This paper deals with the behavior of electronic assemblies, which are loaded by the vibrations, especially in the context of computer simulations use. The main objective is to establish a procedure for determining the influence of vibration on the electronic boards and components using computer simulation; the definition of all factors affecting the accuracy of the result and evaluation of the individual influences.

The master´s thesis was focused on parametric computer simulations of the energy performance of buildings. The aim is to determine the sensitivity of the individual operating and climatic influences on the final energy demand of the building, which will be reflected in final form Et-curve. Parametric simulation for building energy efficiency is planned to use the BSim and ready climatic database for a specific location in place of the assessed building. The outcome of the evaluation of the real use of property in Et-curve using a custom application.

The thesis at hand is a collection of the publications written and co-authored by the author on the subject of fluid phase equilibria and dynamics in porous materials as studied with computational methods. The first part addresses fluid adsorption in confined mesoporous spaces with a particular focus on hysteresis phenomena. For this purpose, first the sorption mechanisms in canonical pore segments and simple interconnected pores were studied. Based on those insights, a statistical theory describing the phase equilibria in large-scale disordered pore systems was developed, yielding novel understanding of the sorption phenomena in complex mesoporous materials and promising future application for the characterization of these pore spaces. The second part of this thesis considers the mass transfer properties of hierarchical porous solids combining two different porosities. Here, the relationship between the structural biporous composition of the host material and the molecular dynamics were studied using specifically developed statistical simulations. Particularly, micro-mesoporous materials, hollow core-shell silica nanoparticles, and mixed matrix membranes were considered. For each case, comparison to experimental data led to a deeper understanding of the underlying transport processes. Each of the two chapters is preceded by a short introduction into the subject focused on presenting the concepts used in the corresponding publications.:1 Introduction 2 Adsorption in mesoporous solids 2.1 Filling dynamics of closed end nanocapillaries 2.2 Modeling the influence of side stream and ink bottle structures on adsorp- tion/desorption dynamics of fluids in long pores 2.3 Phase transitions in disordered mesoporous solids 3 Diffusion in hierarchical biporous materials 3.1 Mesopore-promoted transport in microporous materials 3.2 Transport properties of hierarchical micro-mesoporous materials 3.3 Diffusion and molecular exchange in hollow core-shell silica nanoparticles 3.4 An untrodden path: Versatile fabrication of self-supporting polymer- stabilized percolation membranes (PSPMs) for gas separation 3.5 Short-time diffusion behavior of Brownian particles in confining potentials Bibliography Author contributions Acknowledgements / Vorliegende Dissertation ist eine Sammlung der vom Autor verfassten und mitverfassten Publikationen über fluide Phasengleichgewichte und Fluiddynamik in porösen Materialien, untersucht mit Hilfe von computergestützten Methoden. Der erste Teil handelt von Flüssigkeitsadsorption in mesoporösen Porenräumen mit Schwerpunkt Hysteresephänomene. Dabei wurden zuerst Sorptionsmechanismen in kanonischen Porensegmenten und einfachen zusammengesetzten Porenmodellen untersucht. Aufbauend auf diese Erkenntnisse wurde dann eine statistische Theorie entwickelt, welche es ermöglicht, Phasengleichgewichte in komplexen ungeordneten Porenräumen zu beschreiben. Die entwickelte Methode erlaubt ein erweitertes Verständnis über Sorptionsphänomene in komplexen mesoporösen Materialien und die Anwendung in der Charakterisierung dieser Porenräume erscheint aussichtsreich. Der zweite Teil der Dissertation beschäftigt sich mit den Gastransporteigenschaften von hierarchischen, aus zwei Porösitäten zusammengesetzten Festkörpern. Dabei stand vor allem der Zusammenhang zwischen der biporösen Komposition des Materials und der Moleküldynamik im Vordergrund, untersucht unter Zuhilfenahme eigens entwickelter statistischer Simulationen. Betrachtet wurden insbesondere mikro-mesoporöse Materialien, hohle Siliziumdioxid-Nanopartikel und Membranen mit gemischter Matrix. Tiefergehendes Verständnis über die zugrundeliegenden Gastransportprozesse wurde im Vergleich mit experimentellen Ergebnissen erreicht. Beide Kapitel werden durch eine kurze Einführung in die jeweilige Thematik und die den nachfolgenden Publikationen zugrundeliegenden Konzepten ergänzt.:1 Introduction 2 Adsorption in mesoporous solids 2.1 Filling dynamics of closed end nanocapillaries 2.2 Modeling the influence of side stream and ink bottle structures on adsorp- tion/desorption dynamics of fluids in long pores 2.3 Phase transitions in disordered mesoporous solids 3 Diffusion in hierarchical biporous materials 3.1 Mesopore-promoted transport in microporous materials 3.2 Transport properties of hierarchical micro-mesoporous materials 3.3 Diffusion and molecular exchange in hollow core-shell silica nanoparticles 3.4 An untrodden path: Versatile fabrication of self-supporting polymer- stabilized percolation membranes (PSPMs) for gas separation 3.5 Short-time diffusion behavior of Brownian particles in confining potentials Bibliography Author contributions Acknowledgements

