Dissertations / Theses on the topic 'Characterization and analytical techniques'
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Pretorius, Nadine Odette. "Multidimensional analytical techniques for the characterization of aliphatic polyesters." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80127.
Full textENGLISH ABSTRACT: Complex polymers are defined by their distributive properties with respect to molecular weight, chemical composition, functionality and molecular topology. As a result, polymer properties are very frequently determined not only by one of these entities but by the correlation of two or more distributions. Aliphatic polyesters are industrially implemented in high performance coatings, paints and varnishes. However, it is typically difficult to correlate the resulting properties with the synthesis parameters as these polymers vary in reactivity and application properties. Copolyester synthesis by direct polyesterification is often assumed to produce randomized products due to the mechanisms involved in stepwise polymerization. The formation of cyclic products by intramolecular reactions of hydroxyl (OH) and carboxylic (COOH) functional groups, sidereactions such as transesterification, alcoholysis, and ester-ester interchange allow even further randomization, enabling a highly complex system. Therefore, in addition to molecular weight distribution, polyesters exhibit chemical composition, functionality type as well as branching distributions, classifying them as complex polymeric systems. The different methods of polymer chromatography in combination with sophisticated spectrometry techniques are useful tools for enabling the full description of the molecular heterogeneity of these complex polyesters. The present study entails method development of different modes of chromatography and mass spectrometry along with their combination, to facilitate the analysis of the various distributions of two model polyester systems, phthalic and maleic anhydride, respectively, in combination with propylene glycol. Gradient HPLC analysis enabled an oligomeric separation based on chemical composition of the respective anhydride/propylene glycol samples. Its off-line coupling to MALDITOF MS and ESI-QTOF MS revealed the presence of several distributions of varying endgroup functionality type and molecular weight distributions at different intervals throughout the polymerization. In addition, online gradient HPLC x size exclusion chromatography (2D-LC) was conducted to obtain the dual chemical composition-molecular weight (CCD-MWD) distribution. The combination of the different coupling techniques provided the opportunity to a more in-depth analysis of the structure-property relationships.
AFRIKAANSE OPSOMMING: Komplekse polimere word gedefinieer deur hul verdelings eienskappe ten opsigte van molekulêre massa, chemiese samestelling, funksionaliteit en molekulêre topologie. Gevolglik, word hul eienskappe dikwels bepaal deur nie net een van hierdie entiteite nie, maar ‘n korrelasie van twee of meer verdelings. Alifatiese poliësters word industrieel geϊmplimenteer in hoë werkverrigting bestrykings, verwe en politoere, dog is dit tipies moeilik om die uiteinde eienskappe met die verwante sintese parameters te korrelleer, aangesien die polimere varieer in reaktiviteit en toepassingseienskappe. Ko-poliëster sintese vanaf direkte poliësterivering word dikwels aanvaar om willekeurige produkte op te lewer as gevolg van die meganismes wat betrokke is tydens trapgroei polimerisasie. Die produsering van sikliese produkte weens intra-molekulêre reaksies van hidroksiel(OH) en karboksiel (COOH) verwante funksionele groepe, newereaksies soos transverestering, alkoholise en ester-ester verwisseling, het verdere ewekansigmaking tot gevolg wat ‘n hoog gekomplekseerde sisteem tot gevolg het. Benewens die molekulere massa verdeling, vertoon poliësters dus chemiese samestelling, funksionaliteit tipe so wel as vertakkings verdeling wat hul as komplekse polimeer sisteme klassifiseer. Die verskillende metodes van polimeer chromatografie in kombinasie met gesofistikeerde spektrometriese tegnieke dien as nuttige bronne vir die volledige beskrywing wat betref die molekulêre heterogeniteit van komplekse poliesters. Die huidige studie stel metode ontwikkeling van verskillende modus van chromatografie, massa spektrometrie sowel as hul aaneenvoeging bekend, om die die verskillende verdelings van twee model poliester sisteme, ftaal- en maleϊensuuranhidried onderskeidelik in kombinasie met propileenglikol, suksesvol te analiseer. Gradiënt hoë-druk vloeistof chromatografie (HPLC) analise het ‘n oligomeriese skeiding, gebaseer op die chemiese samestelling van die verskeie anhidried /propileenglikol monsters, opgelewer. Die nie-gekoppelde skakeling met matriks-assisteerdelaser/ desorpsie-ionisasie tyd-van-vlug (MALDI-TOF) en elektron-sproei-ionisasie kwadrupool-tyd-van-vlug (ESI-QTOF) massa spektrometrie het die teenwoordigheid van verskeie verdelings van varieërende endgroep funksionaliteit tipe en molekulêre verdelings by verskillende intervalle tydens die polimerisasie aan die lig gebring. Gekoppelde skakeling van gradient HPLC en grootte uitsluitings chromatografie is ook uitgevoer om die tweedelige chemiese samestelling-molekulere massa verdeling te bepaal. Aaneenvoeging van die verskeie skakelings tegnieke het die geleentheid gebied om ‘n deeglike studie van die struktuureienskappe verhoudinge suksesvol uit te voer.
