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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.
171

Neutralization reactions of phosphoric acid and of calcium acid phosphate

Parsons, Lemial Deloss, January 1900 (has links)
Thesis (Ph. D.)--Vanderbilt University, 1933. / Bibliography: p. 48-49.
172

Chemically modified electrodes with inorganic films of noble metal complexes and metal oxides : preparation, characterization and applications /

Han, Qi. January 2002 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.
173

Study of the chemical reaction preceding reduction of CdNTA complexes using stationary electrode polarography

Shuman, Mark S. January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
174

An electrometric method for the study of autoxidation reactions the catalysis of hydroquinone oxidation by manganous ion,

Temple, John Wilfred, January 1928 (has links)
Thesis (Ph. D.)--Columbia University, 1928. / Vita. Bibliography: p. 31.
175

The composition of anodic lead dioxide and its use in the quantitative determination of small amounts of lead

Day, Thomas Gordon, January 1900 (has links)
Thesis (Ph. D.)--University of Missouri, 1935. / Vita. By T.G. Day and W.T. Schrenk. Published also as part 2 of "The quantitative determination of lead by the electrolytic deposition of lead dioxide ... By Thomas Gordon Day, Phillip Hall Delano and W.T. Schrenk." Rolla, Mo., 1935. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 62-68.
176

The use of a rotating anode in the electrolytic estimation of zinc and of nitirc acid thesis ... /

Ingham, Leslie Howard, January 1904 (has links)
Thesis (Ph. D.)--University of Pennsylvania, 1904. / Includes bibliographical references.
177

Novel hyphenated technologies for sensing, separation and sample treatment

Wanekaya, Adam. January 2005 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry. / Includes bibliographical references.
178

Synthesis, photophysical properties and applications of aggregation-induced emission materials based on cyanostilbene moiety

Dong, Yujie 05 September 2016 (has links)
The concept of "aggregation-induced emission" (AIE) effect has induced a great deal of attention these days. Now, exploration of new AIE-active molecular system and multiple high technique applications for AIE materials are the two research hotspots. Cyanostilbene, as a classical structural unit in photoelectric functional materials, also exhibited this unique luminescence behavior. The research background was illustrated in Chapter 1, which mainly introduced the development of this subject. In this project, Chapter 2 and Chapter 3 presented two classes of functionalized AIE-active molecules based on cyanostilbene moiety, and their applications were investigated, while Chapter 4 demonstrated a series of donor-acceptor (D-A) molecules with highly emissive unit, and their photophysical properties were studied.;In Chapter 2, four different donor-substituted cyanostilbene-based dipyrrins were synthesized and characterized. The investigation of photophysical properties confirms that these molecules are AIE-active, which should be attributed to the cyanostilbene moiety. The introduction of different donor groups showed little impact on their luminescence. Furthermore, the emission properties of these molecules were found to be sensitive to Zn2+, that is, addition of Zn2+ enormously enhanced its fluorescence in THF. The titration experiments proved they showed good selectivity and sensitivity for Zn2+ detection with relatively low limit of detection. Job's curve and spectral studies of their corresponding zinc complex indicated that the ratio for dipyrrins and Zn2+ is 2:1, which suggested the formation of zinc complex by chelation-enhanced fluorescence (CHEF) effect should be the reason of the enhanced fluorescence. By combining dipyrrin with typical AIE-active moiety tetraphenylethylene (TPE), an AIE-active TPE-based dipyrrin was prepared. The studies of its fluorogenic Zn2+ detection confirmed that the CHEF effect together with AIE effect are responsible for the intense fluorescence, indicating the potential application as a Zn2+ detector in aqueous media.;In Chapter 3, the cyanostilbene backbone was functionalized with a terpyridine unit to construct four terpyridine-based cyanostilbene molecules with different donor substitutents. The investigation of their photophysical properties confirms that they are AIEE-active. With the effect of different electron-donating groups, their solid-state fluorescence color was adjusted from blue to orange-red successfully. According to the calculation results of their frontier molecular orbitals, terpyridine has little impacts on their luminescence, but would influence their solid-state emission obviously owing to its large steric hindrance. This class of molecules displayed higher luminescence efficiency in solid state than in their dissolved state. The twisted molecular conformation in single crystal, which effectively avoids close π-π stacking, was assumed to be responsible for the high luminescence efficiency in solid state. This kind of molecules show distinct switched fluorescence by stimuli of acid/base vapors, and this phenomenon derives from the protonation effect of nitrogen atoms in the terpyridine unit. Moreover, three of these molecules exhibit good electroluminescence properties. Especially, the crystal of non-donor substituted molecule show amplified spontaneous emission (ASE) properties, indicating this blue-emissive material can be used in multiple areas such as chemical sensor, organic light emitting diodes (OLEDs) and organic laser media.
179

