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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.
551

Relative Infrasound Calibration of Microphones with Application to Outdoor Vector Intensity Measurements

Irarrazabal Oliva, Francisco Javier 28 July 2021 (has links)
This thesis describes the phase and amplitude correction of 12.7 mm diameter, Type-1 microphones for three frequency bands, including within the infrasound regime, and its application to acoustic measurements. Previous data stem from acoustic intensity measurements using two-dimensional, four-microphone probes, which emphasized the requirement of having the acoustic phase and amplitude difference be much greater than the interchannel mismatch. Although correcting the amplitude/phase is well-known, obtaining the necessary transfer functions in the infrasound regime is challenging because (1) signal-to-noise ratios are often poor, (2) long measurement times are required for averaging, and (3) microphone responses vary significantly across these low frequencies. In this paper, a convenient infrasound source previously studied for infrasound adverse effects on humans is intended for performing a relative calibration. This work also seeks to elaborate recommendations for probe spacing, averages or length recordings, and instrument mismatch. The last two chapters show the PAGE method application in infrasonic sources. Those chapters have the intensity measurements using free-field microphones with larger separation distances than commercial intensity probes but compact compared to state of the art in infrasonic arrays.
552

Interaction of Plasmons and Excitons for Low-Dimension Semiconductors

Lin, Jie (physicist) 12 1900 (has links)
The effects of surface plasmon for InGaN/GaN multi-quantum wells and ZnO nanoparticles optical linear and nonlinear emission efficiency had been experimentally studied. Due to the critical design for InGaN MQWs with inverted hexagonal pits based on GaN, both contribution of surface plasmon effect and image charge effect at resonant and off resonant frequencies were experimentally and theoretically investigated. With off- resonant condition, the InGaN MQWs emission significantly enhanced by metal nanoparticles. This enhancement was caused by the image charge effect, due to the accumulation of carriers to NPs region. When InGaN emission resonated with metal particles SP modes, surface Plasmon effect dominated the emission process. We also studied the surface plasmon effect for ZnO nanoparticles nonlinear optical processes, SHG and TPE. Defect level emission had more contribution at high incident intensity. Emissions are different for pumping deep into the bulk and near surface. A new assumption to increase the TPE efficiency was studied. We thought by using Au nanorods localized surface plasmon mode to couple the ZnO virtual state, the virtual state’s life time would be longer and experimentally lead the emission enhancement. We studied the TPE phenomena at high and near band gap energy. Both emission intensity and decay time results support our assumption. Theoretically, the carriers dynamic mechanism need further studies.
553

Fluorescent Indicators for Disease Biomarkers

Lim, Soojin 01 January 2012 (has links)
Xanthene dyes are common fluorophores which have been widely used as molecular probes. The xanthene fluorophores can be used as highly selective optical sensors to detect disease biomarkers. A new fluorogenic dye containing an alpha, beta-unsaturated aldehyde moiety exhibits selective fluorescent signal enhancement in the presence of cysteine or peptides containing N-terminal cysteine residues. The mechanism is based on synergistic covalent and supramolecular interactions. A unique rhodamine boronic acid indicator is used in an optimized data collection protocol for wavelength- and time-dependent selectivity of various saccharides and nucleosides. One indicator is thereby capable of selectively distinguishing structurally related analytes in mixtures. Moreover, the rhodamine-based boronic acid responds linearly to increasing riboside concentrations in urine samples, potentially enabling the screening for inborn purine metabolism disorders.
554

Ab-initio design methods for selective and efficient optomechanical control of nanophotonic structures / ナノフォトニック構造の選択的かつ効率的なオプトメカニカル制御のための第一原理設計

Pedro Antonio Favuzzi 23 January 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17985号 / 工博第3814号 / 新制||工||1584(附属図書館) / 80829 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 川上 養一, 教授 藤田 静雄, 准教授 浅野 卓 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
555

Theory of Spin-Excitation Anisotropy in the Nematic Phase of FeSe Obtained From RIXS Measurements

Kreisel, Andreas, Hirschfeld, P.J., Andersen, Brian M. 07 June 2023 (has links)
Recent resonant inelastic x-ray scattering (RIXS) experiments have detected a significant high-energy spin-excitation anisotropy in the nematic phase of the enigmatic iron-based superconductor FeSe, whose origin remains controversial. We apply an itinerant model previously used to describe the spin-excitation anisotropy as measured by neutron scattering measurements, with magnetic fluctuations included within the RPA approximation. The calculated RIXS cross section exhibits overall agreement with the RIXS data, including the high energy spin-excitation anisotropy
556

Correlation of Fluorescence Spectroscopy and Biochemical Oxygen Demand (BOD5) Using Regression Analysis

Narteh, Alexander Tetteh 01 July 2015 (has links) (PDF)
This research uses Regression analysis of fluorescence spectroscopy results to correlate with Biochemical Oxygen Demand (BOD5). Fluorescence spectroscopy was applied to samples taken from seven sample sites in the Provo and Orem waste water treatment plants found in Utah County. A total of 161 samples were collected for this research. 23 samples each were taken from four sites in the Provo waste water treatment plant namely Provo head works, aeration basin, primary filter settlement basin and the Provo effluent basin. The Orem head works, the clarifier and the Orem effluent basin were the three sample sites in the Orem waste water treatment plant where 23 samples each were collected to carry out the analysis. The fluorescent characteristics of the samples were determined using fluorescence spectrometry. These intensities were correlated with standard five day Biochemical Oxygen Demand (BOD5) values which were used as a measure of the amount of biodegradable organic material present. Chemical oxygen demand (COD) data were also taken from these treatment plants for correlation purposes. Three different correlation analyses were made which were the correlation of fluorescence spectroscopy excitation-emission matrix (EEM) against (1) individual sites BOD and COD values (2) Provo only and Orem only BOD and COD values (3) combined Provo and Orem BOD and COD values. The correlation of Individual site EEMs against BOD and COD values produced the best results. There was a higher correlation of EEM with BOD data than COD data. The R-squared for the combined Provo and Orem BOD data was 0.756 and that for COD was 0.729. Very high R-squared was obtained for Provo Influent data and Orem Influent data which were 0.955 and 0.946 respectively. This method can be used by wastewater stakeholders in deriving quick results in determining potential pollution events within a shorter time frame. This research demonstrates that there is a correlation between EEM and BOD/COD.
557

Behavioral, Functional, and Neurophysiological Responses to One-week Administration of Escitalopram

Molloy, Eóin 12 July 2022 (has links)
Doctoral thesis assessing the effects of one-week of escitalopram administration on healthy humans during sequence motor learning training. Published in 3 research articles.
558

Selection and development of algorithms based on surface fluorescence compounds of fish for non-destructively monitoring freshness during storage / 貯蔵段階における魚体表の蛍光物質を用いた非侵襲的な鮮度評価のためのアルゴリズムの選定と開発

OMWANGE, KEN ABAMBA 26 September 2022 (has links)
京都大学 / 新制・課程博士 / 博士(農学) / 甲第24245号 / 農博第2524号 / 新制||農||1094(附属図書館) / 学位論文||R4||N5416(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 近藤 直, 教授 飯田 訓久, 准教授 小川 雄一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
559

Quantum Optics in Coupled Quantum Dots

Garrido, Mauricio 21 July 2010 (has links)
No description available.
560

Ultrawideband Low-Profile Arrays of Tightly Coupled Antenna Elements: Excitation, Termination and Feeding Methods

Tzanidis, Ioannis 20 October 2011 (has links)
No description available.

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