Li, Linlin. "Microstructure characterization of polymers by modern NMR techniques." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1353000762.
Full textMaku, Lebogang Jennifer. "Identification and characterization of additives in colourants by advanced analytical techniques." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/98084.
Full textENGLISH ABSTRACT: Various types of anionic, non-ionic, cationic and zwitterionic additives are used in the coatings industry for the production of paints and colourants. These additives are added to enhance properties such as stabilization of pigment dispersions, wetting of pigments and improvement of open time and freeze/thaw stability. Very often the exact chemistry of these commercial additives is unknown and this is a limitation for new product developments. The identification and characterization of these multi-component polymeric materials continues to be a challenging task. This research presents the use of various advanced analytical techniques to identify and characterize commercial additives that are used in a multi-component colourant formulation. The focus of the present study is on additives that are based on poly(ethylene glycol) (PEG). The molar mass distribution of PEG-based additives was determined with liquid chromatography coupled to mass spectrometry (LC-MS) using solvent gradient elution and at critical conditions of adsorption (LCCC) of PEG. Using the combination of LC-MS, proton nuclear magnetic resonance spectroscopy (1H NMR), pyrolysis gas chromatography (py-GC-MS) and Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), different additives were identified in terms of the number and type of polymer end groups. The efficiency of the extraction and identification protocol was demonstrated for a blend of additives in a colourant formulation.
AFRIKAANSE OPSOMMING: Verskeie tipes anioniese, nie-ioniese, kationiese en zwitterioniese bymiddels word gebruik in die bedekking nywerheid vir die vervaardiging van verwe en kleurmiddels. Hierdie bymiddels word bygevoeg om sekere eienskappe, soos die stabilisering van pigment dispersie, benatting van pigmente en die verbetering van ope tyd en vries/dooi stabiliteit te versterk. Dikwels is die presiese chemie van hierdie kommersiële bymiddels onbekend en het dit ʼn beperking vir nuwe produk ontwikkeling tot gevolg. Die identifisering en karakterisering van hierdie meer-komponent polimeriese materiaal duur voort om ʼn uitdagings te wees. Hierdie navorsingstudie stel voor die gebruik van verskeie tegnieke om kommersiële bymiddels te identifiseer en karakteriseer wat in meer-komponent kleurmiddel formulasies gebruik word. Die fokus is geplaas op bymiddels wat gebaseer is op poli(etileen glikol) (PEG). The molêre massa verdeling van PEG-gebaseerde bymiddels was bepaal met vloeistofchromatografie gekoppel tot massaspektrometrie (VC-MS) met die gebruik van oplosmiddel gradient eluasie en by kritiese toestande van adsorpsie (VCKT) van PEG. Deur die kombinasie van VC-MS, proton kern magnetiese resonansie spektroskopie (1H KMR), pirolisegaschromatografie (pir-GC-MS) en Fourier-transformasie infrarooi spektroskopie in verswakking totale refleksie modus (FTIR-VTR), is verskillende bymiddels geïdentifiseer in terme van die hoeveelheid en tipe polimeer eindgroep teenwoordig. Die doeltreffendheid van die ekstrahering en identifisering protokol is gedemonstreer vir ʼn mengel van bymiddels in ʼn kleurmiddel formulering.
Lenart, William R. "EXPANDING EXPERIMENTAL AND ANALYTICAL TECHNIQUES FOR THE CHARACTERIZATION OF MACROMOLECULAR STRUCTURES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1584358701735061.
Full textMatos, João Tiago Viana de. "Organic matter in atmospheric aerosols: molecular characterization using high-resolution analytical techniques." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22234.
