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Wan, Chenchen. "Optical Tweezers Using Cylindrical Vector Beams". University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1353515022.
Pełny tekst źródłaBolsa, Ferruz Marta. "Oxygen effect in medical ion beam radiation combined with nanoparticles". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS476/document.
Pełny tekst źródłaAbout 50% of the cancer patients who are treated benefit from radiation therapy. Conventional radiotherapy consists of high energy X-rays traveling through the tissues, so that deeply sited tumors are treated in a non-invasive way. Unfortunately, X-rays are not tumor selective and healthy tissues may be damaged. This lack of selectivity is responsible for severe side effects and/or secondary cancers. Hence, improving the differential of radiation effects between the tumor and surrounding tissues remains a major challenge. Particle therapy (treatment by protons or carbon ion beams) is considered as one of the most promising technique because, by opposition to X-rays, the energy deposition of ions is maximum at the end of their tracks. When the beam is tuned so that the maximum reaches the tumor, there is no damage induced in tissues siting after the tumor. Another important added value is that heavy ions are more efficient to treat radioresistant tumors. The use of this modality is however restricted by the low but significant damage that is induced to normal tissues located at the entrance of the track prior to reaching the tumor. To improve the performance of particle therapy, a new strategy based on the combination of high-Z nanoparticles with ion beam radiation has been developed by the group at ISMO. This approach aims at using nano-agents not only to increase radiation effects in the tumor but also to improve medical imaging with the same agent (theranostic). Nanoparticles present a remarkable surface chemistry, which allows functionalization with ligands able to improve biocompatibility, stability as well as blood circulation and accumulation in tumors. The group already demonstrated the efficiency of small (≈ 3 nm) gold and platinum nanoparticles to amplify the effects of medical carbon ions in normoxic conditions (in the presence of oxygen). However, radioresistant tumors may host hypoxic regions. It is thus urgent to quantify and characterize the influence of oxygen on the radio-enhancement effect. The goal of my thesis was to study the influence of oxygen on medical ion radiation effects in the presence of gold and platinum nanoparticles. This was performed using two radioresistant human cancer cell lines: HeLa (uterine cervix) and BxPC-3 (pancreas). Different radiation modalities were used: carbon and helium ion beams delivered by a passive scattering delivery system and carbon ion beams delivered by a pencil beam scanning system. The major results of this work are the following. In oxic conditions (O₂ concentration = 20%), an enhancement of ion radiation effects was observed for the two nanoparticles (at the same concentration in metal). This effect decreased with the oxygen concentration but remained significant for a concentration of 0.5%. No significant difference was found between the cell lines. Interestingly, the oxygen-dependence varied with the type of radiation. An attempt to explain the effect of oxygen by molecular processes is proposed. Perspectives of further developments are suggested
Tabor, Christopher Eugene. "Some optical and catalytic properties of metal nanoparticles". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31794.
Pełny tekst źródłaCommittee Chair: El-Sayed, Mostafa; Committee Member: Perry, Joseph; Committee Member: Wang, Zhong; Committee Member: Whetten, Robert; Committee Member: Zhang, John. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Powell, Tremaine Bennett. "The Use of Nanoparticles on Nanometer Patterns for Protein Identification". Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194368.
Pełny tekst źródłaArribard, Yann. "Analyse de matière extraterrestre primitive par imagerie hyperspectrale infrarouge et spectrométrie de masse TOF-SIMS". Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASP005.
Pełny tekst źródłaSo-called primitive extraterrestrial matter is characterized by its low chemical evolution since its formation. It is found in particular as one of the constituents of the fragments of small bodies of the Solar system, such as asteroids. The study of samples from these bodies can thus make it possible to better understand its origin and its evolution.In this thesis, my work focused on the analysis of primitive matter and more particularly on the study of carbonaceous chondrites having undergone aqueous alteration. The first part of my thesis focuses on the analysis of mineral and organic phases within petrological type 2 CM chondrites using infrared and Raman spectroscopy techniques as well as time-of-flight secondary ionization mass spectrometry. (TOF-SIMS). These techniques benefit from a good complementarity in the characterization of the different phases that interest us. They are also coupled with imagery, which makes it possible to study the link that may exist between the different mineral and organic phases. I used a new unsupervised process for analyzing infrared hyperspectral data, which made it possible to determine spectral parameters characterizing the state of progress of the aqueous alteration of the samples, in particular of their mineral phase, while relating to their chemical evolution. Raman spectroscopy made it possible to highlight differences in the structure of the polyaromatic organic matter within the different samples. Finally, the TOF-SIMS also highlighted a difference in the structure of the organic matter while confirming and clarifying the differences in co-localization between organic matter and mineral phase observed by hyperspectral imaging between the samples.The second part of my thesis focused on the study of the effectiveness of a new linear accelerator - Andromeda (IJCLab) - as a primary source for TOF-SIMS on analogues of primitive chondrite matter. I produced these organic analogues in the laboratory to simulate insoluble organic matter, the majority of organic matter in chondrites. I checked the characteristics of these analogues by infrared spectroscopy, X-ray spectroscopy and TOF-SIMS. They remain different from CM organic matter in terms of poly-aromatic structure, but similar in terms of elemental composition and insoluble character. I have produced mineral analogues from earth rocks similar to minerals found in CM chondrite. The measurements that I carried out on these analogues and on chondrites show both the potential and the current limits of TOF-SIMS coupled to Andromede, and suggest areas for improvement with a view to increasing, in particular, the masse resolution
Do, Jaekwon. "Controlled spatial arrangement of gold nanoparticles using focused laser beams and DNA origami". Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-171381.
