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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Dopad přeměny tištěných novin v internetové mutace na informování o extrémismu / Analysis of the impact of the conversion of printed newspapers to online versions of information on extremist groups

Křížová, Kristýna January 2010 (has links)
KŘÍŽOVÁ, Kristýna, The impact of Internet Versions of Printed Newspapers on Information about Extremism, Faculty of Humanities, Charles University, Prague, 2010, diploma thesis ------------------------------------------------------------------------------------------ Key words: electronic media, printed media, audience ------------------------------------------------------------------------------------------ The theoretical part of the work concerns the possible consequences of transforming printed media into electronic form with respect to the reporting of extremism. A cultural approach was selected which highlights the way in which the final form of a report and its interpretation is subject to cultural factors. The work draws on the Three Party Model of Communication Situations devised by Winfried Schulz, which models the mutual relationship between the three protagonists of an event - the main figures (representatives of extremist movements), journalists (mass media - Internet sites), and the audience (readership, recipients). Investigation of the possible interest of these three parties in information on extremism is considered on the basis of theories of critics of contemporary media. Interpretation reveals the difficulties associated with transforming the daily papers into electronic news sites and...
352

Screen-Printed Soft-Nitrided Carbon Electrodes for Detection of Hydrogen Peroxide

Ogbu, Chidiebere I., Feng, Xu, Dada, Samson N., Bishop, Gregory W. 01 September 2019 (has links)
Nitrogen-doped carbon materials have garnered much interest due to their electrocatalytic activity towards important reactions such as the reduction of hydrogen peroxide. N-doped carbon materials are typically prepared and deposited on solid conductive supports, which can sometimes involve time-consuming, complex, and/or costly procedures. Here, nitrogen-doped screen-printed carbon electrodes (N-SPCEs) were fabricated directly from a lab-formulated ink composed of graphite that was modified with surface nitrogen groups by a simple soft nitriding technique. N-SPCEs prepared from inexpensive starting materials (graphite powder and urea) demonstrated good electrocatalytic activity towards hydrogen peroxide reduction. Amperometric detection of H2O2 using N-SPCEs with an applied potential of −0.4 V (vs. Ag/AgCl) exhibited good reproducibility and stability as well as a reasonable limit of detection (2.5 µM) and wide linear range (0.020 to 5.3 mM).
353

Deep Learning for Printed Image Quality

Jianhang Chen (12275537) 20 April 2022 (has links)
This research focuses on developing algorithms to automatically classify, detect, simulate and improve the quality of defective printed images since the human visual system is unreliable. With the development of deep learning algorithms, state-of-the-art accuracy could be achieved for many computer vision tasks. This research applies the deep learning method to printed image quality assessment. Because most deep learning approaches require a large amount of data even after data augmentation, we propose to use Generative Adversarial Networks for simulation images generation. The simulated images with artifacts could be used for training classifier, detector and corrector networks for printed image quality. Another essential preprocessing step for printed image quality assessment is image registration, which can detect the defect and difference between two input images. This research proposes to use the deep learning framework for global image registration by parallel computation acceleration. For deformable local registration, we implement the U-Net VoxelMorph-based method for printed image registration. Then we further propose the recurrent network-based method, R-RegNet. The experimental results show that the proposed R-RegNet method outperforms the U-Net VoxelMorph-based method in all three datasets that we considered. Finally, we propose a photorealistic image dataset simulation method for training deep neural networks. A new dataset with simulated images, named Extra FAT, is introduced for object detection and 6D pose estimation.
354

