Sökning: "Size dependent properties"

Visar resultat 1 - 5 av 310 avhandlingar innehållade orden Size dependent properties.

1. 1. ZnO Quantum Dots : Size Dependent Optical, Vibrational and Photoelectrochemical Properties

   Författare :Jesper Jacobsson; Tomas Edvinsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ZnO; nanoparticels; quantum dots; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

   Sammanfattning : This thesis is devoted to quantum dots of ZnO in the size regime 2.5-10 nm.The focus is directed towards their size dependent properties with specialemphasis on the optical, vibrational and photocatalytic properties. The particleswere synthesized by hydrolysis in alkaline zinc acetate solution. LÄS MER

3. 2. Highly Efficient CIGS Based Devices for Solar Hydrogen Production and Size Dependent Properties of ZnO Quantum Dots

   Författare :T. Jesper Jacobsson; Tomas Edvinsson; Laurence Peter; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ZnO; Nanoparticles; Quanum Dots; Size Dependent Properties; Hematite; CIGS; Solar Water Splitting; Hydrogen Production; PEC; Photoelectrochemical cells; PV-electrolysis; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

   Sammanfattning : Materials and device concepts for renewable solar hydrogen production, and size dependent properties of ZnO quantum dots are the two main themes of this thesis.ZnO particles with diameters less than 10 nm, which are small enough for electronic quantum confinement, were synthesized by hydrolysis in alkaline zinc acetate solutions. LÄS MER

4. 3. Materials prepared using graphite oxides : properties and applications

   Författare :Artem Iakunkov; Aleksandr V. Talyzin; Josef Breu; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Graphene oxide; Activated Graphene; Swelling; Supercapacitor; Sorption of radionuclides; Materials Science; materialvetenskap; fysik; Physics;

   Sammanfattning : Graphite oxides are hydrophilic materials, which have attracted a lot of attention due to unique properties and possible applications. The current thesis includes studies of fundamental properties and applications of graphite oxides as well as materials prepared from graphite oxides such as graphene oxide membranes, defect-rich graphite oxide, reduced graphene oxide and activated reduced graphene oxide. LÄS MER

5. 4. Optimization of Electron Beam Melting for Production of Small Components in Biocompatible Titanium Grades

   Författare :Joakim Karlsson; Håkan Prof.; Mikael Bäckström; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive Manufacturing; 3D-printing; Electron Beam Melting; Titanium alloys; Chemical properties; Mechanical properties; Surface properties; Additiv tillverkning; 3D-skrivare; Electron Beam Melting; Titan; Kemiska egenskaper; Mekaniska egenskaper; Ytegenskaper; Teknisk fysik med inriktning mot materialvetenskap; Engineering Science with specialization in Materials Science;

   Sammanfattning : Additive manufacturing (AM), also called 3D-printing, are technologies where parts are formed from the bottom up by adding material layer-by-layer on top of each other. Electron Beam Melting (EBM) is an AM technique capable of manufacturing fully solid metallic parts, using a high-intensity electron beam to melt powder particles in layers to form finished components. LÄS MER

7. 5. Properties of Activated Sludge Flocs

   Författare :Britt-Marie Wilen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; floc strength; aerobic microbial activity; reflocculation; dissolved oxygen concentration; settling; deflocculation; filamentous microorganisms; shear forces; floc size; activated sludge;

   Sammanfattning : The quality of the effluent from activated sludge treatment plants is highly dependent on the efficiency of the solid-liquid separation process. The aim of this thesis was to study (i) the effects of dissolved oxygen (DO) concentration on effluent turbidity and flocculation, as well as on the settling properties of activated sludge, for both short term and long term scales, and (ii) the influence of aerobic microbial activity on the stability of activated sludge flocs. LÄS MER