Pełny tekst źródłaKrishnappa, Arjun. "Optical Steering of Microbubbles for Nanoparticle Transport". University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1469461239.
Pełny tekst źródłaKong, David Sun 1979. "Nanostructure fabrication by electron and ion beam patterning of nanoparticles". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28346.
Pełny tekst źródłaIncludes bibliographical references (leaves 82-83).
Two modes of energetic beam-mediated fabrication have been investigated, namely focused ion beam (FIB) direct-writing of nanoparticles, and a technique for electrostatically patterning ionized inorganic nanoparticles, termed nanoxerography. A FIB has been used to directly pattern thin films of organometallic Ag-precursors down to a resolution of 100 nm. The sensitivity of the resist to 30 keV Ga+ ions was measured to be approximately 5 C/cm2. Using this technique arbitrary structures were fabricated in two and three dimensions with resistivity on the order of 1x10 4 Q-cm and 1x1 0-5 Q-cm for single- and multi-layer structures, respectively. A new unit of merit for characterizing direct-write processes, termed resistivity-dose (Q-jC/cm), has been introduced. A Nanocluster Source capable of generating a beam of charged, inorganic nanoparticles has been characterized. The relationship between power supplied to the magnetron of the source and the size of deposited clusters has been plotted. Techniques for utilizing such clusters to develop latent electrified images patterned by an electron beam (EB) have been proposed. The charge-storing characteristics of a variety of substrates such as mylar and polyimide were studied by developing EB-patterned charge images with toner particles.
David Sun Kong.
S.M.
MELONI, MARIA CRISTINA. "Preparazione e caratterizzazione di due sistemi carrier: beads a base di chitosano e chitosano/alginato; nanoparticelle di N-trimetilchitosano". Doctoral thesis, Università degli Studi di Cagliari, 2012. http://hdl.handle.net/11584/266151.
Pełny tekst źródłaTijiwa, Birk Felipe. "Spin electronics in metallic nanoparticles". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39525.
Pełny tekst źródłaDorn, Marco. "Nachweis und Quantifizierung von Nanopartikeln". Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-162158.
Pełny tekst źródłaGuler, Urcan. "Localized Surface Plasmons In Metal Nanoparticles Engineered By Electron Beam Lithography". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610934/index.pdf.
Pełny tekst źródła200 nm are produced and optically analyzed. Size and shape of the nanoparticles are found to affect the resonance behavior. Furthermore, lattice constants of the particle arrays and surrounding medium are also shown to influence the reflectance spectra. Axes with different lengths in ellipsoidal nanoparticles are observed to cause distinguishable resonance peaks when illuminated with polarized light. Peak intensities obtained from both polarizations are observed to decrease under unpolarized illumination. Binary systems consisting of nanosized particles and holes provided better contrast for transmitted light.
Meader, Victoria K. "Metal Nanoparticle Synthesis by Photochemical Reduction with a High-Intensity Focused Laser Beam". VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/6001.
Pełny tekst źródłaNear, Rachel Deanne. "Theoretical and experimental investigation of the plasmonic properties of noble metal nanoparticles". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52181.
Pełny tekst źródłaMalmström, David. "Interfacing Complementary Separation Techniques with Mass Spectrometry Utilizing Electrophoresis, Nanoparticles, and Functionalized Magnetic Beads". Doctoral thesis, Uppsala universitet, Analytisk kemi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183666.
Pełny tekst źródłaDo, Jaekwon [Verfasser], i Jochen [Akademischer Betreuer] Feldmann. "Controlled spatial arrangement of gold nanoparticles using focused laser beams and DNA origami / Jaekwon Do. Betreuer: Jochen Feldmann". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1053913850/34.
Pełny tekst źródłaF, SARRI. "Optical microstructuring of alkali metal nanoparticle coatings on porous silica substrates induced by Bessel beam". Doctoral thesis, Università di Siena, 2019. http://hdl.handle.net/11365/1075534.
Pełny tekst źródłaAntonsson, Egill [Verfasser]. "Photoexcitation, photoionization, and X-Ray scattering of free nanoparticles prepared in a beam / Egill Antonsson". Berlin : Freie Universität Berlin, 2011. http://d-nb.info/102626619X/34.
Pełny tekst źródłaRivera, Felipe. "Electron Microscopy Characterization of Vanadium Dioxide Thin Films and Nanoparticles". BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/2975.
Pełny tekst źródłaCosta, Jessica. "Use and characterisation of free or immobilised enzymatic systems for the synthesis and functionalisation of novel materials". Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1127196.
Pełny tekst źródłaMALAQUIN, Laurent. "Dispositifs ultra-sensibles pour le nano-adressage electrique. Application a la detection de biomolecules". Phd thesis, Université Paul Sabatier - Toulouse III, 2004. http://tel.archives-ouvertes.fr/tel-00009243.
Pełny tekst źródłaLarsson, Mina. "Application of Raman and Fluorescence Spectroscopy to Single Chromatographic Beads". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5741.
Pełny tekst źródłaJohansson, Anders. "Template-Based fabrication of Nanostructured Materials". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7364.
