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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The nearby field galaxy survey a spectrophotometric study of 196 galaxies in the local field /

Jansen, Rolf Arthur, January 2000 (has links)
Thesis (Doctoral)--Rijksuniversiteit Groningen, 2000. / Includes bibliographical references.
32

Desenvolvimento de um método de análise por injeção em fluxo (FIA) para determinação de dissulfeto de tetrametiltiuram (tiram) utilizando reagente imobilizado em reator de fase sólida (RFS) /

Silva Junior, Ranulfo Combuca da. January 2011 (has links)
Resumo: No presente trabalho, foi desenvolvido um método analítico destinado à quantificação do fungicida Tiram baseado na capacidade que este possui de complexar íons Cu2+. A quantificação foi efetuada por meio do acoplamento de espectrofotometria visível a um reator de fase sólida (RFS) utilizando de técnicas de análise em fluxo. O RFS utilizado foi constituído por um tubo de plástico (12 cm e 2 mm d.i.) preenchido por resina poliéster finamente triturada contendo fosfato de Cu2+ imobilizado. Durante o contato de 100 µL de Tiram com íons Cu2+ imobilizados na resina, forma-se o complexo Cu2+ / Tiram. Nesta etapa, o complexo é liberado para a solução carregadora (água) a uma vazão de 2,5 mL min-1. Sendo intensamente colorido esta espécie é a base do presente método de quantificação a 439 nm. Com o desenvolvimento da reação, a curva analítica obtida foi linear no intervalo de concentração de 3,0 x 10-5 a 3,4 x 10-4 mol L-1, com limite de detecção de 6,95 x 10-5 mol L-1 e freqüência de amostragem de 60 determinações por hora / Abstract: In this dissertation an analytical method for the Thiram fungicide quantification, based on the capacity which it has a complex copper ions was developed. The quantification was performed by mean of visible spectrophotometry coupling a solid-phase reactor using flow techniques. The solid-phase reactor used is consisting of a plastic tube (12 cm and 2 mm diameter) filled with finely crushed polyester resin containing copper phosphate immobilized. During the contact of 100 µL Thiram with Cu2 + ions immobilized on the resin is formed the complex Cu2 + / Thiram. At this stage, the complex is released into the carrier solution (water) with flow rate of 2,5 mL min-1 being intensely colored and this species is the basis of this method of quantification at 439 nm. With the development of the reaction, analytical curve was linear on the concentration range of 3,0 x 10-5 to 3,0 x 10-4 mol L-1 with a detection limit of 6,95 x 10-5 mol L-1 and a sampling frequency of 60 determinations per hour / Orientador: Marcos Fernando de Souza Teixeira / Coorientador: Homero Marques Gomes / Banca: Mario Sergio Galhiane / Banca: Ronaldo Spezia Nunes / Mestre
33

Metodo espectrofotometrico para determinação de vancomicina / Spectrophotometric method for vancomycin determination

Rodrigues Junior, Alvino 13 August 2018 (has links)
Orientador: Matthieu Tubino / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-13T14:10:39Z (GMT). No. of bitstreams: 1 RodriguesJunior_Alvino_M.pdf: 694987 bytes, checksum: 1b71ae2953ae2ae4410308e036a7f084 (MD5) Previous issue date: 2008 / Resumo: Este trabalho teve por objetivo o desenvolvimento de um método analítico quantitativo de para análise de vancomicina (em sua forma denominada vancomicina base - VCM, e na forma de cloridrato de vancomicina - HVCM), com utilização de espectrofotometria na região do visível. O método tem como princípio a reação da vancomicina com íons cobre(II), resultando na formação de um complexo de coloração lilás, que apresenta absorção máxima em 555 nm. Realizaram-se estudos para a otimização da reação entre a vancomicina e o íon cobre(II). Dentre estes fatores, destacam-se: a escolha do sal de cobre(II) utilizado na reação com vancomicina; a utilização de etanol, no preparo das soluções e como componente do meio reacional; pH do meio reacional; proporção molar entre vancomicina e íon cobre(II). A otimização destes parâmetros resultou em um método com faixa de trabalho de 1,0 × 10 mol L a 1,0 × 10 mol L, com coeficiente de correlação de 0,9997 e limite de detecção (LOD) e limite de quantificação (LOQ) de 4,0 × 10 mol L e 1,0 × 10 mol L, respectivamente. O método proposto também foi estudado em relação à recuperação de vancomicina frente a excipientes comumente utilizados na indústria farmacêutica. Os resultados obtidos foram comparados com método de referência cromatográfico, onde foi observado que o método proposto apresentou maior repepetibilidade para as amostras de HVCM e maior recuperação para as amostras de VCM. O procedimento para a realização de análises pelo método proposto é de fácil execução e de baixo custo / Abstract: The aim of this work was to develop a quantitative spectrophotometric analytical method, in the visible region of the spectrum, for the determination of vancomycin (in the form known as base ¿ VCM, and in the form of chloridrate, HVCM). The developed method uses the reaction between vancomycin and ions copper(II) that forms a lilac complex which spectrum shown a maximum at 555 nm. Studies were done in order to optimize the method. Among them can be cited: selection of the copper(II) salt to be used in the reaction with vancomycin; use of ethanol as component of the reaction for the preparation of the solution and as component of the reaction medium; pH of the reaction medium; molar proportion between vancomycin and copper(II) ions. The parameters optimization resulted in a method with a linear range from 1,0 × 10 mol L to 1,0 × 10 mol L, with correlation coefficient value of 0,9997, limit of detection (LOD) and limit of quantification (LOQ) values of 4,0 × 10 mol L and 1,0 × 10 mol L, respectively. The proposed medium was also studied with respect to the vancomycin recovering when mixed with excipients commonly used in the pharmaceutical industry. The obtained results were compared with those of the reference chromatographic method (HPLC), where it was observed the proposed method showed a better reprodutibility for HVCM samples and higher recoveries for VCM samples. The analytical procedure that is proposed in this work is simple to be performed and the cost is very low / Mestrado / Quimica Analitica / Mestre em Química
34

