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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.
361

Evaluation of near infrared spectroscopy for prediction of quality attributes and authentication of green coffee beans

Adnan, Adnan 23 November 2017 (has links)
No description available.
362

Performance of near infared digital imaging transillumination for detection of non-cavitated approximal caries

Abogazalah, Naif Nabel Fouad 01 June 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Objective: The objectives of this in-vitro study were: 1) to evaluate the ability of Near-Infrared Digital Imaging Transillumination (NIDIT) to detect non-cavitated approximal caries lesions; and 2) to compare the performance among NIDIT, Digital Radiography (DR), Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI) and International Caries Detection and Assessment System (ICDAS). Methods: Thirty human extracted premolars were selected. The approximal surface status ranged from sound to surfaces with non-cavitated caries lesions into the outer one-third of the dentin. Lesion depth was determined by micro-computed tomography (μ-CT) and used as a gold standard. Teeth were mounted in a custom-made device to simulate approximal contact. ICDAS, DR, DIFOTI and NIDIT examinations were performed and repeated by three trained and calibrated examiners. Sensitivity, specificity, area under ROC curve (Az), inter- and intra-class correlation coefficients (ICCs) of each method, and correlation among the methods were determined. Results: ICCs for intra-/inter-examiner agreement were almost perfect for DIFOTI (0.85/0.83), substantial for ICDAS (0.79/0.72) and NIDIT (0.69/0.64), and moderate for DR (0.52/0.48). Sensitivity/specificity for DIFOTI, ICDAS, DR, and NIDIT were 0.91/0.69, 0.89/0.83, 0.50/0.64, and 0.68/0.93, respectively. Az of DR (0.61) was significantly lower than that of DIFOTI (0.91, p = 0.002) and ICDAS (0.90, p = 0.005), but was not significantly different from NIDIT (0.81, p = 0.052). DIFOTI, ICDAS, and NIDIT were not significantly different from each other (p > 0.13). Spearman correlation coefficients for DIFOTI (0.79, p < 0.001), ICDAS (0.74, p < 0.001), and NIDIT (0.65, p < 0.001) demonstrated a moderate association with μ-CT, while that of DR suggested no association (0.19, p = 0.289). Conclusion: Within the limitations of this in-vitro study, NIDIT system demonstrated a potential for early approximal caries detection. ICDAS, DIFOTI, and NIDIT were superior to DR in terms of validity and reliability.
363

Illuminating Biology with Membrane Penetrating Sulfonate Delivery Scaffolds and Near-Infrared Azasiline Fluorophores

Choi, Adam 07 September 2018 (has links)
Near-infrared (NIR) light, with wavelengths of 650 to 900 nanometers, effectively penetrates tissues. The high signal to noise ratio and low phototoxicity of NIR light makes this wavelength range ideal for deep tissue imaging. However, current NIR fluorophores are generally large hydrophobic molecules that are prone to aggregation. Sulfonation can enhance aqueous solubility, but their anionic nature prevents membrane diffusion, and thus, restricts the applications of sulfonated molecules to in vitro or fixed cells. The repertoire of commercially available sulfonated NIR probes is mostly limited cyanines, which have low photostability. Moreover, larger cyanines require multiple sulfonates to maintain aqueous solubility. For example, Indocyanine Green is only sparingly soluble in PBS, despite having two sulfonates. My work has focused on the delivery of sulfonated dyes into live cells and the development of a new, ultra-compact NIR dye scaffold. First, to expand the in-cell applications of sulfonated fluorophores, I designed reductively-labile sulfonate protecting groups. Using these scaffolds, I have successfully delivered the fluorophore dansyl sulfonate into live cells, where the cytosolic reducing environment unmasks the anionic sulfonate. Secondly, to create a compact, photostable NIR fluorophore, I pioneered the discovery of azasilines dyes. The two azasiline derivatives, ASiFluor710 and ASiFluor730, fluoresce over 700 nanometers and are among the most compact NIR fluorophores currently known. ASiFluor730 also retains the high photostability of oxazine dyes, highlighting their potential in long exposure applications. Beyond the immediate applications in fluorescence microscopy and in vivo imaging, I envision that my work will serve as a framework for the future design of soluble, membrane permeable, NIR fluorescent probes.
364

