268 research outputs found

    GEOREFERENCING AND REPROJECTION ERROR INVESTIGATION ON IMAGE BASED 3D DIGITIZATION AND MAPPING OF HISTORICAL BUILDINGS

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    Image based dense point cloud creation is easy and low-cost application for three dimensional digitization of small and large scale objects and surfaces. It is especially attractive method for cultural heritage documentation. Reprojection error on conjugate keypoints indicates accuracy of the model and keypoint localisation in this method. In addition, sequential registration of the images from large scale historical buildings creates big cumulative registration error. Thus, accuracy of the model should be increased with the control points or loop close imaging. The registration of point point cloud model into the georeference system is performed using control points. In this study historical Sultan Selim Mosque that was built in sixteen century by Great Architect Sinan was modelled via photogrammetric dense point cloud. The reprojection error and number of keypoints were evaluated for different base/length ratio. In addition, georeferencing accuracy was evaluated with many configuration of control points with loop and without loop closure imaging

    Some chemical and physical properties at physiological maturity and ripening period of kiwifruit (‘Hayward’)

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    This study was carried out to determine some chemical and physical properties at physiological maturity and ripening period of kiwifruit. The average geometric mean diameter, sphericity, bulk density, porosity, projected area along three axes (X, Y, Z) and colour characteristics (L*, a*, b*) were measured at physiological maturity and ripening period. Total soluble solid content, titratable acidity, pH, total phenolic, total antioxidant activity and total sugar of kiwifruit were also determined. The total antioxidant value was higher at physiological maturity than ripening period.Key words: Kiwifruit (Hayward), chemical properties, physical properties, physiological maturity, ripening period

    Electrical characteristics of B-GaN2O3 thin films grown by PEALD

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    Cataloged from PDF version of article.In this work, 7.5 nm Ga2O3 dielectric thin films have been deposited on p-type (111) silicon wafer using plasma enhanced atomic layer deposition (PEALD) technique. After the deposition, Ga2O3 thin films were annealed under N-2 ambient at 600, 700, and 800 degrees C to obtain beta-phase. The structure and microstructure of the beta-Ga2O3 thin films was carried out by using grazing-incidence X-ray diffraction (GIXRD). To show effect of annealing temperature on the microstructure of beta-Ga2O3 thin films, average crystallite size was obtained from the full width at half maximum (FWHM) of Bragg lines using the Scherrer formula. It was found that crystallite size increased with increasing annealing temperature and changed from 0.8 nm to 9.1 nm with annealing. In order to perform electrical characterization on the deposited films, Al/beta-Ga2O3/p-Si metal-oxide-semiconductor (MOS) type Schottky barrier diodes (SBDs) were fabricated using the beta-Ga2O3 thin films were annealed at 800 degrees C. The main electrical parameters such as leakage current level, reverse breakdown voltage, series resistance (R-S), ideality factor (n), zero-bias barrier height (phi(Bo)), and interface states (N-SS) were obtained from the current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. The RS values were calculated by using Cheung methods. The energy density distribution profile of the interface states as a function of (E-SS-E-V) was obtained from the forward bias I-V measurements by taking bias dependence of ideality factor, effective barrier height (phi(e)), and R-S into account. Also using the Norde function and C-V technique, phi(e) values were calculated and cross-checked. Results show that beta-Ga2O3 thin films deposited by PEALD technique at low temperatures can be used as oxide layer for MOS devices and electrical properties of these devices are influenced by some important parameters such as NSS, RS, and beta-Ga2O3 oxide layer. (C) 2014 Elsevier B.V. All rights reserved

    Effect of post-deposition annealing on the electrical properties of B-Ga2O3 thin films grown on p-Si by plasma-enhanced atomic layer deposition

