1,277 research outputs found
Dielectronic recombination data for astrophysical applications: Plasma rate-coefficients for Fe^q+ (q=7-10, 13-22) and Ni^25+ ions from storage-ring experiments
This review summarizes the present status of an ongoing experimental effort
to provide reliable rate coefficients for dielectronic recombination of highly
charged iron ions for the modeling of astrophysical and other plasmas. The
experimental work has been carried out over more than a decade at the heavy-ion
storage-ring TSR of the Max-Planck-Institute for Nuclear Physics in Heidelberg,
Germany. The experimental and data reduction procedures are outlined. The role
of previously disregarded processes such as fine-structure core excitations and
trielectronic recombination is highlighted. Plasma rate coefficients for
dielectronic recombination of Fe^q+ ions (q=7-10, 13-22) and Ni^25+ are
presented graphically and in a simple parameterized form allowing for easy use
in plasma modeling codes. It is concluded that storage-ring experiments are
presently the only source for reliable low-temperature dielectronic
recombination rate-coefficients of complex ions.Comment: submitted for publication in the International Review of Atomic and
Molecular Physics, 8 figures, 3 tables, 68 reference
Interference effects in the photorecombination of argonlike Sc3+ ions: Storage-ring experiment and theory
Absolute total electron-ion recombination rate coefficients of argonlike
Sc3+(3s2 3p6) ions have been measured for relative energies between electrons
and ions ranging from 0 to 45 eV. This energy range comprises all dielectronic
recombination resonances attached to 3p -> 3d and 3p -> 4s excitations. A broad
resonance with an experimental width of 0.89 +- 0.07 eV due to the 3p5 3d2 2F
intermediate state is found at 12.31 +- 0.03 eV with a small experimental
evidence for an asymmetric line shape. From R-Matrix and perturbative
calculations we infer that the asymmetric line shape may not only be due to
quantum mechanical interference between direct and resonant recombination
channels as predicted by Gorczyca et al. [Phys. Rev. A 56, 4742 (1997)], but
may partly also be due to the interaction with an adjacent overlapping DR
resonance of the same symmetry. The overall agreement between theory and
experiment is poor. Differences between our experimental and our theoretical
resonance positions are as large as 1.4 eV. This illustrates the difficulty to
accurately describe the structure of an atomic system with an open 3d-shell
with state-of-the-art theoretical methods. Furthermore, we find that a
relativistic theoretical treatment of the system under study is mandatory since
the existence of experimentally observed strong 3p5 3d2 2D and 3p5 3d 4s 2D
resonances can only be explained when calculations beyond LS-coupling are
carried out.Comment: 11 pages, 7 figures, 3 tables, Phys. Rev. A (in print), see also:
http://www.strz.uni-giessen.de/~k
Анализ данных о смертности в России для разработки корпоративной системы пропаганды здорового образа жизни населения
Выпускная квалификационная работа 117 с., 13 рис., 34 табл., 16 источников, 1 прил. Объектом исследования являются данные, предоставленные МО 슫Здоровье슻, стандартизованных вопросников на умерших лиц. Цель работы установить закономерности в уже существующих статистических данных и данных проведенных в данном исследовании для дальнейшего использования в корпоративной системе пропаганды здорового образа жизни. В процессе исследования проводился ряд исследований по влиянию курения на смертность, распространенности курения среди населения, влияние различных факторов на смертность от болезней систем-кровообращения, обзор методов статистического анализа для медицинских исследований и практика их применеия.Final qualifying work 117 p., 13 fig., 34 tab., 16 Sources, Appendix 1. The object of research is the data provided by the Medical Association "Health", standardized questionnaires on deceased persons. The goal of the work to establish patterns in the existing statistics and data conducted in this study for further use in the corporate system of promoting a healthy lifestyle. The study was conducted a number of studies on the effect of smoking on mortality, the prevalence of smoking among the population, the impact of various factors on mortality from diseases of the circulatory systems, a review of methods of statistical analysis for medical research and practice them of use
Storage-ring measurement of the hyperfine induced 47Ti18+(2s 2p 3P0 -> 2s2 1S0) transition rate
The hyperfine induced 2s 2p 3P0 > 2s2 1S0 transition rate AHFI in
berylliumlike 47Ti18+ was measured. Resonant electron-ion recombination in a
heavy-ion storage ring was employed to monitor the time dependent population of
the 3P0 state. The experimental value AHFI=0.56(3)/s is almost 60% larger than
theoretically predicted.Comment: 4 pages. 3 figures, 1 table, accepted for publication in Physical
Review Letter
Impact of fungicide applications for late blight management on huckleberry yields in Cameroon
The influence of late blight infections, caused by Phytophthora infestans, was evaluated on thirteen huckleberry (Solanum scabrum) varieties during the 2000 and 2001 cropping seasons in Dschang, Cameroon. A randomised split block design was used. Plants were sprayed four times with Ridomil Plus® (12% metalaxyl + 60% cuprous oxide) at 2.5 kg ha-1 on a 21-day schedule while control plots were not sprayed. Late blight intensity was recorded weekly and fresh shoot yields were evaluated six times at 14-day intervals. Fungicide applications significantly reduced late blight intensity and consequently increased huckleberry yields. Cumulative shoot yields varied with the variety and fungicide treatment, from 54.14 to 238.33 t ha-1. Yield losses due to late blight infection were estimated at up to 46%. Economic analyses indicated that fungicide sprays are necessary for a late blight protection programme in huckleberry. This spray regime based on fungicide application resulted in net profits of US 8,467 ha-1, depending on the variety used and the trial period. The results show that late blight infections if not controlled, decrease huckleberry yields, and consequently net farm incomes. High yielding resistant varieties or foliar applications of Ridomil Plus® may be incorporated in integrated pathogen management schemes against late blight in huckleberries with a view to minimise use of fungicides.
