80 research outputs found
The impact of seeding date on the yield and quality of oats
Non-Peer ReviewedMost of the research conducted on the optimum seeding date of oats has been done outside of western Canada. The objective of this research is measure the effect of planting dates and cultivars on the yield and quality of oats. Four seeding dates, early May, Mid May, early June, and mid June and four cultivars, AC Medallion, AC Juniper, CDC Boyer and CDC Pacer were used. Delayed seeding resulted in reduced yield and quality of oats. Seeding dates had a larger effect on yield and quality than cultivars except when a high level of crown rust was present in the field. Early and mid May planting dates tend to provide farmers with the least amount of risk when growing oats
A New Tool for the Lamb Shift Calculation
We solve the Bethe-Salpeter equation for hydrogenic bound states by choosing
an appropriate interaction kernel . We want to use our solution to
calculate up to a higher order the hydrogen Lamb-shift, and as a first
application we present up to order \left(\aa / \pi\right)(\za)^7 the
contribution of the lowest order self-energy graph, calculated {\it exactly}.
The basic formalism is a natural extension to the hydrogenic bound states of
the one previously presented by R. Barbieri and E. Remiddi and used in the case
of positronium.Comment: 21 pages, Latex, Preprint DFUB-94-0
Expansion of bound state energies in powers of m/M and (1-m/M)
Elaborating on a previous letter, we use a new approach to compute energy
levels of a non-relativistic bound-state of two constituents, with masses m and
M, by systematic expansions - one in powers of m/M and another in powers of
(1-m/M). Technical aspects of the calculations are described in detail.
Theoretical predictions are given for O(alpha(Z*alpha)^5) radiative recoil and
O((Z*alpha)^6) pure recoil corrections to the average energy shift and
hyperfine splitting relevant for hydrogen, muonic hydrogen, and muonium.Comment: 9 pages, revte
Optical frequency measurement of the 1S-3S two-photon transition in hydrogen
This article reports the first optical frequency measurement of the
transition in hydrogen. The excitation of this
transition occurs at a wavelength of 205 nm which is obtained with two
frequency doubling stages of a titanium sapphire laser at 820 nm. Its frequency
is measured with an optical frequency comb. The second-order Doppler effect is
evaluated from the observation of the motional Stark effect due to a transverse
magnetic field perpendicular to the atomic beam. The measured value of the
frequency splitting is with a relative uncertainty of
. After the measurement of the
frequency, this result is the most precise of the optical frequencies in
hydrogen
Two-loop corrections to the decay rate of parapositronium
Order corrections to the decay rate of parapositronium are
calculated. A QED scattering calculation of the amplitude for electron-positron
annihilation into two photons at threshold is combined with the technique of
effective field theory to determine an NRQED Hamiltonian, which is then used in
a bound state calculation to determine the decay rate. Our result for the
two-loop correction is in units of times the
lowest order rate. This is consistent with but more precise than the result
of a previous calculation.Comment: 26 pages, 7 figure
Previous Crop Sequences Effect on Fusarium Head Blight of Cereals in the Prairies
Non-Peer ReviewedFusarium head blight (FHB) is a disease of concern across the Canadian prairies; low crop diversity within rotations increases disease risk. Approximately 60% of the area seeded to annual crops in Alberta, Manitoba and Saskatchewan consists of wheat and canola. The present study focusses on the effect of previous crop sequences on the severity of FHB of cereals across the prairies. From 2018 to 2020, six locations were seeded with a core set of five crops including wheat, barley, canola, pea, and maize; at some sites, a sixth crop was included such as lentil. Each year, yield, crop quality and FHB severity were recorded; also, Fusarium spp. were isolated and identified from cereal kernels. Several Fusarium spp. caused FHB among cereal crops and were associated with host crops. The experiment consisted of a factorial arrangement in a split block design. The diversity criteria were established by using groups A, B, and C. Where A is the crop sequences that included cereals, pulses and oilseeds in the rotation. Treatment B, consisted of cereals and pulses, or cereals and oilseeds; while C, consisted only of cereals. This year data from Saskatoon shows that the diversity criteria played an important role in the proportion of the various Fusarium spp.. Fusarium spp. shows a significant difference between treatments and the frequency of F. graminearum isolated was similar in sequences with only cereals and cereal with pulses/ oilseeds, but both differed from a crop sequence that include three-different crops. The lack of crop diversity across western Canada is a risk factor for future disease outbreaks. Link to Video Presentation: https://youtu.be/zbUD6Lp7-c
Prospects for e+e- physics at Frascati between the phi and the psi
We present a detailed study, done in the framework of the INFN 2006 Roadmap,
of the prospects for e+e- physics at the Frascati National Laboratories. The
physics case for an e+e- collider running at high luminosity at the phi
resonance energy and also reaching a maximum center of mass energy of 2.5 GeV
is discussed, together with the specific aspects of a very high luminosity
tau-charm factory. Subjects connected to Kaon decay physics are not discussed
here, being part of another INFN Roadmap working group. The significance of the
project and the impact on INFN are also discussed. All the documentation
related to the activities of the working group can be found in
http://www.roma1.infn.it/people/bini/roadmap.html.Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 table
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7ââfbâ1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
Penicilinoterapia intravenosa em altas doses na neurossĂfilis: estudo de 62 casos II. Avaliação do lĂqĂŒido cefalorraqueano
- âŠ