Pełny tekst źródłaKhaywah, Mohammad Yehia. "New ultrasensitive bimetallic substrates for surface enhanced Raman scattering". Thesis, Troyes, 2014. http://www.theses.fr/2014TROY0041/document.
Pełny tekst źródłaDriven by the interest in finding ultrasensitive sensors devices, reliable surface enhanced Raman scattering (SERS) based substrates are fabricated. Silver and gold nanoparticles are two of the best candidates for SERS substrates where Ag nanoparticles exhibit large enhancing ability in Raman intensity while Au nanostructures are stable in biological systems. Hence, combining the two metals in bimetallic nanostructures appeared to be a promising approach in order to sum the merits of Au surface properties and Ag enhancing ability. Thermal annealing of thin metallic films is used as a simple and relatively inexpensive technique to elaborate homogenous and reproducible Ag/Au bimetallic nanoparticles SERS substrates with high enhancing ability. The fabricated nanoparticles proved their enhancing stability even after one year of fabrication. Manipulating the composition of Ag/Au bimetallic NPs resulted in tuning the Localized Surface Plasmon Resonance (LSPR) over the whole visible spectrum, where the substrates are characterized with higher SERS enhancement when they exhibit LSPR closer to the Raman excitation wavelength. Additionally, bimetallic nanoparticles patterns with different size, composition and lattice constants have been conducted by electron beam lithography. The systematic study of their interesting plasmonic and SERS enhancing properties revealed maintenance in the LSPR-SERS relation by changing the nanoparticle size
Muhsin, Mohammad Didare Alam. "Preparation and in vitro evaluation of a polymer based controlled release dry powder inhaler formulation for pulmonary delivery". Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71806/1/Mohammad%20Didare%20Alam_Muhsin_Thesis.pdf.
Pełny tekst źródłaShuwaikan, Mohammed Salem. "Investigation of the uptake, co-localisation, biological effects, and toxicity mechanism(s) of carboxyl-modified polystyrene nanoparticles (COO-PS-NPs) onto human bronchial epithelial (BEAS-2B) cells". Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6155/.
Pełny tekst źródłaJafri, Syed Hassan Mujtaba. "Building Systems for Electronic Probing of Single Low Dimensional Nano-objects : Application to Molecular Electronics and Defect Induced Graphene". Doctoral thesis, Uppsala universitet, Tillämpad materialvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160630.
Pełny tekst źródłaVandenhecke, Ellick. "Nanostructuration de surfaces diélectriques par pulvérisation ionique pour guider la croissance de nanoparticules métalliques". Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2272/document.
Pełny tekst źródłaOn the one hand, the aim of this work is to understand and control the formation of periodic nanometric ripples produced by ion sputtering of dielectric thin films. On the other hand, these nanostructured surfaces are used to guide the growth and organization of silver nanoparticles. These anisotropic systems are characterized by a surface plasmon resonance whose spectral postion is dependent on the polarization of the incident light. We first study the influence of different ion beam sputtering parameters (the ions incidence angle and energy, temperature, energy, flux, fluence) on the ripple morphology (period, amplitude, order, ...) by AFM and GISAXS. The relevant parameters for the control of the ripple morphology are identified as well as some of the physical mechanisms involved. Then, we study the influence of the growth conditions on the structural properties of the nanoparticles (metal deposition angle, ripples pattern quality) by HAADF-STEM. We show that the preferential growth along the ripples is promoted by shadowing effects, thus leading to the formation of linear chains with period similar to the underlying ripples and with more or less elongated and aligned nanoparticles. This results in a far-field tunable optical anisotropy arising from polydisperse interparticle gaps (less than a few nanometers) as well as from more or less strong near-field coupling phenomena. These structures could offer potential for surface enhanced Raman spectroscopy (SERS) applications
Kulaga, Emilia. "Antimicrobial coatings for soft materials". Thesis, Mulhouse, 2014. http://www.theses.fr/2014MULH5312/document.
Pełny tekst źródłaDespite strict operative procedures to minimize microbial contaminations, bacterial infection of implants significantly raises postoperative complications of surgical procedures. One of the promising approaches is to adjust and control antimicrobial properties of the implant surface. New types of antibacterial coatings prepared via plasma polymer functionalization step have been developed. These coatings contain and release in a control way a bioactive agent. Controlled release was achieved by the fabrication of plasma polymer multilayer systems, which consist of two layers of Maleic Anhydride Plasma Polymer deposited on the surface of Polypropylene made surgical mesh. In between plasma polymer layers, silver nanoparticles are trapped as an antibacterial agent reservoir. Owing to differences between mechanical properties of the plasma-polymer thin films and the elastic bulk substrates, tensile strengths generate cracks within the plasma polymer, which might be used as diffusive channels for bioactive substances, here silver ions. The cracks can be controlled mechanically in a reversible way. The tailoring of the spontaneous release of bioactive agent is achieved by the modification of the second plasma polymer deposition conditions. In addition, during mechanical stimulation of the designed material, control over silver ion release is achieved through an elongation-dependent releasing process allowed by the reversible control of the cracks. In the field of textiles and other soft biomaterials, this strategy is promising due to the mechanical stresses that naturally occur at the implant location. In regard of possible application of the developed system as a future biomaterial, the impact of different types of commonly used sterilization procedures on the properties of developed material was studied. The effects of autoclaving and electron beam sterilization methods on the surface chemistry, the dispersion of embedded silver nanoparticles in the plasma polymer and the cracks formation of the developed material was verified. Results showed the compatibility of the developed system with electron beam sterilization method. The antibacterial properties of the new material have been evaluated. The effect of developed system on planktonic bacteria, bacterial adhesion and biofilm formation on stretched and unstretched system was studied. The membrane integrity of the adhered bacteria and bacteria in biofilms was followed during the study as an indicator of the physiologic state of bacteria. Results suggested that the sensitivity of bacteria to low concentrations of released silver ions resulted in the formation of different types of structures of the biofilms on the studied materials. The results give a strong base on the future of intelligent, silver containing materials that control the release at the site of infection. Our results show that low doses of silver may be sufficient to control infection by acting on the structure of bacterial biofilms
MIGLIORINI, LORENZO. "DEVELOPMENT OF FUNCTIONAL NANOCOMPOSITE MATERIALS TOWARDS BIODEGRADABLE SOFT ROBOTICS AND FLEXIBLE ELECTRONICS". Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/704286.
