Sökning: "2004"

Visar resultat 11 - 15 av 4335 avhandlingar innehållade ordet 2004.

1. 11. Properties of molecular sieve membranes

   Författare :Charlotte Andersson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Technology; Kemisk teknologi;

   Sammanfattning : Zeolites are crystalline aluminosilicates with molecular sieving properties and are widely used in industry for catalysis, sorption and ion-exchange applications. Zeolite membranes are commercially interesting since this technology may be employed for continuous separation of molecules under severe conditions. LÄS MER

3. 12. Studies of artificial mass bias in isotopic measurements by inductively coupled plasma mass spectrometry

   Författare :Henrik Andrén; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

   Sammanfattning : Mass spectrometry, and especially inductively coupled plasma mass spectrometry (ICP-MS), suffers heavily from mass bias, or instrumental mass discrimination. The nett result of this effect is the preferential transmission, most often of heavier ions through the mass spectrometer. LÄS MER

4. 13. Constrained optimization of rotor-bearing systems by evolutionary algorithms

   Författare :Anders Angantyr; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

   Sammanfattning : In the design of mechanical components and systems, nature has often been the source of inspiration. It is easy to point out solutions in nature that are optimal in some sense. One example is the structure of the surface of a shark's skin. This is designed by nature to minimize the resistance when the shark swims in the water. LÄS MER

5. 14. Aspects of precipitation in alloy Inconel 718

   Författare :Saied Azadian; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

   Sammanfattning : A study was made of the microstructure of the Ni-base alloy Inconel 718 with emphasis on the precipitation and stability of intermetallic phases as affected by heat treatments. In addition the effect of the precipitation on selected mechanical properties namely hardness, creep notch sensitivity and hot ductlity were investigated. LÄS MER

7. 15. Efficient aggregate queries on data cubes

   Författare :Fredrik Bengtsson; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dependable Communication and Computation Systems; Kommunikations- och beräkningssystem;

   Sammanfattning : As computers are developing rapidly and become more available to the modern information society, the possibility and ability to handle large data sets in database applications increases. The demand for efficient algorithmic solutions to process huge amounts of information increases as the data sets become larger. LÄS MER