Дисертації з теми "Energy X-ray Dispersive Spectroscopy (EDX)"
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Canli, Sedat. "Thickness Analysis Of Thin Films By Energy Dispersive X-ray Spectroscopy." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612822/index.pdf.
Повний текст джерелаGharehbaghi, Ali. "Precipitation Study in a High Temperature Austenitic Stainless Steel using Low Voltage Energy Dispersive X-ray Spectroscopy." Thesis, KTH, Materialens processteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103492.
Повний текст джерелаHubbard, Philip J. "Understanding biomineralization of polycaprolactone surfaces." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/119039/1/Philip_Hubbard_Thesis.pdf.
Повний текст джерелаRueda-Fonseca, Pamela. "Magnetic quantum dots in II-VI semiconductor nanowires." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GRENY015/document.
Повний текст джерелаIn this PhD work a novel type of magnetic semiconductor object has been developed: Cd(Mn)Te quantum dots embedded in ZnTe/ZnMgTe core-shell nanowires. The goal was to investigate the growth, by molecular beam epitaxy, and the fundamental properties of these complex heterostructures. For that purpose, two main issues were addressed: i) gaining control of the structural, electronic and magnetic properties of these quantum objects by mastering their growth; and ii) obtaining quantitative local knowledge on the chemical composition of those non-homogeneous nanostructures. To tackle these topics, our research was divided into four stages. The first stage was devoted to perform a quantitative study of the formation process of the Au particles that catalyze the growth of nanowires. The second stage involved the analysis of the mechanisms and parameters governing the growth of ZnTe nanowires. In particular, two different types of nanowires were found: cone-shaped nanowires with the zinc-blende crystal structure and cylinder-shaped nanowires with the hexagonal wurtzite structure. A diffusion-driven growth model is employed to fit some of the quantitative results presented in this part. The third stage focused on the insertion of pure CdTe quantum dots containing Mn ions in the core-shell nanowires. An initial study of the relevant parameters influencing the magneto-optical properties of these objects, such as the quantum dot confinement, the Mn incorporation, and the strain anisotropy, was performed. The four and last stage of this work concerned the quantitative interpretation of Energy-Dispersive X-ray spectroscopy measurements performed on single core-multishell nanowires. A geometrical model was proposed to retrieve the shape, the size and the local composition of the quantum dot insertions and of the multiple layers of the heterostructures. This study was coupled to other complementary characterization measurements on the same nanowire, such as cathodo-luminescence, micro-photo-luminescence and magneto-optical spectroscopy
Lepinay, Kevin. "Développement et applications de la tomographie chimique par spectroscopie EDX." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0124/document.
Повний текст джерелаThis thesis focuses on the evaluation of the STEM EDX chemical tomography technique: development of experimental procedures, data processing and volumes reconstruction, quality analysis of the results and evaluation of the overall complexity. Until now, STEM EDX analysis performances were very limited, so only few studies about this technique have been realized. However, very significant progress procured by the new SDD detectors as well as by the high brightness electronic sources (X-FEG), making the STEM EDX 2D analysis very fast, have revived the possibility of the chemical tomography, although the technique has to be developed and evaluated (performance and complexity). We have worked on a Tecnai Osiris which acquires EDX chemical mapping of hundreds of thousands of pixels with resolution of one nanometer and in a few minutes. We chose to prepare the rod-shaped samples by FIB and use a sample holder allowing an angle of exploration of 180° without shadowing effects. Then, using model samples (SiO2 balls in resin), we evaluated the sample deformation due to the electron beam irradiation. This allowed us to propose a method to reduce this effect by depositing a 20 nm chromium layer. Images simulations were used to evaluate the software and the reconstruction methods. The methodology of each step of the STEM EDX tomography analysis is then explained and the technique interest is demonstrated by comparing the 2D and the 3D analysis of a transistor 28 nm FDSOI. The quality of the reconstructions (signal-to-noise ratio, spatial resolution) was evaluated, in function of experimental parameters, using simulations and experiments. A resolution of 4 nm is demonstrated through the analysis of a test pattern and a "gate all around” transistor. For the same transistor, the possibility and the interest of a failure analysis at the nanoscale is proven. Analyses of a SRAM gate fail or of the holes in a copper pillar explain the benefits of a combination between a HAADF volume (morphology and resolution < 4 nm) and an EDX volume (chemical information). To conclude, this technique, which still needs to be improved in terms of simplicity, is already showing its usefulness for the analysis and the development of advanced technologies (20nm node and beyond)
Ozaslan, Mehtap, Wei Liu, Maarten Nachtegaal, Anatoly Frenkel, Bogdan Rutkowski, Matthias Werheid, Anne-Kristin Herrmann, et al. "Homogeneity and Elemental Distribution in Self-Assembled Bimetallic Pd-Pt Aerogels prepared by a spontaneous one-step gelation process." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-210970.
Повний текст джерелаLu, Shifeier. "Analytical study of osteoporosis of maxilla in ovariectomized rats." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/88474/1/Shifeier_Lu_Thesis.pdf.
Повний текст джерелаFairbrother, P. J. "Thermal diffuse scattering in energy-dispersive x-ray spectroscopy." Thesis, University of Exeter, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232967.
Повний текст джерелаVídeňský, Ondřej. "Analýza bateriových hmot metodami EDS." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-399522.
Повний текст джерелаKleinhans, Henrik. "Evaluation of the Carbonization of Thermo-Stabilized Lignin Fibers into Carbon Fibers." Thesis, Linköpings universitet, Kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-120519.
Повний текст джерелаSlater, Thomas Jack Alfred. "Three dimensional chemical analysis of nanoparticles using energy dispersive X-ray spectroscopy." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/three-dimensional-chemical-analysis-of-nanoparticles-using-energy-dispersive-xray-spectroscopy(3eb607a2-eb03-4d45-b9eb-71b0ca45c2db).html.
Повний текст джерелаLee, Ester Mi Ryoung. "Análise in vitro da morfologia superficial de uma nova formulação de biovidro associado ao laser de Nd:YAG e laser de CO2 sobre dentina humana." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/23/23155/tde-24082017-140846/.
Повний текст джерелаAmong desensitizing therapies options, the most recent proposal for Dentin Hypersensitivity treatment is the use of bioglass. This new material presents the ability to promote the formation of hydroxyapatite on dentin surface, representing a more stable and lasting chemical bond on dentin tubules. This work compared the effect of a new formulation of bioglass dispersed in 30% phosphoric acid, associated with Nd: YAG laser and CO2 laser in the obliteration of exposed dentin tubules. 96 human dentin samples were obtained, divided into 6 experimental groups (n = 16) and distributed as follows: G1 - negative control (no additional treatment);? G2- Nd: YAG laser;? G3 - CO2 laser;? G4 - bioglass paste (bioglass + 30% phosphoric acid);? G5 - bioglass paste + Nd: YAG laser;? G6 - bioglass paste + CO2 laser. Groups G5 and G6 were irradiated with Nd:YAG laser and CO2 laser, respectively, after treatment with the slurry dispersed in phosphoric acid. At the end of the experiment, all groups were qualitatively analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-ray Energy Dispersion Spectroscopy (EDS). The analysis showed that the dispersion of bioglass in 30% phosphoric acid forms calcium hydrogen phosphate crystals and when the formulated paste is applied on dentin surface, chemical reactions occur with the dental structure, forming monetite crystals. When irradiating these crystals with Nd: YAG and CO2 laser, dehydration of these crystals occurred leading to the formation of hydroxyapatite. MEV images demonstrate the formation of crystalline and amorphous precipitates of varying dimensions on the dentin surface and at the entrance of dentinal tubules in all groups receiving treatment with the bioglass formulation. The CO2 laser was able to promote changes in the morphology of the formed material even more evident especially in the dimension and arrangement of hydroxyapatite crystals formed on the surface. The analysis of EDS showed the presence of silicon, a compound that is not naturally present in the tooth structure, but only in the bioglass composition. Thus, it can be concluded that the association of bioglass powder with 30% phosphoric acid allowed the formation of a layer of crystals on the surface and its entrance of the dentinal tubules, evidencing that the formulated paste enables the application and maintenance of bioglass on dentin surface. Its association with the Nd:YAG and CO2 laser seems to improve the interaction of these crystals with dentin, forming hydroxyapatite crystals. In this study. CO2 laser promoted better crystals distribution and conformation on dentin surface.