Pełny tekst źródłaČangelová, Katarína. "Studium možných aplikací polymeru kyseliny glutamové". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401873.
Pełny tekst źródłaShe, Zhe. "Generation of micro/nano metallic nanostructures using self-assembled monolayers as template and electrochemistry". Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3089.
Pełny tekst źródłaDethlefsen, Mark Georg Bernhard. "Charge transfer processes of atomic hydrogen Rydberg states near surfaces". Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:1ef5ece3-43cf-40fc-a1fd-bf7c637e2d23.
Pełny tekst źródłaKoneti, Siddardha. "In situ and 3D environmental transmission electron microscopy of Pd-Al2O3 nano catalysts : Fast tomography with applications to other catalytic systems in operando conditions and to electron beam sensitive nanomaterials". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI123/document.
Pełny tekst źródłaIn the beginning of the XXIst century, Environmental Transmission Electron Microscopy has become one of the reliable characterization techniques of nanomaterials in conditions mimicking their real life. ETEM is now able to follow the dynamic evolution of nanomaterials under various conditions like high temperature, liquid or various gas pressures. Among various fields of research, catalysis can benefit significantly from Environmental Microscopy. This contribution starts with the study of the Palladium-Alumina catalytic system. Pd nanoparticles supported by α-Al2O3 and δ-Al2O3 are of an important physicochemical and environmental interest, particularly in the field of selective hydrogenation in petrochemistry, for the synthesis of polymers or CO2 hydrogenation for methane production. We first performed 2D analyses at different steps of the synthesis process, then the same synthesis steps were performed under in situ conditions. The motivation of this approach was to compare post mortem treatments with ETEM observations. In general, 2D data provide limited insights on, for example, the morphology and position of supported nanoparticles. We have then developed a new fast acquisition approach to collect tomographic tilt series in very short times, enabling to reconstruct nano-systems in 3D during their dynamical evolution. Taking advantage of this approach, we have determined the activation energy for soot combustion on YSZ oxidation catalysts for diesel motors from volumetric data extracted from in situ experiments. Fast electron tomography was also applied to electron beam sensitive materials, like polymer nanocomposites and biological materials, showing the wide spectrum of possible applications for rapid 3D characterization of nanomaterials
Stanislav, Silvestr. "Příprava nízkodimenzionálních III-V polovodičů". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443735.
Pełny tekst źródłaLiu, Yang. "‘Tri-3D’ electron microscopy tomography by FIB, SEM and TEM : Application to polymer nanocomposites". Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0076/document.
Pełny tekst źródłaThis work is focused on the characterization and quantification of the 3D distribution of different types of fillers (nanoparticles, nanotubes, etc.) in polymer matrices. We have essentially used tomography techniques in electron microscopy. Multiple approaches to electron tomography were performed: FIB-SEM (focused ion beam/scanning electron microscope) tomography, SEM tomography and TEM (transmission electron microscope) tomography. Polymer nanocomposites are basically synthesized in order to improve the physical properties (mechanical, electric, etc.) of the pure polymer constituting the matrix, by a controlled addition of fillers at the nanoscale. The characterization of such materials and the establishment of accurate correlations between the microstructure and the modified properties require a three-dimensional approach. According to the nanometric size of the fillers, electron microscopy techniques are needed. Two systems of polymer nanocomposites have been studied by multiple electron tomography approaches: P(BuA-stat-S)/MWNTs (statistical copolymer poly(styrene-co-butyl acrylate) reinforced by multi-walled carbon nanotubes) and P(BuA-stat-MMA)/SiO2 (statistical copolymer poly(butyl acrylate-co-methyl methacrylate) reinforced by silica nanoparticles). By combining various techniques, the characterization and the quantification of nanofillers were possible. In particular, statistics about size, distribution and volume fraction of the fillers were measured. This study has then provided 3D information, which contributes to a better understanding of properties of the nanocomposites. Attention has been paid to analyze carefully original data, and artifacts and causes of errors or inaccuracy were considered in the 3D treatments. We also attempted to compare benefits and drawbacks of all techniques employed in this study, and perspectives for future improvements have been proposed
Owusu-Mensah, Martin. "Understanding the first formation stages of (Y,Ti) nano-oxides in Oxide Dispersion Strengthened (ODS) steels". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS310.
