14,692 research outputs found
Efficiency of low versus high airline pressure in stunning cattle with a pneumatically powered penetrating captive bolt gun
The efficiency of stunning cattle was assessed in 443 animals (304 pure Zebu and 139 crossbred cattle), being mainly mature bulls and cows. Cattle were stunned using a Jarvis pneumatically powered penetrating captive bolt gun operating with low (160–175 psi, N = 82) and high (190 psi, N = 363) airline pressure, which was within the manufactures specifications. Signs of brain function and the position of the shots on the heads were recorded after stunning. Velocity of the captive bolt and its physical parameters were calculated. Cattle shot with low pressures showed more rhythmic respiration (27 vs. 8%, P < 0.001), less tongue protrusion (4 vs. 12%, P = 0.03) and less masseter relaxation (22 vs. 48%, P < 0.001). There was an increased frequency of shots in the ideal position when cattle were shot with the low compared to high airline pressures (15.3 vs. 3.1%). Bolt velocity and its physical parameters were significantly (P < 0.01) higher when using high pressure. Airline pressures below 190 psi are inappropriate when shooting adult Zebu beef cattle with pneumatically powered penetrating captive bolt guns
The Spectroscopic Age of 47 Tuc
High signal-to-noise integrated spectra of the metal-rich globular cluster 47
Tuc, spanning the H-gamma(HR) and Fe4668 line indices, have been obtained. The
combination of these indices has been suggested (Jones & Worthey 1995, ApJ,
446, L31) as the best available mechanism for cleanly separating the
age-metallicity degeneracy which hampers the dating of distant, unresolved,
elliptical galaxies. For the first time, we apply this technique to a nearby
spheroidal system, 47 Tuc, for which independent ages, based upon more
established methods, exist. Such an independent test of the technique's
suitability has not been attempted before, but is an essential one before its
application to more distant, unresolved, stellar populations can be considered
valid. Because of its weak series of Balmer lines, relative to model spectra,
our results imply a spectroscopic ``age'' for 47 Tuc well in excess of 20 Gyr,
at odds with the colour-magnitude diagram age of 14+/-1 Gyr. The derived metal
abundance, however, is consistent with the known value. Emission ``fill-in'' of
the H-gamma line as the source of the discrepancy cannot be entirely excluded
by existing data, although the observational constraints are restrictive.Comment: 17 pages, 4 figures, LaTeX, accepted for publication in The
Astronomical Journal, also available at
http://casa.colorado.edu/~bgibson/publications.htm
Galactic chemical evolution
We analyze the evolution of oxygen abundance radial gradients resulting from our chemical evolution models calculated with different prescriptions for the star formation rate (SFR) and for the gas infall rate, in order to assess their respective roles in shaping gradients. We also compare with cosmological simulations and confront all with recent observational datasets, in particular with abundances inferred from planetary nebulae. We demonstrate the critical importance in isolating the specific radial range over which a gradient is measured, in order for their temporal evolution to be useful indicators of disk growth with redshift
Room-temperature single-photon emission from zinc oxide nanoparticle defects and their in vitro photostable intrinsic fluorescence
published_or_final_versio
Manual de manejo de bacurizeiros.
Introdução; Bacurizeiro nasce até dentro de casa; Escolha da área; Tamanho da área; Manejo ou plantio?; Produção dos primeiros frutos; O bacurizeiro no contexto agroecológico; Bacurizeiro em sistema agroflorestal; Algumas questões sobre o manejo do bacurizeiro; Cuidados com o fogo; Colheita dos frutos; Comercialização; Beneficiamento; Armazenamento; Aproveitamento de sub-produto; Financiamento.bitstream/item/145322/1/MANUAL-MAN-BACURIZEIRO-2ED.pdf2. ed
Bamboo fibre processing: insights into hemicellulase and cellulase substrate accessibility
A biological approach for degumming bamboo substrates has been assessed. The ability of various commercially available
enzymes, including cellulase, xylanase, pectinase and mannanase, to hydrolyze bamboo powders was investigated. In addition, a commercial cellulase preparation was applied onto bamboo fibre bundles obtained by natural retting. It was found
that almost all enzymes applied can use bamboo material as a substrate. Mild autoclave pre-treatment can enhance reducing sugar yield from different enzyme treatments. A most pronounced effect was observed with cellulase treatment in which
the hydrolysis degree increased 1.7 fold as measured by reducing sugars for autoclave pre-treated bamboo powders versus
non-treated powders after only a short period of incubation. The combined treatment of hemicellulase preparations showed no effect on the hydrolysis of bamboo substrates. The effect of autoclave pre-treatment on cellulase-treated samples was confirmed by the increase of sugar yield, protein absorption as well as by the enhancement of surface modification and
enzyme penetration observed by CLSM (confocal laser scanning microscopy). This work establishes a base for future
