Trace element composition of archaeological artifacts is commonly used for provenance studies. Limestone has generally studied by geologists and there are a few researches done by various archaeological sciences. Although it is a common material for buildings and sculpture it is been thought that limestone used had not imported like marbles. Limestone figurines from Dat&ccedil / a/Emecik excavations are classified as Cypriote type, which was very popular through 6th century B.C. in the Mediterranean region. Since this type of figurines was found at Emecik numerously to determine its provenance was an important problem. Emecik figurines were examined for their some major, trace elements and REE compositions and results were compared with geological samples which were taken from a near by quarry. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), Inductively Coupled Plasma-Mass Spectrometry (ICPMS) have been used for analysis. The methods have been optimized by using standard reference material NIST 1d, NCS DC 73306, and IGS40.

M. Tech. Chemistry. / Objectives of this study was to assess the levels of heavy metals in bovine meat, hair, sediment, peat and water from the study areas using ICP-MS and internal standard calibration.The specific objectives are to: collect hair and meat of impala and cattle, sediment, peat, soil and water samples; digest samples; determine the level of some of the following heavy metals Cd, Cr, Cu, Hg, Mn, Pb, Sr, U, V depending on the background information on the above samples; compare the levels of Hg in sediment and peat using ICP-MS and Zeeman mercury spectrometer; determine the limit of detection of trace elements in different matrices using ICP-MS; establish correlations among concentrations of heavy metals in specified samples.

Requirements of high performing engine oil are today necessary since the development of new machinery with modern standardsis a cutting edge technology demanding highly optimized components. One way of increasing the lubricating properties of engineoil is through the addition of antioxidants. Antioxidants included in lubricants have a number of functions, one being buffering theinorganic acids sulphuric acid and nitric acid.A novel method expected to lower the hydrogen ion concentration in acidified engine oil was evaluated in this thesis. Thecapability of four different types of cation exchangers to serve as complements for buffering additives in heavy vehicle engineswas assessed. Two cation exchangers were weak and two were strong. The analysis techniques used to evaluate what effect thecation exchangers have on engine oil were standard test method ASTM D4739, for measurements of the total base number (TBN),and inductively coupled plasma – atomic emission spectroscopy (ICP-AES). With ASTM D4739 it was found that weak cationexchangers give positive results with respect to the ability to decrease the hydrogen ion concentration in acidified engine oil.However, after begin subjected to strong cation exchangers, ASTM D4739 indicated that the hydrogen ion concentration in theacidified engine oil remains the same or increases.With additional literature studies of a variety of cation exchangers currently on the market, further optimization of the cationexchanging material could likely be achieved. In addition, the preparation method used during the evaluation of the cationexchangers should be optimized to give more reliable results.

The main object of this work is the technology of radio frequency controlled inductively coupled plasma, abbreviated RF-ICP. The specific goal of the work was the application of surface layers of tungsten and analysis of the influence of changes in process conditions on the resulting microstructure and chemical composition of deposited coatings. The monitored conditions were torch power, choice of carrier gas, powder feedrate.