Alexandrina, Eduardo Carlos. "Caracterização e composição química do material particulado grosso (MP10) no centro da cidade de São Carlos (SP)." Universidade Federal de São Carlos, 2015. https://repositorio.ufscar.br/handle/ufscar/7241.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coarse particulate matter with aerodynamic diameter smaller than 10μm (PM10) have long been considered as air pollutants associated with health issues. They penetrate into the upper respiratory tract, causing respiratory problems such as worsening of asthma. The aim of this study was to determine and quantify the distribution of chemical elements in the PM10 particulate matter present in the atmosphere of the city of Sao Carlos (Sao Paulo). Samples were collected daily for a period of 23h and 30 minutes, from April 16, 2014 to April 16, 2015. A high-volume sampler (AGV-PM10) with micro quartz and fiber glass filters were used. The filters were subjected to gravimetric analysis to obtain the mass of PM10 and were then analyzed by energy dispersive X-ray fluorescence and Laser Induced Breakdown Spectroscopy to identify and quantify the chemical composition of the samples. The highest average concentration during twelve-month period was 70.41μg/m³ (August, 2014) and the smallest was 22.59μg/m³ (January, 2015). The annual arithmetic average found for the twelve months period was 42.71μg/m³. If compared with annual arithmetic average limit of 40μg/m³, established by CETESB, the value is slightly above and below 50 μg/m³ (CONAMA). If we consider the limit established by the World Health Organization (WHO), which is 20μg/m³, this value is much higher than recommended. The chemicals elements found were characteristic of urban areas
O material particulado, cujo diâmetro aerodinâmico é menor do que 10μm vem sendo considerado como poluente atmosférico muito associado a questões de saúde, uma vez que são os que penetram em vias respiratórias, agravando problemas como o da asma, por exemplo. O objetivo deste trabalho foi avaliar os níveis de concentração de material particulado (MP10) e determinar a distribuição dos elementos químicos deste material particulado presente no ar atmosférico do centro da cidade de São Carlos (São Paulo). As amostras foram coletadas diariamente, por um período de 23h e 30 minutos, entre 16 de abril de 2014 a 16 de abril de 2015. Foi utilizado um amostrador de grandes volumes (AGV-MP10), submetendo os filtros, de fibra de vidro e de micro quartzo, à análise gravimétrica para obtenção de massa de MP10, Fluorescência de Raios-X de Energia Dispersiva de (EDX) e a Espectroscopia de ruptura induzida por laser (LIBS) para identificação e quantificação da composição química elementar das amostras. A maior concentração média do período de doze meses amostrado foi de 70,41μg/m³ em agosto/2014 e a menor de 22,59μg/m³ em janeiro/2015. A média aritmética anual encontrada para o período de doze meses foi de 42,71μg/m³. Se comparada com a média aritmética anual do limite estabelecido pela CETESB, de 40μg/m³, o valor está um pouco acima e um pouco abaixo de 50 μg/m³(CONAMA). Se for considerado o limite estabelecido pela Organização Mundial da Saúde (OMS), que é de 20 μg/m³, este valor encontra-se muito acima do recomendado. Os elementos químicos encontrados são característicos de áreas urbanas e apresentam resultados semelhantes a estudos anteriores na cidade.
Unuigbe, David Moweme. "Characterisation of silicon nanoparticles produced by mechanical attrition using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoemission spectroscopy." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/12105.
Повний текст джерелаIncludes bibliographical references.
The establishment of printing technologies, using nanoparticle based inks, promises inexpensive manufacture of electronic devices. However, to produce working devices, nanoparticles have to meet requirements on size, shape, and composition. In the application of silicon nanoparticles in electronics, it is important that a network of interconnecting particles is formed through which charge transport can take place. Of further importance is that there is an absence of surface oxide in order to maintain a direct silicon-silicon connection within the network. In this work, cheap and scalable production of silicon nanoparticles is achieved efficiently with a top-down process of mechanical attrition by high energy milling.
Bhattacharya, Arunodaya. "Ion irradiation effects on high purity bcc Fe and model FeCr alloys." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112398/document.
Повний текст джерелаFeCr binary alloys are a simple representative of the reduced activation ferritic/martensitic (F-M) steels, which are currently the most promising candidates as structural materials for the sodium cooled fast reactors (SFR) and future fusion systems. However, the impact of Cr on the evolution of the irradiated microstructure in these materials is not well understood in these materials. Moreover, particularly for fusion applications, the radiation damage scenario is expected to be complicated further by the presence of large quantities of He produced by the nuclear transmutation (~ 10 appm He/dpa). Within this context, an elaborate ion irradiation study was performed at 500 °C on a wide variety of high purity FeCr alloys (with Cr content ranging from ~ 3 wt.% to 14 wt.%) and a bcc Fe, to probe in detail the influence of Cr and He on the evolution of microstructure. The irradiations were performed using Fe self-ions, in single beam mode and in dual beam mode (damage by Fe ions and co-implantation of He), to separate ballistic damage effect from the impact of simultaneous He injection. Three different dose ranges were studied: high dose (157 dpa, 17 appm He/dpa for the dual beam case), intermediate dose (45 dpa, 57 appm He/dpa for dual beam case) and in-situ low dose (0.33 dpa, 3030 appm He/dpa for the dual beam case). The experiments were performed at the JANNuS triple beam facility and dual beam in situ irradiation facility at CEA-Saclay and CSNSM, Orsay respectively. The microstructure was principally characterized by conventional TEM, APT and EDS in STEM mode. The main results are as follows: 1) A comparison of the cavity microstructure in high dose irradiated Fe revealed strong swelling reduction by the addition of He. It was achieved by a drastic reduction in cavity sizes and an increased number density. This behaviour was observed all along the damage depth, upto the damage peak. 2) Cavity microstrusture was also studied in the dual beam high dose irradiated FeCr alloys, and the results were compared to bcc Fe. The analysis was performed at an intermediate depth 300 – 400 nm below the surface (to avoid injected interstitial effect and surface effects), corresponding to 128 dpa, 13 appm He/dpa. TEM study revealed that the addition of small quantities of Cr, as low as 3wt.%, is highly efficient in strongly reducing void swelling. It was achieved by a drastic reduction of cavity sizes. For instance, average cavity size in Fe3%Cr was 0.9 nm as opposed to 6.8 nm in bcc Fe. Furthermore, the variation of void swelling as a function of Cr content is non-monotonic, with alocal maxima around 9 - 10wt.%Cr. 3) Coupling of conventional TEM, STEM/EDS and APT analysis on low and intermediate dose irradiated FeCr alloys revealed the presence of Cr enriched zones on the habit plane of the dislocation loops. This is expected to be due to radiation induced segregation (RIS) of Cr close to the core of the loops. As the loop grows under irradiation, the segregated areas are probably prevented from re-dissolution by impurity elements such as C. When imaged by TEM using classical diffraction contrast imaging techniques, these enriched zones produce displacement fringe contrast on the loop plane. A quantitative estimate of this enrichment was deduced by STEM/EDSand APT. The Cr content in these areas was between 23 - 35 at.% measured by EDS and 22 ± 2 at.% obtained by APT, whichis well below the Cr content of the Cr-rich α’ phase
Ouma, Linda Achiengꞌ. "Synthesis, optical and morphological characterization of pbse quantum dots for diagnostic studies: a model study." Thesis, University of the Western Cape, 2013. http://hdl.handle.net/11394/3975.
