1,674 research outputs found

    Pre-plant release enhanced the earlier establishment of Nesidiocoris tenuis in open field tomato

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    Ο εχθρός της τομάτας, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) που εισέβαλε στη χώρα μας, πολύ σύντομα έγινε σημαντικός εχθρός τόσο των υπαίθριων όσο και των θερμοκηπιακών καλλιεργειών. Η εξαπόλυση του αρπακτικού Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) στο φυτώριο έχει βρεθεί ότι μπορεί να συμβάλει στην αντιμετώπιση του T. absoluta σε καλλιέργειες τομάτας στο θερμοκήπιο. Ο στόχος της παρούσας μελέτης είναι να αξιολογηθεί κατά πόσο σε υπαίθρια καλλιέργεια τομάτας, η εξαπόλυση του N. Tenuis στο φυτώριο μπορεί να συμβάλει στην έγκαιρη εγκατάστασή του. Συμπερασματικά, η εξαπόλυση του N. tenuis συνέβαλε ουσιαστικά στην έγκαιρη αποίκηση της καλλιέργειας σε σύγκριση με τα τεμάχια του μάρτυρα. Επίσης, ο ρόλος του ιθαγενούς πληθυσμού του M. pygmaeus πρέπει να λαμβάνεται σοβαρά υπόψη στα προγράμματα ολοκληρωμένης αντιμετώπισης. Η μέθοδος αυτή είναι αποτελεσματική στην πιο έγκαιρη εγκατάσταση του N. tenuis και θα πρέπει να αξιολογηθεί περαιτέρω η συμβολή της στην αντιμετώπιση του Τ. absoluta.The invasive pest of the tomato crops, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), soon after its establishment became a major problem of outdoor and greenhouse tomato crops across the Mediterranean countries. The pre-plant release of the predator Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) has been found to substantially contribute to its establishment on the crop and efficient control of T. absoluta in greenhouses. The aim of the current study was to assess whether the pre-plant release of N. tenuis could contribute to its earlier establishment. It was concluded that the release of N. tenuis in the nursery contributed substantially in the earlier increase of its numbers in the field in comparison to the control plots. The native populations of M. pygmaeus appeared on the tomato plants before the native populations of N. tenuis. Thus, the conservation of both predators should be taken into consideration in the integrated management strategies against T. absoluta. Therefore, the application of this method in open field tomato crop enhances the earlier establishment of N. tenuis and should be further evaluated in the control of T. absoluta

    A Detailed XRD and FTIR Analysis of Bi2O3 Doped ZnO-SnO2 Ceramics

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    Poster presented at the 2nd International Congress on Ceramics, Verona, Italy, June 29 - July 4, 200

    Evidences for Tsallis non-extensivity on CMR manganites

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    We found, from the analysis of MM vs. TT curves of some manganese oxides (manganites), that these systems do not follow the traditional Maxwell-Boltzmann statistics, but the Tsallis statistics, within the \QTR{em}{normalized} formalism. Curves were calculated within the mean field approximation, for various ferromagnetic samples and the results were compared to measurements of our own and to various other authors published data, chosen at random from the literature. The agreement between the experimental data and calculated MqM_{q} vs. TT^{\ast} curve, where TT^{\ast} is an effective temperature, is excellent for all the compounds. The entropic parameter, qq, correlates in a simple way with the experimental value of TcT_{c}, irrespect the chemical composition of the compounds, heat treatment or other details on sample preparation. Examples include q<1q<1 (superextensivity), q=1q=1 (extensivity) and q>1q>1 (subextensivity) cases.Comment: 12 pages, 3 figure

    Structure inhomogeneities, shallow defects, and charge transport in the series of thermoelectric materials K2Bi8−xSbxSe13

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    The charge transport properties of the low-dimensional thermoelectric materials K2Bi8-xSbxSe13 (02Bi8-xSbxSe13 was analyzed on the basis of the classical semiconductor theory and discussed in the context of recent band calculations. The results suggest that the K2Bi8-xSbxSe13 materials possess coexisting domains with semimetallic and semiconducting characters whose ratio is influenced by the value of x and by local defects. The extent and relative distribution of these domains control the charge transport properties. Electron diffraction experiments performed on samples of K2Bi8-xSbxSe13 with x=1.6 show evidence for such domains by indicating regions with long range ordering of K+/Bi3+ atoms and regions with increased disorder. The semiconducting behavior is enhanced with increasing x (i.e., Sb/Bi ratio) in the composition through a decrease of the semimetallic fraction

    Interplay of superexchange and orbital degeneracy in Cr-doped LaMnO3

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    We report on structural, magnetic and Electron Spin Resonance (ESR) investigations in the manganite system LaMn_{1-x}Cr_{x}O_{3} (x<=0.5). Upon Cr-doping we observe a reduction of the Jahn-Teller distortion yielding less distorted orthorhombic structures. A transition from the Jahn-Teller distorted O' to the pseudocubic O phase occurs between 0.3<x<0.4. A clear connection between this transition and the doping dependence of the magnetic and ESR properties has been observed. The effective moments determined by ESR seem reduced with respect to the spin-only value of both Mn^{3+} and Cr^{3+} ions
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