Dans un propulseur à courant de Hall, la création des ions et leur accélération sont régis par le même phénomène physique. L'idée du propulseur de Hall double étage (DSHT) est de découpler l'ionisation du gaz (poussée) et l'accélération des ions (ISP), de sorte à rendre le système davantage versatile. Les travaux menés durant cette thèse visent à démontrer, grâce à des essais expérimentaux, la pertinence et la faisabilité d'un tel concept. Dans un premier temps, un prototype de DSHT, baptisé ID-HALL, a été conçu et assemblé. Il est constitué d'une source inductive magnétisée insérée dans un tube en céramique et d'un étage d'accélération identique à une barrière magnétique de propulseur simple étage. La source inductive a été optimisée de sorte à réduire le couplage capacitif et à maximiser l'efficacité du transfert de puissance par ajout de pièces en ferrite et diminution de la fréquence RF d'excitation. Dans un deuxième temps, la source inductive du propulseur a été caractérisée indépendamment du propulseur en argon et xénon pour différentes pressions. Le dispositif expérimental a permis notamment de tracer une cartographie 2D de la densité et de la température. Enfin, le propulseur a été monté dans son caisson et des mesures préliminaires (caractéristiques courant-tension, mesures par sonde RPA) ont été menées. En parallèle, des simulations utilisant un modèle hybride 2D ont été effectuées en mode simple et double étage. Elles mettent en évidence un fonctionnement versatile du moteur pour des tensions inférieures à 150 V. A terme, on visera à démontrer que la densité de courant et l'énergie des ions peuvent être, dans certaines conditions, significativement découplées. / In Hall thrusters, the same physical phenomenon is used both to generate the plasma and to accelerate ions. Furthermore, only a single operating point is experimentally observed. The double stage Hall thruster (DSHT) design could allow a separate control of ionization (thrust) and ions acceleration (ISP) to make the system more versatile. The work carried out during this PhD aims to experimentally demonstrate the relevance and the feasibility of this concept. Firstly, a new design of DSHT, called ID-HALL, was proposed and a new prototype was built. It combines the concentric cylinder configuration of a single stage Hall thruster with a magnetized inductively coupled RF plasma source (ICP) whose coil is placed inside the inner cylinder. The ICP source was improved in terms of power coupling efficiency by adding ferrite parts and by decreasing the heating RF frequency. The ICP source used in the ID-HALL thruster was then characterized independently of the thruster using argon and xenon and varying pressure. The experimental setup has allowed to measure the spatial variations of the electron density and temperature. Finally, the thruster was mounted in its vacuum chamber and preliminary measures (voltage-current characteristics, RPA measurements) were led. At the same time, simulations using a two-dimensional hybrid model were performed in single and double stage. A versatile operation for voltages lower than 150 V was highlighted. An emphasis will be given to demonstrate that the current density (given by the ion flux probe) and the ions energy (given by the RPA) might be significantly decoupled.

Mass spectrometry (MS) as an analytical approach could provide comprehensive identification and quantitation of the biomolecules (proteins, peptides, nucleic acids, lipids) in a cell, tissue, or organism, from biomarker discovery to prediction of response to therapy or intervention. Inductively coupled plasma mass spectrometry (ICP-MS), can determine the elemental composition of materials and has been used for below ppt levels (ppq) and better in some cases (transuranics and non-metals) to detect metals and other elements in water, soil, and air or blood and urine samples. Mass cytometry is an implementation of ICP-MS to single-cell analysis; it is based on metal isotope-tagged antibodies to quantify these bioconjugates. Imaging mass cytometry (IMC), a commercially available immunohistochemistry laser ablation-inductively coupled plasma-time-of-flight-mass spectrometry (LA-ICP-TOF-MS) system, was designed for molecular biomarkers imaging in the tissue sections (e.g., brain) through metal-tagged antibodies (typically, lanthanides). This thesis highlights the contributions of ICP-TOF-MS-based approaches towards advanced developments of mass cytometry (CyTOF) and discusses its biomedical applications for investigating neurodegenerative diseases while comparing it to other imaging modalities such as PET, MRI, Allen brain, etc. In conclusion, CyTOF, as a high-dimensional imaging tool, provides information on many clinical applications, such as hematopoiesis, transplantation, cancer, and autoimmunity.

No description available.