The purpose of this study is to observe what modifying the surface of cellulose nanofibrils may imply for their interactions with a surrounding saline aqueous solution. This will be studied by using GROMACS, a molecular dynamic simulation software. In particular, we will analyse the modified surfaces hydrophilicity compared to native nanocellulose. This will subsequently have an impact on the nanofibrils readiness to aggregate to one another and disperse in the solution. Specifically two types of surface modifications will be studied, sulfonation and carboxy- lation. The hydrophilicity of the surfaces will be determined by analysing the density profiles of the systems wherein the modified surfaces interacts with the aqueous solutions. Also, the energies from the interactions of the simulated systems will be studied. We concluded that both modifications increases the surfaces interactions with the sur- rounding solution. Modifying the surface of the cellulose nanofibril with sulfonate will increase the surfaces attraction towards water and may provide the best rate of dispersion in aqueous solutions and best prohibit aggregation. Carboxylation of the surface provides similar hydrophilic results as the sulfonation but not as prevalent.

A small report on modelling an electrolyte flow-battery using the software COMSOL.

Cellular biophysics deals with, among other things, transport processes within cells. This thesis presents two studies where mathematical models have been used to explain how two of these processes occur. Cellular membranes separate cells from their exterior environment and also divide a cell into several subcellular regions. Since the 1970s lateral diffusion in these membranes has been studied, one the most important experimental techniques in these studies is fluorescence recovery after photobleach (FRAP). A mathematical model developed in this thesis describes how dopamine 1 receptors (D1R) diffuse in a neuronal dendritic membrane. Analytical and numerical methods have been used to solve the partial differential equations that are expressed in the model. The choice of method depends mostly on the complexity of the geometry in the model. Calcium ions (Ca2+) are known to be involved in several intracellular signaling mechanisms. One interesting concept within this field is a signaling microdomain where the inositol 1,4,5-triphosphate receptor (IP3R) in the endoplasmic reticulum (ER) membrane physically interacts with plasma membrane proteins. This microdomain has been shown to cause the intracellular Ca2+ level to oscillate. The second model in this thesis describes a signaling network involving both ER membrane bound and plasma membrane Ca2+ channels and pumps, among them store-operated Ca2+ (SOC) channels. A MATLAB® toolbox was developed to implement the signaling networks and simulate its properties. This model was also implemented using Virtual cell. The results show a high resemblance between the mathematical model and FRAP data in the D1R study. The model shows a distinct difference in recovery characteristics of simulated FRAP experiments on whole dendrites and dendritic spines, due to differences in geometry. The model can also explain trapping of D1R in dendritic spines. The results of the Ca2+ signaling model show that stimulation of IP3R can cause Ca2+ oscillations in the same frequency range as has been seen in experiments. The removing of SOC channels from the model can alter the characteristics as well as qualitative appearance of Ca2+ oscillations. / Cellulär biofysik behandlar bland annat transportprocesser i celler. I denna avhandling presenteras två studier där matematiska modeller har använts för att förklara hur två av dess processer uppkommer. Cellmembran separerar celler från deras yttre miljö och delar även upp en cell i flera subcellulära regioner. Sedan 1970-talet har lateral diffusion i dessa membran studerats, en av de viktigaste experimentella metoderna i dessa studier är fluorescence recovery after photobleach (FRAP). En matematisk modell utvecklad i denna avhandling beskriver hur dopamin 1-receptorer (D1R) diffunderar i en neural dendrits membran. Analytiska och numeriska metoder har använts för att lösa de partiella differentialekvationer som uttrycks i modellen. Valet av metod beror främst på komplexiteten hos geometrin i modellen. Kalciumjoner (Ca2+) är kända för att ingå i flera intracellulära signalmekanismer. Ett intressant koncept inom detta fält är en signalerande mikrodomän där inositol 1,4,5-trifosfatreceptorn (IP3R) i endoplasmatiska nätverksmembranet (ER-membranet) fysiskt interagerar med proteiner i plasmamembranet. Denna mikrodomän har visats vara orsak till oscillationer i den intracellulära Ca2+-nivån. Den andra modellen i denna avhandling beskriver ett signalerande nätverk där både Ca2+-kanaler och pumpar bundna i ER-membranet och i plasmamembranet, däribland store-operated Ca2+(SOC)-kanaler, ingår. Ett MATLAB®-verktyg utvecklades för att implementera signalnätverket och simulera dess egenskaper. Denna modell implementerades även i Virtual cell. Resultaten visar en stark likhet mellan den matematiska modellen och FRAP-datat i D1R-studien. Modellen visar en distinkt skillnad i återhämtningsegenskaper hos simulerade FRAP-experiment på hela dendriter och dendritiska spines, beroende på skillnader i geometri. Modellen kan även förklara infångning av D1R i dendritiska spines. Resultaten från Ca2+-signaleringmodellen visar att stimulering av IP3R kan orsaka Ca2+-oscillationer inom samma frekvensområde som tidigare setts i experiment. Att ta bort SOC-kanaler från modellen kan ändra karaktär hos, såväl som den kvalitativa uppkomsten av Ca2+-oscillationer. / QC 20101111

