To see the other types of publications on this topic, follow the link: Analytical instruments.
Dissertations / Theses on the topic 'Analytical instruments'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Analytical instruments.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Sweedler, Jonathan VanSyckle. "The use of charge transfer device detectors and spatial interferometry for analytical spectroscopy." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184683.
Full textAbstract:
The research described in this dissertation conclusively demonstrates the superior qualitative and quantitative performance of spectroscopic systems which employ a new class of optical detectors--charge transfer device (CTD) detectors. An overview of the operation and characteristics of these detectors, as well as theoretical models predicting their performance are presented. The evaluation of a unique prototype single element CID detector, a commercially available linear CCD detector, and a prototype two-dimensional CCD detector are described. Outstanding characteristics include the ability of the single element CID to quantitate photon fluxes ranging over eleven orders of magnitude, a quantum efficiency of the linear CCD in excess of 90%, and a read noise of the two-dimensional CCD of under 5 electrons. In addition, the use of the linear CCD for molecular fluorescence spectroscopy is demonstrated. A direct comparison of CCD and CID detection for atomic emission spectroscopy using a custom echelle system is described. The second part of these investigations focus on the design of spectrometers compatible with the format of these multichannel detectors. While a large number of spectrometer designs exist, the spectrometer and detector combination which produces the highest possible signal-to-noise ratio (SNR) spectra for a given experimental system is almost always desired. The investigations into optimum spectrometer design have led to the use of a unique spatial interferometer system. The performance of a common path interferometer using a linear charge-coupled device detectors is presented and compared to conventional dispersive systems. The throughput, resolution, and other practical factors are discussed. The common path system has a much larger light gathering ability compared to dispersive systems; however, spatial interferometry suffers from the multiplex disadvantages encountered with other forms of UV/Vis interferometry. A unique crossed interferometric dispersive arrangement allows the simultaneous acquisition of the spectral information while greatly reducing these multiplex disadvantages. Preliminary work on the crossed interferometric system is presented demonstrating significant reduction of these multiplex disadvantages.
2
Zhang, Boyu. "Mathematical rhythmic structure of Chinese percussion music : an analytical study of Shifan Luogu collections /." Turku : Turun Yliopisto, 1997. http://catalogue.bnf.fr/ark:/12148/cb38877189v.
Full text
3
Шитко, О. П. "Удосконалення аналітичного інструментарію інтерпретації результатів фінансової політики." Thesis, Українська академія банківської справи Національного банку України, 2011. http://essuir.sumdu.edu.ua/handle/123456789/62178.
Full textAbstract:
Прискорення глобалізаційних процесів та інтеграції України до світового фінансового простору вимагає впровадження сучасного інформаційного забезпечення аналізу фінансової політики, розробки нових підходів до її оцінки та інструментів для коригування стійкості фінансової системи в бік зміцнення.The acceleration of globalization processes and Ukraine's integration into the world financial space requires the introduction of modern information support for the analysis of financial policy, the development of new approaches to its evaluation and tools for adjusting the stability of the financial system towards strengthening.
4
Wood, James J. "A Historical and Analytical Examination of the Stravinsky Octet for Wind Instruments, with a Guide to Performance Preparation of the Two Trumpet Parts." Thesis, connect to online resource, 2007. http://digital.library.unt.edu/permalink/meta-dc-3593.
Full textAbstract:
Thesis (D.M.A.)--University of North Texas, 2007.System requirements: Adobe Acrobat Reader. Accompanied by recitals, recorded Mar. 22, 1999, Nov. 29, 1999, and Sept. 11, 2006. Includes bibliographical references (p. 52-53).
5
Garnyk, Liudmyla Petrivna, Y. P. Vitkovskyi, I. I. Snihurova, and O. O. Mishchenko. "Guanxi: Chinese social networks building in prism of international economic relations." Thesis, ВД "Гельветика", 2020. http://repository.kpi.kharkov.ua/handle/KhPI-Press/49189.
Full text
6
McCallum, Kirstie. "Instrumental developments in analytical single bubble sonoluminescence." Thesis, Glasgow Caledonian University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404615.
Full text
7
Holmes, James R. "Development of Operational and Teaching Software for a Complex Analytical Instrument Using Virtual Instrument Technology." Curtin University of Technology, Department of Applied Physics, 2002. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=13792.
Full textAbstract:
It is not always possible to provide students and new users of complex instrumentation with sufficient hands-on use to fully develop the required knowledge of the instrument. Access may also be limited when there is a need to develop data collection and processing procedures. One solution to this problem is to develop a simulation of the instrument in readily accessible computer software. Modern computer-based technology allows traditional instrumentation to be replaced with Virtual Instruments consisting of digital control/acquisition hardware and software that graphically represents the functions of the physical instrument.In this thesis, operating and analysis software to simulate the operation of complex analytical instrumentation was successfully developed using a numerical model of the instrument. The approach will reduce the need for machine time for operator training and the development of data collection processing procedures. In particular the thesis developed software to emulate the behaviour of a VG-354 Thermal Ionisation Mass Spectrometer. Graphical programming tools were employed to create a modular set of Virtual Instruments that formed the basis of the model. The Simulated Mass Spectrometer produced results that compared well with real data obtained from the physical instrument.Virtual Instrument peak centring and measurement modules were then developed to operate the Simulated Mass Spectrometer in peak jumping mode. Uncertainties were reduced with improved analysis techniques employing polynomial least-squares fits for peak centring and single-collector isotope ratio measurements. The techniques also have the potential to accommodate hysteresis effects in the magnetic sector analyser, further reducing uncertainty.
8
Webb, Douglas P. "Intelligent autonomous inductively coupled plasma instrumental operation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0010/NQ30413.pdf.
Full text
9
Rossi, Maura Vincenza. "Aspectos teóricos e experimentais do uso do EDTA tetraneutralizado como titulante em determinações complexométricas." Universidade de São Paulo, 1992. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-05072018-100829/.
Full textAbstract:
O presente trabalho, teve como objetivo, dar continuidade ao estudo apresentado na forma de dissertação de mestrado, utilizando a complexona EDTA, totalmente \"neutralizada\". na forma de Y4-. Na titulação de íons metálicos, a hidrólise acentuada deste ânion, Y4-, causa um aumento marcante de pH após o ponto estequiométrico. Esta variação de pH pode ser acompanhada potenciometricamente, utilizando um eletrodo de vidro, ou visualmente com um indicador ácido/base como a fenolftaleina, em substituição a indicadores metalocrômicos. Uma série de parâmetros foram considerados na preparação do reagente, sua armazenagem e padronização bem como os problemas ligados a percentagem de \"neutralização\". Vários equilíbrios foram considerados no desenvolvimento de um programa em linguagem BASIC, para interpretar a curva teórica da titulação de Mg2+ com EDTA \"tetraneutralizado\", na qual participam também espécies como MgHY-, antes do ponto estequiométrico. Um método complexométrico rápido e preciso foi desenvolvido com este titulante para determinar Mg2+ e SO42- simultaneamente (este por método indireto para o excesso de íons Ba2+) com viabilidade para ser aplicado em água do mar e em concentrados salinos. O método mostrou-se adequado, também, para a determinação da mistura Ca2+ e Mg2+, em substituição ao método clássico com tampão e indicador metalocrômico, eriocromo T.This thesis has the purpose to give continuity to a former study from the master dissertation, about the use of the complexon EDTA, totally \"neutralized\", as the species Y4-. During the titration of metallic cations the marked hydrolysis of the y4- anion causes a marked pH increase after the stoichiometric point. This change of pH can be followed potentiometrically with the glass electrode or by visual end point indication by on acid/base indicator as phenolphtalein instead of metalochromic indicators. A serie of parameters were considered in the preparation of the titrant, its storage and standardization as well as problems related with the percent neutraIization\". Equilibria were considered and used in a computer program in BASIC language in order to interpret the theoretical titration curve. The species MgHY- was found in significant contribution before the end point. A fast and precise complexometric method was developed with this titrant for Mg2+ and SO42- simultaneously (this last by titration of excess of standard Ba2+ solution). The method has been found adequate to determine mixture of Ca2+ and Mg2+ instead of the classic method which uses a buffer and eriochrome T as indicator.
10
Tang, Xiaoting. "New analytical tools for systems biology." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Fall2006/x_tang_081706.pdf.
Full text
11
Willcox, Simon Ware. "Robust sensor fault diagnosis for aircraft based on analytical redundancy." Thesis, University of York, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329855.
Full text
12
Rignall, Michael. "Characterisation and development of a new multi-purpose surface analytical instrument." Thesis, Sheffield Hallam University, 2000. http://shura.shu.ac.uk/20280/.
Full textAbstract:
A new multi-purpose surface analytical instrument (the Hallam instrument) is described, which combines the surface specific information obtained using x-ray photoelectron spectroscopy (XPS), with bulk information obtained using Energy Dispersive X-ray (EDX) detection. A 15kV electron gun and an ultra high vacuum EDX detector give the instrument an EDX mapping capability. To exploit this to its full potential, spatial alignment of EDX maps acquired at various electron beam energies, E[o], was required. The misalignment of images acquired at various E[o] values was investigated, and a means of describing the misalignment as a function of E[o] was presented. An algorithm was developed which would allow the alignment of offline images acquired at different E[o] values. This was demonstrated on images acquired on both the Hallam instrument and on a Phillips XL40 electron microscope. The small area XPS system developed by Kratos analytical gave a spatial resolution of 30pm at the centre of the field of view, although this deteriorated away from the centre. The reasons for this deterioration in spatial resolution were investigated, and two methods of improving the system were presented. The improvements were implemented on the Hallam instrument and demonstrated using a standard silver grid sample. The small area XPS was applied to a TiAINi coated stainless steel sample to demonstrate its application to real samples, and to display the spatial alignment between the XPS and EDX maps. Finally, the instrument was calibrated for quantitative XPS studies. This involves determining the response of the instrument as a function of the photoelectron kinetic energy. From several methods presented in the literature, the most appropriate was chosen for calibration of the 'Hallam' instrument. The effectiveness of the method used was assessed by recording spectrum intensity from pure elemental standards, and comparing the results with intensity values calculated using the calibration curves.
13
He, Yan M. Eng Massachusetts Institute of Technology. "Supplier selection and supplier management improvements at an analytical instrument manufacturing company." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93845.
Full textAbstract:
Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 61-62).
This thesis addresses the challenges of improving the quality of parts received from suppliers at Waters, an analytical instrument manufacturing company. Preliminary analysis identified improvement opportunities at evaluation of supplier's capability, agreement on requirements with suppliers at early supplier selection stage as well as closed loop supplier management. A 4-step sequential process was designed to improve the supplier selection and management process. First, an initial supplier capability assessment process is incorporated in the quotation process and the Analytical Hierarchy Process is used to make an integrated supplier selection decision. Second, a production part approval process ensures that the supplier fully understands the requirements and proves whether or not it can meet the requirements consistently. Third, a formal inspection report acceptance process for the new product is established to utilize the supplier's inspection resource. Fourth, a formal supplier corrective request process for nonconformance is suggested to provide corrective feedback to the supplier in addition to instructions for improvement. The overall new supplier selection and management process is expected to benefit both Waters and the suppliers. The suggested process is expected to have more visibility to the supplier's capability and improve the supplier quality. The non-value added activities such as incoming inspection rejections and the related disposition process are to be reduced and thus cost saving can be achieved.
by Yan He.
M. Eng. in Manufacturing
14
Tandon, Shubhang. "Process reengineering for the product development process at an analytical instrument manufacturer." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93853.
Full textAbstract:
Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 84-85).
In an analytical instrument manufacturing company, the new product development process was analyzed with the objective of reducing time to market, to full scale production of new products and to improve project management and communication in the organization. Several problem areas were identified in the study and the thesis focuses mainly on the systems level changes that the organization would have to make in order to address the identified issues. The problem areas in the organization were the lack of categorization of development efforts, lack of a clear project plan to guide the development effort, functional integration issues and the lack of activities for process evolution. In order to address the lack of categorization of development efforts, a categorization strategy based on the product being developed and the associated deviations in the development process for each of the categories are discussed. To tackle the issue of no project plan, an up-front project planning process which should precede the development effort is laid out for the organization along with templates of the tools that could be used as aids in the process. Finally, to address the functional integration challenge, a dedicated development team that would be responsible for the project over the entire project timeline is recommended which would also help in achieving better communication across different functional units working on the same project. It is expected that the up-front work of project planning and development effort categorization would help in reducing the time to market and full scale production by having a more structured and specific development process for the new product and also by appropriately utilizing the existing knowledge in the organization. The other changes are expected to primarily advance the project management and communication challenges faced by the organization.
by Shubhang Tandon.
