402 research outputs found

    Marginalia and commentaries in the papyri of Euripides, Sophocles and Aristophanes

    Get PDF
    The purpose of the thesis is to examine a selection of papyri from the large corpus of Euripides, Sophocles and Aristophanes. The study of the texts has been divided into three major chapters where each one of the selected papyri is first reproduced and then discussed. The transcription follows the original publication whereas any possible textual improvement is included in the commentary. The commentary also contains a general description of the papyrus (date, layout and content) as well reference to special characteristics. The structure of the commentary is not identical for marginalia and hypomnemata: the former are examined in relation to their position round the main text and are treated both as individual notes and as a group conveying the annotator's aims. The latter are examined lemma by lemma with more emphasis upon their origins and later appearances in scholia and lexica. After the study of the papyri follows an essay which summarizes the results and tries to incorporate them into the wider context of the history of the text of each author and the scholarly attention that this received by the Alexandrian scholars or later grammarians. The main effort is to place each papyrus into one of the various stages that scholarly exegesis passed especially in late antiquity. Special treatment has been given to P.Wurzburg 1, the importance of which made it necessary that it occupies a chapter by itself. The last chapter of the thesis deals with the issue of glosses, namely their origin and use in the margins of papyri. The focus is again on the history of early collections of tragic and comic vocabulary and their appearance in the margins or hypomnemata. The parallel circulation of hypomnemata and glossaries often compiled by the same people and some special features of the glosses in our material led to the conclusion that most glosses at least in the earlier periods were copied from hypomnemata. The thesis ends with a presentation of all conclusions from the previous chapters in relation to the history of scholarship and book production in late antiquit

    Photochemical synthesis: Effect of UV irradiation on gold nanorods morphology

    Get PDF
    Abstract Gold nanorods (AuNRs) were synthesized by photochemical method, through irradiation of a reaction solution, containing gold precursor, surfactant and a mild reducing agent to speed up the process. The effects of the irradiation parameters on the morphology of the formed AuNRs were investigated by UV–Vis absorption spectra and transmission electron microscopy. Specifically, the control of the UV irradiance (irradiation power per unit area) and irradiation time allowed the preparation of AuNRs with a wide range of sizes. Increase of the irradiation power leads to the formation of smaller AuNRs, with concomitant decrease of length and diameter. Since both axes show a simultaneous size decrease, the produced AuNRs have increased aspect ratio. Overall we show that application of high UV irradiance for short times favors the synthesis of small AuNRs with increased anisotropy. We propose that the rise of the irradiation power primarily accelerates the reduction of the gold precursor, promoting in such way the formation of smaller seeds. Short irradiation times guard against dissolution effects on the formed nanorods

    Plasmonic polyaniline/gold nanorods hybrid composites for selective NIR photodetection: Synthesis and characterization

    Get PDF
    Abstract In this study, we present the development of polyaniline/gold nanorod nanocomposites and the effect of the nanorods' aspect ratio and concentration on the overall electrical conductivity of nanocomposite systems. The electrical characterization showed that at the same atomic gold concentration, the conductivity of the nanocomposites increased by about 14% after increasing the gold nanorods' aspect ratio from 2.9 to 3.8. Furthermore, the conductivity of the nanocomposites increases linearly with the concentration of atomic gold, keeping the nanorods' aspect ratio stable, due to increasing the metallic content. The interaction between polyaniline and gold nanorods was investigated by FTIR, micro Raman, and XPS spectroscopic techniques, indicating the delocalization of the charges across the polymer chains induced by the incorporation of the nanorods. The interaction most likely occurs through the imine nitrogen of the polymer's backbone. The homogenous distribution of the gold nanorods in the polyaniline matrix was verified by TEM. Furthermore, the selective photosensitivity of the developed nanocomposites to NIR light was examined, and an increase in their current density was detected when the nanocomposites were irradiated at the wavelength that coincides with the longitudinal plasmonic resonance absorption of the incorporated nanorods. We foresee applications of the developed nanocomposites in numerous optoelectronic sectors

    Advanced piezoresistance of extended metal/insulator core shell nanoparticle assemblies

    Full text link
    Assembled metal/insulator nanoparticles with a core/shell geometry provide access to materials containing a large number (>106) of tunneling barriers. We demonstrate the production of ceramic coated metal nanoparticles exhibiting an exceptional pressure sensitive conductivity. We further show that graphene bi- and trilayers on 20 nm copper nanoparticles are insulating in such core/shell geometry and show a similar pressure dependent conductivity. This demonstrates that core/shell metal/insulator assemblies offer a route to alternative sensing materials.Comment: 14 pages, 3 figures, published in Physical Review Letter

    Insecticidal action of the combined use of spinosad and deltamethrin against three storedproduct pests in two stored hard-wheat varieties.

    Get PDF
    The combined use of spinosad with deltamethrin against adults of Sitophilus oryzae, Sitophilus granarius and Tribolium confusum was evaluated in a series of laboratory bioassays in two hard wheat varieties (Athos and Sifnos). Two groups of bioassays were carried out. In the first group of bioassays, spinosad or deltamethrin were applied alone at the tested wheat varieties at the doses of 0.01, 0.1 and 0.5 ppm for spinosad and 0.125 ppm for deltamethrin. In the second group of bioassays, the tested wheat varieties were treated with the combination of the above spinosad rates with 0.125 of deltamethrin. In both series of bioassays, mortality of the tested species was evaluated after 7 d of exposure on the treated wheat varieties at 25oC and 65% r.h. Mortality for all species was always significantly higher in Athos than Sifnos. The highest mortality of S. oryzae (73 and 40% for Athos and Sifnos respectively) or S. granarius (88% and 58% for Athos and Sifnos respectively) was recorded in the cases that spinosad was applied alone at 0.5 ppm. On the contrary, in the case of T. confusum, 0.125 ppm of deltamethrin was significantly more effective than any of the application rates of spinosad either when applied alone or in combination with deltamethrin. Despite the fact that the highest mortality of S. granarius adults was recorded after exposure on the wheat varieties treated with 0.1 ppm of spinosad x 0.125 ppm of deltamethrin, in light of the results of the present study, the combination of spinosad with deltmethrin requires further investigation since in most of the tested cases of the present study, single application of spinosad or deltamethrin was more effective or of equal effectiveness than the respective combination of spinosad with deltamethrin. Keywords: Spinosad, Deltamethrin, Tribolium, Sitophilus, Wheat, Variet