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Many experiments demonstrate that the effects of hydrogen solutes decrease macroscopic fracture stresses and strains in ductile materials. Hydrogen-related failures have occurred in nearly all industries involving hydrogen-producing environments. The financial losses incurred from those failures reaches millions if not billions of dollars annually. With the ever-urgent needs for alternative energy sources, there is a strong push for a hydrogen economy from government and private sectors. Safe storage and transportation of hydrogen increases the momentum for studying hydrogen-related failures, especially in ductile materials. To quantify ductile material damage with the effects of hydrogen embrittlement, it is necessary to add hydrogen effects into the void nucleation, void growth, and void coalescence equations. In this research, hydrogen-enhanced void nucleation is our focus, with hydrogen-enhanced void growth and void coalescence t be studied in the future. Molecular Dynamic (MD) and Monte Carlo (MC) simulations with Embedded Atom Method (EAM) potentials were performed to study how hydrogen affects dislocation nucleation, dislocation structure formation and nanovoid nucleation at nickel grain boundaries. The results were inserted into the continuum void nucleation model by Horstemeyer and Gokhale, and the relationships between stress triaxiality-driven void nucleation, grain boundary hydrogen concentrations and local grain geometries were extracted. MD and MC simulations with EAM potentials were also performed to study how hydrogen interstitials affect the dislocation nucleation, dislocation structure formation and subsequent anovoid nucleation of single crystal nickel in different hydrogen-charging conditions. Evolutions of dislocation structures of nickel single crystal with different hydrogen concentrations were compared. The effects of nanovoid nucleation stress and strain at different hydrogen concentrations were quantified. The results were also inserted into the Horstemeyer and Gokhale model and the relationship between stress triaxiality-driven void nucleation and hydrogen concentration caused by stress gradient, which showed similar trends as the grain boundary studies. From nanoscale studies and existing experimental observations, a continuum void nucleation model with hydrogen effects was proposed and used in a continuum damage model based upon Bammann and coworkers. The damage model was implemented into user material code in FEA code ABAQUS. Finite element analyses were performed and the results were compared to the experimental data by Kwon and Asaro.

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