The main focus of the PhD study was to develop new gel electrophoresis and ICP-MS based methods to analyze a wide variety of the bio-molecules such as proteins, phosphoproteins and metalloproteins etc. The tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (tricine-SDS-PAGE) method is commonly used to resolve low molecular mass proteins, however, it requires a high percentage gel and a very complicated procedure to achieve this separation. This study describes a modification to tricine-SDS-PAGE to make it more effective for the separation of smaller proteins and for coupling to ICP-MS. The modified method employs low percentage PAGE gels and low reagent concentrations that provide efficient separations, good quantitation and low matrix levels that are compatible with ICP-MS. This modified method was applied to analyze phosphopeptides. Phosphopeptides are very small in size and difficult to separate using the other techniques such as Laemmli SDS-PAGE, original tricine-SDS-PAGE, immobilized metal affinity chromatography (IMAC), size exclusion chromatography (SEC) etc. In this study a simplified procedure is described based on modifying the original tricine-SDS-PAGE method. A comparative study showed that this modified method successfully resolved a digest mixture of very low to high molecular mass phosphopeptides/peptides. In off-line coupling of this method with ICP-MS, much better recoveries of the peptides from the gel were obtained as compared to traditional methods which indicate the compatibility of this modified method for quantitative studies. An on-line coupling of the modified system with ICP-MS was also demonstrated and it was applied for the separation, detection and quantification of phosphopeptides. Another application of this modified system was the separation of serum proteins. Blood serum contains five major protein groups i.e., albumin, alpha-1 globulin, alpha-2 globulin, beta globulin and gamma globulin. The separation of these five major proteins in a single gel is difficult to achieve using traditional methods. The modified system was shown to be superior for the separation of these serum proteins in a 7% (m/v) native-PAGE gel and a cellulose acetate membrane. A further study was carried out into controlling the factors that cause metal loss and protein fragmentation in SDS-PAGE. Using a reducing sample buffer, and heating to high temperatures (90-100ºC) in alkaline or acidic conditions may cause protein fragmentation and decrease the metal binding affinity. 70ºC was found suitable to prepare the sample at neutral, alkaline or acidic pH as no fragmentation observed. To prevent metal loss, the binding constant (log K) values of metal-amino acids, play the major role. Those metals which have high binding affinities with the amino acids in proteins can also be affected by the variation of the pH so prior information about pH to maintain the binding constant values is essential to minimize metal loss. This was observed in the loss of zinc, and to a lesser extent copper from human serum albumin (HSA) as measured by inductively coupled plasma mass spectrometry (ICP-MS). The method described above was applied for the separation and quantification of the serum proteins obtained from age-related macular degeneration (AMD) patients (where the AMD patients were from Moorfields Eye Hospital, London). Zn and Cu were quantified employing external calibration. Zn concentration showed variation whilst Cu did not show any significant variations in samples from AMD patients. A brief study of the interaction of cisplatin and oxaliplatin with HSA and transferrin was also performed. Cisplatin bound much faster than oxaliplatin with HSA. After 24 hours incubation, cisplatin showed a decrease in signal intensity which indicates that cisplatin binding decreases with time. Cisplatin binding with transferrin as compared to HSA was not significant, which could be the result of unstable Pt-transferrin complex formation. Oxaliplatin did not show high binding to either protein, perhaps due to the presence of the bulky, non polar DACH ligand.

In the design of a thermal protection system for atmospheric entry, aerothermal heating presents a major impediment to efficient heat shield design. Recombination of atomic species in the boundary layer results in highly exothermic surface-catalyzed recombination reactions and an increase in the heat flux experienced at the surface. The degree to which these reactions increase the surface heat flux is partly a function of the heat shield material. Characterization of the catalytic behavior of these materials takes place in experimental facilities, however there is a dearth of detailed computational models for the fluid dynamic and chemical behavior of such facilities. A numerical model coupling finite rate chemical kinetics and high temperature thermodynamic and transport properties with a computational fluid dynamics flow solver has been developed to model the chemically reacting flow in the inductively coupled plasma torch facility at the University of Vermont. Simulations were performed modeling the plasma jet for hybrid oxygen-argon and nitrogen plasmas in order to validate the models developed in this work by comparison to experimentally-obtained data for temperature and relative species concentrations in the boundary layer above test articles. Surface boundary conditions for wall temperature and catalytic efficiency were utilized to represent the different test article materials used in the experimental facility. Good agreement between measured and computed data is observed. In addition, a code-to-code validation exercise was performed benchmarking the performance of the models developed in this dissertation by comparison to previously published results. Results obtained show good agreement for boundary layer temperature and species concentrations despite significant differences in the codes. Lastly, a series of simulations were performed investigating the effects of recombination reaction rates and pressure on the composition of a nitrogen plasma jet in chemical nonequilibrium in order to better understand the composition at the boundary layer edge above a test article. Results from this study suggest that, for typical test conditions, the boundary layer edge will be in a state of chemical nonequilibrium, leading to a nonequilibrium condition across the entire boundary layer for test article materials with high catalytic efficiencies.