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    Cataloged from PDF version of article.Ga2O3 dielectric thin films were deposited on (111)-oriented p-type silicon wafers by plasma-enhanced atomic layer deposition using trimethylgallium and oxygen plasma. Structural analysis of the Ga 2O3 thin films was carried out using grazing-incidence x-ray diffraction. As-deposited films were amorphous. Upon postdeposition annealing at 700, 800, and 900°C for 30min under N2 ambient, films crystallized into β-form monoclinic structure. Electrical properties of the β-Ga2O3 thin films were then investigated by fabricating and characterizing Al/β-Ga2O3/p-Si metal-oxide-semiconductor capacitors. The effect of postdeposition annealing on the leakage current densities, leakage current conduction mechanisms, dielectric constants, flat-band voltages, reverse breakdown voltages, threshold voltages, and effective oxide charges of the capacitors were presented. The effective oxide charges (Qeff) were calculated from the capacitance-voltage (C-V) curves using the flat-band voltage shift and were found as 2.6×1012, 1.9×1012, and 2.5×10 12 cm-2 for samples annealed at 700, 800, and 900°C, respectively. Effective dielectric constants of the films decreased with increasing annealing temperature. This situation was attributed to the formation of an interfacial SiO2 layer during annealing process. Leakage mechanisms in the regions where current increases gradually with voltage were well fitted by the Schottky emission model for films annealed at 700 and 900°C, and by the Frenkel-Poole emission model for film annealed at 800°C. Leakage current density was found to improve with annealing temperature. β-Ga2O3 thin film annealed at 800°C exhibited the highest reverse breakdown field value. © 2014 American Vacuum Society

    Effect of Film Thickness on the Electrical Properties of AlN Films Prepared by Plasma-Enhanced Atomic Layer Deposition

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    In this paper, AlN thin films with two different thicknesses, i.e., 7 and 47 nm, were deposited at 200 °C on p-type Si substrates by plasma-enhanced atomic layer deposition using trimethylaluminum and ammonia. To investigate the electrical characteristics of these AlN films, MIS capacitor structures were fabricated and characterized using current-voltage and high-frequency (1 MHz) capacitance-voltage measurements. The results showed that the current transport mechanism under accumulation mode is strongly dependent on the applied electric field and thickness of the AlN film. Possible conduction mechanisms were analyzed, and the basic electrical parameters were extracted and compared for AlN thin films with different thicknesses. Compared with 7-nm-thick film, a 47-nm-thick AlN film showed a lower effective charge density and threshold voltage along with a higher dielectric constant. © 2015 IEEE

    Current transport mechanisms in plasma-enhanced atomic layer deposited AlN thin films

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    Here, we report on the current transport mechanisms in AlN thin films deposited at a low temperature (i.e., 200°C) on p-type Si substrates by plasma-enhanced atomic layer deposition. Structural characterization of the deposited AlN was carried out using grazing-incidence X-ray diffraction, revealing polycrystalline films with a wurtzite (hexagonal) structure. Al/AlN/ p-Si metal-insulator-semiconductor (MIS) capacitor structures were fabricated and investigated under negative bias by performing current-voltage measurements. As a function of the applied electric field, different types of current transport mechanisms were observed; i.e., ohmic conduction (15.2-21.5 MV/m), Schottky emission (23.6-39.5 MV/m), Frenkel-Poole emission (63.8-211.8 MV/m), trap-assisted tunneling (226-280 MV/m), and Fowler-Nordheim tunneling (290-447 MV/m). Electrical properties of the insulating AlN layer and the fabricated Al/AlN/p-Si MIS capacitor structure such as dielectric constant, flat-band voltage, effective charge density, and threshold voltage were also determined from the capacitance-voltage measurements. © 2015 AIP Publishing LLC

    PHOTOGRAMMETRIC WIREFRAME AND DENSE POINT CLOUD 3D MODELLING OF HISTORICAL STRUCTURES: THE STUDY OF SULTAN SELIM MOSQUE AND YUSUF AGA LIBRARY IN KONYA, TURKEY

