Sökning: "Block"

Visar resultat 16 - 20 av 1162 avhandlingar innehållade ordet Block.

1. 16. Preconditioning for block matrices with square blocks

   Författare :Ivo Dravins; Maya Neytcheva; Svetozar Margenov; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; preconditioning; block preconditioning; PDE-constrained optimization; Implicit Runge-Kutta methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Linear systems of equations appear in one way or another in almost every scientific and engineering problem. They are so ubiquitous that, in addition to solving linear problems, also non-linear problems are typically reduced to a sequence of linear ones. LÄS MER

3. 17. Mixed Block Copolymer Solutions: Self-Assembly and Interactions

   Författare :Solmaz Bayati; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polymer; Block Copolymer; PEO-PPO-PEO; Pluronics©; Bile Salt; NaGDC; PNIPAAM; PAMPTMA; PAMPS; Mixed Micelle; Self-Assembly; Mixed Complexes;

   Sammanfattning : This thesis incorporates studies on the aqueous systems of two types of thermoresponsive amphiphilic block copolymers; a series of nonionic triblock copolymers comprising blocks of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) denoted as PEO-PPO-PEO block copolymers, and a series of ionic diblock copolymers consisting of one charged block and one block of poly(N-isopropylacrylamide) (PNIPAAM). Various techniques, such as dynamic and static light scattering (DLS and SLS), small angle X-ray and neutron scattering (SAXS and SANS), high sensitivity differential scanning calorimetry (HSDSC), turbidimetry, electrophoretic mobility measurements, and two-dimensional proton NMR nuclear Overhauser effect spectroscopy (2D 1H NMR NOESY), were applied to study these block copolymer systems. LÄS MER

4. 18. On Bundle Branch Block and Acute Myocardial Infarction

   Författare :Gunnar Thor Gunnarsson; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Acute myocardial infarction; left bundle branch block; right bundle branch block; diagnosis; prognosis; continuous vectorcardiography;

   Sammanfattning : Studies from the pre-thrombolytic era showed that patients with bundle branch block suffering acute myocardial infarction had worse prognosis compared to patients without bundle branch block. It seems that this difference still exists in the thrombolytic era, at least for short-term mortality. LÄS MER

5. 19. Enhanced block sparse signal recovery and bayesian hierarchical models with applications

   Författare :Jianfeng Wang; Jun Yu; Anders Garpebring; Jia Li; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetic resonance imaging; Bayesian hierarchical models; Weather Research and Forecasting; Compressive sensing; Block sparsity; Multivariate isotropic symmetric a-stable distribution; q-ratio block constrained minimal singular value;

   Sammanfattning : This thesis is carried out within two projects ‘Statistical modelling and intelligentdata sampling in Magnetic resonance imaging (MRI) and positron-emission tomography(PET) measurements for cancer therapy assessment’ and ‘WindCoE -Nordic Wind Energy Center’ during my PhD study. It mainly focuses on applicationsof Bayesian hierarchical models (BHMs) and theoretical developments ofcompressive sensing (CS). LÄS MER

7. 20. Ternary Block Copolymer Systems - Phase Behaviour and Phase Structure

   Författare :Birgitta Svensson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; lyotropic; thermotropic; SANS; SAXS; scattering; semicrystalline; reverse micelle; micellar solution; liquid crystalline; phase diagram; phase behaviour; block copolymer; pluronic; poly ethylene oxide ; poly propylene oxide ; quantum chemistry; Teoretisk kemi; kvantkemi;

   Sammanfattning : Ternary isothermal (25°C) polyoxyalkylene triblock block copolymer ((EO)x(PO)y(EO)x where x is the number of ethylene oxide, EO, segments and y is the number of propylene oxide, PO, segments) systems with water and p-xylene as selective solvents for the PEO and PPO blocks, respectively, were chosen as study systems in this thesis as these ternary systems are good model systems for the self-assembly of block copolymers. The phase behaviour has been studied at varied block copolymer molecular weight and relative PEO/PPO block ratio. LÄS MER