69 research outputs found

    Resonant spin-dependent electron coupling in a III-V/II-VI heterovalent double quantum well

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    We report on design, fabrication, and magnetooptical studies of a III-V/II-VI hybrid structure containing a GaAs/AlGaAs/ZnSe/ZnCdMnSe double quantum well (QW). The structure design allows one to tune the QW levels into the resonance, thus facilitating penetration of the electron wave function from the diluted magnetic semiconductor ZnCdMnSe QW into the nonmagnetic GaAs QW and vice versa. Magneto-photoluminescence studies demonstrate level anticrossing and strong intermixing resulting in a drastic renormalization of the electron effective g factor, in perfect agreement with the energy level calculations.Comment: 4 pages, 5 Postscript figures, uses revtex

    The influence of LiF layer abd ZnO nanoparticels addings on the performances of flexible photovoltaic cells based on polymer blends

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    International audienceFlexible organic solar cells were successfully prepared using spin-coating technique on PET substrates covered with a thick layer of ITO. The goal of this study is to identify the effects of the LiF layer and ZnO nanoparticles mixing in PEDOT:PSS solution and to compare the photovoltaic properties of these „customized” cells PET/ITO/PEDOT:PSS + ZnO nanoparticles/P3HT:PCBM(1:1)/Al, PET/ITO/PEDOT:PSS + ZnO nanoparticles/P3HT:PCBM(1:1)/LiF/Al, with ones of the “conventional” structures, PET/ITO/PEDOT:PSS/P3HT:PCBM(1:1)/Al. The thickness of the LiF layer, deposited by thermal vacuum evaporation, was two nanometers. Composite samples were prepared by adding ZnO nanoparticles into PEDOT:PSS solution, followed by ultrasonication. I-V characteristics were measured in dark and under A.M.1.5 conditions for all samples immediately and after one month from the preparation date. The action spectra measurements revealed that the structures which have a nanometric LiF layer are more stable than those without. Photoelectrical measurements indicate that the ZnO nanoparticles have a positive influence on the conversion efficiency and also to reduce the serial resistance of the structure

    Extreme Energy Cosmic Rays (EECR) Observation Capabilities of an "Airwatch from Space'' Mission

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    The longitudinal development and other characteristics of the EECR induced atmospheric showers can be studied from space by detecting the fluorescence light induced in the atmospheric nitrogen. According to the Airwatch concept a single fast detector can be used for measuring both intensity and time development of the streak of fluorescence light produced by the atmospheric shower induced by an EECR. In the present communication the detection capabilities for the EECR observation from space are discussed.Comment: 3 pages (LaTeX). To appear in the Proceedings of TAUP'9

    HbA1c levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions

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    Aims/hypothesis: We evaluated seasonal HbA1c_{1c} changes in children with type 1 diabetes and its relation with measures of weather conditions. Methods: HbA1c_{1c} changes over more than 3 years were evaluated in type 1 diabetic patients who were younger than 18 years and had diabetes duration of more than 12 months, and correlated with measures of weather conditions (ambient temperature, hours of sunshine and solar irradiance). After comparison of autocorrelation patterns, patterns of metabolic control and meteorological data were evaluated using Spearman rank correlation. Results: A total of 3,935 HbA1c_{1c} measurements in 589 school (≄7 years) and 88 preschool (<7 years) children were analysed. Mean (±SD) HbA1c_{1c} level for the whole study period was 7.65±1.12%. The lowest HbA1c_{1c} levels were observed in late summer and the highest in winter months, with differences consistently exceeding 0.44%. Autocorrelation analysis of HbA1c_{1c} levels in schoolchildren showed a sine-wave pattern with a cycle length of roughly 12 months, which mirrored changes in ambient temperature. Strong negative correlations of HbA1c_{1c} with ambient temperature (R=−0.56; p=0.0002), hours of sunshine (R=−0.52; p=0.0007) and solar irradiance (R=−0.52; p=0.0006) were present in schoolchildren, but not in preschoolers (p≄0.29 for each correlation). Conclusions/interpretation: Seasonal changes of HbA1c_{1c} levels in schoolchildren with type 1 diabetes are a significant phenomenon and should be considered in patient education and diabetes management. They may potentially affect the results of clinical trials using HbA1c_{1c} levels as their primary outcome, as well as HbA1c_{1c}-based diagnosis of diabetes

