1,553 research outputs found

    Nanotechnology research in Turkey: A university-driven achievement

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    We deal with nanotechnology research activities in Turkey. Based on publication data retrieved from ISI Web of SSCI database, the main actors and the main characteristics of nanotechnology research in Turkey are identified. Following a brief introduction to nanoscience and nanotechnology research, it goes on with a discussion on nanotechnology related science and technology policy efforts in developing countries and particularly in Turkey. Then using bibliometric methods and social network analysis techniques, this paper aims to understand the main actors of the nanoscale research in Turkey and how they collaborate across institutes and disciplines. The research indicates that there has been an exponential growth in the number of research articles published by Turkish nanoscience and nanotechnology (NST) scholars for the last ten years. However, the analysis of the main characteristics of nanotechnology research carried out at Turkish universities indicates some drawbacks and barriers to the future development of nanotechnology research in Turkey. These barriers are (i) a high concentration of nanoscale research at certain universities; (ii) low level of interdisciplinarity; (iii) a large number of universities which are not well connected to other universities in the field, and finally (iv) low level of international collaborations. Finally, science and technology policy implications of this research are discussed in the conclusion.Emerging technologies nanotechnology, nanoscience, scientific publications, SSCI, bibliometric data, social network analysis, collaborations, interdisciplinarity, science and technology policies, emerging economies, Turkey.

    Spatially resolving the atmosphere of the non-Mira-type AGB star SW Vir in near-infrared molecular and atomic lines with VLTI/AMBER

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    We present a near-infrared spectro-interferometric observation of the non-Mira-type, semiregular asymptotic giant branch star SW Vir. Our aim is to probe the physical properties of the outer atmosphere with spatially resolved data in individual molecular and atomic lines. We observed SW Vir in the spectral window between 2.28 and 2.31 micron with the near-infrared interferometric instrument AMBER at ESO's Very Large Telescope Interferometer (VLTI). Thanks to AMBER's high spatial resolution and high spectral resolution of 12000, the atmosphere of SW Vir has been spatially resolved not only in strong CO first overtone lines but also in weak molecular and atomic lines of H2O, CN, HF, Ti, Fe, Mg, and Ca. Comparison with the MARCS photospheric models reveals that the star appears larger than predicted by the hydrostatic models not only in the CO lines but also even in the weak molecular and atomic lines. We found that this is primarily due to the H2O lines (but also possibly due to the HF and Ti lines) originating in the extended outer atmosphere. Although the H2O lines manifest themselves very little in the spatially unresolved spectrum, the individual rovibrational H2O lines from the outer atmosphere can be identified in the spectro-interferometric data. Our modeling suggests an H2O column density of 10^{19}--10^{20} cm^{-2} in the outer atmosphere extending out to ~2 Rstar. Our study has revealed that the effects of the nonphotospheric outer atmosphere are present in the spectro-interferometric data not only in the strong CO first overtone lines but also in the weak molecular and atomic lines. Therefore, analyses of spatially unresolved spectra, such as for example analyses of the chemical composition, should be carried out with care even if the lines appear to be weak.Comment: 8 pages, 6 figures, accepted for publication in Astronomy and Astrophysic

    Individual and Organizational Aspects of University-Industry Relations in Nanotechnology: The Turkish Case

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    Emerging nanotechnologies bring a new challenge for developing countries to improve knowledge and technology transfer between universities and firms. In developing countries, weaker ties between academia and the industry seem to be one of the main barriers to the dissemination of nanotechnology innovations. This study aims to understand individual and organizational factors affecting university-industry interactions in emerging nanotechnologies in a developing country context, namely Turkey. For this study, 181 questionnaires were collected from a sample of nano-science and nanotechnology academics who are currently employed by Turkish universities. The results provide that informal / interpersonal and research-related interactions are the most common forms of relationship between academics and firms. On the other hand, the study provides a useful insight to understand how human and social capitals of university-scientists as well as organizational resources/ capabilities influence the formation of links between universities and the industry.Nanotechnology, nanoscience, emerging technologies, technology transfer, university-industry relations, science and technology policies, probit model, disproportionate stratified sampling, emerging economies, Turkey.