M. Eng. in Manufacturing
15
Ranjan, Aditya. "Process reengineering for new product introduction at an analytical instrument manufacturing firm." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93850.
Full textAbstract:
Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 107-111).
The process of transforming Research and Development knowledge to successfully introducing new products in the market forms a key competency of an innovative company. This new product introduction process was studied at an analytical instrument manufacturing firm. The process of commercialization spanned a number of departments and the process flow lacked functional integration. The current introduction process also lacked a number of management processes, structured feedback loops for information transfer and data metrics for process assessment and evaluation. Due to this, the information related to product knowledge was lost in the process flow creating isolated compartments which was never shared in the process flow. It was also seen that problems created earlier in the process cascaded through the flow and an amplification effect of the problems was seen later. This combined with micro-management of key processes deliverables and inadequate documentation led to a phenomenon of 'firefighting' during the product introduction process. A new process was created for the creation of a Quality Inspection Plan, which was earlier missing. The two important deliverables were created as part of the process describing the critical dimensions and design tolerances of the new product. These documents were linked to the existing introduction process as a part of the phase gate review deliverables and would hence establish a structured method for information communication and feedback to Research and Development. These documents would also drive the creation of the Quality Inspection Plan by integrating downstream departments earlier in the process. Certain sub-process within the commercialization process were selected and the process was standardized for feedback- in terms of information as well as possible data base for metrics creation for continuous improvement initiatives. Also a set of recommendations were made to further strengthen and functionally integrate the process in order to reduce redundancies in the current commercialization process.
by Aditya Ranjan.
M. Eng. in Manufacturing
16
Yakabe, Clarice. "Determinação espectrofotométrica da nimesulida em formulações farmacêuticas." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-15042015-105032/.
Full textAbstract:
Um método espectrofotométrico no visível, simples, rápido, exato, preciso e econômico foi desenvolvido para determinação da nimesulida nas formas farmacêuticas comprimido, suspensão, granulado e supositório. Solução de hidróxido de sódio 0,1 M foi utilizada como solvente. Nesta solução, a nimesulida desenvolveu coloração amarela estável à temperatura ambiente, obtendo-se um pico de absorção máximo em 393 nm. O método obedeceu a lei de Lambert-Beer na faixa de concentração de 7,0 a 16,0 µg/mL (R2 = 0,9999). Não houve interferência dos excipientes da formulação, e no intervalo de concentração de 25,0 a 125,0 mg, o método mostrou-se linear.A simple, fast, accurate, precise and economical visible spectrophotometric method for nimesulide determination in tablets, suspension, granulate and suppository was developed. Sodium hydroxide 0,1 M solution was used as solvent. In this solution nimesulide developed a yellow color which is stable at room temperature, presenting a maximum absorption at 393 nm. The method obeyed Lambert-Beer\'s law in a concentration range from 7,0 to 16,0 µg/mL (R2 =0,9999). The formulation\'s excipients did not interfere and in the range of concentration from 25,0 to 125,0 mg the method showed to be linear.
17
Kosminsky, Luís. "Eletrodos modificados por óxidos de molibdênio: estudos eletroquímicos e aplicação na determinação de Iodato em sal de cozinha." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-02032018-094909/.
Full textAbstract:
O presente trabalho versa sobre a modificação de eletrodos de carbono vítreo por óxidos de molibdênio e estudos referentes à catálise de redução de oxiânions, bem como o emprego do sensor assim preparado para análise de bromato e iodato em amostras sintéticas e naturais. Estudos executados em solução contendo Mo (VI) na faixa de pH de 1,8 a 3,0 indicaram que em meios mais ácidos a resposta catalítica é muito maior, envolvendo a participação de prótons na abstração de oxigênio ao reduzir o substrato. Os resultados dos experimentos voltamétricos realizados com eletrodo de carbono vítreo modificado demonstraram que iodeto é gerado na eletroredução de iodato. O processo de modificação do eletrodo consistiu na execução de experimentos voltamétricos sucessivos com o eletrodo de carbono vítreo em solução contendo Mo (VI), em pH ajustado para otimização da formação do filme e minimização das perdas de depósito por solubilização ácida. O material imobilizado assim obtido foi analisado por técnicas espectrais e microscópicas, observando-se a existência de centros preferenciais de formação de depósito (grumos) ao qual foi atribuída a fórmula mínima de MoO2,78. O óxido de valência mista mostrou grande potencialidade de catálise na redução de oxiânions oxidantes, observando-se antecipação do potencial de redução do iodato, acompanhada de grande intensificação no sinal de corrente. Trabalhando-se em condições de convecção forçada regida pela rotação do eletrodo de trabalho, foram observadas anomalias nos sinais de corrente durante o decorrer dos experimentos eletroquímicos. Explicações para tal fato foram associadas à formação de diferentes fases de óxidos de molibdênio com atividades catalíticas distintas. O sensor desenvolvido para determinação de iodato foi utilizado em sistema em fluxo após otimização de parâmetros como pH do transportador e da amostra, bem como condições relacionadas à modificação do eletrodo (espessura do filme). Amostras de sal de cozinha foram analisadas pelo método proposto e os resultados obtidos foram concordantes com aqueles oriundos do emprego de metodologia padrão.The electroreduction of both iodate and bromate at glassy carbon discs modified by molybdenum oxide films in sulfuric acid medium is discussed. Studies carried out at the 1.8 - 3.0 pH range with Mo(VI) in solution show that at more acidic conditions the catalytic response is much larger since protons participate in the oxygen abstraction step when the substrate is reduced. The results of voltammetric experiments carried out with a glassy carbon electrode coated by the molybdenum oxide layer established that iodide is generated in the electroreduction of iodate. The electrochemical modification of the glassy carbon electrode was carried out by cycling consecutively the potential in a solution containing Mo(VI) at a convenient pH. At the optimal condition an adherent film is obtained and the acidic solubilisation is minimised. The immobilised material was analysed by spectral techniques and scanning electronics microscopy, indicating the existence of preferential centres of deposition of material whose formula was calculated to be MoO2,78. The electroreduction of the analyte occurs at a glassy carbon disc modified electrode, the film acting as an efficient electrocatalyst for the mass transport controlled reduction. Rotating disc experiments performed in solutions containing both Mo(VI) and iodate at pH 1.8 confirmed that an immobilised form of molybdenum is responsible for the reduction of the substrate, even though at more acidic solutions the film is partially solubilised. The response from chronoamperometric experiments shows unexpected results explained by the existence of different catalytic species in equilibrium as two distinct phases with different catalytical activity. A method for the amperometric determination of iodate with the modified electrode in a flow injection configuration was described and the sensor was applied to the determination of iodate in commercial salt samples in a wall-jet cell coupled to a flow injection apparatus after convenient desoxygenation of the carrier solution.
18
Sullivan, Lynne Elaine. "Malingering of head injury on neuropsychological instruments, a meta-analytic review." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ61685.pdf.
Full text
19
Bierstedt, Andreas. "Implementing Diode-Pumped Solid-State Lasers into Instrumental Analytics." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19525.
Full textAbstract:
Eine der bedeutendsten technischen Errungenschaften des letzten Jahrhunderts beinhaltet
zweifelsfrei die Erfindung des Lasers. Bereits wenige Jahrzehnte nach seiner ersten technischen Umsetzung ist er heute aus so unterschiedlichen Anwendungsbereichen wie der
Mess- und Regeltechnik, der Unterhaltungselektronik, sowie der industriellen Fertigung
und Materialbearbeitung nicht mehr wegzudenken. Die analytische Chemie bildet hier
keine Ausnahme. Die Möglichkeit mittels Laserstrahlung sowohl räumlich als auch zeitlich
definiert einen maßgeschneiderten Energieeintrag in Materialsysteme vorzunehmen, wird
heute umfangreich in diversen Analyseverfahren eingesetzt. Ein Meilenstein auf dem Gebiet
der Laserentwicklung stellt die Einführung diodengepumpter Festkörperlaser (DPSS)
dar. Diese neuartige Lasergeneration vereint die Vorteile einer begünstigten Energiebilanz
durch resonante Anregung im Lasermedium mit einer erhöhten Flexibilität der zeitlichen
Modulation der Laserausgangsleistung. Während DPSS Laser auf dem Gebiet der Materialbearbeitung bereits die Hälfte des Marktanteils ausmachen, finden sie bislang in den
analytischen Wissenschaften nur wenig Verbreitung. Auch hier könnten die inhärenten
Vorteile von DPSS Lasern bezüglich Konversionseffizienz, Stabilität, Flexibilität und Strahlprofil maßgeblich zu einer Optimierung relevanter Teilschritte beitragen. Die vorliegende Arbeit schließt diese Lücke, indem sie die Anwendbarkeit eines modernen DPSS Lasers für solch unterschiedliche Aufgaben wie der Laserablation, der Raman-Spektroskopie, der atomaren und molekularen Emissionsspektroskopie, bis hin zur Erzeugung eines neuartigen quasi-kontinuierlichen, luftgetragenen Plasmas für die Atmosphärendruck-Ionisation untersucht. In allen Studien konnten die Verbesserungen der jeweiligen analytischen Verfahren auf die Eigenschaften des verwendeten Lasers zurückgeführt werden.Without any doubt, one of the most momentous technical achievements of the last century has been the invention of the laser. Today, merely some decades after its first technical realization, the laser has established a leading role in such broad application fields as sensing and control engineering, consumer electronics, as well as industrial production and materials processing. Analytical chemistry does not make an exception. The possibility of both spatially and temporally well-confined introduction of precisely dosed and defined energy into any material is nowadays widely exploited in a plethora of analytical techniques. A milestone in the field of laser technology was the advent of diode-pumped solid-state (DPSS) lasers. This new generation of laser systems combines the benefits of an advantageous energy balance, caused by resonant excitation of the laser medium, with an enhancement in flexibility in terms of modulation of the laser output. While DPSS lasers already account for half of the devices used in materials processing, the dissemination in the analytical sciences has so far hardly occurred. Also here, the inherent advantages of DPSS lasers regarding efficiency, reliability, flexibility, and beam profile could greatly contribute in a multitude of analytically relevant sub-steps. This thesis closes this gap by studying the applicability of a current state-of-the-art DPSS laser for as different tasks as laser ablation, Raman spectroscopy, atomic and molecular emission spectroscopy, all the way to generating a generally new quasi-continuous airborne plasma for ambient ionization. In all cases studied, the improvement of the respective analytical techniques could be ascribed to the intrinsic properties of the used laser.
20
Azevedo, Carla Maria Nunes. "DDesenvolvimento de eletrodos modificados e métodos analíticos." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-11092014-164650/.
