435 research outputs found
Finger weeder for cabbage and lettuce cultures
Summer 2002 we compared finger weeder against net harrow and herbicides in cabbage. Field trial 2003 was dedicated to lettuce: we compared different intensities of finger weeding in two different lettuce cultivars
Laser Spectroscopy of Niobium Fission Fragments: First Use of Optical Pumping in an Ion Beam Cooler Buncher
A new method of optical pumping in an ion beam cooler buncher has been developed to selectively enhance ionic metastable state populations. The technique permits the study of elements previously inaccessible to laser spectroscopy and has been applied here to the study of Nb. Model independent mean-square charge radii and nuclear moments have been studied for Nb to cover the region of the N=50 shell closure and Nâ60 sudden onset of deformation. The increase in mean-square charge radius is observed to be less than that for Y, with a substantial degree of ÎČ softness observed before and after N=60
Multisite musculoskeletal pain predicts medically certified disability retirement among Finns
BackgroundMusculoskeletal pain at several sites (multisite pain) is more common than single-site pain. Little is known on its effects on disability pension (DP) retirement. MethodsA nationally representative sample comprised 4071 Finns in the workforce aged 30 to 63. Data (questionnaire, interview, clinical examination) were gathered in 2000-2001 and linked with national DP registers for 2000-2011. Pain during the preceding month in 18 locations was combined into four sites (neck, upper limbs, low back, lower limbs). Hazard ratios (HR) of DP were estimated by Cox regression. ResultsThe HR of any DP (n=477) was 1.6 (95% confidence interval 1.2-2.1) for one, 2.5 (1.9-3.3) for two, 3.1 (2.3-4.3) for three and 5.6 (4.0-7.8) for four pain sites, when adjusted for age and gender. When additionally adjusted for clinically assessed chronic diseases, the HRs varied from 1.4 (1.0-1.8) to 3.5 (2.5-4.9), respectively. When further adjusted for physical and psychosocial workload, education, body mass index, smoking, exercise and sleep disorders, the HRs were 1.3 (0.9-1.7), 1.6 (1.2-2.2), 1.8 (1.3-2.5) and 2.5 (1.8-3.6). The number of pain sites was especially strong in predicting DPs due to musculoskeletal diseases (HRs in the full model; 3.1 to 4.3), but it also predicted DPs due to other somatic diseases (respective HRs 1.3 to 2.3); pain in all four sites was also predictive of DPs due to mental disorders (full model HR 2.2). ConclusionsThe number of pain sites independently predicted DP retirement. Employees with multisite pain may need specific support to maintain their work ability.Peer reviewe
Astrometric accuracy of phase-referenced observations with the VLBA and EVN
Astrometric accuracy of complex modern VLBI arrays cannot be calculated
analytically. We study the astrometric accuracy of phase-referenced VLBI
observations for the VLBA, EVN and global VLBI array by simulating VLBI data
for targets at declinations -25, 0, 25, 50,
75 and 85. The systematic error components considered in this
study are calibrator position, station coordinate, Earth orientation and
troposphere parameter uncertainties. We provide complete tables of the
astrometric accuracies of these arrays for a source separation of 1
either along the right ascension axis or along the declination axis.
Astrometric accuracy is 50microas at mid declination and is 300microas at low
(-25) and high (85) declinations for the VLBA and EVN. In
extending our simulations to source separations of 0.5 and 2,
we establish the formula for the astrometric accuracy of the VLBA: Delta =
(Delta_1-14)*d+ 14 (microas) where Delta_1 is the astrometric
accuracy for a separation d=1 provided in our tables for various
declinations and conditions of the wet troposphere. We argue that this formula
is also valid for the astrometric accuracy of the EVN and global VLBI array.Comment: 10 pages, 4 figures, accepted for publication in Journal of
Astrophysics and Astronom
Radiative decay branching ratio of the Hoyle state
The triple-alpha process is a vital reaction in nuclear astrophysics,
characterized by two consecutive reactions
() that drive
carbon formation. The second reaction occurs through the Hoyle state, a 7.65
MeV excited state in with .The rate of the
process depends on the radiative width, which can be determined by measuring
the branching ratio for electromagnetic decay. Recent measurements by Kib\'edi,
\textit{et al.} conflicted with the adopted value and resulted in a significant
increase of nearly 50\% in this branching ratio, directly affecting the
triple-alpha reaction. This work aims to utilize charged-particle spectroscopy
with magnetic selection as a means to accurately measure the total radiative
branching ratio () of the Hoyle state in . The Hoyle state in was populated via inelastic scattering. The scattered -particles
were detected using a E-E telescope, while the recoiled
ions were identified in a magnetic spectrometer. A radiative branching ratio
value of was obtained. The radiative branching ratio for
the Hoyle state obtained in this work is in agreement with the original adopted
value. Our result suggests that the proton-- spectroscopy
result reported by Kib\'edi \textit{et al.} may be excluded
Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path
The Penning trap mass spectrometer JYFLTRAP, coupled to the Ion-Guide Isotope Separator On-Line (IGISOL) facility at Jyvaskyla, was employed to measure the atomic masses of neutron rich 85 to 92Br and 94 to 97Rb isotopes with a typical accuracy less than 10 keV. Discrepancies with the older data are discussed. Comparison to different mass models is presented. Details of nuclear structure, shell and subshell closures are investigated by studying the two-neutron separation energy and the shell gap energy
Rebaling of silage and haylage and its effects on forage microbial and chemical composition - A pilot study
Use of big bale silage and haylage can be difficult on farms where daily forage consumption is comparatively low as speed of deterioration of forage after bale opening may be faster than feed-out rate. Production of smaller bales at harvest is possible, but expensive and work-intensive. Therefore, a pilot study of rebaling forage stored in big bales to smaller bales was conducted. Three separate experiments were included, where microbial and chemical composition of silage and haylage was studied before and after rebaling. In Experiment III, residual big bale forage stored and opened together with rebaled forage was included. Results showed that rebaled haylage and silage had higher yeast counts compared to initial forage; however, residual bales in Experiment III had yeast counts similar to rebaled forage, indicating an effect of storage time rather than of rebaling. In Experiment II, mould counts were higher in rebaled compared to initial silage, but not in haylage. Chemical composition was similar in initial and rebaled forage except for ammonia-N. In Experiment III, ammonia-N was higher in rebaled compared to initial and residual forage and was the only chemical variable affected by rebaling. Bale temperature during aerobic storage followed ambient temperature until day 6-8 in Experiment I and until day 14 in Experiment III where ambient temperature was lower. In conclusion, rebaling can be done without large changes in chemical composition of the forage, but yeast and mould counts may be higher in rebaled forage, and this risk should be considered when using this procedure
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