Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 173 for “"sonication"”.
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Transient Radicals Produced by Sonication and the Investigation of Paramagnetic Effects
… that the sample temperature increased during sonication. To counter this, gated sonication was used to minimize temperature increase. During sonication, the sample was vigorously mixed. Experiments where the sample was mixed through alternate means and theoretical simulations indicate that …
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Study of degradation of aflatoxins after sonication and their determination by HPLC-QqQ-MS
Οι αφλατοξίνες (AFs) είναι φυσικώς απαντώμενοι, τοξικοί, θερμικώς σταθεροί, δευτερογενείς μεταβολίτες που παράγονται από στελέχη μυκήτων, κυρίως του γένους Aspergillus. Η παρουσία τους σε μεγάλη ποικιλία αγροδιατροφικών προϊόντων αποτελεί απειλή για την ασφάλεια των τροφίμων, με αυστηρά ρυθμιστικά …
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Experimental investigation of the effect of sonication on the precipitation of grieseofluvin by impinging jets
… were carried out for different values of the sonication power, impinging jet velocity, and reactor volume. Their effect on the size and morphology of the precipitated crystals was quantified. The crystals were analyzed using a laser diffraction method (for particle size distribution), electron …
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The Sonochemistry of Some Metal Carbonyl Complexes (Iron, Chromium)
… give rise to high energy species in solution. Sonications were performed using a Heat-Systems Ultrasonics model W375 Sonicator cell disruptor with a sample cell equipped for cryogenic and inert atmosphere work. Sonication of the stable free radical diphenylpicryhydrazyl in a variety of solvents …
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Ultrasonically Enhanced Mass Transport and Degradation of Polycyclic Aromatic Hydrocarbons in Solid-Liquid Two Phase Partitioning Systems
… work examined the possibility of applying sonication in solid-liquid partitioning systems to enhance delivery and degradation of PAHs. Small scale physical testing revealed delivery rates of PAHs from Desmopan, increased by 5 fold under intermittent sonication relative to non-sonicated …
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Mixing performance of a novel, continuous confined impinging jets mixer using competitive reactions
… flow rate of the other solution was changed. The sonication power was also varied. It was experimentally found here that improved mixing was achieved by increasing volumetric flow rate with or without sonication. If sonication was applied, mixing also improved significantly and it was further …
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Potential use of ultrasound in chemical monitoring
… study was to examine the potential of combining sonication with other technologies for monitoring specific classes of organic pollutants in water. The research specifically addressed using ultrasonic processors to decompose organochlorine compounds into ions which could be detected using a …
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Variations in bacterial adenosine triphosphate values due to genus and environmental conditions
… highest value in stationary phase. The effect of sonication on ATP/cell was tested for each bacterium at one set of factors. Sonication studies showed that L. brevis cells were clumping, especially in aged cultures. After sonication, ATP/cell remained relatively constant from lag through …
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Nanocellulose: Preparation, Characterization, Supramolecular Modeling, and its Life Cycle Assessment
… (TEMPO-mediated oxidation followed by intensive sonication), and this new material was named molecularly thin nanocellulose (MT nanocellulose). The overarching objective of this study was to understand the formation and supramolecular structure of MT nanocellulose and contribute to the knowledge …
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The Isolation and Differentiation of Adipose Derived Mesenchymal Stem Cells
… I assessed the capacity of a non-enzymatic sonication based method to the collagenase digestion based method of isolating MSCs from human adipose. Sonication yielded fewer total cells than collagenase. However, alizarin red staining revealed that cells obtained using sonication possessed a …
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Biomedical ultrasonics, cavitation, and sonoporation
… with the aid of ultrasound. During 1-hour sonication in the clinical diagnostic range, we forced blue-green algae to sink, thus promoting natural decay. In medical diagnostics, ultrasound contrast agents are added to the blood stream to differentiate between blood and other tissue types. We …
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Detection and characterization of nanoparticles in the surface water: challenges and findings
… emission spectroscopy (AES) at discrete time of sonication. Results clearly showed that the dispersion of the ENPs is very small but increased with time of sonication. Among the metallic analytes studied, Copper had better dispersion compared to the rest of the ENPs studied. In general, …
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Development of an acid mine drainage treatment technology and recovery of minerals
… in batch experiment comparing flocculation and sonication techniques in treatment of AMD with calcined magnesite. Sonication technique was more effective in treatment of AMD because it raised pH faster and it enhanced precipitation of minerals than flocculation. Due to the superiority of …
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Testing and characterization of carbon nanotubes as strain sensors
… have on the strain sensors, the effect of the sonication time, and the effect that leaving the strain sensors inside the solution for different amount of times has on the strain sensors. It was discovered that the samples dried overtime, thus decreasing the conductivity of the samples and …
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Bubbles and crystals: time-resolved sonoluminescence, sonocrystallization, and sonofragmentation
… methods. Particle breakage during sonication of liquid/aspirin slurries was investigated, establishing relationships between particle size and sonication time or sonication intensity. Particle size distributions were modeled using a population-balance method assuming simple binary …
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A systematic study of the effect of ultrasound on food enzymes and bioactives in model and real food systems (strawberry puree)
… for mushroom PPO. HRP inactivation kinetics upon sonication followed a first order model, whereas those of PPO fitted to the Weibull model. Fluorescence analysis of US treated samples of HRP revealed the removal of the haem from the active centre and the formation of di-tyrosine, possibly mediated …
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Antimicrobial mechanism of action of ultrasound technology : a macroscopic, genetic and transcriptomic perspective for the disinfection of (waste)water
… • Characterise the major effect of sonication stress on Escherichia coli mutants that miss important genes involved in general stress tolerance. The role of these genes in the protection or sensitivity against ultrasound generated radicals are also assessed. • Identify and quantify …
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Removal of Biofilm through Controlled Cavitation
… cavitation. The proposed method involves sonication or bombarding the material surface with cavitation bubbles to remove the bacterial biofilm.</p> <p>This thesis includes the various experiments done with respect to removal rate for varying parameters (i.e. depth, sonication time, etc). …
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Algae Lysis with Pulsed Electric Fields
… use enzymes, pressure homogenization, and/or sonication to lyse cells; however, these methods are costly and complicate oil extraction [9], [10].</p> <p>This project examines a novel method of cell lysis through pulsed electric field (PEF) application that enables cost-effective extraction …
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Nano-Modification for High Performance Cement Composites with Cellulose NanoCrystals and Carbon Nanotubes
… when the agglomerates start prevailing. The sonication is employed to effectively reduce the agglomerates and the strength of the cement paste is improved significantly with sonicated CNCs. Due to the hygroscopic and hydrophilic nature of CNCs, the agglomerates may lead to larger and more …
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