298 research outputs found
Effect of seeding rate and row spacing on the agronomic performance of winter wheat
Non-Peer ReviewedThe effect of row spacings and seed rates on the agronomic performance of "stubbled in" winter wheat (Triticum aestivum L.) were studied over a period of two years at locations in central, northeast, and southeast Saskatchewan. In both years of the study there was a highly significant relationship between row spacing and yield with increased yields at narrower row spacings. The yield response to seeding rate
indicated different trends in each of the two years of the study. In 1985/86 there was a highly significant relationship between seed rate and yield with increased yields at higher seed rates. In 1986/87 the relationship between seeding rate and yield was not significant. In 1985/86 higher head counts/m2 at higher seeding rates resulted in the higher yields. In 1986/87 the head counts/m2 were also higher at higher seeding rates however a reduction in seeds/head and/or 1000k weight counteracted the effects of the higher head populations resulting in non-significant yield differences
Effect of seeding depth on the performance of winter wheat
Non-Peer Reviewe
The effect of lamb carcase weight and GR depth on the production of value-added cuts â A short communication
Times for the progressive breakdown of 95 lamb carcases were recorded to determine the impact of carcase weight and GR tissue depth on the time and therefore cost to produce value added retail cuts. Further analysis also assessed the potential to use these carcase traits as predictors of fabrication times. Regression modeling demonstrated there was a limited ability to predict the difference in time to fabricate mid value-added (R2 = 0.18) and extreme value-added (R2 = 0.12) cuts compared to traditional cuts, suggesting that other factors need to be considered. However, this study highlighted the significant increases in time required to fabricate more value-added cuts and to breakdown heavier carcases. Furthermore, this study demonstrated the changes to the saleable meat yield as the degree of fabrication increased, such that the average product prices increased (28.72/kg for extreme value added) compared to traditional retail cuts ($15/kg) to offset the increased labour of fabricating value-added cuts
Carbon clusters near the crossover to fullerene stability
The thermodynamic stability of structural isomers of ,
, and , including
fullerenes, is studied using density functional and quantum Monte Carlo
methods. The energetic ordering of the different isomers depends sensitively on
the treatment of electron correlation. Fixed-node diffusion quantum Monte Carlo
calculations predict that a isomer is the smallest stable
graphitic fragment and that the smallest stable fullerenes are the
and clusters with and
symmetry, respectively. These results support proposals that a
solid could be synthesized by cluster deposition.Comment: 4 pages, includes 4 figures. For additional graphics, online paper
and related information see http://www.tcm.phy.cam.ac.uk/~prck
Stellar structure and compact objects before 1940: Towards relativistic astrophysics
Since the mid-1920s, different strands of research used stars as "physics
laboratories" for investigating the nature of matter under extreme densities
and pressures, impossible to realize on Earth. To trace this process this paper
is following the evolution of the concept of a dense core in stars, which was
important both for an understanding of stellar evolution and as a testing
ground for the fast-evolving field of nuclear physics. In spite of the divide
between physicists and astrophysicists, some key actors working in the
cross-fertilized soil of overlapping but different scientific cultures
formulated models and tentative theories that gradually evolved into more
realistic and structured astrophysical objects. These investigations culminated
in the first contact with general relativity in 1939, when J. Robert
Oppenheimer and his students George Volkoff and Hartland Snyder systematically
applied the theory to the dense core of a collapsing neutron star. This
pioneering application of Einstein's theory to an astrophysical compact object
can be regarded as a milestone in the path eventually leading to the emergence
of relativistic astrophysics in the early 1960s.Comment: 83 pages, 4 figures, submitted to the European Physical Journal
Spinor condensates and light scattering from Bose-Einstein condensates
These notes discuss two aspects of the physics of atomic Bose-Einstein
condensates: optical properties and spinor condensates. The first topic
includes light scattering experiments which probe the excitations of a
condensate in both the free-particle and phonon regime. At higher light
intensity, a new form of superradiance and phase-coherent matter wave
amplification were observed. We also discuss properties of spinor condensates
and describe studies of ground--state spin domain structures and dynamical
studies which revealed metastable excited states and quantum tunneling.Comment: 58 pages, 33 figures, to appear in Proceedings of Les Houches 1999
Summer School, Session LXXI
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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