Повний текст джерелаIn this study PbSe quantum dots (QDs) were successfully synthesized via the organometallic and aqueous routes. Optical characterization was carried out using photoluminescence (PL) spectroscopy, structural and morphological characterization were carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Energy-dispersive X-ray spectroscopy (EDS) was used to determine the composition of the QDs. All the synthesized QDs were found to have emissions within the near-infrared region of the spectrum (≥1000 nm) with most of them being less than 5 nm in size. The aqueous synthesized QDs had a perfect Gaussian emission spectrum with a FWHM of ~23 nm indicating pure band gap emission and narrow size distribution respectively. The QDs were determined to have a cubic rock-salt crystal structure consistent with bulk PbSe. The aqueous synthesized QDs were however not stable in solution with the QDs precipitating after approximately 48 h. The organometallic synthesized QDs were transferred into the aqueous phase by exchanging the surface oleic acid ligands with 11-mercaptoundecanoic acid ligands. The ligand exchanged QDs were however stable in solution for over two weeks. The effects of reaction parameters on the optical and structural properties of the organometallic synthesized QDs were investigated by varying the reaction time, temperature, ligand purity, lead and selenium sources. It was observed that larger QDs were formed with longer reaction times, with reactions proceeding faster at higher reaction temperatures than at lower temperatures. Varying the ligand purity was found to have minimal effects on the properties of the synthesized QDs. The lead and selenium sources contributed largely to the properties of the QDs with lead oxide producing spherical QDs which were smaller compared to the cubic QDs produced from lead acetate. TBPSe was seen to produce smaller QDs as compared to TOPSe. The cytotoxity of the synthesized QDs was determined following the WST-1 cell viability assay with the QDs being found to be non-toxic at all the tested concentrations
Sorel, Julien. "Tomographie électronique analytique : Automatisation du traitement de données et application aux nano-dispositifs 3D en micro-électronique." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI078.
Повний текст джерелаThe aim of this thesis is to automate the process of hyperspectral analysis for analytical electron tomography applied to nanodevices. The work presented here is focused on datasets obtained by energy-dispersive X-ray spectroscopy in a scanning transmission electron microscope (STEM-EDX). STEM-EDX tomography has benefited greatly from recent developments in electron sources such as the ‘X’-FEG (Field Emission Gun), and multiple X-ray detector systems such as the Super-X, incorporating four SSD (Silicon Drift Detectors) detectors. The technique remains however very time-consuming, and low X-ray count rates are necessary to minimize the total acquisition time and avoid beam damage during the experiment. In addition, tomographic stacks of STEM-EDX datacubes, acquired at different tilt angles, are too large to be analyzed by commercial software packages in an optimal way. In order to automate this process, we developed a code based on Hyperspy, a Python library for multidimensional data analysis. Multivariate statistical analysis techniques were employed to optimize and automate the denoising, the energy calibration and the separation of overlapping X-ray lines, with the aim to achieve quantitative, chemically sensitive volumes. Moreover, a compressed sensing based algorithm was employed to achieve high fidelity reconstructions with undersampled tomographic datasets. The code developed during this thesis was used for the 3D chemical analysis of four microelectronic nanostructures: FinFET, HEMT and GAA transistors, and a GeTe thin film for memory device applications. The samples were prepared in a needle shape using a focused ion beam, and the data acquisitions were performed using a Titan Themis microscope equipped with a super-X EDX detector system. It is shown that the code yields 3D morphological and chemical information with high accuracy and fidelity. Ways to improve the current methodology are discussed, with future efforts aiming at developing a package dedicated to analytical electron tomography
Gullayanon, Rutchanee. "A calibration methodology for energy dispersive X-ray fluorescence measurements based upon synthetically generated reference spectra." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42771.
Повний текст джерелаJabeen, Fauzia. "III-V semiconducting nanowires by molecular beam epitaxy." Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3097.
Повний текст джерелаThis thesis is devoted to the study of the growth of III-V nanowires (NWs) by catalyst assisted and catalyst free molecular beam epitaxy (MBE). The nanostructures have been routinely characterized by scanning electron microscopy (SEM) and, to a minor extent by transmission electron microscopy (TEM). X-ray photoemission spectroscopy (XPS), scanning photoemission microscopy (SPEM), extended X-ray absrorption fi ne structure analysis (EXAFS), photoluminescence (PL) and trans- port measurements have given an important contribution on specifi c topics. The first section of this thesis reports on GaAs, InAs, and InGaAs NWs growth by Au assisted MBE. A substrate treatment is proposed that improves uniformity in the NWS morphology. Thanks to a careful statistical analysis of the NWs shape and dimensions as a function of growth temperature and duration, evidence is found of radial growth of the NWs taking place together with the axial growth at the tip. This eff ect is interpreted in term of temperature dependent diff usion length of the cations on the NWs lateral surface. The control of the NWs radial growth allowed to grow core shell InGaAs/GaAs NWs, displaying superior optical quality. A new procedure is proposed to protect NWs surface from air exposure. This procedure allowed to perform ex-situ SPEM studies of electronic properties of the NWs. The second part of this thesis is devoted to Au-free NWs growth. GaAs and InAs NWs were successfully grown for the first time using Mn as catalyst. Incorporation of Mn in the NW is studied using EXAFS technique. It is shown that Mn atoms are incorporated in the body of GaAs NWs. Use of low growth temperature is suggested in order to improve the Mn incorporation inside GaAs NWs and obtain NWs with magnetic properties. Finally, growth of GaAs and InAs NWs on cleaved Si subtrate is demonstrated without the use of any outside metal catalyst. Two kinds of nanowires have been obtained. The experimental findings suggest that the two types of nanowires grow after di fferent growth processes.
