1,632 research outputs found
Comparative study of hormonal counterregulation during GCIIS-guided hypoglycemia tests using human Proinsulin and Human Insulin (recombinant DNA)
Schlechte Scanvorlage
Intrinsic peculiarities of real material realizations of a spin-1/2 kagome lattice
Spin-1/2 magnets with kagome geometry, being for years a generic object of
theoretical investigations, have few real material realizations. Recently, a
DFT-based microscopic model for two such materials, kapellasite Cu3Zn(OH)6Cl2
and haydeeite Cu3Mg(OH)6Cl2, was presented [O. Janson, J. Richter and H.
Rosner, arXiv:0806.1592]. Here, we focus on the intrinsic properties of real
spin-1/2 kagome materials having influence on the magnetic ground state and the
low-temperature excitations. We find that the values of exchange integrals are
strongly dependent on O--H distance inside the hydroxyl groups, present in most
spin-1/2 kagome compounds up to date. Besides the original kagome model,
considering only the nearest neighbour exchange, we emphasize the crucial role
of the exchange along the diagonals of the kagome lattice.Comment: 4 pages, 4 figures. A paper for the proceedings of the HFM 2008
conferenc
Ă–kologischer Anbau von Zierpflanzen und Baumschulerzeugnissen - Struktur, Entwicklung, Probleme, politischer Handlungsbedarf
In the Federal Organic Farming Scheme Project "Organic production of ornamental plants and nursery trees - structure of the industry, development, problems and required policy initiatives“a quantitative and qualitative survey of certified organic and conventional / integrated nurseries was carried out. The aim was to assess the current status of production and marketing of organic ornamentals in Germany and to provide an overview of the general framework of this industry.
• Currently approximately 1 % of the nurseries producing ornamentals in Germany are organic. Considering the small scale of many of the organic units, the share of total sales (2.4 billion Euro or 7.6 % of agricultural production in 2001) is likely to be lower.
• Field and greenhouse production of organic annuals and perennials constitutes an estimated 56 ha and 12 ha, respectively. Organic field and container production of trees and shrubs constitutes an estimated 370 ha and 7 ha, respectively.
• 90% of the organic nurseries surveyed would choose organic production again, if faced with the question of conversion a second time.
• Fewer problems than anticipated were encountered in production - even in pest and disease management. However, problems persist in weed control and continuity of nutrient supply from the growing media. Other challenges were the sourcing of organically acceptable inputs (such as seedlings or growing media) in the production of annuals and perennials. In tree nurseries especially the decline in plant vigour caused by the common practice of successive planting of rosaceae raised difficulties.
• Marketing was quoted to be the biggest problem for nurseries which engage in direct marketing. Wholesalers anticipated the biggest problems with the continuity and consistency of the supply of quality product.
• The majority of organic operations surveyed encountered financial difficulties during the conversion period and afterwards.
• 32 % of growers from integrated operations have already considered organic production, but have - for economic reasons - not pursued this idea further.
• The operations surveyed noted that organic standards need expansion and revisions to cover their industry; and that organic inspectors were lacking sufficient technical knowledge. State subsidies for organic ornamental nurseries were found to be inconsistent between the member states of the Federal Republic of Germany.
• A high need for an organic advisory service for these types of operations was indicated, but has not been sufficiently met to date. Further, there was almost no research about the organic production of ornamentals.
Conclusion
Organic production of ornamentals, trees and shrubs is technically feasible - but for further development this sector requires improvement of the basic conditions such as market structure, advisory services, subsidies and research activities
Resonances of the systems \pi-\eta and \pi-\eta' in the reactions \pi-p --> \pi-\eta p and \pi-p --> \pi-\eta' p at COMPASS
We describe partial-wave analyses of the systems \pi-\eta and \pi-\eta'
produced in interactions of a \pi- beam (190 GeV/c) with a liquid hydrogen
target. The data were recorded during the 2008 COMPASS run, where a slow
recoiling proton (|t|>0.1 GeV^2) was required by the trigger. We compare
analyses of the \pi-\eta and \pi-\eta' data. Significant contributions can be
attributed to the resonances a_2(1320), observed in the D_+-wave, and
a_4(2040), observed in the G_+-wave. Between the two systems, we find similar
compositions of the even partial waves D_+ and G_+ after taking phase-space
factors into account, but a much enhanced P_+-wave in \pi-\eta'. Relative
phase-differences indicate a large incoherent contribution of in the P_+-wave
of the \eta'\pi- system, but other interpretations are not excluded. The known
resonances a_2(1320), a_4(2040) and their parameters could be extracted from
the data; their branchings are found to roughly agree with predictions from
\eta\eta' mixing.Comment: Proceedings of the Sixth International Conference on Quarks and
Nuclear Physics (QNP2012), 7 pages. PoS(QNP2012)074, deviates from version in
proceedings by including arXiv hyperlinks in bibliograph
The impact of celestial pole offset modelling on VLBI UT1 Intensive results
Very Long Baseline Interferometry (VLBI) Intensive sessions are scheduled to
provide operational Universal Time (UT1) determinations with low latency. UT1
estimates obtained from these observations heavily depend on the model of the
celestial pole motion used during data processing. However, even the most
accurate precession-nutation model, IAU 2000/2006, is not accurate enough to
realize the full potential of VLBI observations. To achieve the highest
possible accuracy in UT1 estimates, a celestial pole offset (CPO), which is the
difference between the actual and modelled precession-nutation angles, should
be applied. Three CPO models are currently available for users. In this paper,
these models have been tested and the differences between UT1 estimates
obtained with those models are investigated. It has been shown that neglecting
CPO modelling during VLBI UT1 Intensive processing causes systematic errors in
UT1 series of up to 20 microarcseconds. It has been also found that using
different CPO models causes the differences in UT1 estimates reaching 10
microarcseconds. Obtained results are applicable to the satellite data
processing as well.Comment: 8 pp., accepted for publication in Journal of Geodes
Temperature dependence of the chemical sputtering of amorphous hydrogenated carbon films by hydrogen
Angular Correlations in Internal Pair Conversion of Aligned Heavy Nuclei
We calculate the spatial correlation of electrons and positrons emitted by
internal pair conversion of Coulomb excited nuclei in heavy ion collisions. The
alignment or polarization of the nucleus results in an anisotropic emission of
the electron-positron pairs which is closely related to the anisotropic
emission of -rays. However, the angular correlation in the case of
internal pair conversion exhibits diverse patterns. This might be relevant when
investigating atomic processes in heavy-ion collisions performed at the Coulomb
barrier.Comment: 27 pages + 6 eps figures, uses revtex.sty and epsf.sty,
tar-compressed and uuencoded with uufile
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