Full textEsta dissertação focou-se na caracterização química de amostras de aerossóis atmosféricos finos recolhidas numa região urbana situada na costa da Europa Ocidental, durante oitenta semanas, e representativas das diferentes estações do ano. Os dados adquiridos proporcionam um maior conhecimento sobre a composição molecular da fração orgânica dos aerossóis, bem como uma visão global sobre a contribuição de diferentes fontes e sazonalidade dos componentes carbonáceos e inorgânicos nos aerossóis. A cromatografia líquida bidimensional abrangente foi utilizada para investigar a heterogeneidade química e mapear a hidrofobicidade vs. distribuição de peso molecular das frações de ácidos mais hidrofóbicos da matéria orgânica solúvel em água (WSOM, na sigla em inglês) de aerossóis atmosféricos, revelando que a WSOM, amostrada nas estações quentes, é enriquecida em estruturas alifáticas, enquanto que a WSOM recolhidas nas estações frias contém estruturas com ligações conjugadas juntamente com estruturas alifáticas. Foi também realizado uma comparação das características estruturais da matéria orgânica presente em extratos aquosos e extratos alcalinos, sequencialmente extraídos de aerossóis finos. Para isso, foi utilizado um método quimiométrico multidirecional para decompor conjuntos de espectros de fluorescência em modo matriz excitação-emissão de WSOM e de matéria orgânica solúvel em meio alcalino (ASOM, na sigla em inglês), numa tentativa de identificar as estruturas fluorescentes atmosfericamente mais relevantes, bem como a sua variabilidade anual. A metodologia utilizada demonstrou diferenças sazonais num dos componentes fluorescentes identificados nas amostras de WSOM, contrastantes com os resultados obtidos para as amostras ASOM, nas quais os componentes identificados foram constantes ao longo do ano. A espectroscopia de ressonância magnética nuclear (RMN) de protão foi igualmente utilizada para investigar e comparar as características estruturais das frações de WSOM e ASOM, mostrando que estas frações contêm grupos funcionais de protão semelhantes, mas com uma diferente distribuição relativa ao longo do ano. As amostras recolhidas nas estações frias apresentam um carácter menos alifáticos e oxidado e com uma maior contribuição de estruturas aromáticas que as amostras recolhidas nas estações quentes. Adicionalmente, a aplicação das técnicas bidimensionais (2D) de RMN forneceram uma excecional resolução e uma incomparável representação da assinatura molecular das amostras, o que permitiu obter um perfil detalhado da composição estrutural destas frações, assim como decifrar as suas principais fontes de emissão ao longo do ano. As frações ASOM são menos hidrofílicas e estruturalmente diversas das frações de WSOM, sendo estas últimas constituídas maioritariamente por estruturas alifáticas ramificadas ricas em hétero-átomos, de origem primária (antropogénica e natural) e secundária. Estruturas do tipo da lignina, sacarídeos, dissacarídeos, e anidrosacarídeos foram identificados nas amostras de WSOM, refletindo a influência queima de biomassa. Os dados espectrais obtidos para cada ligação H-C identificada foram também utilizados para construir um modelo estrutural semiquantitativo da fração WSOM, o qual poderá ser utilizado em futuros estudos acerca do efeito da composição química e estrutural dos aerossóis orgânicos no respetivo comportamento e impacto na química da atmosfera.
This dissertation focus on the chemical characterization of fine atmospheric aerosol samples collected at an urban site in the Western European Coast, during eighty weeks, representative of different seasons. The acquired data set provide a comprehensive and new insight on the molecular composition of the organic fraction of the aerosol components, as well as, provide a seasonal source apportionment overview of both carbonaceous and inorganic aerosol components. Comprehensive two-dimensional liquid chromatography was introduced to investigate the chemical heterogeneity and map the hydrophobicity vs. molecular weight distribution of the most hydrophobic acid fractions in water-soluble organic matter (WSOM) from atmospheric aerosols, revealing that the WSOM samples collected in warm seasons are enriched in aliphatic structures, while those from colder seasons exhibit a higher degree of structures with conjugation of -bonds alongside aliphatic structures. A comparison of the features of the organic matter present in water and alkaline extracts, sequentially extracted, from fine aerosol samples during different seasons, are also carried out. For that, a multiway chemometric method was used to decompose sets of excitation-emission matrices fluorescence spectra of WSOM and alkaline-soluble organic matter (ASOM), in an attempt to identifying the most atmospherically-relevant fluorescent structures, as well as their variability over seasons. The method shows differences between the colder and warmer seasons in the fluorescence map of one WSOM fluorescent component, which contrast with the results obtained for the ASOM, where the fluorescence signatures were found to be constant along the seasons. Proton nuclear magnetic resonance (1H NMR) spectroscopy was used for investigating and comparing the structural features of WSOM and ASOM, showing that these fractions hold similar 1H functional groups; however, they differ in terms of their relative distribution throughout the different seasons. Samples collected during the cold seasons have a less aliphatic and oxidized character and higher contributions from aromatic groups than those from warmer conditions. Furthermore, a synergistic combination of 2D NMR techniques provided an exceptional resolution and depicted unsurpassed resolved molecular signatures, which allowed portraying the annual background of the structural composition of these fractions, as well as deciphering their major source types over seasons. The ASOM fractions are less hydrophilic and structurally diverse than their WSOM counterparts. This latter component is mostly composed of heteroatom-rich branched aliphatics, having both primary (natural and anthropogenic) and secondary origin. Lignin, disaccharides, and anhydrosaccharides signatures were also identified in the WSOM samples, reflecting the biomass burning influence. The derived dataset on the H–C molecules backbone were also used to build a semi-quantitative structural model of WSOM, which can be used as a proxy to further distil key features on the atmospheric behaviour of organic aerosols.
Sinner-Hettenbach, Martin. "SnO 2 (110) and Nano-SnO 2 characterization by surface analytical techniques /." [S.l. : s.n.], 2000. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB8884756.
Full textDixon, Daniel Wayne. "Characterization of Commercial Pectin Preparations by Spectroscopic and Chromatographic Techniques." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etd/1910.
Full textGebremichael, Ermias. "Pharmaceutical Eutectics: Characterization and Evaluation of Tolbutamide and Haloperidol using Thermal Analytical and Complementary Techniques." Toledo, Ohio : University of Toledo, 2010. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1271439418.