O objetivo deste estudo foi avaliar parâmetros para o desenvolvimento de métodos visando à determinação elementar em alumina, cimento e quartzo por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) com amostragem de suspensão. Alguns elementos foram investigados como possíveis candidatos a padrões internos (PIs) Be, Dy, Gd, In, La, Sc, Y, Yb eTl. Amostras de material de referência certificado (CRM) de alumina (Alumina Reduction Grade 699), de cimento Portland (1889a Blended with Limestone e 1886a White Portland cement with low iron) do National Institute of Standard and Technology (NIST), e amostras de quartzo, cedidos pelo Departamento de Física da Universidade Federal de São Carlos (UFSCar), denominados T-4FI, T-2FI e T-4GR, foram utilizadas na otimização instrumental, no desenvolvimento e na avaliação da exatidão do método. Nanopartículas de sílica de alta pureza (Wacker HDK® T40), Wacker Chemie AG foram utilizadas no estudo de adsorção dos elementos e padrões internos como proposta de produção de material calibrante para a análise direta de sólidos. Para a escolha dos PIs foram construídos gráficos de correlação usando valores de potenciais de excitação, energias de ionização e temperaturas de fusão dos analitos e dos candidatos a PIs. Análise exploratória por agrupamentos hierárquicos (HCA) e análise dos componentes principais (PCA), também foram realizadas. A avaliação de desempenho do ICP OES foi feita em meio das suspensões das amostras a partir do estabelecimento de figuras de mérito como sensibilidade, robustez, seletividade e repetibilidade. Na otimização do foram considerados os parâmetros potência, vazão de nebulização e vazão de gás auxiliar. A determinação de Ca, Fe, Ga, Na, Si e Zn em alumina foi feita após dissolução em forno de micro-ondas com posterior precipitação do Al(III) com NH3. O uso de padrão interno foi essencial para a exatidão do método, com recuperações do CRM que variaram de 83 a 117%. Para a matriz cimento foram avaliados o efeito da concentração de ácido nítrico na extração dos analitos ( Al, Ca, Cr, Fe, K, Mg, Mn, Na, P, S, Si, Sr, Ti e Zn) e na adsorção dos elementos candidatos a PIs (Be, Sc, In, Dy). As determinações por suspensão e uso de padrão interno (exceto para Cr, S e Zn), com 0,5% v v-1 de HNO3, nebulizador Burgener e condições robustas do ICP geraram resultados com recuperações entre 68 e 119%. As determinações de Al, Ba, Cr, Fe, K, Li, Mg, Na, Sr e Ti em quartzo foram executadas com introdução de suspensão e ausência de padrão interno, usando condições do ICP similares àquelas adotadas na determinação elementar para matriz de cimento. Nesse caso as recuperações variaram de 90 a 107%. A adsorção dos analitos e padrões internos sobre as nanopartículas de sílica pode ser uma alternativa para a preparação de padrões de calibração quando se deseja realizar a introdução direta do material sólido em suspensão. / The aim of this study was to evaluate parameters for the development of methods for elements determination in alumina, cement and quartz by inductively coupled plasma optical emission spectrometry (ICP OES) with slurry sampling. Some elements were investigated as candidates for internal standards (ISs) Be, Dy, Gd, In, La, Sc, Y, Yb and Tl. Samples of certified reference material (CRM) of alumina (Alumina Reduction Grade - 699), Portland cement (blended with the 1889a and 1886a Limestone White Portland cement with low iron) from the National Institute of Standards and Technology (NIST), and quartz samples, suplied by the Department of Physics from Federal University of São Carlos (UFSCar), named T-4FI, T-2FI and T4GR were used to optimize instrumental, method development and accuracy evaluation of the method. Nanoparticles of high purity silica (Wacker HDK T40 ®), Wacker Chemie AG were used in the study adsorption of the analytes and internal standards as calibrating material for direct analysis of solids. Correlation graphs using excitation potentials, ionization energies and melting point temperatures were used for chosing the best ISs. Exploratory analysis using hierarchical cluster analysis (HCA) and principal component analysis (PCA) were also performed. Optimization of ICP OES was performed in aqueous and slurry samples to establishment figures of merit, such as sensitivity, robustness, selectivity and repeatability. In the optimization of ICP, power supply, nebulizer flow rate and auxiliary gas flow rate were considered. The determination of Ca, Fe, Ga, In, Si and Zn in alumina was made after decomposition in a microwave oven with subsequent precipitation of Al(III) with NH3 gas. The internal standard was essential to obtain the accuracy of the method, with recoveries of CRM analysis ranging from 83 to 117%. For the cement analysis was evaluated the effect of nitric acid concentration over analytes extraction (Al, Ca, Cr, Fe, K, Mg, Mn, Na, P, S, Si, Sr, Ti and Zn) and ISs candidate adsorption (Be, Sc, In and Dy). Determinations of the elements in cement slurry with the internal standard (except for Cr and Zn), with 0.5% v v-1 HNO3, nebulizer Burgener and robust conditions of ICP produced results with recoveries between 68 and 119%. The determinations of Al, Ba, Cr, Fe, K, Li, Mg, Na, Sr and Ti in quartz were performed with the slurry introduction and without of internal standard, using similar conditions of those adopted for cement matrix. In this case the recoveries ranged from 90 to 107% with addition and recovery test. The adsorption of the analytes and internal standards on silica nanoparticles could be an alternative for the preparation of calibration standards when considering performing the direct introduction of solid material.