Nitrogen Doping of Electrochemically Activate Carbon Screen-Printed Electrodes

Galloway, Ethan 01 May 2022 (has links)
Screen printed electrodes (SPEs), which are prepared by patterning conductive inks or pastes onto an insulating support (e.g., plastic film), are widely employed as sensing and biosensing platforms due to their ease of fabrication and relatively low cost. This is especially applicable to electrodes of this nature prepared with carbon-based inks (SPCEs). To date, the most successful and significant commercial application of SPEs has been as test strips for glucose meters. Despite the maturity of this technology, SPE research remains very active as improvements in sensitivity and selectivity, which often involve modifying the electrode surface, hold the key to advancing their utility in routine applications and extending their benefits to other target analytes. Recent studies in the Bishop research group have demonstrated that nitrogen-doped SPCEs (N-SPCEs) exhibit enhanced electrochemical response towards hydrogen peroxide (H2O2), a product of oxidase enzyme (e.g., glucose oxidase, lactate oxidase, etc.) reactions and a common target in biosensing strategies. The presence of nitrogen heteroatoms on the carbon surface facilitates breakage of oxygen-oxygen bonds, a key step in reduction of H2O2. Since previous studies showed only modest incorporation of nitrogen species on SPCEs prepared from commercial ink, these studies aim to investigate the possibility of enhancing N-doping by performing a simple pre-treatment strategy that reportedly increases surface oxygen content of SPCEs prior to N-doping. Since surface oxygen sites have been previously reported to be preferentially modified with nitrogen during N doping strategies, this seems like a promising technique for improving sensitivity of N-SPCEs for H2O2 reduction. To quantify the actuality of these claims, experimental groups were fabricated having undergone no enhancement, pretreatment enhancement only, nitrogen-doping enhancement only, and a combination of the pretreatment and nitrogen-doping enhancements. Here the electrochemical behaviors of pretreated SPCEs, N-SPCEs, and pretreated N-SPCEs for the detection of H2O2 by completing comparative cyclic voltammetry (CV) experiments with and without the presence of H2O2 and with it present in varying concentrations is compared. It is projected that, if successful, the fabricated electrodes that have undergone both the pretreatment protocol and the nitrogen-doping process will have an increased sensitivity and detection limit towards H2O2.
355

Nitrogen Doping of Electrochemically Activated Carbon Screen Printed Electrodes

Galloway, Ethaniel L, Bishop, Gregory W, Ph.D. 06 April 2022 (has links)
Screen printed electrodes (SPEs), which are prepared by patterning conductive inks or pastes onto an insulating support (e.g., plastic film), are widely employed as sensing and biosensing platforms due to their ease of fabrication and relatively low cost. This is especially applicable to electrodes of this nature prepared with carbon-based inks (SPCEs). To date, the most successful and significant commercial application of SPEs has been as test strips for glucose meters. Despite the maturity of this technology, SPE research remains very active as improvements in sensitivity and selectivity, which often involve modifying the electrode surface, hold the key to advancing their utility in routine applications and extending their benefits to other target analytes. Recent studies in the Bishop research group have demonstrated that nitrogen-doped SPCEs (N-SPCEs) exhibit enhanced electrochemical response towards hydrogen peroxide (H2O2), a product of oxidase enzyme (e.g., glucose oxidase, lactate oxidase, etc.) reactions and a common target in biosensing strategies. The presence of nitrogen heteroatoms on the carbon surface facilitates breakage of oxygen-oxygen bonds, a key step in reduction of H2O2. Since previous studies showed only modest incorporation of nitrogen species on SPCEs prepared from commercial ink, these studies aim to investigate the possibility of enhancing N-doping by performing a simple pre-treatment strategy that reportedly increases surface oxygen content of SPCEs prior to N-doping. Since surface oxygen sites have been previously reported to be preferentially modified with nitrogen during N-doping strategies, this seems like a promising technique for improving sensitivity of N-SPCEs for H2O2 reduction. To quantify the actuality of these claims, experimental groups were fabricated having undergone no enhancement, pretreatment enhancement only, nitrogen-doping enhancement only, and a combination of the pretreatment and nitrogen-doping enhancements. Here the electrochemical behaviors of pretreated SPCEs, N-SPCEs, and pretreated N-SPCEs for the detection of H2O2 by completing comparative cyclic voltammetry (CV) experiments with and with out the presence of H2O2 and with it present in varying concentrations is compared. It is projected that, if successful, the fabricated electrodes that have undergone both the pretreatment protocol and the nitrogen-doping process will have an increased sensitivity and detection limit towards H2O2.
356

Peroxide Sensing Using Nitrogen-Doped and Platinum Nanoparticle-modified Screen-Printed Carbon Electrodes

