Sökning: "partially saturated"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden partially saturated.

  1. 1. Numerical models for degradation of concrete in hydraulic structures due to long-term contact with water

    Författare :Daniel Eriksson; Anders Ansell; Richard Malm; Erik Nordström; Katja Fridh; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; degradation; deterioration mechanisms; hydraulic structures; air-entrained concrete; multiphase model; long-term moisture conditions; pore size distribution; freezing; partially saturated; finite element method; Civil and Architectural Engineering; Byggvetenskap;

    Sammanfattning : The durability of concrete is of major concern in all types of concrete structures where the combined effect of exposure conditions and the type and quality of the concrete material usually determines the rate of degradation. Furthermore, there are synergy effects between different deterioration mechanisms, which means that the combined rate of degradation is higher than the sum of the individual rates of each mechanism. LÄS MER

  3. 2. Experimental studies of ion transport in cementitious materials under partially saturated conditions

    Författare :Nilla Olsson; Avdelningen för Byggnadsmaterial; []
    Nyckelord :Cement; Bruk; Betong; Jontransport; Fukttransport; Sorptionsisoterm; Tillsatsmaterial; Kiselstoft; Masugnsslagg; Ciment; Mortier; Béton; Transport ionique; Transport d humidité; Sorption de vapeur d eau; Additions minérales; Fumée de silice; Laitier de haut fourneau granulé moulu; Cement; Mortar; Concrete; Ion transport; moisture transport; Water vapor sorption; Supplementary cementitious materials SCMs ; Silica fume; Ground granulated blast furnace slag;

    Sammanfattning : Cement production is responsible for a significant portion of manmade CO2 emissions. This motivates the development of cementitious binders with a lower carbon footprint. Considering the emissions in a longer perspective, the durability of concrete structures is absolutely essential. LÄS MER

  4. 3. Modelling of Groundwater Conditions in Silts and Fine Sands. A Study of Induced Groundwater Changes Based on Laboratory and Full-Scale Field Tests

    Författare :Marius Tremblay; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fine sand; laboratory tests; numerical simulation; silt; soil mechanics; groundwater; pore pressure; field tests; soil matric suction; partially saturated soil; groundwater conditions;

    Sammanfattning : Every day, geotechnical engineers have to deal with groundwater problems. In order to find suitable solutions to these problems, modelling of the groundwater conditions and their variations in time has to be performed. A study of the groundwater conditions in silts and fine sands was made including laboratory and full-scale field tests. LÄS MER

  5. 4. Infrared spectroscopy of O2 and N2 adsorption on the clean and hydrogen covered Pt(111) surface

    Författare :Kristian Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Infrared Spectroscopy; Adsorption; Hydrogen; Nitrogen; Pt 111 ; Oxygen;

    Sammanfattning : This thesis is devoted to the investigation of O2and N2 adsorption on the clean and the hydrogen covered Pt(111) surface. Using infrared reflection absorption spectroscopy (IRAS) both physisorbed and chemisorbed molecular adsorptionstates have been identified and characterized via theircharacteristic internal vibration spectra. LÄS MER

  7. 5. Secondary chlorophyll a luminescence decay kinetics from green algae and higher plants : mechanisms and application

    Författare :Lars-Göran Sundblad; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; luminescence; fluorescence; photosynthesis; far red; CO2 accumulation; S-states; QA; reverse coupling; qE; frost hardiness;

    Sammanfattning : Barley protoplasts were shown to be a suitable experimental system for studies on the relative maximum during the decay of luminescence observed in most photosynthetic systems after excitation with far red light and in the presence of O2. The far red induced relative luminescencemaximum was shown to be a result of three coinciding events:*Randomization of the S-states of the water splitting system during illumination with far red light. LÄS MER