Full textTypescript. "Submitted to the Graduate Faculty as partial fulfillment of the requirements of the Master of Science degree in Pharmaceutical Sciences with Industrial Pharmacy Option." "A thesis entitled"--at head of title. Title from title page of PDF document. Bibliography: p. 87-102.
Sinner-Hettenbach, Martin. "SnO2(110) and Nano-SnO2 characterization by surface analytical techniques = SnO2(110) und Nano-SnO2 /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=963195433.
Full textDanziger, James Lee. "Characterization of molecular semiconductor and multilayer molecular organic photoconductor interfaces by photoelectrochemistry and surface analytical techniques." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185217.
Full textMacKenzie, Sabrena E. "Isolation and characterization of new fumonisins from Fusarium moniliforme NRRL 13616 and development of new analytical techniques." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ36942.pdf.
Full textChen, Siying. "Characterization of crystalline and solution-processable phthalocyanine assemblies by electrochemical, photoelectrochemical, and surface spectroscopic techniques." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282120.
Full textNielsen, Michael Lund. "Characterization of Polypeptides by Tandem Mass Spectrometry Using Complementary Fragmentation Techniques." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7409.
Full textJoyce, Karen Elaine. "Development of Reactive Ion Scattering Spectrometry (RISS) as an Analytical Surface Characterization Technique." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193593.
Full textCasiano-Maldonado, Madalis. "Mass Spectrometry Techniques for the Characterization of Synthetic Polymers, Biopolymers, Biodegradation Products and Their Interactions." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1332962590.
Full textBrown, Anna Laura. "Bismuth Nanoparticles as Medical X-ray Contrast Agents: Synthesis, Characterization and Applications." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1523.
Full textHeuett, Nubia Vanesa. "Target and Non-target Techniques for the Quantitation of Drugs of Abuse, Identification of Transformation Products, and Characterization of Contaminants of Emergent Concern by High Resolution Mass Spectrometry." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2194.
Full textMastricola, Nicholas Palma. "Nonlinear Stiffness and Edge Friction Characterization of Coned Disk Springs." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480346443676492.
Full textAbdelraouf, Mostafa. "Virtual reality for the characterization of blood vessel to airway geometric relationships." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6355.
Full textVabbilisetty, Pratima. "Fabrication and Characterization of Substrate Materials for Trace Analytical Measurements by Surface Enhanced Raman Scattering (SERS) Spectroscopy Technique." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1231794465.
Full textSHAH, MONIKA. "CHARACTERIZATION OF BIOLOGICALLY IMPORTANT VOLATILE AND NON-VOLATILE MOLECULES VIA HETEROATOM DETERMINATION USING CHROMATOGRAPHY AND MASS SPECTROMETRY." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148309632.
Full textBhogavalli, Sridhar. "Characterizatin of a Type II Metallothionein from Helianthus annuus Using Recombinant DNA Techniques." Cleveland, Ohio : Cleveland State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=csu1198989836.
Full textAbstract. Title from PDF t.p. (viewed on May 8, 2008). Includes bibliographical references (p. 41-45). Available online via the OhioLINK ETD Center. Also available in print.
Du, Liangfen. "Characterisation of air-borne sound sources using surface coupling techniques." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI028/document.
Full textThe thesis investigates possibilities of air-borne sound characterisation of arbitrary sound sources. To this end a particular approach is studied where the source characterisation is done via an interface surface which fully or partially envelopes the physical source. Two frequency dependent descriptors are defined across such a surface: the blocked sound pressure and the source impedance. The former represents the sound pressure created by the operating source which acts on the enveloping surface when this is made immobile. The latter represents the ratio of pressure response amplitudes and normal velocity excitation amplitudes across the surface. The enveloping surface defines an air volume containing the physical source, called the source space. The two source descriptors defined on the source space, the blocked pressure and the source impedance, are shown to be intrinsic to the source, i.e. independent of the surrounding acoustical space. Once defined, these descriptors allow one to find the sound pressure and normal particle velocity at the interface surface when the source space is coupled to an arbitrary receiver space, i.e. a room. This in turn allows for sound prediction in the receiver space. The coupling conditions require that the receiver space is characterised using the same enveloping surface as the source space. Bearing the measurement simplicity in mind, the enveloping surface has been conceived as consisting of one or several rectangular plane surfaces. The research challenge was then to obtain meaningful surface impedance across a (continuous) rectangular plane surface as well as the blocked pressure compatible with impedance formulation. This has led to a spatial decomposition of sound pressure and particle velocity into finite number of components, each defined by a complex amplitude and a particular spatial distribution. In this way the blocked pressure reduces to a vector of complex pressure amplitudes while the impedance becomes a matrix of pressure and velocity complex amplitude ratios. Two decomposition methods have been investigated in detail: the surface harmonic method and the patch method. The former approximates the surface pressure and normal velocity by combinations of 2D trigonometric surface functions while the latter splits the surface into small patches and treats each patch in a discrete way, using patch-averaged values
Elbaa, Mohamed. "Caractérisation et modélisation des matériaux supraconducteurs à haute température critique." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0196.