Questa tesi e' dedicata allo studio della crescita di nanofili di semiconduttori III- V tramite epitassia da fasci molecolari (MBE) assistita da catalizzatore e senza l'uso di catalizzatori. Le nanostrutture sono state caratterizzate sistematicamente tramite microscopia elettronica a scansione (SEM), e in maniera minore microscopia elettronica in trasmissione (TEM). Altre tecniche come la spettroscopia di fotoemissione da raggi x (XPS), la microscopia da fotoemissione in scansione (SPEM), la spettroscopia di assorbimento x (in particolare la extended X-ray absorpition fine structure analysis (EXAFS)) la fotoluminescenza (PL), e il trasporto elettrico hanno dato importanti contributi su problematiche specifiche. La prima parte di questa tesi riguarda la crescita di nanofili di GaAs, InAs e InGaAs tramite MBE assistita da oro. Viene proposto un trattamento del substrato che migliora nettamente l'omogeneita' morfologica dei nanofili. Grazie ad un'attenta analisi statistica della forma e delle dimensioni dei nanofili in funzione della temperatura e del tempo di crescita e' stata dimostrata la crescita radiale dei nanofili, che avviene insieme alla crescita assiale che ha luogo alla punta del nanofilo. Le osservazioni sperimentali sono state interpretate in termini di dipendenza dalla temperatura della lunghezza di diffusione dei cationi sulle super ci laterali dei nanofili. Il controllo della crescita radiale ha permesso di crescere nanofili di InGaAs/GaAs core shell, costituiti cioe' da una anima centrale di InGaAs (core) e uno strato esterno di GaAs (shell) , che hanno dimostrato eccellente qualita' ottica. Viene quindi proposta una nuova procedura per proteggere la super ficie dei nanofili durante l'esposizione all'aria. Grazie a questa e' stato possibile realizzare ex-situ uno studio SPEM delle proprieta' elettroniche dei nanofili. La seconda parte della tesi riguarda la crescita di nanofili senza l'uso di oro. Viene per la prima volta dimostrata la possibilita' di crescere nanofili di GaAs e InAs usando il manganese come catalizzatore. L'incorporazione del Mn come impurezza nei nanofili e' stata studiata tramite EXAFS. Le misure hanno dimostrato che atomi di Mn sono effettivamente incorporate nel corpo dei nano fili. La crescita delle nanostrutture a temperatura piu' bassa potrebbe migliorare qualitativamente l'incorporazione del Mn e permettere la crescita di nanofili con proprieta' magnetiche. Viene in fine dimostrata la crescita di nanofili di GaAs e di InAs senza l'utilizzo di materiali diversi da quelli costituenti il semiconduttore. Tale risultato e' ottenuto su superfici sfaldate di silicio. Sono state osservate nanostrutture di due tipi, che sulla base dei dati sperimentali sembrano essere dovuti a due diversi meccanismi di crescita.
XXI Ciclo
1977
Aquilanti, Giuliana. "Challenges for energy dispersive X-ray absorption spectroscopy at the ESRF : microsecond time resolution and Megabar pressures." Université Joseph Fourier (Grenoble), 2002. http://www.theses.fr/2002GRE10195.
Повний текст джерелаThis Thesis concerns the development of two different applications of energy-dispersive Xray absorption spectroscopy at the ESRF: time-resolved (TR) studies pu shed to the microsecond time resolution and high-pressure (HP) studies at the limit of the Megabar pressures. The work has been developed in two distinct parts, and the underlying theme has been the exploitation of the capabilities of an X-ray absorption spectrometer in dispersive geometry on a third generation synchrotron source. For TR studies, the study of the triplet excited state following a laser excitation of Ph(P20sH2)44- has been chosen to push the technique to the us time resolution. In the HP part, the suitability of the energy dispersive Xray absorption spectrometer for HP studies using diamond anvils cell is stressed. Sorne technical developments carried out on beamline ID24 are discussed. Finally, the most extensive scientific part concerns a combined X-ray absorption and diffraction study of InAs under pressure
Green, Heather F. "Casting no shadow : overlapping soilscapes of European-Indigenous interaction in northern Sweden." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/13133.
Повний текст джерелаFagerland, Steffen Knut. "Investigation of Focused Ion Beam/Scanning Electron Microscope parameters for Slice and View and Energy Dispersive X-ray Spectroscopy of Embedded Brain Tissue." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25765.
Повний текст джерелаKuei, Chun-Fu. "Transmission electron microscopy study on the formation of SiNX interlayer during InAlN growth on Si (111) substrate." Thesis, Linköpings universitet, Tunnfilmsfysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-125472.
Повний текст джерелаGul, Sheraz. "Synthesis, Optical and Structural Characterization, and Exciton Dynamics of Doped ZnSe Nanocrystals, and, Simultaneous X-ray Emission Spectroscopy of Two Elements Using Energy Dispersive Spectrometer." Thesis, University of California, Santa Cruz, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3630692.
Повний текст джерелаDoped semiconductor quantum dots (QDs) comprise an important subclass of nanomaterials in which a small quantity of impurity is added intentionally, adding another degree of freedom to alter their size-dependent physical and electronic properties. Intense, tunable, long lived and stable photoluminescence make them quintessential candidates for many opto-electronic applications including solid-state lighting, display devices and biomedical imaging. ZnSe QDs, which are blue-emitting fluorophores, were doped with Cu+1 to redshift their photoluminescence (PL) to green region of the visible spectrum. These Cu-doped ZnSe QDs were then codoped with Al3+, Ga 3+ and In3+ to improve the PL quantum yield (QY) by eliminating the defect states originating from charge imbalance created by aliovalent doping. Codoping also resulted in further redshifting of the PL, covering most of the visible spectrum, making them potential candidates for use in solid-state lighting and as optical down converters in next generation light emitting diodes (LEDs). To better understand the optical properties of these materials, local structure around the luminescent centers was investigated by extended X-ray absorption fine structure (EXAFS). Cu was found to occupy a distorted tetrahedral site with the codopant residing in a substitutional Zn site. Based on the structural information obtained by EXAFS, density functional theory calculations (DFT) were performed to get a clear picture of the energy levels associated with the electronic transitions. Furthermore, the dynamics studies of the exciton and charge carriers were carried out to get deeper insight of the various photophysical processes involved. The fluorescence lifetime was increased approximately 10 times after doping.
The multielectron catalytic reactions often involve multimetallic clusters, where the reaction is controlled by the electronic and spin coupling between metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. A method was developed to detect X-ray emission signal from multiple elements simultaneously to probe the electronic structure and sequential chemistry that occurs between the elements. A wavelength dispersive spectrometer based on the von-Hamos geometry was used, that disperses Kβ emission signals of multiple elements onto an area detector, and enables an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the Rowland circle spectrometers, and the data is free from temporal and normalization errors, and therefore ideal to follow sequential chemistry at multiple sites. This method was applied to MnOx based electrocatalysts, and the effect of Ni addition was investigated. Electro-deposited Mn oxide catalyses oxygen-evolution reaction (OER) and oxygen-reduction reaction (ORR) at different electrochemical potentials under alkaline condition. Incorporation of Ni reduced the low valent Mn component resulting in higher average oxidation state of Mn in MnNiOx under ORR and OER conditions, when compared to MnO x under similar conditions. The reversibility of the electrocatalyst was also found to improve by the inclusion of Ni.
Yamane, H., T. Kawano, K. Tatsumi, Y. Fujimichi, and S. Muto. "Site occupancy determination of Eu/Y doped in Ca2SnO4 phosphor by electron channeling microanalysis." Elsevier, 2011. http://hdl.handle.net/2237/20827.
Повний текст джерелаSILVA, NETO Oscar Gomes da. "Extração e avaliação das propriedades físicas, quimicas e biológicas do gel de aloe vera para aplicação em ecografia." Universidade Federal de Campina Grande, 2018. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1028.
