7,640 research outputs found

    Flashing LEDs for microalgal production

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    Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production.Foundation for Science and Technology (FCT, Portugal) [CCMAR/Multi/04326/2013]Nord UniversityNordland County Government (project Bioteknologi en framtidsrettet naering)INTERREG V-A Espana-Portugal project [0055 ALGARED + 5E]Portuguese Foundation for Science and Technology [SFRH/BD/105541/2014, SFRH/BD/115325/2016]info:eu-repo/semantics/publishedVersio

    Sparsity-Based Super Resolution for SEM Images

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    The scanning electron microscope (SEM) produces an image of a sample by scanning it with a focused beam of electrons. The electrons interact with the atoms in the sample, which emit secondary electrons that contain information about the surface topography and composition. The sample is scanned by the electron beam point by point, until an image of the surface is formed. Since its invention in 1942, SEMs have become paramount in the discovery and understanding of the nanometer world, and today it is extensively used for both research and in industry. In principle, SEMs can achieve resolution better than one nanometer. However, for many applications, working at sub-nanometer resolution implies an exceedingly large number of scanning points. For exactly this reason, the SEM diagnostics of microelectronic chips is performed either at high resolution (HR) over a small area or at low resolution (LR) while capturing a larger portion of the chip. Here, we employ sparse coding and dictionary learning to algorithmically enhance LR SEM images of microelectronic chips up to the level of the HR images acquired by slow SEM scans, while considerably reducing the noise. Our methodology consists of two steps: an offline stage of learning a joint dictionary from a sequence of LR and HR images of the same region in the chip, followed by a fast-online super-resolution step where the resolution of a new LR image is enhanced. We provide several examples with typical chips used in the microelectronics industry, as well as a statistical study on arbitrary images with characteristic structural features. Conceptually, our method works well when the images have similar characteristics. This work demonstrates that employing sparsity concepts can greatly improve the performance of SEM, thereby considerably increasing the scanning throughput without compromising on analysis quality and resolution.Comment: Final publication available at ACS Nano Letter

    Dilemma that cannot be resolved by biased quantum coin flipping

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    We show that a biased quantum coin flip (QCF) cannot provide the performance of a black-boxed biased coin flip, if it satisfies some fidelity conditions. Although such a QCF satisfies the security conditions of a biased coin flip, it does not realize the ideal functionality, and therefore, does not fulfill the demands for universally composable security. Moreover, through a comparison within a small restricted bias range, we show that an arbitrary QCF is distinguishable from a black-boxed coin flip unless it is unbiased on both sides of parties against insensitive cheating. We also point out the difficulty in developing cheat-sensitive quantum bit commitment in terms of the uncomposability of a QCF.Comment: 5 pages and 1 figure. Accepted versio

    Floristic Structure of Fire Experimental Plots of Olokemeji Forest Reserve, Ogun State, Nigeria

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    Total enumeration of tree species was carried out fire experimental plot of Olokemeji forest reserve for relative importance value (RIV) mean heights, mean diameter at breast height and mean basal area. Three investigative plot (Plot A, B and C) were established. Plot A which represents Early Burn is burnt annually during the dry season while Plot B was burnt annually during the rainy season when the trees are still wet and Plot C serves as the protected area. Gmelina arborea had the highest relative importance value (28.31), this is followed by Dalbergia sissoo which had RIV of 10.94. Plot C recorded the highest frequency of trees with the highest tree heights, this is closely followed by Plot A and Plot B being the plot with the lowest mean height. Plot C has the highest mean diameter at breast height (DBH) of trees and it is followed by Plot B and Plot A with very close mean DBH. The highest mean basal area was also recorded in Plot C, the highest total basal area and tree volume was also recorded at Plot C as 32.2 m2 ha-1 and 188.8 m3. The size distribution of tree species depicts that Plot C has been protected just as expected Keywords: Forest, Structure, Flora, Dynamics, Fir

    Chemical profiling of infusions and decoctions of Helichrysum italicum subsp picardii by UHPLC-PDA-MS and in vitro biological activities comparatively with green tea (Camellia sinensis) and rooibos tisane (Aspalathus linearis)

