Sökning: "rocks"

Visar resultat 1 - 5 av 252 avhandlingar innehållade ordet rocks.

  1. 1. Dissolving the Rocks : Solubility Enhancement of Active Pharmaceutical Ingredients using Mesoporous Silica

    Författare :Xin Xia; Alfonso E. Garcia-Bennett; Xiaodong Zou; Göran Frenning; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; mesoporous silica; drug delivery; solubility enhancement; active pharmaceutical ingredients; oral toxicity; confinement; crystallization; pharmaceutical excipients; bioavailability; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : Poor aqueous solubility is one of the greatest barriers for new drug candidates to enter toxicology studies, let alone clinical trials. This thesis focuses on contributing to solving this problem, evaluating the oral toxicity of mesoporous silica particles, and enhancing the apparent solubility and bioavailability of active pharmaceutical ingredients in vitro and in vivo using mesoporous silica particles. LÄS MER

  2. 2. Ice, wood and rocks : regulating elements in riverine ecosystems

    Författare :Johanna Engström; Christer Nilsson; Roland Jansson; James Helfield; Tenna Riis; Umeå universitet; []
    Nyckelord :riparian zone; timber floating; river restoration; cut-off side channels; hydrochory; large wood; anchor ice; fish;

    Sammanfattning : Riparian ecosystems are of great importance in the landscape, connecting landscape elements longitudinally and laterally and often encompassing sharp environmental gradients in ecological processes and communities. They are influenced by fluvial disturbances such as flooding, erosion and sediment deposition, which create dynamic and spatially heterogeneous habitats that support a high diversity of species. LÄS MER

  3. 3. Strength and deformability of fractured rocks

    Författare :Majid Noorian-Bidgoli; Lanru Jing; John A. Hudson; KTH; []
    Nyckelord :Fractured crystalline rocks; Numerical experiments; Discrete element methods DEM ; Discrete fracture network DFN ; Representative elementary volume REV ; Coupled hydro-mechanical processes; Anisotropy; Effective stress; Failure criteria; Stochastic realizations; Mark- och vattenteknik; Land and Water Resources Engineering;

    Sammanfattning : This thesis presents a systematic numerical modeling framework to simulate the stress-deformation and coupled stress-deformation-flow processes by performing uniaxial and biaxial compressive tests on fractured rock models with considering the effects of different loading conditions, different loading directions (anisotropy), and coupled hydro-mechanical processes for evaluating strength and deformability behavior of fractured rocks. By using code UDEC of discrete element method (DEM), a series of numerical experiments were conducted on discrete fracture network models (DFN) at an established representative elementary volume (REV), based on realistic geometrical and mechanical data of fracture systems from field mapping at Sellafield, UK. LÄS MER

  4. 4. Stress Effects on Solute Transport in Fractured rocks

    Författare :Zhihong Zhao; Lanru Jing; Ivars Neretnieks; Auli Niemi; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Fractured rocks; Solute transport; Stress effects; Coupled stress-flow-transport processes; Analytical solution; Particle mechanics model; Fracture surface damage; Discrete element method; Particle tracking method;

    Sammanfattning : The effect of in-situ or redistributed stress on solute transport in fractured rocks is one of the major concerns for many subsurface engineering problems. However, it remains poorly understood due to the difficulties in experiments and numerical modeling. LÄS MER

  5. 5. Solute transport through fractured rocks : the influence of geological heterogeneities and stagnant water zones

    Författare :Batoul Mahmoudzadeh; Longcheng Liu; Ivars Neretnieks; David Hodgkinson; KTH; []

    Sammanfattning : To describe reactive solute transport and retardation through fractured rocks, three models are developed in the study with different focuses on the physical processes involved and different simplifications of the basic building block of the heterogeneous rock domain. The first model evaluates the effects of the heterogeneity of the rock matrix and the stagnant water zones in part of the fracture plane. LÄS MER