Full textThe aim of this thesis is to optimize the process of magnetization of superconducting pellets at high critical temperature (SHTC) by pulsed field magnetization (PFM) in order to use them in applications in the field of electrical engineering. In the design phase of the inductor necessary to magnetize these SHTC pellets, modeling and simulation are strongly recommended to perform the necessary calculations of the various electrical characteristics of the magnetization system. Therefore, we have developed an analytical model to study the influence of the presence of a superconducting bulk on the value of the inductance of an induction coil in a ferromagnetic circuit. The aim is to solve the Laplace and Poisson equations in different regions of interest through the magnetic vector potential. The analytical resolution was performed (carried out) using a computer code developed under MATLAB where the results obtained were in good agreement with those obtained by numerical simulation under COMSOL. The inhomogeneity of YBaCuO type SHTC pellets in terms of critical current density Jc was also investigated. To do this, we carried out experiments on the magnetization of these bulks by the PFM method. We have shown that the flat surface containing the crystallization germ (seed) of these pellets is characterized by a higher Jc than the other surface. Also, we studied the influence of the position of the seed crystallization in the two-pellet characterization method
Mallek, Maryam. "Analytical methodology based on a silicone rod (SR) micro extraction combined with HPLC-DAD method for the determination of pharmaceuticals and antibacterial products in effluent wastewaters: characterization of the sorption removal processes by cork." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/669295.
Full textLes tècniques de microextracció en fase sòlida (SPME) permeten obtentir alts factors d'enriquiment emprant petits volums de solvents fent possible que s'assoleixin els baixos límits de detecció requerits per la determinació de ketoprofen, naproxen, carbamazepina, diclofenac i triclosan en matrius d'interès ambiental emprant HPLC-DAD. S'ha revisat l'estat de l'art de les diferents tècniques de SPME i les seves darreres innovacions. S'ha desenvolupat i validat un mètode analític basat en la microextracció amb vareta polidimetilsiloxà (PDMS) i HPLC-DAD per la determinació de PPCPs, estudiant-ne els diferents paràmetres i condicions que afecten a les etapes d'extracció (pH, modificador orgànic, força iònica, cinètica i volum de mostra) i de desorció (dissolvent, volum, temps de desorció i aplicació de sonicació). S'ha demostrat que el suro granulat pot ser una alternativa de baix cost per l'eliminació de PPCPs i compostos fenòlics de les aigües atès que la seva capacitat per adsorbir aquests contaminants és alta
Wong, Won Gina Micheline. "Selected analytical techniques in dendroanalysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ58102.pdf.
Full textHreczuk-Hirst, Dale. "Rapid analytical techniques for ondansetron." Thesis, University of Sunderland, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284754.
Full textSeetohul, L. Nitin. "Novel applications of optical analytical techniques." Thesis, Teesside University, 2009. http://hdl.handle.net/10149/117905.
Full textRobert, Rodolphe. "Analytical characterization of porous geomaterials." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2005. http://dx.doi.org/10.18452/15286.
Full textIn this study, five typical sedimentary rocks, two sandstones (Fontainebleau, “Grès à Meules”), a chalk and two limestones (tuffeau, Vuillecin) were analyzed with regards to their porous structure, mineral structure and fluid transport properties. The aim of this study was first to assess the different characteristics of the rocks regarding their variations and their inter-dependences. Relationships were established using techniques such as water and mercury porosimetry, gas adsorption, X-ray computed tomography, optical and electron microscopy, and performing gas permeability and water imbibition measurements and pore model analyses. In particular, the role of clay mineral concentrations was exposed and the porous structure parameters, on which the fluid transport properties significantly depend, were identified regarding the degree of their influence. Furthermore, new ideal pore models were schematized. These models describe the fluid transport behaviours of the rocks either for gas flow or water imbibition. The second main goal was to express if or not these geomaterials could become useful reference materials or standards. It was shown that the degrees of homogeneity of the rocks were low in comparison with any existing certified reference materials, which are industrially synthesized. For this major reason, the possibilities of the elaboration of useful reference values using the rocks were found to be restraint. For instance, it was evident that the Vuillecin limestone had a too low homogeneity degree to be reasonably used in any way as reference material. The variations of many structure parameters of the other rocks were low for big samples (over 15 cm³). In this case, standards could be elaborated using methods such as the water porosimetry or the capillary water imbibition kinetics. Such standards would be useful in the field of geomaterial research for qualitative inter-comparisons and for the control or the development of pore models applied to the analysis of fluid transport properties. For small sample volumes (generally below 2 or 3 cm³) measured using techniques such as mercury porosimetry or gas adsorption, the accuracy of the structure parameters was too low and the rocks were found to be unsuitable for elaborating reference or standard values in the aim of the calibrating instruments, testing the efficiency of apparatus or validating new methods.
Kahoul, Asma. "Reconfigurable architecture floorplan optimisation using analytical techniques." Thesis, Imperial College London, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.550949.
Full textSimjee, Nafeesa. "Development of microelectrode techniques for analytical measurements." Thesis, University of Warwick, 2003. http://wrap.warwick.ac.uk/2664/.