Key Words: Integrated management, Phytophthora infestans, Solanum scabrum, yield loss
Résumé
L'influence du mildiou, causé par Phytophthora infestans, était évalué sur treize variétés de la morelle noire (Solanum scabrum) pendant les saisons culturalles de l'an 2000 et 2001 à Dschang, Cameroun. Les éssais étaient réalisés en split-blocs pris au hazard. Les plantes étaient traitées quatre fois avec Ridomil Plus (12% de métalaxyl + 60% oxyde cuivreux) à 21 jours d'intervalle à la dose de 2.5 kg ha-1. L'intensité du mildiou a été évalué hebdomadairement et les pousses fraiches ont été récoltées six fois à l'intervalle de 14 jours. Des traitements fongicides ont significativement réduit l'intensité du mildiou et par conséquent augmenté le rendement en pousses. Le rendement total en pousses fraiches a été variable. De 54, 14 à 238,33 t ha-1, selon la variété et le traitement fongicide. Des pertes en rendements associées aux attaques du mildiou ont atteint 46%. Des analyses économiques indiquent que quatre traitements au Ridomil plus"sont nécessaires dans un bon programme de protection de la morelle noire contre le mildiou. Ce régime de traitement a poduit des augmentations en revenu net de USS 694 à 8.467 ha-1, selon la variété utilisée et la période d'essai. Des résultats indiquent que le mildiou peut baisser le rendement de la morelle noire et par conséquent le bénéfice net des planteurs de la morelle noire si les actions appropriées ne sont pas menées pour rayer les effets néfastes de cette maladie. En outre, l'utilisation des variétés résistantes ou des traitements foliaires au Ridomil plus" peut etre incorporée dans des programmes de lutte intégrée contre le mildiou de la morelle noire.
Mots Clés: Gestion intégrée, Phytophthora infestans, Solanum scabrum, perte de rendement
(Af Crop Sci J 2003 Vol 11 No 3 pp163-170
Automatisch voorbehandelen bij melken
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Dielectronic Recombination of Fe XV forming Fe XIV: Laboratory Measurements and Theoretical Calculations
We have measured resonance strengths and energies for dielectronic
recombination (DR) of Mg-like Fe XV forming Al-like Fe XIV via N=3 -> N' = 3
core excitations in the electron-ion collision energy range 0-45 eV. All
measurements were carried out using the heavy-ion Test Storage Ring at the Max
Planck Institute for Nuclear Physics in Heidelberg, Germany. We have also
carried out new multiconfiguration Breit-Pauli (MCBP) calculations using the
AUTOSTRUCTURE code. For electron-ion collision energies < 25 eV we find poor
agreement between our experimental and theoretical resonance energies and
strengths. From 25 to 42 eV we find good agreement between the two for
resonance energies. But in this energy range the theoretical resonance
strengths are ~ 31% larger than the experimental results. This is larger than
our estimated total experimental uncertainty in this energy range of +/- 26%
(at a 90% confidence level). Above 42 eV the difference in the shape between
the calculated and measured 3s3p(^1P_1)nl DR series limit we attribute partly
to the nl dependence of the detection probabilities of high Rydberg states in
the experiment. We have used our measurements, supplemented by our
AUTOSTRUCTURE calculations, to produce a Maxwellian-averaged 3 -> 3 DR rate
coefficient for Fe XV forming Fe XIV. The resulting rate coefficient is
estimated to be accurate to better than +/- 29% (at a 90% confidence level) for
k_BT_e > 1 eV. At temperatures of k_BT_e ~ 2.5-15 eV, where Fe XV is predicted
to form in photoionized plasmas, significant discrepancies are found between
our experimentally-derived rate coefficient and previously published
theoretical results. Our new MCBP plasma rate coefficient is 19-28% smaller
than our experimental results over this temperature range
The use of online support by people with intellectual disabilities living independently during COVID‐19
Background During the COVID-19 outbreak, service providers in the Netherlands had to switch towards providing remote support for people with intellectual disabilities living independently. This study aims to provide insight into the use of online support during the outbreak. Methods We analysed quantitative data on planned and unplanned contacts between the online support service DigiContact and its service users. Results The results indicate that the COVID-19 outbreak and the related containment measures had a strong impact on online support use, specifically on the unplanned use of online support. Conclusion Offering online support as a standard component of services for independently living people with intellectual disability enables service providers to be flexible and responsive towards fluctuations in both support needs and onsite support availability during a social crisis such as COVID-19
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