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    The photogrammetry enables to getting high accuracy measurement with low-cost and easy application in documentation of historical structures. The object details are signified with lines in cultural heritage documentation by photogrammetry. The combination of all the lines create 3D wireframe model of the measurement object. In addition, patch surfaces of the wireframe are mapped with the texture from the images for more realistic visualization. On the other hand, the progress on computer vision and image processing techniques is allowing automatically perform the photogrammetric process. A large number of points that are called dense point cloud can be measured from coverage area of multi view images. The dense point cloud represents the object shape with small space measured points while the wireframe photogrammetry is representing the object with lines. In this study these two photogrammetric methods were evaluated with respect to visualization, cost, labour and measurement time through 3D modelling of historical structures of Sultan Selim Mosque and Yusuf Aga Library

    Apium plants: Beyond simple food and phytopharmacological applications

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    Apium plants belong to the Apiaceae family and are included among plants that have been in use in traditional medicine for thousands of years worldwide, including in the Mediterranean, as well as the tropical and subtropical regions of Asia and Africa. Some highlighted medical benefits include prevention of coronary and vascular diseases. Their phytochemical constituents consist of bergapten, flavonoids, glycosides, furanocoumarins, furocoumarin, limonene, psoralen, xanthotoxin, and selinene. Some of their pharmacological properties include anticancer, antioxidant, antimicrobial, antifungal, nematocidal, anti-rheumatism, antiasthma, anti-bronchitis, hepatoprotective, appetizer, anticonvulsant, antispasmodic, breast milk inducer, anti-jaundice, antihypertensive, anti-dysmenorrhea, prevention of cardiovascular diseases, and spermatogenesis induction. The present review summarizes data on ecology, botany, cultivation, habitat, medicinal use, phytochemical composition, preclinical and clinical pharmacological efficacy of Apium plants and provides future direction on how to take full advantage of Apium plants for the optimal benefit to mankind.N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

    Catheter-related bacteremia due to Kocuria rosea in a patient undergoing peripheral blood stem cell transplantation

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    BACKGROUND: Micrococcus species may cause intracranial abscesses, meningitis, pneumonia, and septic arthritis in immunosuppressed or immunocompetent hosts. In addition, strains identified as Micrococcus spp. have been reported recently in infections associated with indwelling intravenous lines, continuous ambulatory peritoneal dialysis fluids, ventricular shunts and prosthetic valves. CASE PRESENTATION: We report on the first case of a catheter-related bacteremia caused by Kocuria rosea, a gram-positive microorganism belonging to the family Micrococcaceae, in a 39-year-old man undergoing peripheral blood stem cell transplantation due to relapsed Hodgkin disease. This uncommon pathogen may cause opportunistic infections in immunocompromised patients. CONCLUSIONS: This report presents a case of Kocuria rosea catheter related bacteremia after stem cell transplantation successfully treated with vancomycin and by catheter removal

    ResearchFlow: Understanding the Knowledge Flow between Academia and Industry

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    Understanding, monitoring, and predicting the flow of knowledge between academia and industry is of critical importance for a variety of stakeholders, including governments, funding bodies, researchers, investors, and companies. To this purpose, we introduce ResearchFlow, an approach that integrates semantic technologies and machine learning to quantifying the diachronic behaviour of research topics across academia and industry. ResearchFlow exploits the novel Academia/Industry DynAmics (AIDA) Knowledge Graph in order to characterize each topic according to the frequency in time of the related i) publications from academia, ii) publications from industry, iii) patents from academia, and iv) patents from industry. This representation is then used to produce several analytics regarding the academia/industry knowledge flow and to forecast the impact of research topics on industry. We applied ResearchFlow to a dataset of 3.5M papers and 2M patents in Computer Science and highlighted several interesting patterns. We found that 89.8% of the topics first emerge in academic publications, which typically precede industrial publications by about 5.6 years and industrial patents by about 6.6 years. However this does not mean that academia always dictates the research agenda. In fact, our analysis also shows that industrial trends tend to influence academia more than academic trends affect industry. We evaluated ResearchFlow on the task of forecasting the impact of research topics on the industrial sector and found that its granular characterization of topics improves significantly the performance with respect to alternative solutions
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