Printed Electrochemical Sensors For Bioanalysis

Chen, Sensen 01 December 2017 (has links)
Recently, point-of-care diagnostics has gained great attention because it can improve patient’s quality of life. Electrochemical diagnostic systems are promising because of their miniaturizability and low-cost. However, fabrication of such devices requires special skills as well as expensive equipment and supplies. This thesis is based on a research project aimed at fabricating electrochemical sensors combing wax printing and inkjet printing or wax printing and hand painting. The electrochemical sensors can be used for measuring different kinds of electrochemical analytes like dopamine, uric acid by electrochemical methods like amperometry, which can show great calibration curve. The LOD of dopamine, uric acid, ascorbic acid, Nile Blue, hydrogen peroxide and ferrocene is 0.015 µM, 7.3 µM, 30 µM, 1.3 µM, 8 nM and 30 µM, respectively. Further, we can modify the electrochemical sensor by using multiwall carbon nanotube in order to improve the sensitivity of the electrochemical sensors. This modified electrochemical sensor can also be used as immunoassay by sandwich format ELISA for detecting carcinoembryonic antigen (CEA), which has been designated as a reliable biomarker for several types of cancers. We found that the CNT modified hand-painting device can detect CEA down to 0.6 ng/mL, which is three times lower than the cut-off value of diagnosis, i.e. 5 ng/mL in blood.
180

Development of reduced graphene oxide based nanocomposities for electrochemical biosensing applications

Bai, Xiaoyun 12 November 2014 (has links)
The modification of electrodes is always an important task in electrochemical detection of electroactive and biological molecules. Chemically modified electrodes can offer improved selectivity and sensitivity for the target analyte, which greatly enhance the electrode performance. Various materials such as conducting polymers, metal nanoparticles and carbon nanomaterials have been exploited and widely used for the modification of electrodes. Electrochemical or spontaneous deposition, electrostatic adsorption, layer-by-layer self assembly and covalent binding have also been developed for electrode modification and offer improved performance. Both Prussian blue (PB) and toluidine blue O (TBO) are excellent redox mediators and very popular in electrode modification. PB has shown strong catalytic property for the reduction of hydrogen peroxide, but the application in biosensor fabrication is limited for its instability at neutral pH. Graphene, as a single-atom-thick carbon material, is considered an ideal platform for designing composite nanomaterials for high-performance electrochemical or electrocatalytic devices. The combination of PB with reduced graphene oxide (RGO) and poly(toluidine blue O) (PTBO) will greatly improve the stability of PB. An amperometric biosensor based on glassy carbon (GC) electrode modified with reduced graphene oxide, PB and poly(toluidine blue O) was developed. Experimental results showed that the GC/RGO/PB/PTBO modified electrode offered an excellent electrocatalytic activity toward the reduction of hydrogen peroxide due to the possible synergistic effects of the PB-PTBO composite material. After codeposition of glucose oxidase (GOD) and chitosan (CHIT) coating, the resulting GC/RGO/PB/ PTBO/CHIT-GOD electrode exhibited excellent response to glucose with a sensitivity of 59 mA M1 cm2, a low detection limit of 8.4 μM and a linear range from 0.02 to 1.09 mM at a detection potential of +0.2 V vs. Ag.

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