Full textShams, Saleema Bashir. "Some new micro analytical techniques in biochemistry." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245056.
Full textNigam, Atish 1981. "Analytical techniques for debugging pervasive computing environments." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17962.
Full textIncludes bibliographical references (p. 63-65).
User level debugging of pervasive environments is important as it provides the ability to observe changes that occur in a pervasive environment and fix problems that result from these changes, especially since pervasive environments may from time to time exhibit unexpected behavior. Simple keepalive messages can not always uncover the source of this behavior because systems can be in an incorrect state while continuing to output information or respond to basic queries. The traditional approach to debugging distributed systems is to instrument the entire environment. This does not work when the environments are cobbled together from systems built around different operating systems, programming languages or platforms. With systems from such disparate backgrounds, it is hard to create a stable pervasive environment. We propose to solve this problem by requiring each system and component to provide a health metric that gives an indication of its current status. Our work has shown that, when monitored at a reasonable rate, simple and cheap metrics can reveal the cause of many problems within pervasive environments. The two metrics that will be focused on in this thesis are transmission rate and transmission data analysis. Algorithms for implementing these metrics, within the stated assumptions of pervasive environments, will be explored along with an analysis of these implementations and the results they provided. Furthermore, a system design will be described in which the tools used to analyze the metrics compose an out of bound monitoring system that retains a level of autonomy from the pervasive environment. The described system provides many advantages and additionally operates under the given assumptions regarding the resources available
(cont.) within a pervasive environment.
by Atish Nigam.
M.Eng.
Stamatopoulos, Ioannis D. "Analytical techniques for modelling the laminated waveguide." Thesis, University of Surrey, 2003. http://epubs.surrey.ac.uk/844108/.
Full textCardoso, dos Santos Josué. "Study of the dynamics around celestial bodies using analytical and semi-analytical techniques." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/155950.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Nowadays, despite the technological development experienced by science in general, a fact especially evident by the available powerful computer machines, the analytical and semi-analytical methods to study different space problems are still of great importance in the fields of astrodynamics and celestial mechanics. From the physical understanding of the motion of celestial bodies to the planing and designing of space missions, the use of mathematical models to deal with a very large number of contemporary problems plays a fundamental role in the progress of human knowledge. In this context, the present thesis presents the use of different mathematical techniques to deal with different various and current problems in astrodynamics and celestial mechanics. The studies developed throughout this work are applicable to both areas. The topics studied are the following ones: (1) The development of disturbing potentials using the double-averaging process, in order to be included in the Lagrange planetary which are numerically integrated to study features of orbits around Mercury and the Galilean moon Callisto; (2) The use of different perturbation integrals, techniques to identify and map different perturbations present in a planetary system, with focus on the analysis of systems of Giant planets with their massive moons; (3) The use of the concept of intermediary Hamiltonian and the use of a canonical transformation called elimination of the parallax, both to deal with binary systems in the context of the roto-orbital dynamics, this one as an approach of the fulltwo body problem; (4) An updated analysis of Gauss variational equations to study quasisatellite orbits around the Martian moon Phobos and with analytical predictions made after obtaining linear and averaged equations of motions. Therefore, this thesis intend not only to provide important analysis and results for each specific problem which it deals with along its pages, but also seeks to highlighting the merit and current relevance of different analytical and semi-analytical methods to be used in the fields of astrodynamics and celestial mechanics. Additionally, the author also hopes to offer an outcome of diverse interesting ideas and methods to be explored in future investigations in these research fields
Na atualidade, a despeito do desenvolvimento tecnológico experimentado pela ciência em geral, algo especialmente evidenciado por poderosas máquinas computacionais disponíveis, os métodos analíticos e semianalíticos para o estudo de diferentes problemas espaciais ainda são de grande importância nos campos de astrodinâmica e mecânica celeste. Desde a compreensão física do movimento de corpos celestes até ao planejamento e projeto de missões espaciais, o uso de modelos matemáticos para lidar com um grande número de problemas contemporâneos desempenha um papel fundamental no progresso do conhecimento humano. Neste contexto, a presente tese apresenta o uso de diferentes técnicas matemáticas para lidar com diversos e atuais problemas em astrodinâmica e mecânica celeste. Os estudos desenvolvidos ao longo deste trabalho são aplicáveis à ambas as áreas. Os tópicos estudados são os seguintes: (1) O desenvolvimento de potenciais perturbadores usando o processo de dupla média, de forma a serem incluídos nas equações planetárias de Lagrange que são integradas numericamente para estudar características de órbitas ao redor de Mercúrio e da lua galileana Calisto; (2) A utilização de diferentes integrais de perturbação, técnicas para identificar e mapear diferentes perturbações presentes em um sistema planetário, com foco na análise de sistemas de planetas gigantes com suas luas massivas; (3) A utilização do conceito de hamiltoniana intermediária e o uso de uma transformação canônica chamada eliminação da paralaxe, ambos para lidar com sistemas binários no contexto da dinâmica roto-orbital, essa sendo uma aproximação do problema completo de dois corpos; (3) Uma análise atualizada de equações variacionais de Gauss para o estudo de órbitas quasi-satélite ao redor da lua marciana Fobos e com predições analíticas realizadas após serem obtidas equações de movimento linearizadas e com média. Portanto, esta tese pretende não somente prover importantes análises e resultados para cada problema específico com os quais a mesma lida ao longo de suas páginas, mas também procura destacar o mérito e relevância atual de diferentes métodos analíticos e semianalíticos a serem utilizados nos campos de astrodinâmica e mecânica celeste. Adicionalmente, o autor também espera oferecer um produto de variadas ideias e métodos a serem explorados em futuras investigações nesses campos de pesquisa
2013/26652-4
2015/18881-9
Pla, i. Vilanova Pepita. "Development of emerging analytical techniques for speciation studies." Doctoral thesis, Universitat de Lleida, 2020. http://hdl.handle.net/10803/671154.