Full textAbstract:
Neste trabalho foram desenvolvidos eletrodos modificados e procedimentos para a sua utilização na determinação de diversas espécies químicas de interesse analítico, dentre as quais sulfito, ácido ascórbico, nitrito, dopamina, NADH e peróxido de hidrogênio. Foram realizados estudos envolvendo eletrodos de carbono vítreo modificados com filmes contendo uma única metaloporfirina tetrarrutenada (catiônica) e aplicações analíticas destes sensores associando-os à análise por injeção em fluxo (FIA). Estes eletrodos apresentaram efeitos catalíticos sobre a oxidação de vários analitos, intensificando o sinal de corrente e deslocando seus picos de oxidação para a região de oxidação dos átomos de Ru(II) à Ru(III), sítios ativos das porfirinas. Contudo, para a obtenção de sensores estáveis, foi necessária a utilização de uma elevada concentração do contra-íon trifluorometanossulfonato em solução, prevenindo a gradual solubilização do filme modificador. Tal dificuldade foi contornada recobrindo-se os eletrodos com filmes laminares contendo simultaneamente pares de porfirinas catiônicas e aniônicas. Estes sensores apresentaram ação catalítica igual aos eletrodos recobertos por uma única porfirina, uma vez que os sítios ativos continuaram sendo os átomos de rutênio. Esta nova geração de eletrodos modificados exibiu excelente desempenho tanto em análises de amostras sintéticas, quanto de amostras reais (sulfitos em vinhos e ácido ascórbico em sucos e medicamentos). Os sensores modificados com metaloporfirinas apresentaram excelente sensibilidade (limites de detecção entre 10-8 e 10-6 mol L-1) e minimizaram os efeitos de envenenamento da superfície, além de serem de fácil preparo. No presente trabalho também foram realizados estudos preliminares envolvendo eletrodos de pasta de carbono dopados com o óxido misto de NdNiO3. Estes destacaram-se, principalmente, por antecipar a oxidação de peróxido de hidrogênio para 0,00 V em meio alcalino. Análises utilizando o sistema BIA (Batch Injection Analysis) possibilitaram a detecção de H2O2 em concentrações da ordem de 10-6 mol L-1.In this work modified electrodes were developed and proceedings for their utilization in the detection of a variety of species with analytical importance, such as sulfite, ascorbic acid, nitrite, dopamine, NADH and hydrogen peroxide were investigated. During the studies, modified electrodes with films containing one porphyrin were developed and analytical applications with these sensors were done in association with flow injection analysis (FIA). These electrodes presented interesting catalytic properties for the oxidation of many species, increasing the current signal and changing the oxidation peaks of the analytes to the Ru(II)/(III) oxidation region. In these studies, it was necessary high concentrations of trifluormethanesulfonate in solution to avoid the gradual solubilization of the film from the electrode surface. This difficulty was surpassed by developing of modified electrodes with laminar films containing simultaneously two porphyrins, one cationic and other anionic. This new geration of modified electrodes exhibited excellent performance for analysis of the synthetic samples as much as real samples (sulfites in wines and ascorbic acid in juices and medicaments). The metalloporphyrins modified electrodes presented very high sensitivity (detection limit between 10-8 and 10-6 mol L-1), were able to minimize the poisoning effects of the sensor and are very easy to prepare. In this work were also performed some preliminary studies involving carbon paste electrodes doped with NdNiO3 oxide, which stand out specially due to anticipate the oxidation of hydrogen peroxide to 0.00 V in alkaline media. Analysis using batch injection analysis (BIA) makes possible the detection of H2O2 in the 10-6 mol L-1 level.
21
Korn, Mauro. "Desenvolvimento de processo de titulação por procura binária, em fluxo contínuo, com detecção espectrofotométrica." Universidade de São Paulo, 1996. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-01022017-104925/.
Full textAbstract:
O processo de análise química denominado de titulação por procura binária foi desenvolvido e aplicado em sistema de injeção em fluxo. Este procedimento de análise, baseado no método das variações contínuas, procura o menor intervalo em fração volumétrica do titulante, ou da solução da amostra, que contenha o ponto final de uma titulação. Ao ser introduzida alíquota da solução da amostra no percurso analítico, o sinal gerado pelo detector deve ser significativamente diferente daquele gerado com a inserção de uma alíquota da solução do titulante. Neste processo descontínuo, a procura do ponto final segue a lógica binária, reduzindo os incrementos de fração volumétrica, da solução de amostra ou do titulante, em 50%, a cada nova tentativa de procura. Os sinais gerados por um detector espectrofotométrico, acoplado ao sistema de fluxo, eram convertidos em sinais digitais e comparados com os sinais fornecidos pelo detector nas duas tentativas iniciais da procura. Um programa foi desenvolvido para gerenciar este procedimento de titulação, determinando o volume das alíquotas das soluções, para cada tentativa, bem como estabelecendo a rota de procura. O procedimento foi aplicado à uma série de titulações envolvendo reações de neutralização e complexação. Uma titulação, aplicando este procedimento, pode ser executada em 3 minutos, consumindo aproximadamente 2 cm3 das soluções reagentes. As limitações para a aplicação deste procedimento de análise são discutidas, bem como a inviabilidade de sua aplicação sem o emprego de recursos de automatização.A flow injection analytical procedure named as binary search titrimetric process was studied. It was based on volumetric fraction variation methodology. Under its directive, the microcomputer can control the titrand and titrant solutions delevering into the analytical path, by varying both volumetric fractions, following an algorithm based on successive aproximation method. Analytical signals assessed from the analog output of the spectrophotometer for each tentatives were converted to digital making use of an interface card, attached in the microcomputer main board. After each solutions handling cycles, the data collected were processed in order to decide about the next tentative to be carried out, obeying the settled binary search algorithm. The feasibility was ascertained by titrating solutions employing neutralization and complexation reactions. The time interval to perform this titration process employing binary search concept was about 3 minutes, consuming ca 2 cm3 of reagents solutions. No significant difference at 5 % probability level was observed by comparing of the results obtained applying this procedure with those produced by manual procedures.
22
Javadova, Jamila. "Anthoni van Noordt historical and analytical aspects of his Tabulatuurboeck van Psalmen en fantasyen of 1659 /." connect to online resource, 2008. http://digital.library.unt.edu/permalink/meta-dc-6092.
Full textAbstract:
Thesis (D.M.A.)--University of North Texas, 2008.System requirements: Adobe Acrobat Reader. Accompanied by recitals, recorded Sept. 30, 2002, Nov. 27, 2007, and one recital of unknown date, at the University Park United Methodist Church, Dallas, Tex. Includes bibliographical references (p. 62-66).
23
Comandini, Patrizia <1983>. "Development of instrumental and sensory analytical methods of food obtained by traditional and emerging technologies." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4439/.
Full textAbstract:
The consumer demand for natural, minimally processed, fresh like and functional food has lead to an increasing interest in emerging technologies.
The aim of this PhD project was to study three innovative food processing technologies currently used in the food sector. Ultrasound-assisted freezing, vacuum impregnation and pulsed electric field have been investigated through laboratory scale systems and semi-industrial pilot plants. Furthermore, analytical and sensory techniques have been developed to evaluate the quality of food and vegetable matrix obtained by traditional and emerging processes.
Ultrasound was found to be a valuable technique to improve the freezing process of potatoes, anticipating the beginning of the nucleation process, mainly when applied during the supercooling phase.
A study of the effects of pulsed electric fields on phenol and enzymatic profile of melon juice has been realized and the statistical treatment of data was carried out through a response surface method.
Next, flavour enrichment of apple sticks has been realized applying different techniques, as atmospheric, vacuum, ultrasound technologies and their combinations.
The second section of the thesis deals with the development of analytical methods for the discrimination and quantification of phenol compounds in vegetable matrix, as chestnut bark extracts and olive mill waste water. The management of waste disposal in mill sector has been approached with the aim of reducing the amount of waste, and at the same time recovering valuable by-products, to be used in different industrial sectors.
Finally, the sensory analysis of boiled potatoes has been carried out through the development of a quantitative descriptive procedure for the study of Italian and Mexican potato varieties. An update on flavour development in fresh and cooked potatoes has been realized and a sensory glossary, including general and specific definitions related to organic products, used in the European project Ecropolis, has been drafted.
24
Bennetts, Kathryn. "Solo recorder music of the 1990s : analytical approaches to the repertoire and its performance." Thesis, Canterbury Christ Church University, 2016. http://create.canterbury.ac.uk/16332/.
Full textAbstract:
This thesis is the result of practice-based research concerning the analysis and performance of solo recorder repertoire composed during the 1990s. Its purpose is to demonstrate that recorder music can support critical scrutiny, and that knowledge gained from analysis can develop a deeper understanding of the rational and empirical aspects of both structure and content, leading to compelling performances governed by, and reflecting, informed choices. This work includes a catalogue of solo pieces for the recorder composed during the 1990s, totalling 326 items, from which five have been selected for detailed analysis and performance. They are by: Peter Crossley-Holland; Calliope Tsoupaki; Donald Bousted; Gerhard Braun, and Maki Ishii. These pieces have been contextualised with reference to some of the important aesthetic concepts prevalent in the 1990s, particularly those regarding conservative and progressive ideas. Three methods of analysis have been used for the repertoire in focus: structural, paradigmatic, and parametric, leading to an understanding of the compositional process at both macro and micro levels. The repertoire demands a vast range of instrumental techniques, many rediscovered from historical treatises as much as from avant-garde style experimentation, including microtones, percussive, and vocalized sounds, providing a serious challenge to both the performer and the instrument. Each is discussed within the context of the selected pieces. The effects of globalisation at the end of the twentieth century are evidenced in the selected composers' use of ideas from many cultures, including historical references to early Western music, as well as to those of Japan and Indonesia. Specific references are made to Derrida and 'différance', and the influence of the Japanese aesthetic and structural principles of 'wabi sabi' and 'jo ha kyū'.
25
Gregor, Annelie. "Limited Military Pressure – An Analytical Framework to Assess No-Fly Zones as a Single Instrument in Coercive Diplomacy." Thesis, Försvarshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-2782.
Full textAbstract:
Coercive diplomacy attempts to use military force in a limited fashion as a diplomatic and political tool in order to persuade an opponent to cease aggression rather than to bludgeon him into stopping. The use of limited military force in coercive diplomacy is not a military strategy, but rather a refined political and psychological instrument used for resolving a crisis. One relatively new instrument in the toolbox of limited force when engaging in coercive diplomacy, fashioned to deter adversaries, is the use of no-fly zones. The term no-fly zone describes the physical area of a nation that is patrolled using the airpower of another sovereign state or coalition. However, despite its relatively frequent use in its short history, it has largely been ignored in theoretical studies of coercive diplomacy. As scholars, such as Daniel Byman and Matthew Waxman, have presented a critical view on the limitations of approaching a study on a single instrument in coercive diplomacy, this paper grounds the argument that there is still value in this approach. Given that the conditions of coercive diplomacy mainly focus on an array of coercive instruments at a political level, are the conditions in the theories of coercive diplomacy sufficient to explain the political success of the military instrument of no-fly zones? Hence, this paper illustrates the theoretical reach of the theories of coercive diplomacy by highlighting the fungibility of the coercive diplomacy’s theoretical ‘success conditions’ when assessing a single military instrument. By studying the political success and failure in four separate cases, this paper proposes an analytical framework, which is by and large, derived from Peter Viggo Jakobsen and Alexander George’s theoretical basis. However, as the theoretical basis does not fully cover all of the political dimensions of no-fly zones, an additional variable is proposed. The resulting analytical framework suggests that this is a viable approach, but only by combining Jakobsen’s revised conditions with the original work of Alexander George, in addition to the proposed variable. Thus, this result contributes to the large body of scholarly work on coercive diplomacy theory and the debate whether one can assess a specific coercive instrument with the political ‘success conditions’ of coercive diplomacy, or not.Master Thesis
26
Araújo, Renata Bernardo. "Instrumentos de avaliação na atividade experimental da disciplina de Química Analítica Qualitativa." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-16102014-192505/.