Повний текст джерелаMade available in DSpace on 2018-06-21T23:28:14Z (GMT). No. of bitstreams: 1 OSCAR GOMES DA SILVA NETO – DISSERTAÇÃO (UAEMa) 2015.pdf: 1645990 bytes, checksum: e448fc8b851a203983ccd784d8234090 (MD5) Previous issue date: 2018-06-21
A ecografia é um dos métodos de diagnóstico por imagem mais versátil e difundido na atualidade, de aplicação relativamente simples, basear-se no fenômeno de interação de uma onda mecânica com os tecidos corporais, ou seja, observa as propriedades mecânicas dos tecidos ao longo da propagação da onda pelos mesmos, necessitando de um gel de acoplamento acústico para aumentar o contato entre a pele e o aparelho. A Aloe vera (Aloe barbadensis Miller) é uma planta suculenta perene, que desenvolve um tecido de armazenamento de água no interior das folhas, o gel, para sobreviver em zonas áridas de pluviosidade baixa ou irregular. Desta forma, este trabalho objetivou a extração do gel de Aloe vera, com subsequente análise de suas propriedades físicas, químicas e biológicas. Foram realizados testes de avaliação da sua funcionalidade para aquisição de imagens por ecografia e, por fim, realizado estudo comparativo com imagens ecográficas adquiridas com o gel de Aloe vera e com o gel comercial atualmente utilizado. O gel de Aloe Vera a 100% foi extraído da própria planta, processado e caracterizado por espectroscopia na Região do Infravermelho com Transformada de Fourier (FTIR), espectroscopia por Energia Dispersiva de raios X (EDS), Ensaio de Citotoxicidade e Ecografia. As análises foram realizadas no Laboratório de Desenvolvimento e Avaliação de Biomateriais (CERTBIO). O gel de Aloe vera quando utilizado para fins de obtenção de imagem, apresentou resultado igual ou superior às imagens obtidas com o gel comercial, podendo ter ocorrido devido a menor resistência oferecida pelo mesmo e consequentemente maior condutividade, provavelmente pela maior quantidade de íons livres, permitindo a diminuição da impedância do transdutor em relação à pele, promovendo a propagação do ultrassom desde o transdutor até os órgãos avaliados. Com base nos resultados obtidos nos ensaios de Espectroscopia na Região do Infravermelho com Transformada de Fourier, Espectroscopia por Energia Dispersiva de raios X, Citotoxicidade e Exames Ecográficos, pode-se concluir que os materiais apresentam características semelhantes, indicando que o gel de Aloe vera possa ser utilizado em exames de ultrassonografia.
Ultrasound is a diagnostic methods for more versatile and widespread image today, relatively simple application, be based on the interaction phenomenon of a mechanical wave with body tissues, ie observe the mechanical properties of tissues along the Wave propagation through the same, necessitating an acoustic coupling gel to increase the contact between the skin and the device. Aloe vera (Aloe barbadensis Miller) is a succulent perennial plant which develops a water storage tissue sheets within the gel, to survive in arid zones of low rainfall or irregular. Thus, this study aimed to extract the gel of Aloe vera, with subsequent analysis of their physical, chemical and biological properties, as well as evaluation tests were carried out of its functionality for image acquisition by ultrasound and finally performed study comparison with ultrasound images acquired with the gel of Aloe vera and commercial gel currently used. The gel of Aloe Vera 100% was extracted from the plant itself, processed and characterized by Spectroscopy in Infrared Region Fourier Transform (FTIR) Spectroscopy Energy Dispersive X-ray (EDS), Cytotoxicity and ultrasound test. The analyzes were performed at the Development Laboratory and Biomaterials Assessment (CERTBIO). The Aloe vera gel when used for the purpose of obtaining image presented results equal to or better than the images obtained with the commercial gel and this may be due to lower resistance of the same and therefore higher conductivity and this can probably allow the reduction of the impedance of the transducer relative to the skin, promoting the propagation of ultrasound from the transducer to the evaluated organs. Since based on the results obtained in tests spectroscopy in the infrared Fourier transform spectroscopy, by Energy Dispersive X-ray, ultrasound examinations and cytotoxicity, it can be concluded that the materials have similar characteristics indicative that the aloe vera gel may be used on ultrasound examination.
Zhang, Shuo. "The Performance and Service Life Prediction of High Performance Concrete in Sulfate and Acidic Environments." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2260.
Повний текст джерелаGonçalves, Ligia Maria Napolitano. "Efeito da radioterapia sobre as propriedades mecânicas, químicas e morfológicas do esmalte e da dentina de dentes permanentes - Estudo in vitro." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/58/58135/tde-23052012-163912/.
Повний текст джерелаThe present study had as objective to evaluate, in vitro, the effect of the radiation of 60 Cobalt (Co 60) in the mechanical, morphological and chemical properties of the enamel and of the dentine of permanent teeth by means of: 1- longitudinal microhardness; 2- scanning electron microscopy (SEM); and 3; energy dispersive X-ray spectroscopy (EDX). The microhardness of the enamel and of the dentine (n = 12 vestibular hemisections) was evaluated in three depths (superficial, medium and deep), before and at each 10 Gy of irradiation, until a total cumulative dose of 60 Gy. The morphology of the enamel and of the dentine was evaluated by means of a SEM (n = 8 hemisections), in 2 irradiated vestibular hemisections with total cumulative dose of 30 Gy, 2 irradiated vestibular hemisections with total cumulative dose of 60 Gy and 4 not irradiated palatine hemisections (control). The chemical composition of the enamel and of the dentine was evaluated by means of EDX (n = 4 hemisections), using the same hemisections previously submitted to SEM (with cumulative dose of 60 Gy of irradiation, and in the not irradiated hemisections). The data were analyzed about their distribution and submitted to the Analysis of Variance at two criteria. For the differentiation of the averages, the test of Fisher was used. The level of significance adopted was of 5%. About the longitudinal microhardness in the enamel, it was possible to be observed that there was no statistically significant difference between the groups (p < 0,05). The microhardness in the not irradiated enamel was similar to the enamel after the irradiation with doses of 40, 50 and 60 Gy (p > 0,05) and higher than the microhardness values in the doses of 10, 20, e 30 Gy (p < 0,05). About the microhardness in the different depths it was observed significant difference (p < 0,05) between them, being observed in the superficial enamel the greatest values of microhardness. In the morphological analysis of the enamel it was observed that the irradiated specimens presented growing alterations, due to the increase of the radiation dose, comparing to the not irradiated enamel. There was no difficulty in observing the prisms and the crystals after the irradiation, however the interprismatic portion became more evident after the radiation doses of 30 and 60 Gy. About the longitudinal microhardness of the dentine, it could be observed that there was significant difference between the groups (p < 0,05). The microhardness of the not irradiated dentine was not statistically significant compared to the microhardness in the dose of 40 Gy (p > 0,05) and it presented higher values to the observed ones in the doses of 10, 20, 30, 50 and 60 Gy (p < 0,05). About the relation to the microhardness in the different evaluated depths it was possible to observe significant difference (p < 0,05) among them, being that the medium dentine presented the highest values of microhardness. In the morphological analysis of the dentine it was observed the presence of cracks in the dentine structure, collapsed/destroyed dentine tubules and fragmentation of the collagen fibers in the doses of 30 and 60 Gy, being the alterations more intense with the increase of the dose of irradiation, for all the analyzed regions, comparing to the not irradiated dentine. In the chemical analysis of the irradiated enamel and the dentine it was observed the slight increase of oxygen (O) and decrease of phosphorus (P) and Calcium (Ca), comparing to the not irradiated specimens. The result allowed to be concluded that the radiotherapy occasioned the decrease of the microhardness of the enamel after the doses from 10 to 30 Gy, but in the following doses there was an increase of the microhardness, which became similar to the not irradiated enamel, being that in the superficial region it was observed the biggest increase of the microhardness. In the dentin, the radiotherapy caused decrease of the microhardness after practically all doses of radiation, comparing to the not irradiated dentine, being that in the region of the medium dentine the lowest values of microhardness were observed. The morphological alterations of the enamel and of the dentine structure were growing with the increase of the radiation doses observing the more evident interprismatic portion, presence of cracks and collapsed/destroyed dentine tubules and progressive fragmentation of collagen fibers. Chemically, after the irradiation, not only in the enamel but also in the dentin, it was observed a slight increase of percentage of the oxygen and decrease in the percentages of phosphorus and calcium.