Development of a rapid and in-field phenotyping tool for screening protein quality in soybeans (Glycine max) using a miniature near infrared sensor

Sia, Xin Rong January 2019 (has links)
No description available.
365

Development and Optimization of Near-infrared spectroscopy

Hahlin, Amanda January 2023 (has links)
With the growing demand for sustainable options, the existing sorting capacities are limiting the potential for fiber-to-fiber recycling. With the help of near-infrared spectroscopy (NIRS), automated sorting of textiles with high accuracy is possible due to the easy access for polymer identification. Despite the effectiveness of NIRS, some limitations of the process still limit its full potential. Possible disruptors may interfere with and disturb the identification of polymer identities and compositions in different ways. In the following thesis, additives, treatments, and other environmental factors that may hinder fiber identification are further acknowledged. The key results of the thesis state that stains and factors due to wear and tear are the most common possible disruptors that could be identified from pre-sorted post-consumer end-of-life textiles. Further on, stains of ketchup, deodorant, and oil affect the polymer recognition by lowering the recognized fiber content. Water-repellent coatings on 100 % polyamide woven fabric were not detected correctly according to the NIR scanner, as the stated polymer composition was &gt;90 %. Even though some investigated factors, e.g., material structures, were correctly identified by the NIR scanner, the internal deviation of the knitted polyester structure indicates that porous and loose structures hold the ability to interfere with the detection of polymers. To what extent the operating software has been developed is highly relevant to the outcome of how accurate textile sorting may be.
366

The use of hyperspectral sensors for quality assessment : A quantitative study of moisture content in indoor vertical farming

Ahaddi, Arezo, Al-Husseini, Zeineb January 2023 (has links)
Purpose: This research will study how hyperspectral sensoring can assess the moisture content of lettuce by monitoring its growth in indoor vertical farming. Research questions: “What accuracy can be achieved when using hyperspectral sensoring for assessing the moisture content of lettuce leaves grown in vertical farming?” “How can vertical farming contribute to sustainability in conjunction with integration of NIR spectroscopy?” Methodology: This study is an experimental study with a deductive approach in which experiments have been performed using the hyperspectral technologies singlespot sensor and the hyperspectral camera Specim FX17 to collect spectral data. To analyze the data from the experiments two regression models were used and trained to make it possible to predict future moisture content values in lettuce. In order to get a better understanding and analyze the results from the experiments, a literature review was also conducted on how hyperspectral imaging has been applied to assess the quality of food products. Conclusion: The achieved accuracies were 58.24 % and 65.54 % for the PLS regression model and the Neural Network model respectively. Employing hyperspectral sensoring as a non-destructive technique to assess the quality of food products grown and harvested in vertical farming systems, contributes to sustainability from several aspects such as reducing food waste, minimizing costs and detecting different quality attributes that affect the food products. / Syfte: Syftet med denna studie är att undersöka hur hyperspektral avbildning kan användas för att bedöma fuktigheten i sallad genom att kontrollera hur den växer i vertikal odling inomhus. Frågeställningar: “Vilken noggrannhet kan uppnås vid användning av hyperspektral avbildning för att bedöma fukthalt hos salladsblad som odlas i vertikal odling?” “Hur kan vertikal odling bidra till hållbarhet i kombination med integration av NIR spectroscopy?”  Metod: Denna studie är en experimentell studie med en kvantitativ metod inom vilken en deduktiv ansats har tillämpats genom användning av de hyperspektrala teknologierna single-spot sensor och hyperspektralkameran Specim FX17 för insamling av spektral data. För att analysera datan från experimenten skapades och tränades två olika regressionsmodeller till att möjliggöra förutsägning av framtida värden av fukthalt i sallad. För att få en bättre förståelse för och kunna göra en bättre analys av resultaten från experimenten, utfördes även en litteraturöversikt på vad tidigare forskning om tillämpningen av hyperspektral avbildning för kvalitetssäkring av matprodukter har visat. Slutsats: Noggrannheten för PLS-regressionsmodellen var 58,24 % och 65,54 % för Neural Network-modellen. Minskat matsvinn och kostnader samt upptäcka olika kvalitetsattribut som påverkar livsmedelsprodukterna är de hållbara resultaten vid bedömning av kvalitet via hyperspektral sensing.
367