Full textAbstract:
A avaliação somativa é a que prevalece nas instituições de ensino superior, os instrumentos de avaliação tradicionalmente utilizados (provas e relatórios) fornecem informações sobre a aprendizagem de conteúdos conceituais e ficam à margem a avaliação dos conteúdos procedimentais e atitudinais. Além disso, provas e relatórios são realizados num momento final das atividades, tardio para um feedback adequado, não havendo tempo para intervir na aprendizagem. Emerge nesse contexto a necessidade de se estudar e refletir sobre os processos avaliativos utilizados na disciplina de Química Analítica Qualitativa (QAQ). Diante disto, tinha-se uma pergunta: haveriam instrumentos adequados e ao mesmo tempo abrangentes que permitissem melhorar o processo avaliativo na disciplina QAQ? Com o objetivo de responder a esta questão foram aplicadas e analisadas duas modalidades de instrumentos de avaliação: pré-exercícios de laboratório (PEL) e grades de observação (GO). Esta pesquisa é de natureza qualitativa, e foi fundamentada em contribuições teóricas de autores que são a favor da avaliação no decorrer do processo de ensino. Sendo assim, teve-se como uma das principais referências Fernandes (2006), que propõe a expressão Avaliação Formativa Alternativa (AFA), alternativa a tradições avaliativas em que o resultado é obtido após o processo de ensino e aprendizagem. Na AFA o professor vai obtendo informações sobre a aprendizagem dos alunos, permitindo assim, o feedback das atividades propostas, interações aluno-professor, e as notas são consideradas pois estas servem como registro. A pesquisa foi desenvolvida no decorrer da disciplina QAQ, com a turma do terceiro semestre do curso de Licenciatura em Química noturno na Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP). Concluiu-se que os instrumentos de avaliação PEL e GO foram eficientes no acompanhamento da aprendizagem dos alunos no decorrer da disciplina. Estes instrumentos proporcionaram a AFA, e complementam a avaliação realizada tradicionalmente na disciplina QAQ, dessa forma reforçam o acompanhamento dos alunos contribuindo para a melhoria na aprendizagem e no processo de avaliação da disciplina.The summative assessment is prevailing in higher education institutions, the traditional evaluation tools used (tests and reports) provide information on conceptual learning does not include assessments of experimental procedures and attitudinal content. Besides, examinations and reports are performed in a final stage of activities without proper feedback, there is no time to help in the learning. Emerges in this context the need to study and reflect on the assessment processes used in the discipline of Qualitative Analytical Chemistry (QAC). This rises to the following question: are there more specific and more comprehensive instruments, which allow an improvement of the evaluation process in the Qualitative Analytical Chemistry (QAC)? In order to answer this question, we applied and analyzed two types of assessment tools: pre-lab work (PLW) and observation grids (GO). This research qualitative in nature was based on theoretical contributions of the authors that are in favor of the assessment during the teaching process. Fernandes (2006) was as one of the main references, he proposed the term Alternative Formative Assessment (AFA), the alternative assessment traditions in which the result is obtained after the process of teaching and learning. While using AFA, the teacher obtains information about students\' learning, allowing the feedback of the proposed activities, student-teacher interactions and considering the marks, as they serve as a record. The research was developed during the discipline of QAC, with the class of the third semester of the degree chemistry at night in the Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP). It was concluded that the assessment instruments PLW and GO were effective in accompaniment students\' learning during the discipline. These instruments provided the AFA, for the evaluation supplement traditionally held in the discipline QAC, and thus reinforce the monitoring of students contributing to the improvement in learning and evaluation process of the discipline.
27
Clutterbuck, Amberlie A. "Method Development for the Collection and Instrumental Analysis of Harmful Compounds in Mainstream Hookah Smoke." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491227953201259.
Full text
28
Ozerkan, Taner. "Instrumented Monitoring And Dynamic Testing Of Metu Cable Stayed Pedestrian Bridge And Comparisons Against The Analytical Model Simulations." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606335/index.pdf.
Full textAbstract:
This study includes structural instrumentation and monitoring of a 48.5 meters long cable-stayed pedestrian bridge located on EskiSehir road near METU campus. The objectives of the study are (1) to monitor the bridge responses during erection and operation stages so that the strain changes are determined during important events such as transportation, lifting, cabling, mid-support removal, slab concrete pouring and tile placement, (2) to determine existing cable forces using vibration frequencies, and (3) comparison of the experimental and analytical results for model updating.
A total of 10 vibrating wire type strain gages were used for strain readings in steel members. The readings are taken at various stages of construction at every 10 to 30 minutes intervals. The bridge responses were monitored about three months and large strain changes in the order of 300 to 500 micro-strain were recorded during important events (e.g., transportation, lifting, cabling, mid-support removal, deck cover placement).
The deck and tower natural vibration frequency measurements are conducted in two main directions. Two different FE models are constructed using two levels of complexity. FEM analysis results are compared against measured natural frequencies of the bridge and tower.
Simplistic analytical model is modified to include temporary support removal in order to perform staged construction simulation and investigate cable force variations. Actual cable tensile forces are obtained using measured cable natural vibration frequencies. The cable frequencies are measured using a CR10X data logger and a PCB 393C accelerometer. Existing cable forces are compared against analytical simulations and symmetrically placed cables
29
Homolková, Marie. "Financování a účetnictví příspěvkových organizací před a po účetní reformě státní správy a samosprávy, v konkrétních podmínkách vyšší odborné a střední průmyslové školy." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-142104.
Full textAbstract:
The final thesis deals with the specific of financing and accounting of the allowance organizations. In connection with the allowance organizations the theses is focused on the reform of state administration and self-government, which has been ongoing since 2009 and still continues. The practical part is devoted to the impact of the reform on specific allowance organization - the higher professional and high industrial school.
30
Larsson, Tom. "Instrumental and methodological developments for isotope dilution analysis of gaseous mercury species." Doctoral thesis, Umeå : Department of Chemistry, Umeå Univ, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1448.
Full text
31
Komolafe, Tomilayo A. "Data Analytics for Statistical Learning." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/87468.
Full textAbstract:
The prevalence of big data has rapidly changed the usage and mechanisms of data analytics within organizations. Big data is a widely-used term without a clear definition. The difference between big data and traditional data can be characterized by four Vs: velocity (speed at which data is generated), volume (amount of data generated), variety (the data can take on different forms), and veracity (the data may be of poor/unknown quality). As many industries begin to recognize the value of big data, organizations try to capture it through means such as: side-channel data in a manufacturing operation, unstructured text-data reported by healthcare personnel, various demographic information of households from census surveys, and the range of communication data that define communities and social networks.
Big data analytics generally follows this framework: first, a digitized process generates a stream of data, this raw data stream is pre-processed to convert the data into a usable format, the pre-processed data is analyzed using statistical tools. In this stage, called statistical learning of the data, analysts have two main objectives (1) develop a statistical model that captures the behavior of the process from a sample of the data (2) identify anomalies in the process.
However, several open challenges still exist in this framework for big data analytics. Recently, data types such as free-text data are also being captured. Although many established processing techniques exist for other data types, free-text data comes from a wide range of individuals and is subject to syntax, grammar, language, and colloquialisms that require substantially different processing approaches. Once the data is processed, open challenges still exist in the statistical learning step of understanding the data.
Statistical learning aims to satisfy two objectives, (1) develop a model that highlights general patterns in the data (2) create a signaling mechanism to identify if outliers are present in the data. Statistical modeling is widely utilized as researchers have created a variety of statistical models to explain everyday phenomena such as predicting energy usage behavior, traffic patterns, and stock market behaviors, among others. However, new applications of big data with increasingly varied designs present interesting challenges. Consider the example of free-text analysis posed above. There's a renewed interest in modeling free-text narratives from sources such as online reviews, customer complaints, or patient safety event reports, into intuitive themes or topics. As previously mentioned, documents describing the same phenomena can vary widely in their word usage and structure.
Another recent interest area of statistical learning is using the environmental conditions that people live, work, and grow in, to infer their quality of life. It is well established that social factors play a role in overall health outcomes, however, clinical applications of these social determinants of health is a recent and an open problem. These examples are just a few of many examples wherein new applications of big data pose complex challenges requiring thoughtful and inventive approaches to processing, analyzing, and modeling data.
Although a large body of research exists in the area of anomaly detection increasingly complicated data sources (such as side-channel related data or network-based data) present equally convoluted challenges. For effective anomaly-detection, analysts define parameters and rules, so that when large collections of raw data are aggregated, pieces of data that do not conform are easily noticed and flagged
In this work, I investigate the different steps of the data analytics framework and propose improvements for each step, paired with practical applications, to demonstrate the efficacy of my methods. This paper focuses on the healthcare, manufacturing and social-networking industries, but the materials are broad enough to have wide applications across data analytics generally. My main contributions can be summarized as follows:
• In the big data analytics framework, raw data initially goes through a pre-processing step. Although many pre-processing techniques exist, there are several challenges in pre-processing text data and I develop a pre-processing tool for text data.
• In the next step of the data analytics framework, there are challenges in both statistical modeling and anomaly detection
o I address the research area of statistical modeling in two ways:
-There are open challenges in defining models to characterize text data. I introduce a community extraction model that autonomously aggregates text documents into intuitive communities/groups
-In health care, it is well established that social factors play a role in overall health outcomes however developing a statistical model that characterizes these relationships is an open research area. I developed statistical models for generalizing relationships between social determinants of health of a cohort and general medical risk factors
o I address the research area of anomaly detection in two ways:
-A variety of anomaly detection techniques exist already, however, some of these methods lack a rigorous statistical investigation thereby making them ineffective to a practitioner. I identify critical shortcomings to a proposed network based anomaly detection technique and introduce methodological improvements
-Manufacturing enterprises which are now more connected than ever are vulnerably to anomalies in the form of cyber-physical attacks. I developed a sensor-based side-channel technique for anomaly detection in a manufacturing processPHD
The prevalence of big data has rapidly changed the usage and mechanisms of data analytics within organizations. The fields of manufacturing and healthcare are two examples of industries that are currently undergoing significant transformations due to the rise of big data. The addition of large sensory systems is changing how parts are being manufactured and inspected and the prevalence of Health Information Technology (HIT) systems in healthcare systems is also changing the way healthcare services are delivered. These industries are turning to big data analytics in the hopes of acquiring many of the benefits other sectors are experiencing, including reducing cost, improving safety, and boosting productivity. However, there are many challenges that exist along with the framework of big data analytics, from pre-processing raw data, to statistical modeling of the data, and identifying anomalies present in the data or process. This work offers significant contributions in each of the aforementioned areas and includes practical real-world applications. Big data analytics generally follows this framework: first, a digitized process generates a stream of data, this raw data stream is pre-processed to convert the data into a usable format, the pre-processed data is analyzed using statistical tools. In this stage, called ‘statistical learning of the data’, analysts have two main objectives (1) develop a statistical model that captures the behavior of the process from a sample of the data (2) identify anomalies or outliers in the process. In this work, I investigate the different steps of the data analytics framework and propose improvements for each step, paired with practical applications, to demonstrate the efficacy of my methods. This work focuses on the healthcare and manufacturing industries, but the materials are broad enough to have wide applications across data analytics generally. My main contributions can be summarized as follows: In the big data analytics framework, raw data initially goes through a pre-processing step. Although many pre-processing techniques exist, there are several challenges in pre-processing text data and I develop a pre-processing tool for text data. In the next step of the data analytics framework, there are challenges in both statistical modeling and anomaly detection I address the research area of statistical modeling in two ways: There are open challenges in defining models to characterize text data. I introduce a community extraction model that autonomously aggregates text documents into intuitive communities/groups In health care, it is well established that social factors play a role in overall health outcomes however developing a statistical model that characterizes these relationships is an open research area. I developed statistical models for generalizing relationships between social determinants of health of a cohort and general medical risk factors o I address the research area of anomaly detection in two ways: A variety of anomaly detection techniques exist already, however, some of these methods lack a rigorous statistical investigation thereby making them ineffective to a practitioner. I identify critical shortcomings to a proposed network-based anomaly detection technique and introduce methodological improvements Manufacturing enterprises which are now more connected than ever are vulnerable to anomalies in the form of cyber-physical attacks. I developed a sensor-based side-channel technique for anomaly detection in a manufacturing process.
32
Padilla, Mercado Jeralyne Beatriz. "Development of a teaching coulometry instrument for the direct determination of sulfur compounds and of zinc indirectly." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1499251632209504.
Full text
33
Capri, Maria da Rosa. "Dissolução química parcial \"on line\" de aço inoxidável seguida de determinação de Cr, Mn e Ni por espectrometria de emissão ótica com plasma indutivamente acoplado (ICP-OES)." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-25102018-140251/.
Full textAbstract:
O objetivo deste trabalho foi o desenvolvimento de metodologia analítica versátil e rápida para a determinação de Cr, Mn e Ni em aços martensíticos e austeníticos, através do processo de dissolução química parcial em sistema de injeção em fluxo acoplado ao Espectrômetro de Emissão Ótica acoplado indutivamente (ICP-OES). O procedimento, também priorizou menor manipulação de amostra e consumo de reagentes. A solução extratora, HNO3 e HCI 7,0 mol L-1 e 6,0 mol L-1 respectivamente 1:1 v/v foi utilizada para a dissolução química parcial dos aços inoxidáveis. A quantificação dos metais dissolvidos foi feita utilizando-se o método da somatória, que relaciona a concentração de um elemento individual com a somatória dos elementos determinados, segundo a fórmula: i% = Ci /Ct x 100, onde Ci é a concentração do elemento i e Ct é a soma das concentrações de todos elementos determinados. Os resultados não apresentaram diferença significativa em um nível de confiança de 95% com os valores certificados das amostras de referência e com os valores da dissolução total assistida por microondas. O procedimento apresentou freqüência analítica de 20 determinações por hora.The objective of this work was the development of a versatile and fast analytical methodology for the determination of Cr, Mn, and Ni in martensitic and austenitic steels, through on-line partial chemical dissolution using a flow injection system coupled to an ICP-OES. The procedure also aimed the smallest sample manipulation and reagents consumption. The extractor solution, 7.0 mol L-1 HNO3 and 6.0 mol L-1 HCI 1:1 v/v, was used to the on-line partial chemical dissolution of the stainless steels. The quantification of the dissolved metals was made using a method, that relate the concentration of an individual element with the sum of all elements concentrations, applying the formula: i% = Ci /Ct x 100, where Ci is the concentration of the element i and Ct is the sum of the concentration of all elements determined. No significant difference has been present by the results, at a confidence level of 95%, with the certified values of the reference materials and with the total dissolution values obtained by microwave - assisted sample pretreatment. The procedure presented analytic frequency of 20 determinations per hour.