Lejonklo, Caroline. "Friction and wear study of lean powder metallurgy steel in a lubricated sliding contact." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-390557.
Повний текст джерелаLuong, Minh Anh. "Etude de la diffusion thermique de l'Aluminium dans des nanofils de Germanium et en alliages de SixGe1-x en utilisant la microscopie électronique en transmission in situ." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY050.
Повний текст джерелаSemiconductor nanowires are receiving widespread interests for their novel applications in field-effect transistors, photodetectors and biosensors. The nanowire geometry provides an interesting possibility to fabricate axial heterostructures that can be easily accessed electrically by contacting the NW edges. Depending on the size, material and composition of the heterostructure, carriers can experience quantum confinement effects, allowing to fabricate quantum dots or quantum disks inside the NW. Recently, the formation of Silicide or Germanide contacts via a thermally activated solid state reaction between the metal and Si or Ge NW has drawn significant attention because of its great advantages for fabricating short channel devices from bottom up grown NWs rather than complex and high-cost photolithography top-down approaches. The advantage of this approach is that upon heating a metal enters a semiconducting NW at both ends, creating an (inter)metallic region in the NW. If the process is well controlled and stopped at the right moment, only a thin section of semiconductor is left between metallic contacts, allowing to fabricate electrically contacted quantum-dot in a wire structures in a single fabrication step. Al/Ge NW thermal induced solid-state diffusion is a promising system since, in contrast to other metal-semiconductor combinations, no intermetallic phase is formed and a pure monocrystalline Al NW is created with a very sharp interface with the remaining Ge NW. Moreover, the combination of the intrinsically strong spin−orbit coupling in Ge and the superconducting properties of Al, make this system a promising platform to study hybrid superconductor-semiconductor devices that could be potential building blocks for superconducting quantum interference devices (SQUIDs). The challenge addressed in this PhD is to study the thermally induced exchange reaction of Al in both pure Ge as well as SixGe1-x alloy NWs using in-situ observations in a transmission electron microscope (TEM), to allow better understanding and control of the mechanisms involved in the reaction
Trueman, Anthony Roger. "Characterization and corrosion studies of high carbon tool steel/tungsten carbide metal matrix composites." Thesis, Queensland University of Technology, 1999.
Знайти повний текст джерелаSchilling, Sibylle. "Liquid in situ analytical TEM : technique development and applications to austenitic stainless steel." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/liquid-in-situ-analytical-tem-technique-development-and-applications-to-austenitic-stainless-steel(fd490551-7d7a-4b2e-9b1f-917b5f8165b3).html.
Повний текст джерелаSeidel, Falko. "Dünne Siliziumschichten für photovoltaische Anwendungen hergestellt durch ein Ultraschall-Sprühverfahren." Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-159507.
Повний текст джерелаGuettler, Barbara Elisabeth. "Effect of Thermal and Chemical Treatment of Soy Flour on Soy-Polypropylene Composite Properties." Thesis, 2012. http://hdl.handle.net/10012/6702.
Повний текст джерелаLiu, Chen-Yen, and 劉俊延. "Evaluation of Scanning Electron Microscopy-Energy Dispersive X-Ray Spectrometer (SEM-EDX) for Detection of Heavy Metals in Himematsutake." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/55795130915924905524.
Повний текст джерела國立中興大學
植物病理學系所
100
Himematsutake (Agaricus blazei Murill) is a popular edible mushroom in the world. Recently, the over accumulation of heavy metals in the himematsutake had been paid attention in Taiwan. Several methods can be used to detect the accumulation of heavy metals in biological materials; however, these methods are time consuming. For detecting the heavy metals and its distribution in fruit body of himematsutake rapidly, the scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDX) was used to analyze eight heavy metals of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in pileus and stipe of fruiting body by pieced and powdery types. Moreover, the atomic percentage of these heavy metals in pileus and stipe were be confirmed by ICP-MS. In this study, the specimens of himematsutake were collected from Taichung (USA and Japanese strain), Changhua (Japanese and Taiwanese strain), Nantou and China. The results of pieced analysis showed that the accumulation of Ni (0.040%) and As (0.009%) in pileus of fruiting body of USA strain from Taichung were significantly higher than in stipe; however, the accumulation of Hg (0.044%) and Pb (0.043%) in stipe of fruiting body of USA strain were significantly higher than pileus. The other side, the accumulation of As (0.008%) in pileus of fruiting body of Japanese strain from Taichung was significantly higher than in stipe; meanwhile, the accumulation of Ni (0.015%), Cu (0.054%), Zn (0.017%), Hg (0.034%)and Pb (0.030%) in stipe of fruiting body of Japanese strain were significantly higher than pileus. The pieced analysis of Japanese strain from Changhua indicated that Cu (0.044%), Hg (0.092%) and Pb (0.069%) in pileus were significantly higher than in stipe, and As (0.013%) and Cd (0.015%) in stipe were significantly higher than in pileus. However, the pieced analysis of Taiwanese strain from Changhua revealed that Ni (0.023%), Cu (0.041%), Zn (0.024%), As (0.013%) and Hg (0.114%) in pileus were significantly higher than in stipe. The pieced analysis of himematsutake from Natou showed that accumulation of Hg (0.088%) in pileus was significantly higher than in stipe, and the accumulation of Ni (0.029%), Cu (0.060%), Zn (0.030%) and Cd (0.025%) in stipe were significantly higher than in pileus. The pieced analysis of himematsutake from China indicated that accumulation of As (0.015%) and Hg (0.067%) in pilues were significantly higher than in stipe, and Cr (0.017%), Ni (0.023%), Cu (0.048%), Cd (0.015%) and Pb (0.052%) in stipe were significantly higher than in pileus. The results of powdery analysis showed that the accumulation of Cu (0.149%), Zn (0.059%), Hg (0.127%) and Pb (0.076%) in pileus of fruiting body of USA strain from Taichung were significantly higher than in stipe; however, the accumulation of As (0.016%), Hg (0.102%) and Pb (0.065%) in pileus of fruiting body of Japanese strain was significantly higher than in stipe. The powdery analysis of Japanese strain from Changhua indicated that Hg (0.087%) in pileus was significantly higher than in stipe, and As (0.050%) in stipe was significantly higher than in pileus. However, the powdery analysis of Taiwanese strain from Changhua revealed that Ni (0.040%), Hg (0.148%) and Pb (0.095%) in pileus were significantly higher than in stipe, and the accumulations of Cr (0.023%) and Cd (0.037%) in stipe were significantly higher than in pileus. The powdery analysis of himematsutake from Natou showed that accumulation of Pb (0.061%) in pileus wa significantly higher than in stipe. The powdery analysis of himematsutake from China indicated that accumulation of As (0.021%), Hg (0.101%) and Pb (0.076%) in pilues were significantly higher than in stipe. For ICP-MS analysis, 0.25 g of pileus and stipe of fruiting body were used for analysis. The results showed that the concentration of Cu (52.263 mg/kg), Zn (164.820 mg/kg), As (1.440 mg/kg), Cd (6.158 mg/kg) and Hg (0.178 mg/kg) in pileus of fruiting body of USA strain from Taichung were significantly higher than in stipe; however, the concentration of Cu (71.975 mg/kg), As (0.450 mg/kg) and Pb (0.260 mg/kg) in pileus of fruiting body of Japanese strain were significantly higher than in stipe. The Japanese strain from Changhua indicated that the concentration of Cu (647.847 mg/kg), Zn (121.450 mg/kg), As (2.270 mg/kg) and Hg (0.130 mg/kg) in pileus were significantly higher than in stipe; meanwhile, the is of Taiwanese strain showed that the concentration of Cu (78.553 mg/kg), Zn (214.230 mg/kg), As (1.418 mg/kg), Cd (19.530 mg/kg) and Hg (0.125 mg/kg) in pileus were significantly higher than in stipe. The analysis of himematsutake from Natou did not show significantly different between pileus and stipe of fruiting bodies. The analysis of himematsutake from China indicated that concentration of Cu (53.460 mg/kg) and Zn (124.310 mg/kg) in pilues were significantly higher than in stipe. For comparing the accumulation and distribution of heavy metals in basidiospore, pilues and stipe, the powdery analysis and ICP-MS analysis were be done. The powdery analysis showed that the heavy metals could be accumulated in basidiospores with lower atomic percentage than in pilues or stipe. Specially, Zn, Hg, and Pb were significantly different among basidiospores, pilues and stipe. Moreover, the sawdust analysis showed that the accumulations of certain heavy metals in fruiting bodies were higher than in sadust. The atomic percentage and concentration of Cu were higher in fruiting bodies than in sawdust. In this study, the analyses results from EDX were compared with the results from ICP-MS. According to correlation analysis, the atomic percentage of As, Cd and Hg based on pieced analysis have positive relationship with the ICP-MS analysis, and the coefficient of As, Cd and Hg were 0.841, 0.672 and 0.497, respectively. The other sides, the atomic percentage of Zn, As, Cd and Pb based on powdery analysis have positive relationship with the ICP-MS analysis, and the coefficient of Zn, As, Cd and Pb were 0.039, 0.277, 0.037 and 0.080. Based on the results, the EDX has potential to detect the eight heavy metals in himematsutake rapidly, and the powdery analysis might better than pieced analysis.
"Determination of Fe, Cu and Zn in human plasma by energy dispersive X-ray fluorescence spectrometry." Chinese University of Hong Kong, 1993. http://library.cuhk.edu.hk/record=b5887819.
Повний текст джерелаThesis (M.Phil.)--Chinese University of Hong Kong, 1993.
Includes bibliographical references (leaves 93-95).
ACKNOWLEDGEMENT --- p.i
ABSTRACT --- p.ii
Chapter CHAPTER 1 --- INTRODUCTION --- p.1
Chapter 1.1 --- General Introduction --- p.1
Chapter 1.2 --- "Clinical Significance of Fe, Cu and Zn" --- p.2
Chapter 1.3 --- Alternative Methods of Analysis --- p.5
Chapter 1.4 --- Principles of Energy Dispersive X-ray Fluorescence Spectrometry --- p.11
Chapter 1.5 --- Research Plan --- p.20
Chapter CHAPTER 2 --- EXPERIMENTAL --- p.22
Chapter 2.1 --- Energy Dispersive X-ray Fluorescence Analysis --- p.22
Chapter 2.1.1 --- Apparatus --- p.22
Chapter 2.1.2 --- Reagents --- p.25
Chapter 2.1.3 --- Procedure --- p.28
Chapter 2.2 --- Atomic Absorption Spectrometric Analysis --- p.32
Chapter 2.2.1 --- Apparatus --- p.32
Chapter 2.2.2 --- Reagents --- p.32
Chapter 2.2.3 --- Procedure --- p.34
Chapter CHAPTER 3 --- RESULTS AND DISCUSSION --- p.38
Chapter 3.1 --- Optimisation of Excitation Conditions --- p.38
Chapter 3.1.1 --- Effect of Filter --- p.38
Chapter 3.1.2 --- Effect of Tube Voltage --- p.43
Chapter 3.1.3 --- Effect of Tube Current --- p.44
Chapter 3.2 --- Optimisation of Preconcentration Procedure --- p.46
Chapter 3.2.1 --- Effect of Sample Area and Collimator Size --- p.46
Chapter 3.2.2 --- Effect of pH --- p.51
Chapter 3.2.3 --- Effect of Ligand Concentration --- p.54
Chapter 3.2.4 --- Effect of Mixing Time --- p.57
Chapter 3.2.5 --- Effect of Standing Time --- p.59
Chapter 3.2.6 --- Study of Sample Homogeneity --- p.61
Chapter 3.3 --- Optimisation for Deproteination --- p.63
Chapter 3.3.1 --- Effect of Different Protein Precipitants --- p.63
Chapter 3.3.2 --- Effect of Trichloroacetic Acid Concentration --- p.65
Chapter 3.3.3 --- Effect of Hydrochloric Acid Concentration --- p.67
Chapter 3.3.4 --- Effect of Temperature --- p.69
Chapter 3.3.5 --- Effect of Incubation Time --- p.71
Chapter 3.4 --- Study of Blanks --- p.74
Chapter 3.5 --- Construction of Calibration Curves --- p.77
Chapter 3.6 --- Determination of Detection Limit and Sensitivity --- p.84
Chapter 3.7 --- Accuracy and Reproducibility Tests --- p.86
Chapter 3.8 --- Parallel Check --- p.89
Chapter CHAPTER 4 --- CONCLUSION --- p.92
REFERENCES --- p.93
汪毓人. "Identification of Automotive Paint Chips by Pyrolysis/ Gas Chromatography (Py/GC) and Scanning Electron Microscopy/ Energy Dispersive X-Ray Analysis (SEM/EDX)." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/08134902094273720299.
Повний текст джерела汪毓人. "Identification of Automitive Paint Chips by Pyrolysis/ Gas Chromatography (Py/GC) and Scanning Electron Microscopy/ Energy Dispersive X-Ray Analysis (SEM/EDX)." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/jjepa9.
Повний текст джерелаLumka, Mandisile. "Chemical characterisation of atmospheric aerosols in Soweto, Bethlehem and Thohoyandou using energy dispersive x-ray fluorescence spectroscopy and ion chromatography." Thesis, 2012. http://hdl.handle.net/10210/4491.
