9,431 research outputs found

    The European Market for Organic Products: Growth and Development

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    The European Market for organic food has been growing rapidly in terms of both supply and demand during the 1990s. However, national markets develop in many different directions. In some countries the market share ist quiet high while in others a market for organic farming products nearly does not exist. This book detects and compares the national markets of the main organic products in 18 European countries - the 15 EU countries plus Switzerland, Norway and the Czech Republic - on the basis of the most comprehensive collection of data ever presented covering the period 1993 - 1997/1998. It is shown that European demand is far from being satisfied and the major efforts in organising a transparent international market and developing marketing strategies is necessary to realise this potential. This book is aimed at policy makers, the private sector, researchers and students in the field of economics and politics of organic farming

    Ellipsoidal Coulomb Crystals in a Linear Radiofrequency Trap

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    A static quadrupole potential breaks the cylindrical symmetry of the effective potential of a linear rf trap. For a one-component fluid plasma at low temperature, the resulting equilibrium charge distribution is predicted to be an ellipsoid. We have produced laser-cooled Be+^+ ellipsoidal ion crystals and found good agreement between their shapes and the cold fluid prediction. In two-species mixtures, containing Be+^+ and sympathetically cooled ions of lower mass, a sufficiently strong static quadrupole potential produces a spatial separation of the species.Comment: 4 pages, 3 figure

    Myomectomy as a pregnancy-preserving option in the carefully selected patient

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    Objectives: To present the indications for myomectomy during pregnancy and to discuss complications possibly related and unrelated to the procedure. Method and Results: A 33-year-old patient at 18 weeks of gestation underwent removal of a 1,570-gram symptomatic fundic myoma. Histologically the patient had a leiomyomatous neoplasm of uncertain malignant potential. The pregnancy was continued under sequential observation with magnetic resonance imaging and ultrasound. At 36 weeks of gestation a healthy girl with an upper extremity limb defect was born via cesarean section. Follow-up of the mother and the child was uneventful. Conclusions: Certain known risk factors in pregnant women with myomas can predispose to complications during pregnancy. Women with such risk factors or women who have failed medical therapy should be offered the option of undergoing myomectomy as a pregnancy-preserving procedure. Copyright (C) 2002 S. Karger AG, Basel

    Sympathetic cooling of 4^4He+^+ ions in a radiofrequency trap

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    We have generated Coulomb crystals of ultracold 4^4He+^+ ions in a linear radiofrequency trap, by sympathetic cooling via laser--cooled 9^9Be+^+. Stable crystals containing up to 150 localized He+^+ ions at ∼\sim20 mK were obtained. Ensembles or single ultracold He+^+ ions open up interesting perspectives for performing precision tests of QED and measurements of nuclear radii. The present work also indicates the feasibility of cooling and crystallizing highly charged atomic ions using 9^9Be+^+ as coolant.Comment: 4 pages, 2 figure

    Itinerant-electron Ferromagnetism in W(Nb)O3-d

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    The crystal structure and the magnetic properties of the W1-xNbxO3-d, (x<0.03) system have been investigated. In contrast to the orthorhombic diamagnetic WO3, the material with x=0.01 is paramagnetic down to 5 K. Introducing of 2.5 at. % of Nb into WO3 leads to a tetragonal structure and to a weak itinerant ferromagnetic ordering below TC= 225 K. The saturation magnetic moment at 5 K is 1.07*10-3 mB, whereas the paramagnetic effective moment is 0.06 mB per mole. This high ratio indicates itinerant ferromagnetism in W0.975Nb0.025O3-d.Comment: accepted to Physica

    Study of storm weather situations in observation and ECHAM3/T42 model simulation

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    In this paper, we provide an estimation of the seasonal distribution of strong wind and storm weather situations in an ECHAM3/T42 climate model simulation in relation to observed conditions. Observational data of the German Eight and the southern Baltic Sea are taken to compare observations and climate model simulation. The results of the study show significant differences in the seasonal Frequency of occurrence for strong wind and storm weather situations between simulation and observations. A new objective classification routine for detecting single strong wind and storm weather situations (Bft 7 and more) in coarse resolution models is used to validate the large-scale parameters of those events in the climate simulation. The objective classification routine is able to detect strong wind and storm weather situations of two flow regimes in the German Eight in winter. The routine is applied to the ECMWF Re-Analysis (T42 resolution) and to a climate simulation of the northern Hemisphere, which was performed with the ECHAM3/T42. It is shown that the large-scale parameters of single strong wind and storm weather situations are simulated quire realistically in the ECHAM3/T42

    Magnon Heat Conductivity and Mean Free Paths in Two-Leg Spin Ladders: A Model-Independent Determination

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    The magnon thermal conductivity κmag\kappa_{\mathrm{mag}} of the spin ladders in Sr14Cu24−xZnxO41\rm Sr_{14}Cu_{24-x}Zn_xO_{41} has been investigated at low doping levels x=0x=0, 0.125, 0.25, 0.5 and 0.75. The Zn-impurities generate nonmagnetic defects which define an upper limit for lmagl_{\mathrm{mag}} and therefore allow a clear-cut relation between lmagl_{\mathrm{mag}} and κmag\kappa_{\mathrm{mag}} to be established independently of any model. Over a large temperature range we observe a progressive suppression of κmag\kappa_{\mathrm{mag}} with increasing Zn-content and find in particular that with respect to pure Sr14Cu24O41\rm Sr_{14}Cu_{24}O_{41} κmag\kappa_{\mathrm{mag}} is strongly suppressed even in the case of tiny impurity densities where lmag≲374l_{\mathrm{mag}}\lesssim 374~{\AA}. This shows unambiguously that large lmag≈3000l_{\mathrm{mag}}\approx 3000~{\AA} which have been reported for Sr14Cu24O41\rm Sr_{14}Cu_{24}O_{41} and La5Ca9Cu24O41\rm La_{5}Ca_9Cu_{24}O_{41} on basis of a kinetic model are in the correct order of magnitude

    Multi-channel ground-penetrating radar to explore spatial variations in thaw depth and moisture content in the active layer of a permafrost site

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    Multi-channel ground-penetrating radar (GPR) was applied at a permafrost site on the Tibetan Plateau to investigate the influence of surface properties and soil texture on the late-summer thaw depth and average soil moisture content of the active layer. Measurements were conducted on an approximately 85 × 60 m&lt;sup&gt;2&lt;/sup&gt; sized area with surface and soil textural properties that ranged from medium to coarse textured bare soil to finer textured, sparsely vegetated areas covered with fine, wind blown sand, and it included the bed of a gravel road. The survey allowed a clear differentiation of the various units. It showed (i) a shallow thaw depth and low average soil moisture content below the sand-covered, vegetated area, (ii) an intermediate thaw depth and high average soil moisture content along the gravel road, and (iii) an intermediate to deep thaw depth and low to intermediate average soil moisture content in the bare soil terrain. From our measurements, we found hypotheses for the permafrost processes at this site leading to the observed late-summer thaw depth and soil moisture conditions. The study clearly indicates the complicated interactions between surface and subsurface state variables and processes in this environment. Multi-channel GPR is an operational technology to efficiently study such a system at scales varying from a few meters to a few kilometers
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