersymmetric CP phases on Chargino-Pair Production via Drell-Yan Process at the LHC
We compute the rates for pp annihilation into chargino-pairs via Drell-Yan
process taking into account the effects of supersymmetric soft phases, at
proton-proton collider. In particular, the phase of the mu parameter gains
direct accessibility via the production of dissimilar charginos. The phases of
the trilinear soft masses do not have a significant effect on the cross
sections.Comment: 24 pages, 7 figure
Plasmonic metamaterials and nanocomposites with the narrow transparency window effect in broad extinction spectra
Cataloged from PDF version of article.We propose and describe plasmonic nanomaterials with unique optical properties. These nanostructured materials strongly attenuate light across a broad wavelength interval ranged from 400 nm to S pm but exhibit a narrow transparency window centered at a given wavelength. The main elements used in our systems are nanorods and nanocrosses of variable sizes. The nanomaterial can be designed as a solution, nanocomposite film or metastructure. The principle of the formation of the transparency window in the broad extinction spectrum is based on the narrow lines of longitudinal plasmons of single nanorods and nanorod complexes. To realize the spectrum with a transmission window, we design a nanocomposite material as a mixture of nanorods of different sizes. Simultaneously, we exclude nanorods of certain lengths from the nanorod ensemble. The width of the plasmonic transparency window is determined by the intrinsic and radiative broadenings of the nanocrystal plasmons. Nanocrystals can be randomly dispersed in a solution or arranged in metastructures. We show that interactions between nanocrystals in a dense ensemble can destroy the window effect and, simultaneously, we design the metastructure geometries with weak destructive interactions. We also describe the effect of narrowing of the transparency window with increasing the concentration of nanocrystals. Two well-established technologies can be used to fabricate such nano- and metamaterials, the colloidal synthesis, and lithography. Nanocomposites proposed here can be used as optical materials and smart coatings for shielding of electromagnetic radiation in a wide spectral interval with a simultaneous possibility of communication using a narrow transparency window
Higher Curvature Quantum Gravity and Large Extra Dimensions
We discuss effective interactions among brane matter induced by modifications
of higher dimensional Einstein gravity via the replacement of Einstein-Hilbert
term with a generic function f(R) of the curvature scalar R. After deriving the
graviton propagator, we analyze impact of virtual graviton exchanges on
particle interactions, and conclude that f(R) gravity effects are best probed
by high-energy processes involving massive gauge bosons, heavy fermions or the
Higgs boson. We perform a comparative analysis of the predictions of f(R)
gravity and of Arkani-Hamed-Dvali-Dimopoulos (ADD) scenario, and find that the
former competes with the latter when f''(0) is positive and comparable to the
fundamental scale of gravity in higher dimensions. In addition, we briefly
discuss graviton emission from the brane as well as its decays into
brane-localized matter, and find that they hardly compete with the ADD
expectations. Possible existence of higher-curvature gravitational interactions
in large extra spatial dimensions opens up various signatures to be confronted
with existing and future collider experiments.Comment: 19 pp, 2 figs. Added references, corrected typo
Volumetric plasmonic resonator architecture for thin-film solar cells
Cataloged from PDF version of article.We propose and demonstrate a design concept of volumetric plasmonic resonators that relies on the idea of incorporating coupled layers of plasmonic structures embedded into a solar cell in enhanced optical absorption for surface-normal and off-axis angle configurations, beyond the enhancement limit of individual plasmonic layers. For a proof-of-concept demonstration in a thin-film organic solar cell that uses absorbing materials of copper phthalocyanine/perylene tetracarboxylic bisbenzimidazole, we couple two silver grating layers such that the field localization is further extended within the volume of active layers. Our computational results show a maximum optical absorption enhancement level of similar to 67% under air mass 1.5 global illumination considering both polarizations. (C) 2011 American Institute of Physics
Relaxation of the Dynamical Gluino Phase and Unambiguous Electric Dipole Moments
We propose a new axionic solution of the strong CP problem with a
Peccei-Quinn mechanism using the gluino rather than quarks. The spontaneous
breaking of this new global U(1) at 10^{11} GeV also generates the
supersymmetry breaking scale of 1 TeV (solving the so-called \mu problem at the
same time) and results in the MSSM (Minimal Supersymmetric Standard Model) with
R parity conservation. In this framework, electric dipole moments become
calculable without ambiguity.Comment: Typos corrected and a footnote added, 10 p
Plasmonic backcontact grating for P3HT:PCBM organic solar cells enabling strong optical absorption increased in all polarizations
Cataloged from PDF version of article.In P3HT:PCBM based organic solar cells we propose and demonstrate numerically plasmonic backcontact grating architectures for strong optical absorption enhanced in both transverse-magnetic and transverse-electric polarizations. Even when the active material is partially replaced by the metallic grating (without increasing the active layer film thickness), we show computationally that the light absorption in thin-film P3HT:PCBM is increased by a maximum factor of similar to 21% considering both polarizations under AM1.5G solar radiation and over a half-maximum incidence angle of 45 degrees (where the enhancement drops to its half) compared to the same cell without a grating. This backcontact grating outperforms the typical plasmonic grating placed in PEDOT:PSS layer. (C)2011 Optical Society of America
Experiments and Simulations of short-pulse laser-pumped extreme ultraviolet lasers
Recent experimental work on the development of extreme ultraviolet lasers undertaken using as the pumping source the VULCAN laser at the Rutherford Appleton Laboratory is compared to detailed simulations. It is shown that short duration (similar topicosecond) pumping can produce X-ray laser pulses of a few picosecond duration and that measurement of the emission from the plasma can give an estimate of the duration of the gain coefficient. The Ehybrid fluid and atomic physics code developed at the University of York is used to simulate X-ray laser gain and plasma emission. Two postprocessors to the Ehybrid code are utilized: 1) to raytrace the X-ray laser beam amplification and refraction and 2) to calculate the radiation emission in the kiloelectronvolt photon energy range. The raytracing and spectral simulations are compared, respectively, to measured X-ray laser output and the output of two diagnostics recording transverse X-ray emission. The pumping laser energy absorbed in the plasma is examined by comparing the simulations to experimental results. It is shown that at high pumping irradiance (>10(15) Wcm(-2)), fast electrons are produced by parametric processes in the preformed long scale-length plasmas. These fast electrons do not pump the population inversion and so pumping efficiency is reduced at high irradiance
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