studies to develop enzymatic hydrolysis of bamboo materials, making them suitable for textile processing.This work was made possible by support from the earmarked fund for Modern Agro-industry Technology Research System (nycytx-19-E23), the European Union Biorenew Project [Sixth Framework Programme (FP6-2004-NMP-NI-4)] and the Fundamental Research Funds for the Central Universities (JUSRP211A02)
The case for inclusive area profiling applied in geographic information systems
This paper introduces the history and role of consultation processes of contemporary planning and, after presenting the popularity and criticisms of different practices including communities in urban decision making, it explores how rational planning tools like the geographic information system (GIS) could be exploited to reshape consultation and formally include subjective data in traditional area profiling. Focusing on the popular consultation tool of community mapping, primary and secondary research methods (a literature review, seven interviews to planners and two observational studies) identified seven different problems with contemporary community mapping: spatial and temporal scale, generalisation, integration, representativeness, accessibility, relatedness and visualisation. The conceptualisation, physical modelling and testing of a new community mapping procedure ‘Submap’ is then used to address these problems and discuss (a) the strengths and limitations of formalising community mapping activities for area profiling in GIS and (b) the role of pragmatic research in promoting inclusive practices in contemporary planning
Identification of Globular Cluster Stars in RAVE data II: Extended tidal debris around NGC 3201
We report the identification of extended tidal debris potentially associated with the globular cluster NGC 3201, using the RAdial Velocity Experiment (RAVE) catalogue. We find the debris stars are located at a distance range of 1–7 kpc based on the forthcoming RAVE distance estimates. The derived space velocities and integrals of motion show interesting connections to NGC 3201, modulo uncertainties in the proper motions. Three stars, which are among the four most likely candidates for NGC 3201 tidal debris, are separated by 80° on the sky yet are well matched by the 12 Gyr, [Fe/H] = −1.5 isochrone appropriate for the cluster. This is the first time tidal debris around this cluster has been reported over such a large spatial extent, with implications for the cluster's origin and dynamical evolution
Antimicrobial and antioxidant linen via laccase-assisted grafting
A laccase from Ascomycetemyceliophthora thermophila was used to assist the binding of chitosan and catechin onto a previous enzymatically oxidized linen surface. The process consists of the pre-treatment of the linen with laccase followed by the application of chitosan in a first step and catechin plus laccase in a second step. The results presented here support the conclusion that laccase is able to oxidize phenols naturally existing in flax fibres, and that the o-quinones formed promote the attachment of chitosan or/and catechin. The pre-treatment of linen with laccase is therefore the key factor for the success of catechin and chitosan grafting. A multifunctional linen product with both antioxidant and antibacterial properties was obtained with an acceptable level of durability in terms of end user requirements.Carla Silva would like to acknowledge the Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) for funding under the scholarship SFRH/BPD/46515/2008
Order-of-magnitude speedup for steady states and traveling waves via Stokes preconditioning in Channelflow and Openpipeflow
Steady states and traveling waves play a fundamental role in understanding
hydrodynamic problems. Even when unstable, these states provide the
bifurcation-theoretic explanation for the origin of the observed states. In
turbulent wall-bounded shear flows, these states have been hypothesized to be
saddle points organizing the trajectories within a chaotic attractor. These
states must be computed with Newton's method or one of its generalizations,
since time-integration cannot converge to unstable equilibria. The bottleneck
is the solution of linear systems involving the Jacobian of the Navier-Stokes
or Boussinesq equations. Originally such computations were carried out by
constructing and directly inverting the Jacobian, but this is unfeasible for
the matrices arising from three-dimensional hydrodynamic configurations in
large domains. A popular method is to seek states that are invariant under
numerical time integration. Surprisingly, equilibria may also be found by
seeking flows that are invariant under a single very large Backwards-Euler
Forwards-Euler timestep. We show that this method, called Stokes
preconditioning, is 10 to 50 times faster at computing steady states in plane
Couette flow and traveling waves in pipe flow. Moreover, it can be carried out
using Channelflow (by Gibson) and Openpipeflow (by Willis) without any changes
to these popular spectral codes. We explain the convergence rate as a function
of the integration period and Reynolds number by computing the full spectra of
the operators corresponding to the Jacobians of both methods.Comment: in Computational Modelling of Bifurcations and Instabilities in Fluid
Dynamics, ed. Alexander Gelfgat (Springer, 2018
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