    Classifying continuous, real-time e-nose sensor data using a bio-inspired spiking network modelled on the insect olfactory system

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    In many application domains, conventional e-noses are frequently outperformed in both speed and accuracy by their biological counterparts. Exploring potential bio-inspired improvements, we note a number of neuronal network models have demonstrated some success in classifying static datasets by abstracting the insect olfactory system. However, these designs remain largely unproven in practical settings, where sensor data is real-time, continuous, potentially noisy, lacks a precise onset signal and accurate classification requires the inclusion of temporal aspects into the feature set. This investigation therefore seeks to inform and develop the potential and suitability of biomimetic classifiers for use with typical real-world sensor data. Taking a generic classifier design inspired by the inhibition and competition in the insect antennal lobe, we apply it to identifying 20 individual chemical odours from the timeseries of responses of metal oxide sensors. We show that four out of twelve available sensors and the first 30 s(10%) of the sensors’ continuous response are sufficient to deliver 92% accurate classification without access to an odour onset signal. In contrast to previous approaches, once training is complete, sensor signals can be fed continuously into the classifier without requiring discretization. We conclude that for continuous data there may be a conceptual advantage in using spiking networks, in particular where time is an essential component of computation. Classification was achieved in real time using a GPU-accelerated spiking neural network simulator developed in our group

    Effect of Oestradiol Administration on Rat Submandibular Gland after Ovariectomized Period

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    In this study, we aimed to investigate exogen estrogen on submandibulargland of adult ovariectomized rats. To this end, thirty-six virgin female WistarAlbino rats were used and were divided into three equal groups. Sham groupsreceived no treatment, all animals in the other two groups were bilaterallyovariectomized. Control groups was designated bilaterally ovariectomized andoestradiol was given application groups.Following the applications all animals were sacrified,then submandibulargland was excised and paraffin wax. Paraffin sections, obtained by routinehistologic methods, were cut at 5Îźm and stained with Hematoxilen-Eozin. Thestained sections were later evaluated under a light microscopy.Histological studies indicated that, after oestrogen deficiency period, theglandular parenchyma and stroma was destroyed. When oestrogen was givenexogenously, it was seen that after ovariectomy, the gland was partially improved.These data demonstrate that oestrogen deficiency play a role in rat of thesubmandibular gland. Exogenous oestrogen leads to partial improvement andoestrogen deficiency doesnt lead to changes of the gland. Exogenous oestrogendoes not completely prevent submandibular gland structur

    Measurement of the neutron electric dipole moment via spin rotation in a non-centrosymmetric crystal

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    We have measured the neutron electric dipole moment using spin rotation in a non-centrosymmetric crystal. Our result is d_n = (2.5 +- 6.5(stat) +- 5.5(syst)) 10^{-24} e cm. The dominating contribution to the systematic uncertainty is statistical in nature and will reduce with improved statistics. The statistical sensitivity can be increased to 2 10^{-26} e cm in 100 days data taking with an improved setup. We state technical requirements for a systematic uncertainty at the same level.Comment: submitted to Phys. Lett.

    Drosophila olfactory receptors as classifiers for volatiles from disparate real world applications

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    Olfactory receptors evolved to provide animals with ecologically and behaviourally relevant information. The resulting extreme sensitivity and discrimination has proven useful to humans, who have therefore co-opted some animals' sense of smell. One aim of machine olfaction research is to replace the use of animal noses and one avenue of such research aims to incorporate olfactory receptors into artificial noses. Here, we investigate how well the olfactory receptors of the fruit fly, Drosophila melanogaster, perform in classifying volatile odourants that they would not normally encounter. We collected a large number of in vivo recordings from individual Drosophila olfactory receptor neurons in response to an ecologically relevant set of 36 chemicals related to wine ('wine set') and an ecologically irrelevant set of 35 chemicals related to chemical hazards ('industrial set'), each chemical at a single concentration. Resampled response sets were used to classify the chemicals against all others within each set, using a standard linear support vector machine classifier and a wrapper approach. Drosophila receptors appear highly capable of distinguishing chemicals that they have not evolved to process. In contrast to previous work with metal oxide sensors, Drosophila receptors achieved the best recognition accuracy if the outputs of all 20 receptor types were used
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