Pełny tekst źródłaOxide Dispersion Strengthened (ODS) steels, that is steels reinforced with a homogeneous distribution of (Y,Ti) oxide nano-particles, are advanced structural materials for nuclear applications. The oxide particles serve as point defect recombination centres and obstacles to dislocation motion thereby improving radiation resistance and high-temperature strength of these steels making them perfect candidate materials for future fusion and fission nuclear reactors. The conventional fabrication of ODS steels is achieved by mechanical alloying followed by thermomechanical heat treatments. This way of ODS steel production seems complicated to understand the physical mechanisms leading to the precipitation of nano-oxide particles. The kinetics of nanoparticle formation can be much better studied using an alternative technique of nanoparticle growth, namely Ion Beam Synthesis (IBS). This approach has many advantages including the precise control of experimental parameters and the ability to de-correlate various factors contributing to precipitation kinetics. A better knowledge gained in this way would be potentially helpful for optimization of ODS steel production routines. In the course of this PhD study, the IBS approach was applied to investigate the co-precipitation of metal (Y and/or Ti) and oxygen ions implanted into a model Fe-Cr alloy with the composition close to those typical for commercial ODS steels. Following the standard IBS schedule, consisting of ion implantation followed by high-temperature heat treatment, ions of Y, Ti and O at low energies were implanted into high-purity Fe10wt%Cr alloy samples at room temperature. The implanted samples were then annealed at various temperatures ranging from 600 to 1100°C to promote the precipitation of nano-oxide particles. A range of Transmission Electron Microscopy techniques were used to characterize the crystallographic structure and chemical composition of the nanoparticles. The study has been performed following three sets of experiments. First of all, the sequential implantation of Ti and O ions was implemented. Subsequent annealing at temperatures below 1000°C revealed that precipitation of titanium oxide was suppressed. Instead, chromium-rich nano-oxide particles with corundum hexagonal structure were found to precipitate. At sufficiently high temperatures these corundum particles were found to contain certain amount of Ti. Only after annealing at the highest temperature of 1100°C, particles of another type with Ti enriched core and Cr enriched shell were additionally fixed. Secondly, sequential Y and O ion implantation resulted in the formation of probable yttrium-rich oxides at 800°C. Annealing at 1100°C promoted their growth to larger sized yttria (Y₂O₃) particles with a Cr enriched shell. Finally, sequential ion implantation of both metal ions (Y and Ti) was performed, followed by O implantation. The order of metal ion implantation has been found to be crucial for subsequent oxide precipitation at the annealing stage. With the Ti implantation first in the sequence, the precipitation of corundum hexagonal chromium-rich oxide was observed, very similar to the case of Ti and O implantation. In contrast, implantation starting with Y produced yttrium-titanium oxide particles with unidentifiable structure. Summing up, the study has demonstrated the feasibility of the formation of Y, Ti and (Y,Ti) oxides by ion implantation. The thesis presents the detailed characterization of the nanoparticles, as well as the discovered specific features of precipitated particles, such as the presence of orientation relationships between the particles and the FeCr matrix, which was observed even for the case of Cr-rich corundum particles. Finally, the implications of the obtained results, in conjunction with the already known data from the existing literature, for the better understanding of the mechanisms involved in the formation of nano-oxide particles in ODS steels are discussed
Badran, Ghidaa. "Pollution atmosphérique particulaire : caractérisation physico-chimique et comparaison des effets toxiques des fractions extractible et non-extractible des PM₂.₅ In-vitro evaluation of organic extractable matter from ambient PM₂.₅ using human bronchial epithelial BEAS-2B cells : Cytotoxicity, oxidative stress, pro-inflammatory response, genotoxicity, and cell cycle deregulation. Toxicity of fine and quasi-ultrafine particles : focus on the effects of organic extractable and non-extractable matter fractions. Toxicological appraisal of the chemical fractions of ambient fine (PM₂.₅-₀.₃) and quasi-ultrafine (PM₀.₃) particles in human bronchial epithelial BEAS-2B cells". Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0547.
Pełny tekst źródłaAir pollution and particulate matter (PM₂.₅) were classified as carcinigens (group 1) by the International Agency for Research on Cancer in 2013. This particulate fraction represents a complex mixture with a highly variable composition influencing the toxicity. However, few studies have determined the respective involvement of the different chemical fractions of PM in their toxic effects. In this work, fine particles (PM₂.₅₋₀.₃) and quasi-ultrafine particles (PM₀.₃) were sampled in an urban site located in Beirut (Lebanon). After performing the physicochemical characterization of these two types of particles, their toxic effects (global cytotoxicity, metabolic activation, genotoxicity, inflammation, oxidative stress, autophagy and apoptosis) were investigated on a human bronchial epithelial cell line (BEAS-2B). The analysis of the organic content revealed differences between the concentrations of polycyclic aromatic hydrocarbons (PAHs), as welle as oxygenated (O-PAH) and nitrated (N-PAH) congeners, respectively 43, 17 and 4 times higher in PM₀.₃ than in PM₂.₅₋₀.₃.The toxicological study was based on the comparison of the toxicity of the fine particles considered in their entirety (PM₂.₅₋₀.₃), the extracted organic fraction (OEM₂.₅₋₀.₃) and the fraction not extracted by the dichloromethane (NEM₂.₅₋₀.₃). In addition, the specific effects of the organic fraction extrated from the quasi-ultrafine particles (OEM₀.₃) were compared with those of the organic fraction extracted from the fine particles (OEM₂.₅₋₀.₃). Our results showed that all the studied fractions were able to induce at least one of the studied mechanisms. PM₂.₅₋₀.₃ was able to induce toxic effects greater than those induced by OEM₂.₅₋₀.₃ and NEM₂.₅₋₀.₃. The organic fraction extracted from the quasi-ultrafine particles (OEM₀.₃), richer in organic compounds and in particular in PAHs and other congeners, appeared to be responsible for deleterious effects globally greater than that extracted from the fine particles (OEM₂.₅₋₀.₃). The results of this work have brought new elements on the relative toxicity of the different fractions of the fine particles and underline the crucial role played by ultrafine particles, still too little studied
Teixeira, Fernanda de Sá. "Implantação iônica de baixa energia em polímero para desenvolvimento de camadas compósitas nanoestruturadas condutoras litografáveis". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-23082010-103839/.