34
Manfro, Paulo Renato. "Aplicação do analytic hierarchy process (AHP) como instrumento de apoio a decisão no gerenciamemto costeiro integrado." Florianópolis, SC, 1998. http://repositorio.ufsc.br/xmlui/handle/123456789/78058.
Full textAbstract:
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro TecnologicoMade available in DSpace on 2012-10-17T09:58:53Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-09T00:20:28Z : No. of bitstreams: 1 149237.pdf: 6293767 bytes, checksum: c09c62a1190d7d772b00f406e0aea854 (MD5)
Desenvolvimento de um módulo de auxílio a tomada de decisão multicritériol para a ferramenta de treinamento do programa Train-Sea-Coast - TSC, entitulada Porto. Este case foi desenvolvido de maneira a trabalhar de forma integrada ao software. O módulo considera um conjunto de estratégias geradas pela ferramenta de treinamento e, tem a função de ordenar as estratégias numa escala qualitativa a partir dos pesos que forem atribuídos a cada uma das variáveis. A nota que cada uma das estratégias virá a receber será calculada com base Método de Análise Hierárquica - AHP. O módulo multicritério tem o objetivo de conduzir os profissionais que recebem treinamento do programa TSC, em gerenciamento costeiro, na tarefa de decidir qual a estratégia gerada pelo software é a mais adequada. Envolvendo estes profissionais em situações diversas que retratam aspectos da vida real, como pluralidade de críticos e atores e backgrounds e interesses diversos, auxiliando-os a tomar decisões. Abstract : The present master dissertation work has the objective to elaborate an auxiliary module for multi-criterion decision making as a training tool for the program Train-SeaCoast - TSC, entitled Porto. This case was developed in a way to work the software integrated form. The module considers a set of strategies generated by training tool and, it has the function to order the strategies in a qualitative scale from the weighs that were attributed to each of the variables. The grade that each of the strategies will receive, it will be calculated based on Analytic Hierarchy Process - AHP. The multi-criterion has the objective to lead the professionals that are trained for TSC program in coastal management with the aim to decide which strategy generated by the software is more adequate. Involving these professionals in several situations that retreat aspects of real life, as the plurality of critics and authors and different interests, helping them making decisions.
35
Ferrari, Angela Aparecida. "Caracterização química de tomates (Lycopersicon esculentum Mill.) empregando análise por ativação neutrônica instrumental." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-26042010-164413/.
Full textAbstract:
O tomate é a segunda hortaliça mais produzida no mundo, superada apenas pela batata, com participação efetiva na dieta humana. O seu valor como alimento traz um paradoxo. Ao mesmo tempo em que é elogiado por ser considerado um alimento funcional, com propriedades nutracêuticas, sofre críticas pela forma como é normalmente produzido, sob pesadas quantidades de fertilizantes sintéticos e pesticidas. Há muitas causas de variação que podem alterar a composição dos frutos. Neste sentido, o presente trabalho procurou coletar amostras em um universo que engloba diferentes fatores, incluindo cultivares para o consumo in natura e para o processamento industrial, sistemas de cultivo convencional e orgânico, regiões geográficas e tipos de solo. O objetivo geral foi caracterizar o tomate quanto aos elementos químicos visando a identificação daqueles de interesse agronômico ou nutricional e o estabelecimento das faixas de concentrações para frutos produzidos sob as fontes diversas de variação. Objetivos específicos envolveram estudos de representatividade amostral e de influência dos estádios de maturação e do solo na composição química dos frutos. Os tomates das cultivares AP 533, Colibri e T-92 foram coletados em propriedades localizadas em municípios do estado de São Paulo. A determinação dos elementos químicos foi feita pelo método primário de análise por ativação neutrônica instrumental (INAA). A qualidade do procedimento analítico foi verificada por meio da exatidão e da reprodutibilidade dos resultados com o emprego de materiais de referência. O estudo de representatividade amostral revelou que o número necessário de amostras para representar o tomate no campo foi inferior a 12, considerando um erro máximo admitido pelo analista de 15%. A variabilidade intra-amostral foi avaliada por meio de 12 repetições analíticas de uma mesma amostra e os resultados indicaram a homogeneidade do material. Os elementos químicos Br, Ca, Co, Cs, Fe, K, La, Na, Rb, Sr e Zn foram determinados nas amostras de polpas, sementes e solos. A análise de frutos nos estádios de maturação verde maduro e rosado indicou maiores concentrações de Ca, Fe, K, Na, Rb e Sr nos tomates rosados, enquanto Br, Co, Cs e Zn não apresentaram diferenças significativas (p < 0,05). Os solos das seis propriedades estudadas apresentaram composição química bastante diferenciada. Contudo, não foram observadas correlações das concentrações de elementos químicos encontradas nas amostras de polpa e de solo. Os resultados da caracterização química dos tomates permitiram realizar importantes inferências com relação ao comportamento dos elementos químicos. K e Ca foram os nutrientes mais abundantes na polpa e na semente. As concentrações de Br, Co, Cs, Rb e Sr na polpa diferiram significativamente (p < 0,05) tanto entre sistemas de cultivo como entre cultivares. Fe, K, Na e Zn na polpa não foram afetados pelos sistemas de cultivo, sendo as diferenças encontradas intrínsecas para cada cultivar. As polpas e as sementes dos tomates das três cultivares não apresentaram diferenças para Ca. Br permitiu a separação entre tomates orgânicos e convencionais, com concentrações maiores em tomates convencionais. Análises multivariadas revelaram que as amostras de polpa possuem uma tendência de agrupamento por categorias, tanto em termos de cultivar como de sistema de cultivo, embora esse último fator tenha apresentado resultados menos evidentes. Por outro lado, as sementes apresentaram maior tendência de agrupamento pelo fator cultivarThe tomato is the second most cultivated vegetable after the potato, having an effective participation in the human diet. Its food value remains paradoxical. At same time it is recognized as a functional food with nutraceutical properties, the tomato receives criticism due to the way it is usually cultivated, i.e. under heavy amounts of synthetic fertilizers and pesticides. There are many causes of variation that may change the fruit composition. In this aspect, the current work aimed at collecting samples in a universe that comprises different factors, including cultivars for fresh market and for processing, conventional and organic cultivation systems, geographical regions and soil types. The main objective of this work was the chemical element characterization of tomato in view of the identification of elements of agronomical and nutritional interest and establishing concentration ranges for the fruits produced under different sources of variation. The specific objectives comprehended studies of sample representativeness and studies of the influence of ripening stages and soil on the chemical composition of tomato fruits. Tomatoes from the cultivars AP 533, Colibri and T-92 were sampled in farms located in cities of São Paulo State. The determination of the chemical elements was carried out by using the primary method of measurement instrumental neutron activation analysis (INAA). The quality of the analytical procedure was evaluated by means of accuracy and reproducibility of reference materials results. The study of sample representativeness showed that the required number of 12 samples to represent the tomato in the field, considering 15% as the maximum deviation allowed by the analyst. The within-sample variability was evaluated by means of 12 analytical portions taken from one sample. The results demonstrated the homogeneity of the material. The chemical elements Br, Ca, Co, Cs, Fe, K, La, Na, Rb, Sr and Zn were determined in the samples of pulp, seeds and soils. The analysis of fruits at mature green and pink stage indicated higher concentrations of Ca, Fe, K, Na, Rb and Sr in the tomatoes at pink stage, while Br, Co, Cs and Zn did not show any significant difference (p < 0.05). The soils from the six studied farms presented different chemical compositions. However, no correlations were observed between the chemical element concentrations found in the samples of pulp and soil. The results of chemical characterization of tomatoes allowed making important inferences with relation to the chemical elements behavior. K and Ca were the most abundant nutrients in the pulp and seeds. Br, Co, Cs, Rb and Sr concentrations in the pulp showed significant differences (p < 0.05) for both cultivation systems and cultivars. Fe, K, Na and Zn concentrations in the pulp were not affected by the cultivation systems, being the differences found intrinsic to each cultivar. The pulp and seeds from the tomatoes of the three cultivars did not present any significant difference for Ca. Br allowed the discrimination of organic and conventional tomatoes, the later showing the higher concentrations. Multivariate analysis of the pulp results revealed a trend in clustering by categories, both in terms of cultivars and cultivation system, although the later showed less clear results. On the other hand, the seeds presented higher trend in clustering by the cultivar factor
36
Antoinat, Léonard. "Contribution à la caractérisation de la déformation et de la rupture dynamique de structures sous impact : Modélisations et approche expérimentale." Thesis, Paris, ENSAM, 2014. http://www.theses.fr/2014ENAM0037/document.
Full textAbstract:
L'objectif de ces travaux de thèse est de proposer des approches de modélisation et d'expérimentation de l'impact de structures déformables et indéformables sur différents milieux. Différents modèles analytiques et des simulations numériques sont développés en comparaison aux résultats expérimentaux. Une première partie se consacre à la caractérisation de la similitude entre la réponse à l'impact à l'eau d'un solide et la réponse d'un solide impactant une structure déformable. Des simulations éléments finis (EF) et SPH sont réalisées pour l'impact à l'eau d'un tube cylindrique (sans rupture). Un modèle analytique d'impact à l'eau est proposé pour prédire l'évolution de l'effort (pic, durée). L'analyse des résultats permet de dimensionner un programmateur d'impact solide reproduisant le pic d'effort. Des simulations EF de l'impact sur un tube cylindrique, à géométrie adapté, dans la direction longitudinale, sont réalisées et comparées à quelques expériences tests. Le «flambage dynamique» (dû au comportement inélastique du matériau et aux ondes de déformations) des tubes est alors observé. Une seconde partie traite du cas de la perforation sous impact d'une tôle mince à faibles vitesses d'impact (< 10 m/s, vitesse de déformation < 1000 s-1). Des essais sur puits de chute instrumenté (force, déplacement, déformée de tôle, avancée de fissure) sont analysés. Des simulations EF en éléments coques avec un critère de rupture ductile par endommagement sont réalisées. Les paramètres de rupture dynamique sont identifiés par méthode inverse à l'aide d'essais de résilience Charpy sur l'alliage d'aluminium de désignation 2024 T3. Une analyse des pics de force lors de l'impact permet une meilleure compréhension des mécanismes de perforation. En parallèle, un nouveau modèle analytique, basé sur les énergies impliquées lors de l'impact, est proposé et comparé aux simulations EF. L'étude numérique de la perforation est étendue aux grandes vitesses d'impact et de déformation (100 - 1000 m/s, vitesse de déformation <100 000 s-1) pour identifier les transitions des différents mécanismes de perforation connus (pétalisation, fragmentation des pétales, fragmentation complète)The objective of this work is to propose approaches to model and to assess experimentally the structural impact on different media. A variety of analytic models and numerical simulations are developed comparing to experimental results. The first part of this work presents a discussion on the similitude between a water impact and an impact on a deformable solid structure. Water impact simulations of a deformable cylinder (without rupture) are performed by finite elements (FE, Coupled Eulerian Lagrangian) and SPH analysis. An analytical model of water impact is proposed for the prediction of peak force evolution. The analysis of results permits to design an impact programmer reproducing this peak force. FE longitudinal impact simulations on cylindrical tubes, with an adapted geometry, are performed and compared with some experiments. The “dynamic buckling” of tubes under impact (due to the material inelastic behavior and to strain waves) is observed. The second part deals with the low velocity perforation (< 10 m/s, strain rate < 1000 s-1) of thin plates. Some experiments on an instrumented drop test (force, displacement, plate shape, crack propagation) are analyzed. Shell FE simulations, with a damage rupture criteria implemented are performed. Parameters are identified by inverse method with the help of Charpy tests made on 2024 T3 aluminum alloy. An analysis of the peak force, during impact, leads to a good understanding of the perforation mechanism. In parallel, a new analytical model, based on an energetic approach of the perforation, is proposed and compared with FE simulations. The numerical perforation study is extended to high velocities and high strain rates (100 - 1000m/s, strain rate < 100 000 s-1) in order to identify different well-known transitions of perforation (Petalisation, petals' fragmentation, total plate's fragmentation)
37
Erickson, Brice Carl. "Multicomponent flow injection analysis and quantitative infrared emission spectroscopy : chemometric applications /." Thesis, Connect to this title online; UW restricted, 1988. http://hdl.handle.net/1773/8633.