Full textEsta tesis ofrece nuevos conocimientos sobre el campo de las técnicas de especiación basados en medidas de concentraciones de iones libres. Las dos contribuciones principales son: (i) la detección de nuevos elementos y (ii) la mejora de las técnicas. La primera parte se centra en la determinación electroquímica de dos elementos trivalentes como son el In y el Sb. Últimamente, estos dos elementos han recibido mucha atención, debido a sus aplicaciones crecientes y los posibles efectos en el medio ambiente. Por lo tanto, es necesario tener técnicas analíticas adecuadas y fiables, para ambos elementos. Para el análisis de In, se midieron concentraciones de In total y libre en solución mediante dos técnicas electroanalíticas complementarias, SCP (Stripping chronopotentiometry) y AGNES (Absence of gradients and Nernstian equilibrium stripping), ambas implementadas con el TMF/RDE (Thin mercury film/rotating disk electrodes). Con ambas técnicas se alcanzaron límites de detección nanomolares. AGNES fue empleada para el estudio de la disolución de nanopartículas In2O3, dado su amplio uso tecnológico. El pH y el efecto de los ligandos lábiles en solución afectaban signicativamente su cuantificación. También se estudiaron las ventajas de utilizar el TMF/RDE ante el HMDE (Hanging mercury drop electrode), consiguiendo tiempos experimentales más cortos incluso cuando se determinan concentraciones libres pequeñas. Las medidas presentadas de Sb representan la primera aplicación de AGNES para detectar una especie particular de Sb(III) en una solución acuosa. El Sb como ion libre es prácticamente inexistente, debido a su extensa hidrólisis. Así pues, su detección se basó en seguir las concentraciones de Sb(OH)3(aq). Dos variantes diferentes de AGNES se emplearon para el análisis de Sb y fueron comparadas. Mediante la variante AGNES-Q se obtuvieron resultados aceptables, pero los tiempos de stripping que necesitaba eran largos. Por otra parte, AGNES-SCP resulta ser la técnica mas ventajosa, ya que demostró ser mas rápida y reproducible. Esta prometedora metodología abre camino para hacer frente a la especiación de Sb con AGNES en otros sistemas y medios. La segunda parte de esta tesis se centra en mejorar la aplicabilidad y la eficiencia de la técnica DMT (Donnan membrane technique). Esto se llevó a cabo estudiando varios cambios en la metodología empleada, agrupadas de la siguiente manera: variables experimentales, modificaciones instrumentales y composición del acceptor. El primer conjunto mejoró la eficacia y la robustez de la técnica, descartando cualquier efecto potencial de la agitación de la muestra (donor), la temperatura del sistema y el muestreo del acceptor. Por su parte, la modificación instrumental se basó en la optimización de la relación superficie-volumen, variaciones en las dimensiones de la celda de campo y la utilización de hollow fibres. Estas modificaciones representan una manera simple y eficaz de acortar los tiempos experimentales. El último conjunto de experimentos se basó en el ajuste de la composición del acceptor y se aportaron nuevas estrategias para superar los principales inconvenientes de la técnica DMT. Utilizar concentraciones de electrolito soporte más pequeñnas en el acceptor que en la solución donor, resultó en una reducción significativa de los tiempos experimentales. También se vio, por el contrario, que cuando hay una mayor concentración de electrolito de soporte en el acceptor que en el donor, es posible medir muestras más diluidas.