Pełny tekst źródłaElectronics using polymers instead of silicon is a recent research area with promising economic perspectives. Polymer with metallic particles composites presents interesting electrical, magnetic and optical properties and they have been produced by a broad variety of techniques. Metal ion implantation using plasma is one of the used methods to obtain conductor composites. In this work it is performed low energy gold ion implantation in PMMA by using plasma. PMMA has great technological importance once it is broadly used as resist in electron-beam, X-ray, ion and deep UV lithography. As a result of low energy ion implantation in PMMA, a nanometric conducting layer is formed. This new material, named insulator-conductor composite, can allow the creation of micro and nanodevices through well known microelectronics techniques. Electrical measurements are performed in situ as a function of metal ions implanted dose, which allows the investigation of electrical transport of these new materials, which can be modeled by the percolation theory. Simulations using TRIDYN computer code provide the prediction of depth profile of implanted ions. Important characterizations are showed such as Transmission Electron Microscopy, Scanning Tunneling Microscopy, Small Angle X-Ray Scattering, X-Ray Diffraction and UV-vis Spectroscopy. These techniques allow to visualize and to investigate the nanostructured character of the metal-polymer composite. Still as a part of this project, the conducting layers formed are characterized in relation to the maintenance of their characteristics as electron-beam resist.
Casimirius, Stéphane. "Croissance localisée de nanotubes de carbone aux échelles micrométrique et nanométrique". Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00136052.
Pełny tekst źródłaCao, Shuiyan. "Using plasmonic nanostructures to control electrically excited light emission". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS042/document.
Pełny tekst źródłaIn this thesis, we use different plasmonic nanostructures to control the emission of electrically-excited light. Our electrical emission is from an “STM-nanosource” which uses the inelastic tunnel current between the tip of a scanning tunneling microscope (STM) and a metallic sample, to locally excite both localized and propagating surface plasmon polaritons. The interaction of our STM-nanosource and a circular plasmonic lens (a series of concentric slits etched in a thick gold film) produces a radially polarized microsource of low angular spread (≈±4°). The influence of the structural parameters on the angular spread of the resulting microsource is also investigated. In addition, a low angular spread (<±7°) for a large wavelength range (650-850 nm) is achieved. Thus this electrically-driven microsource of nearly collimated light has a broad spectral response and is optimal over a wide energy range, especially in comparison with other resonant plasmonic structures such as Yagi-Uda nanoantennas. The interaction of our STM-nanosource and an elliptical plasmonic lens (a single elliptical slit etched in a thick gold film) is also studied. When the STM excitation is located at the focal point position of the elliptical plasmonic lens, a directional light beam of low angular spread is acquired. Moreover, in the experiment we find that by changing the eccentricity of the elliptical plasmonic lens, the emission angle is varied. It is found that the larger the eccentricity of the elliptical lens, the higher the emission angle. This study provides a better understanding of how plasmonic nanostructures shape the emission of light. The interaction of STM-excited SPPs and a planar plasmonic multi-layer stack structure is also investigated. It is demonstrated that using STM excitation we can probe the optical band structure of the Au-SiO₂-Au stack. We find that the thickness of the dielectric plays an important role in changing the coupling between the modes. We also compare the results obtained by both laser and STM excitation of the same stack structure. The results indicate that the STM technique is superior in sensitivity. These findings highlight the potential of the STM as a sensitive optical nanoscopic technique to probe the optical bands of plasmonic nanostructures. Finally, the interaction of an STM-nanosource and an individual triangular plate is also studied. We find that when the STM excitation is centered on the triangular plate, there is no directional light emission. However, when the STM-nanosource is located on the edge of the triangle, directional light emission is obtained. This study provides us a novel avenue to achieve directional light emission. We also study probing the optical LDOS of the triangle with the STM-nanosource. Thus, our results show that the manipulation of light is achieved through SPP-matter interactions. Using plasmonic nanostructures, we control the collimation, polarization, and direction of the light originating from the STM-nanosource
Johannessen, Bernt. "Ion beam formation and modification of metallic nanoparticles". Phd thesis, 2007. http://hdl.handle.net/1885/150441.
Pełny tekst źródłaSprouster, David John. "Ion beam formation and modification of Cobalt nanoparticles". Phd thesis, 2010. http://hdl.handle.net/1885/150492.