Full text
38
Grote, Jan-Philipp [Verfasser], Karl J. J. [Gutachter] Mayrhofer, and Wolfgang [Gutachter] Schuhmann. "Design of an advanced analytical instrument for fast activity and selectivity investigations / Jan-Philipp Grote ; Gutachter: Karl J. J. Mayrhofer, Wolfgang Schuhmann." Bochum : Ruhr-Universität Bochum, 2016. http://d-nb.info/1123282994/34.
Full text
39
Dilema, Mauro. "Carlos Seixas: 25 sonatas para instrumento de tecla interpretadas ao piano." Doctoral thesis, Universidade de Évora, 2014. http://hdl.handle.net/10174/18403.
Full textAbstract:
A interpretação no piano moderno da colectânea de 25 sonatas de Carlos Seixas, editadas por Santiago Kastner, baseada no estudo analítico de três sonatas, selecionadas pela particularidade de melhor representarem as estruturas das composições de Seixas. As problemáticas do uso do pedal, dedilhação, timbre, toque, resolução dos ornamentos e dinâmica. A interpretação historicamente informada baseada nos antigos tratados de interpretação e nos estudos mais recentes. A metodologia da interpretação. Contextualização histórica, organológica e bibliográfica; ABSTRACT: The interpretation in the modern piano of the collectanea of 25 sonatas of Carlos Seixas, edited by Santiago Kastner and based on the analytical study of three sonatas, selected for the particularity of better representing the structures of Seixas compositions. The problematic on the use of the pedal, fingering, tone, touch, ornaments resolution and dynamics. Historically informed interpretation, based on the old treatises and in the most recent studies. The methodology of the interpretation. Historical, organological and bibliographical contexts
40
Catta-Preta, Marisa Vicente. "Sonhos e insônia: o uso de imagens oníricas como instrumento terapêutico no auxílio ao tratamento de indivíduos insones." Pontifícia Universidade Católica de São Paulo, 2009. https://tede2.pucsp.br/handle/handle/15864.
Full textAbstract:
Made available in DSpace on 2016-04-28T20:40:10Z (GMT). No. of bitstreams: 1
Marisa Vicente Catta-Preta.pdf: 1759673 bytes, checksum: 805db40ca7bdd538a0ecc796b421fd2c (MD5)
Previous issue date: 2009-06-25Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This work had as a goal to observe and analyze the dream images as a therapeutic instrument in the assistance of the treatment for patients with primary, chronic and intermediate insomnia. Group work was used in the analyses of dream reports from individuals with insomnia in fifteen meetings. The usage of remembered dreams allowed us to access to unconscious contents and from that we worked therapeutically the conflicts that were presented and that could be interfering in the insomnia. The subjects were three adults of the female sex. The choice of subjects followed the criteria of the diagnoses of chronic and intermediate insomnia, and also the criteria of availability for research, furthermore they had to remember their dreams on a regular basis. We asked the subjects to participate in an individual interview before attending the group meetings, answering questions about their sleep, dreams and also take a polysomnography so that the quality of their sleep could be analyzed. During the meetings the remembered dreams were reported and worked through with the group from the personal associations of the dreamer. Through the analyses of the dream series it was possible to present to the subjects the emotional aspects that were about an ordinary theme, which brought about a certain repetition and should be elaborated and integrated by the subject. Also, during this period, we asked the subjects to register in a diary, supplied by the researcher, the number of hours of sleep, the number of interruptions during the night, if the dream in general was good or bad and the dreams that were remembered. The method used was qualitative, and from that we analyzed the process of each subject. The data acquired was analyzed to the light of analytical psychology, following the reference of dream analyses of this approach. After the termination of the groups, the subjects took a new polysomnography in the Sleep Institute of Santos (Instituto do Sono de Santos); they did a final and individual interview with the same questions about sleep and dream. Considering the amount of hours of sleep, the quality of sleep and the individual s perception of a better quality of life as criteria for improvement, we can say that the group work with the dream images helped in the treatment of the subjects insomnia. Through the dream analyses it was possible to present the subjects the emotional aspects that were about an ordinary theme, that should be elaborated and integrated by the subject
Este trabalho teve como objetivo observar e analisar imagens oníricas como instrumento terapêutico no auxílio ao tratamento de indivíduos diagnosticados com insônia primária crônica e intermediária. Utilizou-se o trabalho em grupo para que fossem analisados sonhos de indivíduos insones durante 15 encontros. O uso de sonhos lembrados permitiu que se pudesse ter acesso a conteúdos inconscientes dos sujeitos e, a partir disso, se trabalhar terapeuticamente os conflitos apresentados que pudessem estar interferindo no quadro de insônia. Os sujeitos foram três adultos do sexo feminino. A escolha dos sujeitos seguiu o critério de terem o diagnóstico de insônia crônica e intermediária e estarem disponíveis para a pesquisa, além de lembrarem-se regularmente de seus sonhos. Foi pedido aos sujeitos que, antes de serem iniciados os encontros grupais, participassem de uma entrevista individual com a pesquisadora para responder a questões sobre seu sono e seus sonhos, e que realizassem uma polissonografia para avaliação da qualidade de seu sono. Durante os encontros, os sonhos lembrados eram relatados e trabalhados com o grupo a partir de associações pessoais do sonhador. Através da análise da série de sonhos foi possível apresentar aos sujeitos aspectos emocionais que versavam sobre um tema comum, que trazia certa repetição e deveria ser elaborado e integrado pelo sujeito. Também durante esse período pediu-se aos sujeitos que registrassem num diário, fornecido pela pesquisadora, itens que incluíam número de horas de sono, número de interrupções durante a noite, se o sono em geral fora bom ou ruim e o registro de sonhos lembrados. O método usado foi o qualitativo, a partir do qual foram feitas análises do processo de cada sujeito. Os dados obtidos foram analisados à luz da psicologia analítica, seguindo a referência de análise de sonhos dessa abordagem. Após o encerramento dos grupos, os sujeitos fizeram nova polissonografia no Instituto do Sono de Santos e uma entrevista final, individual, na qual foram reaplicadas as mesmas perguntas sobre sono e sonhos utilizadas na entrevista inicial. Considerando como critério de melhora de insônia o aumento de horas do sono, a qualidade do sono e a percepção do indivíduo de uma melhor qualidade de vida, pode-se dizer que o trabalho grupal com imagens oníricas auxiliou no tratamento da insônia dos sujeitos
41
Santos, Eder José dos. "Determinação de nutrientes e contaminantes Inorgânicos em café solúvel por espectrometria de emissão atômica com plasma de argônio induzido (ICP-AES)." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-02122014-175023/.
Full textAbstract:
A produção industrial do café solúvel brasileiro destina-se, na sua maior parte, ao mercado externo, constituindo-se em um importante ítem de exportação do país. O objetivo do presente trabalho foi o desenvolvimento e aprimoramento de métodos de análise química adequados à investigação de componentes inorgânicos em café solúvel. Inicialmente foi definido o método de mineralização das amostras através da avaliação de 6 procedimentos diferentes, classificados em 3 classes: (I) microondas focalizado; (II) via úmida convencional e (III) sistema sob pressão em frascos de decomposição com tampas (bombas de teflon). As determinações dos nutrientes e contaminantes inorgânicos: Na, K, Mg, Al, P, S, Ca, Mn, Fe, Ni, Cu, Zn, Cd, Sb, Pb, Cr, Sn, As, Se e Hg, após a utilização do procedimento de mineralização que emprega o sistema de microondas focalizado com os reagentes HNO3 e H2O2, foram realizadas por espectrometria de emissão atômica com plasma induzido, ICP-AES (da nomenclatura inglesa Inductively Coupled Plasma-Atomic Emission Spectrometry). Interferências de matriz e/ou espectrais foram detectadas nas determinações de Pb, Cr, Sn, As, Se e Hg. No caso do Sn, optou-se pela correção da radiação de fundo através do software do equipamento, pois outras linhas de emissão deste analito eram menos sensíveis e igualmente sujeitas a interferências espectrais. Para o Pb e Cr a escolha de comprimentos de ondas alternativos eliminou os problemas de interferências espectrais devido à matriz das amostras. A aplicação das técnicas de geração de hidretos para o As e Se e a geração de vapor frio para o Hg, possibilitaram as determinações destes analitos nas amostras de café solúvel, aumentando a sensibilidade das análises. Os resultados obtidos para os teores dos nutrientes e contaminantes inorgânicos em 21 amostras de café solúvel disponíveis no mercado brasileiro, foram aceitáveis para o consumo humano, tanto no aspecto nutricional como toxicológico, com exceção de uma amostra com teor de Cr igual a 0,52 ± 0,02 mgKg-1, acima do permitido pela legislação brasileira que fixa o valor máximo de 0,10 mgKg-1. A aplicação de técnicas estatísticas, análise de clusters hierárquicos e componentes principais aos resultados obtidos, possibilitaram investigar a variabilidade das composições minerais e classificar grupos de amostras similares. O emprego da técnica instrumental ICP-AES através do sistema de nebulização convencional e a utilização do sistema de geração de hidretos e vapor frio, mostraram-se adequados para as determinações dos nutrientes e contaminantes inorgânicos em café solúvel, uma vez que níveis de precisão e exatidão aceitáveis foram obtidos.The production of Brazilian soluble coffee is almost entirely destined for exporting. Therefore, the objective of this work was the development and the establishment of appropriate methods of chemical analysis of inorganic components in soluble coffee. Firstly, the appropriate digestion procedure for soluble coffee samples was defined through the evaluation of six different digestion techniques that were classified into three groups: (I) focused microwave system, (II) conventional wet digestion and (III) pressure digestion system in teflon bombs. The determinations of nutrients and toxic elements: Na, K, Mg, Al, P, S, Ca, Mn, Fe, Ni, Cu, Zn, Cd, Sb, Pb, Cr, Sn, As, Se, and Hg after the utilization of the focused microwave system with HNO3 and H2O2 reagents, were made by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) technique. Matrix and spectral interferences were detected in the determination of Pb, Cr, Sn, As, Se and Hg. Correction of the background enhancement by the equipment software was made in the determination of Sn, as other analytical lines were unsuitable for this application. For Pb and Cr, the choice of other analytical lines eliminated the problem of matrix and spectral interferences. The application of the hydride generation technique for As and Se and cold atomic vapour with ICP-AES for Hg, were suitable methods to determine these analytes in soluble coffee samples with increased sensitivity of the analysis. The results obtained of nutrients and toxic elements in twenty-one samples of soluble coffee collected from Brazilian market were acceptable to human consumption at nutritional and toxic level with exception of a sample with 0,52 ± 0,02 mgKg-1 of Cr, above the value specified in Brazilian Food Legislation, that fixes the maximum Cr contend in 0,10 mgKg-1. The aplication of statistical techniques analysis of principal components and the hierarchical cluster on the results of mineral compositions, enabled to investigate the variability in the composition and to classify groups of similar samples. The application of the ICP-AES technique using the conventional pneumatic nebulization system, the hydride generation technique and the cold vapour for Hg were suitable to determine the nutrients and toxic elements in soluble coffee, as they provided acceptable results indicating accuracy and precision.
42
Araújo, Mariana Corrêa. "O desenvolvimento da Química Analítica na Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo: contribuições de Paschoal Senise." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/81/81132/tde-24112016-151509/.