Ogbu, Chidiebere 01 August 2019 (has links)
Nitrogen-doped carbon materials have garnered much interest due to their abilities to behave as electrocatalysts for reactions important in energy production (oxygen reduction) and biosensing (hydrogen peroxide reduction). Here, we demonstrate fabrication methods and determine electrocatalytic properties of nitrogen-doped screen-printed carbon (N-SPCE) electrodes. Nitrogen doping of graphite was achieved through a simple soft-nitriding technique which was then used in lab-formulated screen-printing inks to prepare N-SPCEs. N-SPCEs displayed good electrocatalytic activity, reproducibility and long term stability towards the electrochemical reduction of hydrogen peroxide. N-SPCEs exhibited a wide linear range (20 µM to 5.3 mM), reasonable limit of detection of 2.5 µM, with an applied potential of -0.4 V (vs. Ag/AgCl). We also demonstrate that nitrided-graphite can similarly be used as a platform for the deposition of electrocatalytic platinum nanoparticles, resulting in Pt-N-SPCEs with a lower limit of detection (0.4 µM) and better sensitivity (0.52 µA cm-2 µM-1) towards H2O2 reduction.
357

Detection of electrooxidation products using microfluidic devices and Raman spectroscopy

Li, Tianyu 03 September 2020 (has links)
Microfluidic flow devices coupled with quantitative Raman spectroscopy are able to provide a deep insight into the reaction mechanism and kinetics of electrocatalytic reactions. With a microfluidic flow device made with glass microscope slides and polymer building blocks, the feasibility of this technique was examined by methanol electrooxidation reaction with a Pt working electrode. Pre-calibration of the Raman peak area was done with solutions of known concentrations of methanol and its major oxidation product, i.e., formate, which enabled the time-dependent Raman spectra taken during the reaction to be converted to time-dependent concentrations. These were interpreted in terms of a model with one-dimensional convection and the reaction kinetics. An improved version of this technique was then applied to a comparative study of different alcohols with Ni-based electrodes. This showed the production of formate as the major product from the oxidation of alcohols with vicinal OH groups, leading to the discovery that C-C bond dissociation is a major reaction pathway for vicinal diols and triols if Ni electrocatalysts are used. It is also suggested that the cleavage of C-C bonds is the rate-determining step. The potential use of printed circuit boards (PCB) in the next generation of a novel microfluidic device was explored, as PCB have advantages over regular electrochemical microfluidic substrates, such as simpler electrode fabrication strategies, more wiring layers, and customization of size and shape of electrodes. Pretreatments and electrodeposition protocols of nickel, silver, palladium and platinum on PCB were successfully developed, together with four types of PCB-based microfluidic devices designed with an open-source PCB design software. This work establishes a new electrochemical microfluidic platform for online and in-situ monitoring of electrocatalytic reactions, which can quickly determine the reaction mechanism and kinetics. / Graduate
358

Inkjet-Printed Highly Transparent Solar Cell Antennas

Arellano, Jesus A. 01 December 2011 (has links)
Small satellites, especially Cube Satellites (CubeSats), have become important vehicles for space exploration. One of the challenges CubeSats face is limited surface area. This limitation poses a question for antenna design–where to mount the antenna? This thesis presents a study where the antennas are directly integrated on top of solar cells. In order to achieve such integration, the antennas have to be highly transparent to light. This thesis aims at the transparency of 95%. Methods to effectively generate transparent antenna by using inkjet printing are discussed in detail and interaction between solar cells and antennas have been assessed and presented. It is found that the presence of solar cells cast a degree of gain reduction of the antenna, but such a loss may be improved with a more precise integration and by increasing the operational frequency. The effect of the antenna on solar cell performance is concluded to be less than 3%, promising a feasibility of implementing highly transparent antennas on CubeSats.
359

Evaluation of Recyclability and Recycling Efficiency of Metals for Waste Printed Circuit Boards / 廃プリント基板からの金属の回収並びに回収効率の評価

Le, Hoang-Long 25 November 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17966号 / エネ博第291号 / 新制||エネ||60(附属図書館) / 30796 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 東野 達, 教授 酒井 伸一 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM
360

Portable X-Ray Fluorescence Spectrometer with High Sensitivity / 高感度ポータブル蛍光X線分光器

BOLORTUYA, Damdinsuren 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21765号 / 工博第4582号 / 新制||工||1714(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 河合 潤, 教授 神野 郁夫, 准教授 奥田 浩司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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