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    Several medicinal plants are currently used by the food industry as functional additives, for example botanical extracts in herbal drinks. Moreover, the scientific community has recently begun focusing on halophytes as sources of functional beverages. Helichrysum italicum subsp. picardii (everlasting) is an aromatic halophyte common in southern Europe frequently used as spice and in traditional medicine. In this context, this work explored for the first time H. italicum subsp. picardii as a potential source of innovative herbal beverages with potential health promoting properties. For that purpose, infusions and decoctions were prepared from roots, vegetative aerial-organs (stems and leaves) and flowers and evaluated for in vitro antioxidant and anti-diabetic activities. Samples were also assessed for toxicity in different mammalian cell lines and chemically characterized by spectrophotometric methods and ultra-high performance liquid chromatography photo diode array mass-spectrometry (UHPLC-PDA-MS). Results were expressed relating to 'a cup-of-tea' and compared with those obtained with green tea (Camellia sinensis) and rooibos tisane (Aspalathus linearis). Tisanes from the everlasting's above-ground organs, particularly flowers, have high polyphenolic content and several phenolics were identified; the main compounds were chlorogenic and quinic acids, dicaffeoylquinic-acid isomers and gnaphaliin-A. The antioxidant activity of beverages from the everlasting's above-ground organs matched or surpassed that of green tea and rooibos. Its anti-diabetic activity was moderate and toxicity low. Overall, our results suggest that the everlasting is a potential source of innovative and functional herbal beverages. (C) 2017 Elsevier B.V. All rights reserved.national funds through Foundation for Science and Technology (FCT, Portugal) [CCMAR/Multi/04326/2013]FCT [SFRH/BD/94407/2013, SFRH/BD/116604/2016]Research Foundation - Flanders (FWO) [12M8315N]FCT Investigator Programme [IF/00049/2012]info:eu-repo/semantics/publishedVersio

    PERSEPSI MAHASISWA JURUSAN PENDIDlKAN KEPELATlHAN TERHADAP PAKET SENAM AEROBIK PRODUK FIK

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    Penelitian ini bertujuan untuk mengetahui bagaimana per¬sep¬si mahasiswa Jurusan Pendidikan Kepelatihan terhadap paket senam aerobik produk FIK supaya layak digunakan dan dapat di¬sebar¬luaskan pada masyarakat. Paket senam aerobik tersebut belum disebarluaskan di masyarakat, gerakan senam aerobik tersebut baru didasarkan pada teori dan dikonsultasikan dengan beberapa ahli tetapi belum pernah diujicobakan langsung di masyarakat. Untuk dapat dimasyarakatkan, paket senam aerobik tersebut harus melalui uji joba dengan sasaran masyarakat . Untuk lebih memudahkan da¬lam uji coba maka digunakan mahasiswa baru sebagai subyek pe¬ne-litian dengan asumsi mereka sama sekali belum bisa senam se¬hingga dapat mewakili masyarakat pada umumnya. Penelitian ini merupakan penelitian deskriptif dengan meng¬gunakan metode survai dengan teknik angket. Subyek pene¬li¬tian mahasiswa Jurusan Kepelatihan Angkatan 2005 yang meng¬ambil mata kuliah dasar gerak senam, Sampel penelitian diambil menggunakan Purposive Sampling. Data yang dikumpulkan ber¬sifat subyektif dengan Skala Likert, Analisis data menggunakan analisis deskriptif. Hasil penelitian menunjukkan bahwa persepsi mahasiswa jurusan pendidikan kepelatihan terhadap paket senam aerobik pro¬duk FIK adalah baik, dapat dilihat dari hasil data yang diperoleh 5 orang kurang baik, 45 orang baik, 5 orang sangat baik, dari hasil tersebut 45 mahasiswa mempunyai persepsi yang baik sehingga paket senam aerobik produk FIK dapat disebarluaskan pada masya¬rakat. FIK, 2006 (PEND. KEPELATIHAN

    Optimal ratio between phase basis and bit basis in QKD

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    In the original BB84 protocol, the bit basis and the phase basis are used with equal probability. Lo et al (J. of Cryptology, 18, 133-165 (2005)) proposed to modify the ratio between the two bases by increasing the final key generation rate. However, the optimum ratio has not been derived. In this letter, in order to examine this problem, the ratio between the two bases is optimized for exponential constraints given Eve's information distinguishability and the final error probability
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