Full textAbstract:
Buscamos investigar a relação entre a atuação do Prof. Paschoal Ernesto Américo Senise (1917-2011) e o desenvolvimento do ensino de Química Analítica na Universidade de São Paulo. O período em estudo abrange desde o ingresso de Senise na primeira turma do curso da Química oferecido pela antiga Faculdade de Filosofia, Ciências e Letras da USP até o início dos anos 1970, quando suas atividades se voltaram especialmente para questões administrativas. Assim, procuramos delinear o contexto em que se desenvolveu essa trajetória e entender a participação do Prof. Senise nos processos que resultaram: na atualização do ensino de Química Analítica; na expansão dessa área de pesquisa na universidade; na introdução de conhecimentos e práticas relacionados à Análise Instrumental; e nas mudanças estruturais que o curso de graduação em Química sofreu no período em estudo. A pesquisa se fundamentou nos documentos que compõem o Acervo Paschoal Senise, depositado no Centro de Memória do Instituto de Química da USP, bem como entrevistas com ex-alunos e colegas do Prof. Senise, visando obter informações complementares às fontes documentais. O presente estudo de caso pretende oferecer uma contribuição para a compreensão das transformações ocorridas no ensino de Química Analítica no período de implantação e consolidação do curso de graduação em Química na Universidade de São Paulo.This dissertation aims at investigating the relationship between the work of Prof. Paschoal Ernesto Américo Senise (1917-2011) and the development of Analytical Chemistry teaching at the University of São Paulo. The study ranges from Senise\'s enrollment in the first class of the undergraduate Chemistry program offered by the former Faculty of Philosophy, Sciences and Letters of USP to the early 1970s, when his activities turned especially to administrative issues. The context in which the Chemistry program developed is outlined and the role of Prof. Senise is discussed. It was possible to identify his decisive influence on: the updating of Analytical Chemistry teaching; the expansion of this research area in the university; the introduction of knowledge and practices related to Instrumental Analysis; and structural changes in the undergraduate Chemistry program during the period in focus. This research was based on the documents gathered in the Paschoal Senise Archive, deposited in the Memorial Center of the Institute of Chemistry of USP, as well as on interviews with former students and colleagues of Professor Senise, who offered further information from the documentary sources. This case study aims to provide a contribution to the understanding of the transformations in Analytical Chemistry teaching during the beginning and consolidation years of the undergraduate Chemistry program at the University of São Paulo.
43
Moreno, Ruben Gregorio Moreno. "Determinação de mercúrio em amostras ambientais por espectrometria de absorção atômica com atomização eletrotérmica em forno de grafite com superfície modificada." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-15022019-113640/.
Full textAbstract:
Um procedimento eletroquímico para deposição de paládio no interior de um tubo de grafite para modificação química permanente e um sistema de geração de vapor frio para a determinação de níveis traços de mercúrio em água e sedimento através de espectrometria de absorção atômica é proposto. A célula eletroquímica tubular para as deposições de paládio em fluxo foi construída aproveitando a estrutura original do tubo de grafite o qual opera como eletrodo de trabalho. Um tubo de aço inoxidável, posicionado na saída da célula, é usado como o eletrodo auxiliar. O valor do potencial aplicado no eletrodo de grafite é medido contra um micro eletrodo de referência de Ag/AgCl inserido sobre o eletrodo auxiliar. Soluções de paládio em tampão de acetato (100 milimol L-1, pH=4,70), numa vazão de 0,5 mL min-1 foram usados para executar a deposição eletroquímica durante o intervalo de tempo de 60 min. O sistema de geração de vapor frio consiste de um micro-reator de polietileno e frasco separador líquido-gás, volume total de 4,0 ml, que é descartado depois de cada amostragem para evitar inter-contaminação das amostras. Volumes de 1,0 ml de reagente (2,0% m/v NaBH4 em 0,10 mol L-1 de NaOH) e 1,0 ml de soluções analíticas ou amostras em 0,25 mol L-1 de HNO3 são levados para o reator e separador líquido-gás usando uma bomba peristáltica. O vapor de mercúrio é transportado ao tubo de grafite modificado eletroquimicamente com fluxo de argônio de 212 ml min-1 e pré-concentrado durante 120 s. O limite de detecção obtido foi 93 ng L-1 (n=20, 3δ). O desempenho deste sistema foi testado para determinação de mercúrio em água potável, água não potável e sedimentos de lagoa. A confiança de todo procedimento foi confirmada através de testes de recuperação.An electrochemical procedure for palladium deposition on the inner of a graphite tube for permanent chemical modification and a cold vapor generation system for the determination of trace levels of mercury in water and sediment by atomic absorption spectrometry are proposed. The tubular electrochemical cell for the deposition of palladium was assembled on the original geometry of a graphite tube that operates as the working electrode. A stainless steel tube, positioned downstream from the working electrode, is used as the auxiliary electrode. The potential value applied on the graphite electrode is measured against a micro reference electrode (Ag/AgCl) inserted into the auxiliary electrode. Palladium solutions in acetate buffer (100 milimol L-1, pH=4.70), flowing at 0.5 mL min-1 for 60 min was used to perform the electrochemical deposition. A cold vapor generation system consist of a micro polyethylene reactor and gas-liquid separator flask, total volume of 4.0 mL, that is discarded after each sampling to avoid intercontamination of the samples. Volumes of 1.0 mL of reagent (2.0% m/v NaBH4 in 0.10 mol L-1 of NaOH) and 1.0 mL of reference or sample solutions in 0.25 mol L-1 of HNO3 are carried out to the reactor and gas-liquid separator by using a peristaltic pump. The mercury vapor is transported to the graphite tube electrochemically modified with argon flow (200 mL min-1) and pre-concentrated during 120 s. The detection limit obtained was 93 ng L-1 (n=20, 3δ). The performance of these system was tested for determination of mercury in potable and non-potable water and lake sediments. The reliability of the entire procedure was confirmed by recovery tests.
44
Rocha, José Roberto Caetano da. "Estudos eletroquímicos envolvendo eletrodos modificados por metaloporfirinas e aplicação na determinação de nitrato (NO3-) e nitrito (NO2-)." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-27032019-100058/.
Full textAbstract:
O presente trabalho inclui duas etapas da pesquisa. Na primeira fase do projeto, a oxidação eletroquímica do nitrito em eletrodo de carbono vítreo modificado com um filme obtido eletrostaticamente de Co-TRP/Zn-TPPS, foi investigada em pH 4,7. Um aumento de corrente foi detectado em 0,75V, cujo máximo foi proporcional à concentração do íons nitrito, exibindo uma dependência inversa com a espessura do filme. A velocidade de transferência de carga foi avaliada por cronoamperometria, sendo que a velocidade de difusão da carga eletroquímica através do filme é mais alta do que a velodicade de difusão do íon em solução. O processo catalítico envolvendo a oxidação do íon nitrito no filme de pares de depósitos alternados foi também investigado com as técnicas da voltametria cíclica e de disco rotativo. Em concentrações relativamente baixas de substrato, o processo mediado foi tratado como um sub-caso, SR, na notação de Saveant, permitindo o cálculo da constante de velocidade para a reação de troca na interface filme-solução, sendo que tal valor foi estimado em 3,4x103 dm3 mol-1 s-1. Na segunda parte da investigação, a potencialidade analítica do eletrodo modificado foi confirmada por experimentos de injeção em fluxo usando solução carregadora tampão pH 4,7. Devido à atividade catalítica da camada imobilizada, a determinação de nitrito foi realizada em potencial menos positivo do que aqueles obtidos em eletrodos polidos (0,75 V vs. Ag/AgCl) e os dados obtidos demostraram o melhor desempenho do eletrodo modificado, indicando excelente repetibilidade e maior sensibilidade. Na condição experimental otimizada, o nitrito foi determinado na configuração FIA com limite de detecção de 0,1 µmol L-1 e a faixa analítica de aplicabilidade do método foi de 1 a 1000 µmol L-1. Nitrato também foi quantificado após sua redução estequiométrica a nitrito pela passagem da solução através da coluna de cádmio/cobre. Ambos analitos foram quantificados em água mineral e amostras de saliva e os resultados foram concordantes com aqueles obtidos usando método oficial.This present work includes two research steps. ln the first step the electrochemical oxidation on nitrite on a glassy carbon disc electrode, modified with an electrostatically assembled film of tetraruthenated cobalt porphyrin/(meso-tetra(4-sulphonatephenyl)porphyrinate zinc(II), was investigated at pH = 4.7. A current enhancement was observed by using the modified electrode, the signal being proportional to the concentration of nitrite ions and exhibiting an inverse dependence with the film thickness. The charge transfer rate was evaluated by chronoamperometry, showing that the rate of diffusion of electrochemical charge through the film is higher than the rate of diffusion of substrates in solution. The catalytic process involving the oxidation of the nitrite ions at the bilayered film was also investigated based on cyclic and rotating disc voltammetry. At relatively low substrate concentrations the mediated process has been dealt with in terms of the SR sub-case in Saveant\'s notation, allowing the calculation of the rate constant for the cross-exchange reaction at the film-solution interface as 3.4x103 dm3 mol-1 s-1. In the second part the analytical potentiality of the modified electrode was studied by flow injection experiments carried out by using a pH 4.7 buffer as carrier solution. Owing to the catalytic activity of the immobilized layer, the determination of nitrite was performed at less positive potentials (0.75 V versus Ag/AgCl) and the data obtained showed a better performance indicated by both an excellent repeatability and increased sensitivity. At the optimized experimental condition, nitrite was determined in the FIA configuration with a limit of detection of 0.1 µmol L-1. Nitrate was also quantified after its stoichiometric reduction to nitrite by passing the solution through a cadmium/copper column. Both analytes were quantified in mineral water and saliva samples and the results were in agreement with the ones obtained by using an official method.
45
Esper, Alexandre. "Etude et réductiοn des dérives en température aux basses fréquences des magnétοmètres à haute sensibilité à base de Μagnetο-Ιmpédance Géante (ΜΙG) : réduction des fluctuations l'offset en température." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC247.
Full textAbstract:
L'effet Magnéto-Impédance Géante (MIG) se manifeste par une forte variation de l’impédance d’un conducteur ferromagnétique parcouru par un courant alternatif et soumis à un champ magnétique variable. Ces dernières années, de nombreuses activités de recherches ont porté sur l'accroissement de la sensibilité en champ de ces dispositifs. Les valeurs atteintes aujourd’hui permettent de réaliser un magnétomètre à très haute sensibilité. Cependant, peu d’études se sont intéressées aux effets de la variation de la température de MIG et à sa stabilité à long terme. Mon travail de thèse présente une étude détaillée de la sensibilité en température des magnétomètres MIG et des méthodes permettant de s’affranchir des fluctuations induites par la variation de cette température. Sur la base d’un modèle théorique, une étude analytique des fluctuations d’offset engendrées par les variations de température a été réalisée. Ce modèle prend notamment en compte les principaux mécanismes mis en jeu : supposés être la perméabilité magnétique et la résistivité électrique. À partir de cette modélisation, une technique de compensation pour les différents modes de fonctionnement a été proposée. Un prototype de magnétomètre basé sur un micro-fil MIG off-diagonal a été mis en œuvre afin de vérifier l’efficacité de la méthode proposée. Cette dernière met principalement en œuvre une double modulation en courant de l’élément sensible. Les résultats expérimentaux ont été comparés à la configuration classique (simple modulation) et aux valeurs attendues. Ils montrent d’une part l'efficacité de cette technique et d’autre part la cohérence des résultats obtenus. Soit une réduction importante des fluctuations d’offset en température, notamment aux très très basses fréquences (< 10-3 Hz) avec une dérive de -1,8 nT/K pour une variation en température de 24 K et une dérive de 130 pT/h sur 12 heures d’acquisitionThe Giant Magneto-Impedance (GMI) effect is manifested by a strong variation in the impedance of a ferromagnetic conductor when an alternating current flows through it and it is submitted simultaneously to a variable magnetic field. Over the last few years, numerous research activities have been devoted to improving the field sensitivity of these devices. The values reached today make it possible to produce a very high sensitive magnetometer. However, only a few studies have investigated the temperature effects on the GMI material and its long-term stability. My thesis presents a detailed study of the temperature sensitivity of GMI magnetometers, and we proposed some methods to remedy the fluctuations induced by the temperature variation. Based on a theoretical model, an analytic study of the offset fluctuations generated by the temperature variations was carried out. This model takes into account the physic mechanisms involved when a temperature variation occurs, supposed to be the magnetic permeability and the electrical resistivity. From this modeling, a compensation technique for the different modes of operation has been proposed. Subsequently, a magnetometer prototype based on off-diagonal GMI wire was implemented to verify the effectiveness of the proposed method. The latter injects a double current modulation in the GMI sensitive element. The experimental results were compared to the classical configuration (simple modulation) and to the expected values. They show, on the one hand, the efficiency of this technique and, on the other hand, the coherence of the obtained results. A significant reduction in the GMI offset drift depending on temperature has been achieved, especially at very very low frequencies (< 10- 3 Hz) with a drift of - 1.8 nT/K for a temperature variation of 24 K, and a drift of 130 pT/h over 12 hours of acquisition
46
Grigoletto, Tânia. "Dissolução eletrolítica de ligas de alumínio em cavacos e determinação dos elementos constituintes por espectrometria de emissão atômica com fonte de pasma (ICP-OES)." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-12032010-100435/.