Pełny tekst źródła"Synthesis and laser light scattering studies of linear polymer chains and polymeric nanoparticles". 2001. http://library.cuhk.edu.hk/record=b5890650.
Pełny tekst źródłaThesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 77-78).
Abstracts in English and Chinese.
Abstract --- p.i
Chinese Abstract --- p.ii
Acknowledgement --- p.iv
Contents --- p.v
Abbreviations --- p.viii
List of Figures --- p.xiv
List of Tables --- p.xviii
Chapter Chapter 1 --- Introduction --- p.1
Chapter Chapter 2 --- Basic Principle of Laser Light Scattering and Instrumentation --- p.7
Chapter 2.1 --- Static laser light scattering (Static LLS) --- p.8
Chapter 2.2 --- Dynamic laser light scattering (Dynamic LLS) --- p.9
Chapter 2.3 --- Calibration between translational diffusion coefficient D and molar mass M --- p.10
Chapter 2.3.1 --- Tranform G(D) to Molar Mass Distributionfw(M) --- p.10
Chapter 2.3.2 --- Calibration between D and M- Using a set of narrowly distributed standards --- p.12
Chapter 2.3.3 --- Calibration between D and M- Using two or more broadly distributed samples --- p.12
Chapter 2.4 --- Data Analysis --- p.14
Chapter 2.5 --- References --- p.16
Chapter Chapter 3 --- Experimental --- p.17
Chapter 3.1 --- Laser Light Scattering Instrumentation --- p.17
Chapter 3.1.1 --- Overview of laser light scattering spectrometer --- p.17
Chapter 3.1.2 --- Differential Refractometer --- p.18
Chapter 3.2 --- References --- p.21
Chapter Chapter 4 --- Thermally Sensitive and Biocompatible Poly(N-vinylcaprolactam): Synthesis and Characterization of High Molar Mass Linear Chains
Chapter 4.1 --- Introduction --- p.22
Chapter 4.2 --- Sample Preparation --- p.23
Chapter 4.3 --- Results and discussion --- p.24
Chapter 4.4 --- Conclusion --- p.27
Chapter 4.5 --- References --- p.29
Chapter Chapter 5 --- Stabilization and destabilization of potassium persulfate (as an initiator) in an surfactant-free water/acetone mixture emulsion polymerization of styrene under microwave irradiation
Chapter 5.1 --- Introduction --- p.41
Chapter 5.2 --- Experimental --- p.43
Chapter 5.3 --- Results and discussion --- p.44
Chapter 5.4 --- Conclusion --- p.51
Chapter 5.5 --- References --- p.53
Appendix
Chapter A.l --- Static Laser Light Scattering --- p.66
Chapter A.1.1 --- Scattering from a small particles --- p.66
Chapter A.1.2 --- Scattering from a large particles --- p.67
Chapter A.1.3 --- Scattering by solutions of small molecules --- p.69
Chapter A.1.3.1 --- Scattering from polymer solutions --- p.70
Chapter A.2 --- Dynamic laser light scattering --- p.71
Chapter A.2.1 --- Line-width measurement --- p.73
Chapter A.2.2 --- Data analysis --- p.75
"Studies on nanobubbles in aqueous solutions". Thesis, 2007. http://library.cuhk.edu.hk/record=b6074438.
Pełny tekst źródłaChapter 2 introduces the theories of static and dynamic light scattering and Zeta-potential measurements as well as the details of the instrument set-up. In this chapter, the fundamental equations of the scattering theory are figured out basis on the quasi-classical electrodynamics and combination of the statistical mechanics as well as molecular dynamic theory. Finally, the statistical properties of photon counting are discussed.
In chapter 3, aqueous solutions of tetrahydrofuran, ethanol, urea and alpha-cyclodextrin were studied by a combination of static and dynamic laser light scattering (LLS). In textbooks, these small organic molecules are soluble in water so that there should be no observable large structures or density fluctuation in either static or dynamic LLS. However, a slow mode has been consistently observed in these aqueous solutions in dynamic LLS. Such a slow mode was previously attributed to some large complexes or supramolecular structures formed between water and these small organic molecules, Our current study reveals that it is actually due to the existence of small bubbles (∼100 nm in diameter) formed inside these solutions. Our direct evidence comes from the fact that it can be removed by repeated filtration and regenerated by air purging. Our results also indicate that the formation of such nanobubbles in small organic molecules aqueous solutions is a universal phenomenon. Such formed nanobubbles are rather stable. The measurement of isothermal compressibility confirms the existence of a low density micro-phase, presumably nanobubbles, in these aqueous solutions. Using a proposed structural model, i.e., each bubble is stabilized by small organic molecules adsorbed at the gas/water interface, we have, for the first time, estimated the pressure inside these nanobubbles.
In chapter 4, by using a combination of laser light scattering (LLS) and zeta-potential measurements, we investigated effects of salt concentration and pH on stability of the nanobubbles in alpha-cyclodextrin (alpha-CD) aqueous solutions. Our LLS results reveal that the nanobubbles are unstable in solutions with a higher ionic strength, just like colloidal particles in an aqueous dispersion, but become more stable in alkaline solutions. The zeta-potential measurement shows that the nanobubbles are negatively charged with an electric double layer, presumably due to the adsorption of negative OTT ions at the gas/water interface. It is this double layer that plays dual roles in the formation of stable nanobubbles in aqueous solutions of water-soluble organic molecules; namely, it not only provides a repulsive force to prevent the inter-bubble aggregation and coalescence, but also reduces the surface tension at the gas/water interface to decreases the internal pressure inside each bubble.