Optical and Laser Spectroscopic Diagnostics for Energy Applications

Tripathi, Markandey Mani 12 May 2012 (has links)
The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the experimentally measured equivalence ratios within 7 %. A comparative study was performed for equivalence ratios measurement in atmospheric premixed methane-air flames with ungated LIBS and chemiluminescence spectroscopy. It was reported that LIBS-based calibration, which carries spectroscopic information from a “point-like-volume,” provides better predictions of equivalence ratios compared to chemiluminescence-based calibration, which is essentially a “line-of-sight” measurement.
368

Cognitive Neuroscientific Research for Developing Diagram Use Instruction for Effective Mathematical Word Problem Solving / 図表を活かして文章題を効率的に解く指導の認知神経科学的研究

Ayabe, Hiroaki 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(教育学) / 甲第24353号 / 教博第283号 / 新制||教||214(附属図書館) / 京都大学大学院教育学研究科教育科学専攻 / (主査)教授 MANALO Emmanuel, 教授 楠見 孝, 准教授 野村 理朗 / 学位規則第4条第1項該当 / Doctor of Philosophy (Education) / Kyoto University / DGAM
369

Linking remotely-sensed UAS imagery to forage quality in an experimental grazing system

Norman, Durham Alexander 06 August 2021 (has links)
Forage quality is a principal factor in managing both herbivores and the landscapes they use. Nutrition varies across the landscape, and in turn, so do the distributions of these populations. With the rise of remote sensing technologies (i.e. satellites, unmanned aerial vehicles, and multi/hyperspectral sensors), comes the ability to index forage health and nutrition swiftly. However, no methodology has been developed which allows managers to use unmanned aerial systems to the fullest capacity. The following methodologies produce compelling evidence for predicting forage quality metrics (such as fiber, carbohydrates, and digestibility) using 5 measured bands of reflectance (Blue, Green, Red, Red Edge, and NIR), 3 derived vegetation indices (NDVI, EVI and VARI), and a variety of environmental factors (i.e. time and sun angles) in a LASSO framework. Fiber content, carbohydrates, and digestibility showed promising model performance in terms of goodness-of-fit (R2= 0.624, 0.637, and 0.639 respectively).
370

Task-Related Hemodynamic Response Alterations During Slacklining: An fNIRS Study in Advanced Slackliners

Seidel-Marzi, Oliver, Hähner, Susanne, Ragert, Patrick, Carius, Daniel 21 December 2023 (has links)
The ability to maintain balance is based on various processes of motor control in complex neural networks of subcortical and cortical brain structures. However, knowledge on brain processing during the execution of whole-body balance tasks is still limited. In the present study, we investigated brain activity during slacklining, a task with a high demand on balance capabilities, which is frequently used as supplementary training in various sports disciplines as well as for lower extremity prevention and rehabilitation purposes in clinical settings. We assessed hemodynamic response alterations in sensorimotor brain areas using functional near-infrared spectroscopy (fNIRS) during standing (ST) and walking (WA) on a slackline in 16 advanced slackliners. We expected to observe task-related differences between both conditions as well as associations between cortical activity and slacklining experience. While our results revealed hemodynamic response alterations in sensorimotor brain regions such as primary motor cortex (M1), premotor cortex (PMC), and supplementary motor cortex (SMA) during both conditions, we did not observe differential effects between ST and WA nor associations between cortical activity and slacklining experience. In summary, these findings provide novel insights into brain processing during a whole-body balance task and its relation to balance expertise. As maintaining balance is considered an important prerequisite in daily life and crucial in the context of prevention and rehabilitation, future studies should extend these findings by quantifying brain processing during task execution on a whole-brain level.

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