Sökning: "hydrogen sulphide"
Visar resultat 1 - 5 av 21 avhandlingar innehållade orden hydrogen sulphide.
1. Sulphide mineral flotation : a new insight into oxidation mechanisms
Sammanfattning : Formation of hydrogen peroxide (H2O2), an oxidizing agent stronger than oxygen, by sulphide minerals during grinding was investigated. It was found that pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite ((Zn,Fe)S), and galena (PbS), which are the most abundant sulphide minerals on Earth, generated H2O2 in pulp liquid during wet grinding in the presence or devoid of dissolved oxygen in water and also when the freshly ground solids are placed in water immediately after dry grinding. LÄS MER
2. Synchrotron radiation studies of gas phase molecules : from hydrogen to DNA sugars
Sammanfattning : This thesis summarises experimental results on the molecular spectroscopy of gas phase molecules excited by synchrotron radiation in the VUV and soft X-ray regions. We have used three different detection techniques, photon induced fluorescence spectroscopy, photoionisation mass spectroscopy and near edge X-ray absorption fine structure spectroscopy to study molecular deuterium, hydrogen sulphide, ammonia, methanol, pyridine, pyridazine, pyrimidine, pyrazine, s-triazine, and 2-deoxy-D-ribose, the last one also known as the DNA sugar. LÄS MER
3. MEMS-based electrochemical gas sensors and wafer-level methods
Sammanfattning : This thesis describes novel microel ectromechanical system (MEMS) based electrochemical gas sensors and methods of fabrication.This thesis presents the research in two parts. In the first part, a method to handle a thin silicon wafer using an electrochemically active adhesive is described. LÄS MER
4. The effects of fines content and hydrogen sulphide gas pre-treatment on kraft pulping and the strength of polysulphide pulps
Sammanfattning : .... LÄS MER
5. Sulphide Minerals: Surface Oxidation and Selectivity in Complex Sulphide Ore Flotation
Sammanfattning : Metal and energy extractive industries play a strategic role in the economic development of Sweden. At the same time these industries present a major threat to the environment due to multidimensional environmental pollution produced in the course of ageing of ore processing tailings and waste rocks. LÄS MER