Single crystal spectrophotometry of inorganic complexes

Smith, Derek William January 1968 (has links)
No description available.
35

Low noise solar spectroscopy

Peach, John Vincent January 1966 (has links)
No description available.
36

A spectrophotofluorometric method for the quantitative determination of hydrocortisone absorption in the skin from dermatological medications

MacKenzie, Helen May January 1967 (has links)
The assessment of drug activity in skin is hampered by the lack of adequate methods for quantitative measurement of drug penetration in skin. Therefore, a new method was developed with the following features. The drug, hydrocortisone, chosen for its clinical and pharmaceutical importance, was applied under occlusive dressing for varying time intervals. Small skin samples, which ranged from 0.5 to 20 mg in size, were removed, in vivo, from humans or animals by a new dermatome serial slicing technique. The amount of hydrocortisone absorbed into the epidermis and/or dermis was determined by a new spectrophotofluorometric procedure, based on an older technique described for blood. The tissue levels were then correlated with simultaneously determined skin function measurements. The assay was done at 470 mμ and 525 mμ excitation and emission wavelengths, respectively. Hydrocortisone was extracted from homogenized tissue with dichloromethane. Fluorescence was developed with 85:15 w/w sulphuric acid - ethyl alcohol solution. Hydrocortisone was found in epidermis, but not in dermis. These results confirm current theories on hydrocortisone depot formation in the epidermis. Among the 14 patients examined, the concentration of hydrocortisone in epidermis varied greatly from 20 μg to 358 μg per Gm wet weight of tissue. Exploratory correlations between skin respiration rates, vasoconstriction, and the amount of hydrocortisone in epidermis have been done. The analytical reliability has been discussed. / Pharmaceutical Sciences, Faculty of / Graduate
37

Measurement of small shifts of wide lines

Potter, Michael Urwin January 1967 (has links)
A new technique has been devised to obtain time-resolved measurements of small spectral line shifts. Two linear neutral density wedges with opposite transmission gradients were placed over the top and bottom of a monochromator exit slit in such a way that a wavelength shift of a spectral line resulted in a change in light intensity transmitted through the wedges, which was monitored by two photomultipliers. To test this technique, an N II line, for which Griem has calculated the Stark shift as a function of electron density, was observed in the emission spectrum of a small theta-pinch using a monochromator of 10 Å/mm inverse dispersion. Space and time resolved line shift measurements were made and were associated with the axial velocity and the electron density fluctuations of the plasma. An uncertainty of 0.015 Å was estimated, which, for the 1.5 Å line used, corresponds to a shift to width ratio of 10⁻², believed to be lower than any previous shift measuring technique. Time of flight velocity measurements and conservation of mass considerations have confirmed the results as both reasonable and self-consistent. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
38

A spectrophotometric study of temporal variations in the optical spectrum of SS 433/

Wagner, Robert Mark January 1983 (has links)
No description available.
39

A comparison of the spectrophotometric micro-determination of inorganic phosphorus by the Deniges method and molybdenum blue method with application to soil extracts

McGehee, Hiram Temple. January 1932 (has links)
Call number: LD2668 .T4 1932 M34
40

Spectrophotometric determination of manganese (VII) with 6-methoxy-2-methylthio-4-pyrimidinecarboxylic acid and silver (I) with 2-amino-6-methylthio-4-pyrimidinecarboxylic acid

Chung, O. K.(Okkyung Kim) January 1965 (has links)
Call number: LD2668 .T4 1965 C559 / Master of Science

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