Повний текст джерелаAerosol samples were collected at stations using simple filter unit, loaded with a 4 7 mm diameter pore size Nuclepore membrane filter. The sampling duration was 24 hours for each sample, with the total of 11 samples: seven for Thohoyandou and four for Bethlehem. The samples were analyzed with energy dispersive X-ray fluorescence spectrometry for up to 20 elements. Comparison for elemental concentrations of the data showed that the samples fall into three clusters on average (major: Ca, Cl, Si. S, Fe and AI; intermediate: K, Ti, Pb, Brand Zn; minor: Mn, Cr, As, Sr, Ni and Cu), with the samples collected from Bethlehem having high concentrations in all clusters. High concentrations in the samples collected on Bethlehem were attributed to entrainement of dust particles during the dry winter period. The results also show that the elements are associated with anthropogenic emissions. Therefore, the sampling station at Thohoyandou is considered as a background station due to the low aerosol concentration. The aerosol concentration levels at Thohoyandou can be attributed to biogenic sources because of the large presence of large forest areas in the region and in the vicinity of the sampling location. The samples collected in both regions reveal highly enriched sulphur, chlorine, zinc and lead. It is clearly proved that these elements come from local soil. Chromium and copper were both slightly enriched in Thohoyandou, but the concentration data for these two elements are not available. However it is supposed that these elements come from local soil as well. In another aerosol analysis, passive (diffusive) samplers were used to measure concentration levels for sulphur dioxide and nitrogen dioxide. The measurement campaign was carried out from Soweto in Johannesburg and Bohlokong in Bethlehem with the campaign lasting for two months during the w~nter season. A very clear result derived for sulphur dioxide was the dominating source contribution from use of coal for heating and cooking in both areas. For nitrogen dioxide, it was found that contribution from traffic in highly populated areas and from industrial activities in the neighbourhood of the two areas was the source. The role played by wood burning, is also another additional source used for domestic heating and even cooking.
Smoker, Meghan Grace. "Glass population study and discrimination of glass samples using Glass Refractive Index Measurement III and scanning electron microscopy/energy dispersive X-ray spectroscopy." Thesis, 2019. https://hdl.handle.net/2144/36607.
Повний текст джерелаRiego, Daniela Alejandra. "Análisis de contenido de fósforo en cáncer mamario por microfluorescencia de rayos X." Bachelor's thesis, 2022. http://hdl.handle.net/11086/23640.
Повний текст джерелаEn el presente trabajo, se ha implementado el Microanálisis por Fluorescencia de Rayos X para el estudio de tejidos neoplásicos. Esta técnica permite un análisis multielemental simultáneo no destructivo, simplificando la tarea laboriosa que implica el análisis elemental tradicional por histoquímica. En particular la micro-XRF permite el monitoreo de fósforo cuya presencia está asociada a microcalcificaciones y al metabolismo tumoral. El fósforo, muestra un incremento significativo en tumores malignos por lo que recientemente se lo ha empezado a emplear como posible biomarcador en modelos de prognosis del cáncer de mama. Estudios preliminares llevados a cabo por el grupo de investigación del presente trabajo han mostrado la viabilidad de la metodología propuesta particularmente aplicada en la determinación de fósforo.
In the present work, the X-Ray Fluorescence Microanalysis (micro-XRF) was implemented for the study of neoplastic tissues. Through this non-destructive technique, precise quantification of phosphorus and calcium in neoplasms of a murine model of breast cancer was achieved with the purpose of being able to distinguish malignant and benign lesions according to the variety of calcified crystals and also using phosphorus content as an indicator of tumor activity and progression. The experimental tasks and data processing processes were further supported by the simulation of radiation transport by Monte Carlo techniques using the open-source program XMI-MSIM.
Fil: Riego, Daniela Alejandra. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina.
Silva, Sara Margarida Jorge da. "Caracterização Material e Temporal dos Túmulos da Rainha Santa Isabel e de sua Neta, Infanta D. Isabel." Master's thesis, 2019. http://hdl.handle.net/10316/88038.
Повний текст джерелаCom esta dissertação, pretendeu-se analisar o historial/material dos túmulos daRainha Santa Isabel e de sua neta, tendo em conta a cronologia bibliográfica.Este estudo incidiu, em particular, na análise da estratigrafia de amostras recolhidas,nomeadamente da tampa do túmulo da Rainha Santa (TRS) e túmulo da neta da RainhaSanta (TNRS). Posteriormente, foram também analisadas amostras de outras peças paraservir como meio de comparação com as faces laterais respetivas.Os resultados obtidos permitem formular hipóteses sobre janelas temporais para aexecução das várias decorações dos dois túmulos, tendo por base a identificação dospigmentos encontrados (azuis, vermelhos, brancos, castanhos) e composição das ligas deouro (Au) e prata (Ag).Como complemento a este estudo comparativo, procedeu-se também à análise de umterceiro túmulo, possivelmente pertencente à filha da duquesa de Coimbra - D. Isabel deUrgel, D. Catarina de Urgel (TCU), e uma peça escultórica, ambas provenientes do mesmolocal, Mosteiro de Santa Clara-a-Velha. Adicionalmente, foram também incluídoselementos existentes na atual capela mor da igreja do Mosteiro de Santa Clara-a-Nova porforma para complementar o estudo, incidindo este sobre a última camada de pintura doTNRS.Na análise de pigmentação e materiais de suporte foram utilizadas as técnicas deMicroscopia Ótica (MO), Espetroscopia de Fluorescência de Raios-X tanto portátil (p-XRF)como de bancada (b-XRF), Espetroscopia micro-Raman e Microscopia Eletrónica deVarrimento com Espetroscopia de Energia Dispersa de Raios-X (SEM-EDS), e para as ligasmetálicas apenas b-XRF e SEM-EDS.
The aim of this study was to analyze the history/material of the tombs of Rainha SantaIsabel and her granddaughter, in order to achieve it, it was considered the availablebibliographic chronology.This thesis focused, particularly, on the stratigraphy of samples collected, morespecifically in the ones from the Queen Isabel's tomb cover (TRS) and the tomb of theQueen's granddaughter (TNRS), as well as some other samples that allowed to comparewhat was found on the top with the lateral sides.The results obtained lead to a formulation of a hypothesis regarding the temporalwindows for the execution of the different decorations of the two tombs, based on theidentification of the pigments found (blue, red, white, brown), and also the gold and silvercomposition.In order to reinforce this comparative study, a third tomb was also analyzed, which itis thought to belong to the daughter of the Duchess of Coimbra - D. Isabel de Urgel, D.Catarina de Urgel (TCU), and a sculptural piece, both found in the same place, Santa Claraa-Velha Monastery. Additionally, it was further included some elements that can be foundin the current main chapel of the church of Santa Clara-a-Nova Monastery, in order tocomplement the study. In these pieces, the focus was the last coat of paint, to compare tothe one from Queen's granddaughter tomb.For the analysis of pigmentation and support materials it were used the techniques ofOptical Microscopy (MO), X-ray Fluorescence Spectroscopy, both portable (p-XRF) andbench assemble (b-XRF), Micro-Raman Spectroscopy and Scanning Electron Microscopywith Energy Dispersive Spectroscopy X-ray (SEM-EDS), and for the metal alloys it wasonly used bench-top XRF and SEM-EDS.
Guettler, Barbara Elisabeth. "Soy-Polypropylene Biocomposites for Automotive Applications." Thesis, 2009. http://hdl.handle.net/10012/4427.
Повний текст джерелаSeidel, Falko. "Dünne Siliziumschichten für photovoltaische Anwendungen hergestellt durch ein Ultraschall-Sprühverfahren." Doctoral thesis, 2013. https://monarch.qucosa.de/id/qucosa%3A20180.
Повний текст джерела