This thesis offers new insights for the speciation techniques field, based on the measurement of free ions concentrations. Two main contributions are: (i) the detection of novel different elements for the discipline and (ii) the improvement of the techniques. The first part focuses on the electrochemical determination of two trivalent elements such as In and Sb. Lately, both elements have received attention, because of their increasing applications and possible effects on the environment. So, appropriate and reliable analytical techniques, for both elements, are necessary. For the analysis of In, we measured total and free In concentrations in a solution using two complementary electroanalytical techniques, SCP (Stripping chronopotentiometry) and AGNES (Absence of gradients and Nernstian equilibrium stripping), both implemented with the TMF/RDE (Thin mercury film/rotating disk electrode). We achieved nanomolar limits of detection for both techniques. Also, AGNES was employed to study the dissolution of In2O3 nanoparticles, given its wide technological use. pH and the effect of the labile ligands in solution affected significantly free In quantification. We also studied the advantages of using the TMF/RDE in front of the HMDE (Hanging mercury drop electrode), achieving shorter experimental times even when determining extremely low free In concentrations. Sb measurements represent the first application of AGNES to detect one particular specie of Sb(III) in an aqueous solution. Since Sb as a free ion is practically non-existent, because of the extensive hydrolysis of the element, the detection methodology was based on following Sb(OH)3(aq) concentrations. Two different AGNES variants were studied for Sb analysis and were compared. The variant AGNES-Q yielded acceptable results but needed very long stripping times. On the other hand, a clear advantage was presented by AGNES-SCP, which demonstrated to be faster and more reproducible. This promising methodology opens the way to tackle Sb speciation with AGNES in other systems and media. The second part of this thesis focuses on improving DMT's (Donnan membrane technique) applicability and efficiency. It was performed studying a variety of modifications, based on the following sets of concepts: experimental variables, instrumental modifications, and acceptor composition. The first set improved the efficiency and robustness of the technique, ruling out any potential effect from the sample (donor) stirring, the temperature of the system, and the sampling of the acceptor. Conversely, the instrumental modification is based on optimizing the surface-to-volume ratio, modifying the dimensions of the field cell as well as employing hollow fibres. Such modifications represented to be an effective and simple way to shorten the experimental time. The last set of experiments is based on the tuning of acceptor's composition and it revealed new strategies to overcome significantly major drawbacks of the DMT technique. Lower supporting electrolyte concentrations in the acceptor than in the donor solution presented a significant reduction of the experimental times. On the other hand, higher supporting electrolyte concentrations in the acceptor than in the donor, allows to measure more diluted samples.
Altun, Zeki. "New Techniques for Sample Preparation in Analytical Chemistry." Licentiate thesis, Karlstad University, Division for Chemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1374.
Full textSample preparation is often a bottleneck in systems for chemical analysis. The aim of this work was to investigate and develop new techniques to address some of the shortcomings of current sample preparation methods. The goal has been to provide full automation, on-line coupling to detection systems, short sample preparation times and high-throughput.
A new technique for sample preparation that can be connected on-line to liquid chromatography (LC) and gas chromatography (GC) has been developed. Microextraction in packed syringe (MEPS) is a new solid-phase extraction (SPE) technique that is miniaturized and can be fully automated. In MEPS approximately 1 mg of sorbent material is inserted into a gas tight syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. Evaluation of the technique was done by the determination of local anaesthetics in human plasma samples using MEPS on-line with LC and tandem mass spectrometry (MS-MS). MEPS connected to an autosampler was fully automated and clean-up of the samples took one minute. In addition, in the case of plasma samples the same plug of sorbent could be used for about 100 extractions before it was discarded.
A further aim of this work was to increase sample preparation throughput. To do that disposable pipette tips were packed with a plug of porous polymer monoliths as sample adsorbent and were then used in connection with 96-well plates and LC-MS-MS. When roscovitine in human plasma and water samples was used as model substance, a 96-plate was handled in two minutes.
Milne, Kenneth Thallon. "An investigation into IKBS techniques for analytical spectrofluorimetry." Thesis, Heriot-Watt University, 1986. http://hdl.handle.net/10399/1078.
Full textAlmeida, Joao Carlos Gomes Rocha de. "Analytical techniques for the structural evaluation of pavements." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357095.
Full textFancy, Sally-Ann. "Physical and analytical applications of ion trapping techniques." Thesis, University of Kent, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311226.
Full textStarkey, Jason A. "Biochemical applications of microcolumn separation techniques." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3278220.
Full textSource: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5919. Adviser: Milos V. Novotny. Title from dissertation home page (viewed May 9, 2008).
Rämö, J. (Jaakko). "Hydrogen peroxide- metals- chelating agents; interactions and analytical techniques." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514269756.
Full textAlam, Aftab. "Analytical and intelligent techniques for dynamcally [sic] secure dispatches." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1181251728/.
Full textTymis, Nikolaos. "Analytical techniques for acoustic scattering by arrays of cylinders." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/11376.
Full textMcAlister, John J. "Characterisation of basaltic weathering products by modern analytical techniques." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329424.
Full textAbdelsalam, Mamdouh Elsayed. "Development of microelectrode techniques for analytical and environmental applications." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326794.
Full textAlmasoud, Nagla. "Rapid classification and differentiation of bacteria by analytical techniques." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/rapid-classification-and-differentiation-of-bacteria-by-analytical-techniques(fae59630-ef83-47fe-a81b-ccd2f57e3e9e).html.
Full textAngel-Smith, Sarah Jane. "Characterisation of diesel injector deposits using advanced analytical techniques." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50745/.
Full textFrontasyeva, M. V. "Nuclear and related analytical techniques for bio-nano- technology." Thesis, Sumy State University, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20683.
Full textAbel, Hermione. "An analytical study of narrative techniques in Giono's Regain." Thesis, Rhodes University, 1986. http://hdl.handle.net/10962/d1002008.
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