    Mortality and suppression of progeny production of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) in seven different grains treated with an enhanced diatomaceous earth formulation

    Get PDF
    DEBBM, an enhanced diatomaceous earth (DE) formulation consisting of a mixture of DE and the plant extract bitterbarkomycin, was applied to seven different grains (wheat, barley, oats, rye, triticale, paddy rice and maize) at two dose rates 50 ppm and 150 ppm. Unsexed, 7d old adults of Sitophilus oryzae (Coleoptera: Curculionidae) and Tribolium confusum (Coleoptera: Tenebrionidae) were exposed to the DEBBM treated commodities and their mortality was assessed after 7d and 14d of exposure at 25 oC and 65% r.h. Furthermore, progeny production of the tested species per treated commodity was also assessed. Sitophilus oryzae appeared to be more susceptible than T. confusum to DEBBM. Performance of DEBBM was better in barley, wheat and oats compared to the remainder of the tested commodities. DEBBM performed better in rye and triticale than in paddy rice against both species although in many cases, significant differences among these grains were not recorded. Despite that DEBBM reached its highest efficacy levels on barley, wheat, and oats it did not suppress progeny production of the treated species in any of the grains. A significant reduction in progeny production of the treated species was recorded in the DEBBM treated grains in comparison with the untreated ones. This reduction in progeny production was expressed more vigorously to S. oryzae rather than T. confusum. In commodities with high DEBBM performance such as barley, oats or wheat, > 9-fold less progeny of S. oryzae were recorded at 150 ppm of DEBBM than in the untreated commodities. Although significantly less progeny of T. confusum were recorded in DEBBM treated grains than untreated grains, progeny suppression of this species was neither dose nor commodity dependant. Keywords: Diatomaceous earth, Bitterbarkomycin, Tribolium, Sitophilus, Mortality, Commodit

    Effect of precursor solution dark incubation on gold nanorods morphology

    Get PDF
    Abstract Gold nanorods were synthesized in an aqueous solution of hexadecyltrimethylammonium bromide via a combination of chemical reduction and UV photoirradiation. Gold ligand complexes, present in the stock solution, are initially reduced, by ascorbic acid as mild reducing agent. The gold ions nucleation and colloid growth proceeds then by subsequent UV irradiation of the so-obtained precursor solution. We present a systematic study of the effect of incubation of the precursor solution on the dispersion state and aspect ratio of the produced nanorods. Incubation of the precursor solution allows the synthesis of higher aspect ratio nanorods with narrower size distribution compared to those obtained without incubation. We propose a mechanism for the gold nanorods formation including two stages, a nucleation and a diffusive growth. This allows us to explain the synthesis improvement as a consequence of the increase in the size of the gold ligand complexes aggregates, leading to a decrease of the nanorods growth rate

    Efficacy of Modified Atmospheres on Trogoderma granarium (Coleoptera: Dermestidae) and Sitophilus zeamais (Coleoptera: Curculionidae)

    Get PDF
    We investigated the efficacy of two types of modified atmospheres (MA) against adults of the khapra beetle, Trogoderma granarium Everts, and the maize weevil, Sitophilus zeamais Motschulsky, under laboratory conditions. Adults of the above species on wheat were exposed to a carbon dioxide (CO2) concentration of 70% or a low oxygen (O2) concentration of 0.1% for durations of 0.67 (16 h), 1, 2, 4, and 6 d and stored in an environmental chamber set at 28 ± 2°C, 70 ± 5% RH, and a photoperiod of 16:8 (L:D) h. After each exposure interval, immediate mortality and knockdown were recorded, and the surviving or knocked down individuals were transferred to normal atmospheres and returned to the environmental chamber, where survival was recorded 7 d later. In addition, after the immediate and delayed mortality counts, all adults were removed from the substrate, and the number of progeny produced was recorded 60 d later. Both MA conditions totally controlled (100% mortality) the adults of T. granarium and S. zeamais immediately after a 6-d exposure or after a 4-d exposure when delayed mortality was taken into account, showing the postexposure effect of the MA. Moreover, high CO2 was more effective than low O2 for S. zeamais, whereas the reverse was true for T. granarium. The 4-d exposure period was crucial for the production of progeny of both species because after that period surviving insects did not produce offspring. Our results show that both MA conditions can be used with success to control these species.info:eu-repo/semantics/acceptedVersio

    Top Management Team Diversity: A systematic Review

    Get PDF
    Empirical research investigating the impact of top management team (TMT) diversity on executives’ decision making has produced inconclusive results. To synthesize and aggregate the results on the diversity-performance link, a meta-regression analysis (MRA) is conducted. It integrates more than 200 estimates from 53 empirical studies investigating TMT diversity and its impact on the quality of executives’ decision making as reflected in corporate performance. The analysis contributes to the literature by theoretically discussing and empirically examining the effects of TMT diversity on corporate performance. Our results do not show a link between TMT diversity and performance but provide evidence for publication bias. Thus, the findings raise doubts on the impact of TMT diversity on performance
    • …
    corecore