Full textAbstract:
Várias ligas de Al em cavacos, com diferentes granulometrias foram dissolvidas de modo convencional, com ataque por água régia. Este tipo de decomposição resulta, muitas vezes, em resíduos sólidos, cujas quantidades dependem dos teores de silício. A fim de se comparar os resultados, procedeuse, com esses resíduos, de dois modos distintos: ou foram desprezados ou foram decompostos com ácido fluorídrico, eliminando-se o silício, dissolvendo-se o restante com ácido nítrico e agrupando-o à primeira solução para a determinação de Fe, Cu, Mn, Mg, Cr, Ni, Zn, Pb, Sn, Ti e Zr por ICP-OES. Foi avaliada a influência de quantidades crescentes de Al na determinação destes elementos e, também, a provável interferência espectral de Cu na determinação do Zn (com e sem separação eletrolítica de Cu). A dissolução eletrolítica de ligas de alumínio em cavacos foi estudada pressionando-os contra um eletrodo de platina para que se comportassem como se fossem o próprio ânodo e a eletrólise ocorresse. Uma célula foi construída utilizando-se um tubo (corpo de seringa de 2,5 mL) com perfurações ao redor da base aberta, onde foi colocada uma malha sintética (perlon) no fundo e, sobre esta, a amostra. Na parte superior foi introduzido um pequeno tarugo de acrílico com um fio de platina passando pelo seu interior e com um orifício por onde passava o fluxo (4,5 mL min.-1) da solução eletrolítica (ácido nítrico diluído). Na extremidade inferior, prendeu-se, com o fio, uma plaquinha, também de platina, que pressionava a amostra. A solução saía pelos orifícios inferiores para um béquer de onde era recirculada e onde estava colocado o cátodo, um fio de Pt (de forma de losango), sendo novamente captada e introduzida na parte superior do tarugo do ânodo. Com esse circuito, foram obtidos bons resultados utilizando-se ácido nítrico 1 mol L-1, corrente de 0,6A e tempo de eletrólise de 10 minutos. Sendo a dissolução parcial, é necessário que se conheçam as porcentagens dos elementos por dissolução ácida total de uma liga de composição similar ou por um material de referência certificado. Normalizaram-se os dados pelas porcentagens conhecidas dos constituintes das ligas. Compararam-se os cálculos feitos dos seguintes modos: 1-) pela razão entre a concentração do elemento com a do Al, também determinada; 2-) pela a razão entre a concentração do elemento com a soma das concentrações de todos os elementos determinados, inclusive o Al; 3-) pela razão entre a concentração do elemento e a soma das concentrações só dos outros elementos, sem o Al. O desvio padrão e o erro relativo para os elementos Fe, Cu, Mg, Ni e Cr, quando em teores > 0,1%, foram < 10%; para teores de Zn < 0,2%, foram menores de 10% e para teor de 4,8% foram < 15%. Já para o Mn, quando em teor > 0,2% foram <10% (exceto para a liga B.C.S.268/1). O desvio padrão relativo para o Zr, com teor ao redor de 0,002% foi <10%. Os resultados para o elemento Pb nas ligas B.C.S. 216/1 e 380 tiveram desvio padrão e erro relativo <10%, mas o mesmo não ocorreu na liga B.C.S. 268/1. O elemento Sn apresentou resultados piores, ao redor de 20%. O elemento Ti só deu bons resultados quando em teor de cerca de 0,2%. Para estas determinações foram avaliadas as dissoluções químicas dos metais nas ligas pelo ácido nítrico em diferentes concentrações e temperaturas. Além disso, foram avaliadas duas outras células para a verificação da possibilidade de dissolução eletrolítica das ligas de Al on-line com a determinação por ICP-OES.Several aluminum alloys with different chips size were dissolved using aqua regia (HCl:HNO3,3:1). The residues of the dissolution procedure were either rejected or used in silicon volatilization with hydrofluoric acid before determination of Fe, Cu, Mn, Mg, Cr, Ni, Zn, Pb, Sn, Ti and Zr by ICP-OES. The influence caused by crescent amounts of aluminum in the determination of other elements and the probable spectral interference by Cu in determination of Zn (with or without electrolytic separation of Cu) was evaluated. The electrolytic dissolution of aluminum alloys was performed by pressing chips against a platinum electrode for the electrolysis to occur, so that way the chips behaved as the anode. A tube (body of syringe of 2.5mL) with perforations around the open base was used to contain the sample and Pt electrode. The alloy was placed on synthetic wool (perlon) in this tube. An acrylic dowel with a platinum wire across its interior was fixed in the superior part a tube with Teflon film, with an orifice through which the electrolytic solution flowed (HNO3 1 mol L-1; 4.5mL min-1). A platinum dish was fixed at the inferior extremity of the platinum wire to press the sample. The solution came out through the inferior orifices of the tube to a flask, from where it was again captured (with a peristaltic pump) to go into the superior part of the tube. In this flask, a Pt wire cathode was also placed. A current of 0,6A and ten minutes of electrolysis provided good results. Due to the partial dissolution, the knowledge of percentages of previous elements analyzed after total dissolution, or using certified reference material are necessary. The results were normalized by known percentages. The calculations were made by: 1-) the ratio between the concentration of the element determind, with the determined concentration of aluminum; 2-) the ratio between concentration of the element and the sum of the concentrations of the elements determined, including Al; 3-) the ratio between the concentration of element and the sum of the concentrations of the elements determined, without the aluminum. The relative standard deviations and accuracy were <10% for the elements Fe, Cu, Mg, Ni and Cr when the concentrations were >0.1%; for the Zn were 15%, when the concentration >0.2%, and <10% for concentration <0.2%. For Ti with concentration of about 0.1%, were 15%. Relative standards deviations for the Zr, with concentration of 0.002%, were always <10%. The element Pb, Sn and Mn didnt provide good results. For these determinations, the chemical dissolution of the elements with different nitric acid concentrations and temperature was evaluated. Two other cells for the electrolytic dissolution of Al alloys followed by online ICP-OES determination were examined.
47
Matos, Renato Camargo. "Sistemas amperométricos empregando matrizes de microeletrodos e análises simultâneas." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-21022019-103823/.
Full textAbstract:
No presente trabalho são descritos métodos versáteis para determinações simultâneas multicomponentes. Estes são baseados num sistema de detecção multicanal acoplado a célula em fluxo contendo um conjunto de microeletrodos modificados. O primeiro método mostra a quantificação amperométrica em fluxo de ácido ascórbico (AA), dopamina (DA), epinefrina (EP) e dipirona (DI) em misturas (na faixa de µg g-1). Neste trabalho foi utilizado um conjunto de microeletrodos de ouro limpos e modificados, independentemente, com diferentes metais nobres (Pt, Pd e uma mistura equimolar de Pd e Pt), associados com métodos de calibração multivariada. As análises de amostras sintéticas e formulações farmacêuticas contendo AA e DI apresentaram valores muito similares aos encontrados com a iodometria clássica. O método apresentou um erro médio absoluto (em µg g-1) de 0,3, 0,1, 0,4 e 0,3 para AA, DA, EP e DI, respectivamente, para a regressão linear múltipla e 0,3, 0,4, 0,4 e 0,2 para AA, DA, EP e DI, respectivamente, para a regressão por mínimos quadrados parciais. O segundo trabalho apresenta um método para determinação amperométrica diferencial de peróxido de hidrogênio em águas de chuvas em associação com análise por injeção em fluxo e imobilização de catalase em reator tubular usando glutaraldeído e resina amberlite IRA - 743 como suporte. A curva de calibração para o peróxido de hidrogênio foi linear na faixa de concentração de 1 a 10 x 10-6 mol L-1 com um desvio relativo padrão (RSD) < 1%. O limite de detecção do método foi calculado em 2,9 x 10-7 mol L-1. As análises de águas de chuvas foram comparadas com amperometria usando microeletrodo de mercúrio e espectrofotometria, sendo que os resultados mostraram uma boa correlação. O terceiro método descreve a determinação amperométrica simultânea em fluxo de glicose e ácido úrico, usando dois microeletrodos com diferentes composições (Pt e Pt+glicose oxidase+acetato de celulose) e detecção multicanal. A curva de calibração para a glicose foi linear na faixa de concentração de 1 a 10 x 10-4 mol L-1 com um desvio relativo padrão (RSD) < 1%. O limite de detecção do método foi calculado em 5 x 10-5 mol L-1. As análises de amostras sintéticas foram comparadas com o método espectrofotométrico, mostrando uma boa concordância entre os resultados obtidos.In the present work, versatile methods for simultaneous amperometric multicomponent analysis are described. They are based on a multi-channel detection system, coupled to a flow cell containing an array of modified microelectrodes. The first method shows the flow injection amperometric quantification of ascorbic acid (AA), dopamine (DA), epinephrine (EP) and dipyrone (DI) in mixtures (in the µg g-1 range). This work was successfully performed by using an array of microelectrodes bare and with units modified by the electrodeposition of different noble metals (platinum, palladium or a mixture of platinum+palladium), together with multivariate calibration analysis. The analysis of synthetic samples and pharmaceutical compounds containing AA and DI led to very similar values to those obtained by the classical iodometric analysis. The average absolute errors (in µg g-1) calculated for each analyte were 0.3, 0.1, 0.4 and 0.3 for AA, DA, EP and DI, respectively, for multiple linear regression and 0.3, 0.4, 0.4 e 0.2 for AA, DA, EP and DI , respectively, for partial least square regression. The second study presents a method for differential amperometric determination of hydrogen peroxide in rainwater in association with flow injection analysis and immobilized catalase enzymes in a tubular reactor using glutaraldeyde and amberlite IRA - 743 which support. The calibration curves for hydrogen peroxide standards was linear in the concentration range from 1 to 10 x 10-6 mol L-1 with a relative standard deviation (RSD) < 1 %. The detection limit was calculated as 2.9 x 10-7 mol L-1. The rainwater samples analyses where compared with the amperometric using mercury microelectrode and spectrophotometric methods, showing very good correlation between all the methods. The third method describes the flow injection amperometric determination of glucose and uric acid simultaneously, using two microelectrodes with different composition (platinum and platinum+glucose oxidase+cellulose acetate) and a multi-channel detection system. The calibration curves for glucose standards was linear in the concentration range from 1 to 10 x 10-4 mol L-1 with a relative standard deviation (RSD) < 1 %. The detection limit was calculated as 5 x 10-5 mol L-1. The analyses of synthetic samples were compared with the spectrophotometric method, showing very good correlation between the methods.
48
Hood, Derrell L. "Development of a Novel Loeb-Eiber Mass Filter." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1248981763.
Full text
49
Donnell, Anna M. "Bridging Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) from Metalloproteomics to the Undergraduate Curriculum." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504781774657886.
Full text
50
Mark, Jonas [Verfasser], and Frank-Michael [Akademischer Betreuer] Matysik. "Analytical approaches to the analysis of small samples and Hyphenation of fast capillary electrophoresis to other instrumental techniques / Jonas Mark. Betreuer: Frank-Michael Matysik." Regensburg : Universitätsbibliothek Regensburg, 2016. http://d-nb.info/1107761573/34.
Full text