Search for dissertations about: "sandsten"

Showing result 1 - 5 of 8 swedish dissertations containing the word sandsten.

2. 1. Development of infrared spectroscopy techniques for environmental monitoring

   Author : Jonas Sandsten; Atomfysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; environmental pollution measurements; infrared spectrometers; diffraction and scattering; absorption spectroscopy; remote sensing; ray tracing; image processing; Atomic and molecular physics; Atom- och molekylärfysik; Fysicumarkivet A:2000:Sandsten;

   Abstract : Infrared spectroscopy techniques have long been utilized in identifying and quantifying species of interest to us. Many of the elementary molecules in the atmosphere interact with infrared radiation through their ability to absorb and emit energy in vibrational and rotational transitions. READ MORE

4. 2. Waterfowl herbivory on submerged macrophytes in eutrophic lakes

   Author : Håkan Sandsten; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; limnology; Marinbiologi; limnologi; Hydrobiology; Växtekologi; Plant ecology; akvatisk ekologi; Djurekologi; Animal ecology; Anas; Fulica atra; Cygnus; alternative stable states; water depth; distribution; plant species composition; hydrophytes; propagule size; Herbivory; tuber; Potamogeton; marine biology; aquatic ecology;

   Abstract : Submerged macrophytes are thought to stabilize clear-water states of shallow lakes. The aim of this thesis was to elucidate how waterfowl herbivory can affect abundance, distribution and species composition of submerged macrophytes in eutrophic lakes. READ MORE

5. 3. Studies on the frost resistance of natural stone

   Author : Lubica Wessman; Avdelningen för Byggnadsmaterial; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; äldre byggnader; kalksten; laboratorieförsök; sten; granit; sandsten; natursten; frostbeständighet; beständighet;

   Abstract : This work deals with the effects of freeze-thawing on the deterioration of some types of natural stone, especially stones frequently used in old buildings in Sweden. Laboratory studies were performed mainly on Gotland sandstone. This stone has been widely used in old buildings in the whole Baltic region, and is often badly deteriorated. READ MORE

6. 4. Single fluid inclusion analysis using ToF-SIMS : Implications for ancient Earth biodiversiy and paleoenvironment studies

   Author : Sandra Siljeström; Jukka Lausmaa; Andrew Steele; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ToF-SIMS; time-of-flight secondary ion mass spectrometry; fluid inclusions; biomarkers; hopanes; steranes; early life; paleoenvironment; oil; eukaryotes; Earth sciences; Geovetenskap; geokemi; Geochemistry;

   Abstract : When and how life first emerged on the Earth is an area of intense research. Signs of the first life on Earth, including morphological fossils, are scarce and hard to interpret. An alternative approach is to study organic biomarkers, which are molecular fossils commonly considered as bona fide biosignatures. READ MORE

7. 5. Stress, Flow and Particle Transport in Rock Fractures

   Author : Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; laboratory experiments; rock fracture; coupled stress-flow-tracer test; shear displacement; fluid flow; particle transport; finite element method FEM ; particle tracking method; Navier-Stokes equation; Reynolds equation; streamline velocity dispersion.; Geoengineering; Geoteknik;

   Abstract : The fluid flow and tracer transport in a single rock fracture during shear processes has been an important issue in rock mechanics and is investigated in this thesis using Finite Element Method (FEM) and streamline particle tracking method, considering evolutions of aperture and transmissivity with shear displacement histories under different normal stresses, based on laboratory tests. The distributions of fracture aperture and its evolution during shear were calculated from the initial aperture fields, based on the laser-scanned surface roughness features of replicas of rock fracture specimens, and shear dilations measured during the coupled shear-flow-tracer tests in laboratory performed using a newly developed testing apparatus in Nagasaki University, Nagasaki, Japan. READ MORE