Search for dissertations about: "Electrochemical extraction"

Showing result 1 - 5 of 32 swedish dissertations containing the words Electrochemical extraction.

2. 1. Development and Investigations of Novel Sample Preparation Techniques : Electrochemical Extraction and Evaluation of Miniaturized Analytical Devices Coupled to Mass Spectrometry

   Author : Gustav Liljegren; Leif Nyholm; Jean Pettersson; Per Sjöberg; Ari Ivaska; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Electrochemical extraction; Solid-phase microextraction; Solid-phase extraction; Microchip; Mass spectrometry; Polypyrrole; Pressurized-fluid extraction; Preconcentration; Electrospray ionization; Analytisk kemi; Analytical chemistry; Analytisk kemi;

   Abstract : Different sample preparation steps prior to a detection method are often essential in analytical chemistry. In this thesis, both static extractions and on-line coupled solid-phase extractions have been studied in combination with different detection techniques. READ MORE

4. 2. Microdialysis Sampling, Electrochemical Detection and Mass Spectrometry of Carbohydrates in Monitoring Bioprocesses

   Author : Nelson Torto; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; monosaccharides; membrane; IPED; ion spray; probe internal geometry; extraction fraction; electrochemical oxidation; electrochemical detection; disaccharides; desalting; carbohydrates; bioprocess monitoring; Cu; APCI; Au; MS; oligosaccharides; PAD; PEI; Analytical chemistry; Analytisk kemi;

   Abstract : This thesis addresses; (1) the microdialysis experiment, application and methodology to maximise its performance when sampling from enzymatic bioprocesses, (2) electrochemical detection and electrochemical oxidation of carbohydrates on Au as well as Cu electrodes in alkaline solutions, and (3) coupling and maximising the performance of a microdialysis sampling based high performance anion exchange chromatography-integrated pulsed electrochemical detection-mass spectrometry system. Studies were carried out to investigate the effect of temperature, analyte as well as biomatrix complexity, analyte concentration, permeability factors, protein(enzyme)-membrane interaction and membrane material on the performance of microdialysis sampling. READ MORE

5. 3. Pressurised Fluid Extraction of Bioactive Species in Tree Barks : Analysis using Hyphenated Electrochemical Mass Spectrometric Detection

   Author : Michelle Co; Charlotta Turner; Per J.R Sjöberg; Kari Hartonen; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pressurised fluid extraction; antioxidants; DPPH; water; ethanol; antioxidant activity; antioxidant capacity; electrochemial detection; mass spektrometry; Chemistry; Kemi; Analytical Chemistry; Analytisk kemi;

   Abstract : Analytical chemistry has developed throughout time to meet current needs. At present, the interest in biorefinery is growing, due to environmental awareness and the depletion of fossil resources. Biomass from agricultural and forestry industries has proven to be excellent raw material for different processes. READ MORE

6. 4. Electrochemical machining: towards 3D simulation and application on SS316

   Author : A. A. Gomez-Gallegos; UK University of Edinburgh; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electrochemical machining; 3D Simulation; FEM; stainless Steel 316; surface Finish; Maskinteknik; Mechanical Engineering;

   Abstract : Electrochemical machining (ECM) is a non-conventional manufacturing process, which uses electrochemical dissolution to shape any conductive metal regardless of its mechanical properties and without leaving behind residual stresses or tool wear. Therefore, ECM can be an alternative for machining difficult-to-cut materials, complex geometries, and materials with improved characteristics, such as strength, heat-resistance or corrosion-resistance. READ MORE

7. 5. Thin-film ultraviolet light-emitting diodes realized by electrochemical etching of AlGaN

   Author : Michael Alexander Bergmann; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; thin-film flip-chip; light-emitting diodes; UVB; AlGaN; thermocompression bonding; substrate removal; ultraviolet light; electrochemical etching; heterogeneous integration; LEDs;

   Abstract : Ultraviolet (UV) light sources have a direct impact on everyone’s life. They are used to sterilize surfaces as well as for water purification. In addition, they are used in green houses to enhance health-promoting substances in plants, for phototherapy to treat skin diseases, for sensing and material curing. READ MORE