In chapter 5, the addition of salt can induce slow coalescence of nanobubbles (∼100 nm) in an aqueous solution of alpha-cyclodextrin (alpha-CD). A combination of static and dynamic laser light scattering was used to follow the coalescence. Our results reveal that its kinetic and structural properties follow some scaling laws; namely, the average size (<zeta>) of nanobubbles is related to their average mass (<M>) and the coalescence time (t) as <M> <zeta>dr and <zeta> ∼ tgamma with two salt-concentration dependent scaling exponents (df and gamma) For a lower sodium chloride concentration (C NaCl = 40 mM), gamma = 0.13 +/- 0.01 and df = 1.71 +/- 0.02. The increase of CNaCl to 80 mM results in gamma = 0.32 +/- 0.01 and df = 1.99 +/- 0.01. The whole process has two main stages: the aggregation and the coalescence. At the lower C NaCl, the process essentially stops in the aggregation stage with some limited coalescence. At higher CNaCl leads the coalescence after the aggregation and results in large bubbles.
In this thesis, the nanobubbles in the aqueous solutions have been studied by using combination of static and dynamic laser light scattering (LLS), isothermal compressibility measurements and Zeta-potential measurements. We found that the nanobubbles extensively exist in aqueous solutions and the interface of each nanobubble is negatively charged. The addition of electrolytes can destabilize such interface to induce the coalescence of nanobubbles.
Jin, Fan.
"Aug 2007."
Adviser: Chi Wu.
Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1030.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (p. 108).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.
LIN, YONG-FENG, i 林湧峰. "Green Synthesis of Silver Nanoparticles Using Mung Beans Soaking Medium". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/n528ns.
Pełny tekst źródła國立高雄應用科技大學
化學工程與材料工程系碩士在職專班
104
The preparation of silver nanoparticles using mungbean soaking solution as the reducing agent was reported in this study. First, the effect of mungbean soaking condition on the formation of silver nanoparticles was examined. As compared to the germination mungbean, the soaking solution from non-germination mungbeam showed a higher reducing ability. The formation rate of silver nanoparticles was affected by the soaking time of mungbean. It was found that the formation rate of silver nanoparticles in mungbean soaking solution could be attributed to a higher concentration phytic acid releasing from mungbean. Since phytic acid could be degraded by the phytase from soaking mungbean, the mungbean soaking solution was boiled from 30 min for inactivating phytase. The results indicated that the formation rate of silver nanoparticles was further improved in boiled mungbean soaking solution. Phytic acid could be used as a natural reducing agent for synthesizing metal nanoparticles. The process of increasing the phytic acid concentration from plants would improving the formation of metal nanoparticles.
Sanyal, Udishnu. "Modulation of Nanostructures in the Solid and Solution States and under an Electron Beam". Thesis, 2013. http://etd.iisc.ernet.in/2005/3303.
Pełny tekst źródłaSanyal, Udishnu. "Modulation of Nanostructures in the Solid and Solution States and under an Electron Beam". Thesis, 2013. http://etd.iisc.ac.in/handle/2005/3303.
Pełny tekst źródłaAmolo, George Odhiambo. "Optical and electrical properties of ion beam modified materials". Thesis, 2008. http://hdl.handle.net/10539/5409.
Pełny tekst źródłaHsieh, Chang Lin, i 謝長霖. "Optical properties of ion-beam-synthesized Au nanoparticles in SiO2 matrix". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/5e9esx.
Pełny tekst źródła國立清華大學
核子工程與科學研究所
104
In recent years, gold (Au) nanoparticles have been synthesized by means of various methods and have received promising potential in optical and biomedical detection. Au nanoparticles contain some remarkable dimension-dependent optical properties due to surface plasmon resonance (SPR) in Au nanoparticles which causes strong absorption of the incident light in visible light regions. Since SPR in well-crystallized Au nanoparticles can enhance the local electromagnetic field, it is thus expected that a greater efficiency in the photoluminescence (PL), originating from oxygen deficiency centers (ODC), can be achieved in Au-implanted SiO2 matrix. In order to demonstrate the enhancement of PL, in this story, Au nanoparticles were formed in SiO2 film using ion beam synthesis and their optical and microstructural properties were also investigated as well. The results revealed that a clear absorption peak at approximately 520 nm was identified in the UV-Vis spectra and was attributed to SPR induced by Au nanoparticles in SiO2 film. The SPR of Au nanoparticles is also dependent on thermal treatment conditions, such as annealing gas, annealing temperature and annealing time. The Au nanoparticle-containing SiO2 film also displayed several distinctive peaks at approximately 310, 380, 450, and 600 nm in the PL spectra and were found to be associated with ODC-related defects and non-bridging oxygen hole centers (NBOHC) in SiO2 film. In addition, the PL peak intensities increase as annealing temperature increase, a finding contradictory to the defect recovery. The greatest PL emission was achieved when the Au-implanted SiO2 film was annealed at 1100 oC for 1 h under the nitrogen ambient. Therefore, the existence of Au nanoparticles in SiO2 film can induce SPR effects and enhance PL emission which was mainly due to defect dependent luminescence centers.