Sökning: "saturation transfer difference"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden saturation transfer difference.

  1. 1. Study of retention mechanisms in Hydrophilic Interaction Chromatography by Nuclear Magnetic Resonance Spectroscopy

    Författare :Adel Shamshir; Knut Irgum; Tobias Jonsson; Ngoc Phuoc Dinh; Torgny Fornstedt; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HILIC; hydrophilic interaction chromatography; adsorption; STD-NMR; saturation transfer difference; retention mechanism; NMRD; solid state-NMR; Analytical Chemistry; analytisk kemi;

    Sammanfattning : This thesis deals with investigations of the retention mechanisms in hydrophilic interaction liquid chromatography (HILIC) using nuclear magnetic resonance spectroscopy. The aims are to understand how the different types of stationary phases can influence the retention of various solutes and the adsorption abilities of solvent on stationary phases. LÄS MER

  3. 2. Microfluidic Hydrodynamic of Gas-Liquid flow in Single Microchannel and Porous Media with Microchannel Network

    Författare :Shuo Yang; NanoLund: Centre for Nanoscience; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mass transfer; slug flow; porous media; interficial instability; fingering displacement;

    Sammanfattning : In this thesis, a microfluidics platform with high-speed imaging system was built to investigate gas-liquid flow in single microchannel and interfacial instability in porous media with microchannel network:The mass transfer of slug flow in the rectangular and square microchannels was experimentally studied by using water as liquid phase and CO2 as gas phase. Depending on flow rates, flow patterns including slug flow, bubbly flow, and annular flow were observed in rectangular and square microchannels. LÄS MER

  4. 3. Charge carrier transport in field-effect transistors with two-dimensional electron gas channels studied using geometrical magnetoresistance effect

    Författare :Isabel Harrysson Rodrigues; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low-field mobility; high-electron-mobility transistor; velocity saturation; quasi-ballistic charge carrier transport; two-dimensional electron gas; charge carrier scattering mechanisms; geometrical magnetoresistance; low noise and high frequency applications; velocity peak; graphene field-effect transistor; charge carrier trans- port;

    Sammanfattning : During the last decades, significant efforts have been made to exploit the excellent and promising electronic properties exhibited by field-effect transistors (FETs) with two-dimensional electron gas (2DEG) channels. The most prominent representatives of this class of devices are high-electron-mobility transistors (HEMTs) and graphene field-effect transistors (GFETs). LÄS MER

  5. 4. SAR Remote Sensing of Forests, from Microwaves to VHF

    Författare :Hans Israelsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave; backscattering models; SAR; VHF; vegetation;

    Sammanfattning : The number of SAR systems available for civilian remote sensing purposes has grown in the nineties. A Synthetic Aperture Radar produces high resolution images of the earth independent on daylight and atmospheric conditions. This thesis mainly examines the applications of SAR remote sensing to monitoring forested areas. LÄS MER

  7. 5. Effects of Protons and Small Alcohols on the Oxygen-Evolving Complex of Photosystem II

    Författare :Paulina Geijer; Biokemi och Strukturbiologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; EPR; pH; methanol; S3; S2; S0; YZ; Mn cluster; Oxygen-evolving complex; S-states; Biochemistry; Metabolism; Biokemi; metabolism;

    Sammanfattning : Higher plants and algae use oxygenic photosynthesis to convert solar energy to reducing equivalents and chemical energy. The ultimate electron donor to oxygenic photosynthesis is water. Oxidation of water to oxygen occurs in the oxygen-evolving complex (OEC) in Photosystem II (PSII). The OEC is composed of four Mn atoms, Ca2+ and Cl-. LÄS MER