    Influence of solid-state microstructure on the electronic performance of 5,11-Bis(triethylsilylethynyl) anthradithiophene

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    The rich phase behavior of 5,11-bis(triethylsilylethynyl) anthradithiophene (TES ADT) - one of the most promising, solution-processable small-molecular organic semiconductors - is analyzed, revealing the highest performing polymorph among four solid-state phases, opening pathways toward the reliable fabrication of high-performance bottom-gate/bottom-contact transistors.We are very grateful to the UK’s Engineering and Physical Sciences Research Council, the Dutch Polymer Institute (LATFE programme), and the ACS Petroleum Fund (New Directions Proposal) for financial support. We in addition acknowledge the EC’s seventh Framework Program ONE-P project (Grant Agreement 212311) for funding. N.S. is in addition supported by a European Research Council (ERC) Starting Independent Researcher Fellowship, under the grant agreement No. 279587. G.B. and E.P. acknowledges support from the ESF Project GOSPEL (Ref Nr: 09-EuroGRAPHENE-FP-001. G.B. acknowledges support from the Slovenian Research Agency, program P1-0055. N.W.O. is acknowledged for granting the beamtime at BM26B. J.E.A. acknowledges the Office of Naval Research for their support of the synthesis of organic semiconductor materials. G.B. and E.P. acknowledges support from the ESF Project GOSPEL (Ref Nr: 09-EuroGRAPHENE-FP-001). G.B. acknowledges support from the Slovenian Research Agency, program P1-0055

    IS MILTON BENNETT'S MODEL OF INTER CULTURAL SENSITIVITY REALLY INTER CULTURAL?

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    Abstract. Milton Bennett's model of inter cultural sensitivity development is one of the most common and acknowledged models in non-formal education and training. Partially being based on its author's personal overseas living and working experience (US Peace Corps volunteer in Micronesia from 1968-1970 and fifteen years of teaching and training experience in inter cultural communication), it resides theoretically on wider phenomenological approach to the construction of different cultural meanings. The founding hypothesis of the model in question is dynamical. Cultural differences are understood not as posited but as constructed processes and therefore may be subjected to further development. It an ideal case, it is presupposed that development occurs beginning from stage of an utter ethnocentrism and moves forward towards an ultimate ethno-relativistical point of view. The latter stage is reflected in cultural and moral relativism, as well as in capability for fully intentional, (auto-)reflexive empathy. Bennett's model designates six stages of inter cultural sensitivity development. These are: 1) denial of cultural differences; 2) defense of the culturally binary world-view; 3) minimization of differences; 4) their acceptance; 5) adaptation; 6) integration of cultural differences into one's own, constructed and ever constructing self. We analyze all of the stages proposed by Bennett, especially concentrating our attention on the final, integrating stage. Founding our argumentation on theoretical reasons, as well as on personal significant overseas living experience, we question the alleged cultural and moral “statelessness” of this stage. Contrary to Bennett's conception, we show that the so-called integrative stage of inter cultural sensitivity is no more than a pseudo-universalistic outgrowth of one specific type of culture

    On the presence of a secondary cartilage in the mental symphyseal region of human embryos and fetuses.

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    The presence of a secondary cartilage in the mental symphyseal region was examined in this study. A double-staining method with alcian blue and alizarin red S was performed on both whole human embryos and fetuses (developmental age between 8 and 17 weeks, crown-rump length, CRL, between 37 and 124 mm) and their disjointed mandibles. Histological and histochemical techniques were applied to transverse serial sections of whole disjointed fetal heads. The ossification process observed in the mental symphysis is quite different from that of the mandibular body, whose membranous ossification is induced by the contiguous Meckel's cartilage. No evidence of any fusion of Meckel's cartilage with the symphyseal cartilage, that lies within the symphyseal space, was detected. On the basis of these findings, we suggested that the mental secondary cartilage is able to change into bone according to an endochondral ossification process. Moreover, the role of mechanical causes in the development of the mental symphysis was hypothesized
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