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Visar resultat 1 - 5 av 7 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Construction of Adaptive Multistep Methods for Problems with Discontinuities, Invariants, and Constraints

   Författare :Fatemeh Mohammadi; Numerisk analys; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; multistep methods; Initialization; beta-blocking; Discontinuity; Time adaptivity; Strong stability preserving; Differential algebraic equations;

   Sammanfattning : Adaptive multistep methods have been widely used to solve initial value problems. These ordinary differential equations (ODEs) may arise from semi-discretization of time-dependent partial differential equations(PDEs) or may combine with some algebraic equations to represent a differential algebraic equations (DAEs). LÄS MER

3. 2. Acetylation of Solid Wood. Wood Properties and Process Development

   Författare :Pia Larsson Brelid; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microwave heating; deformation; wood; hardness; adhesive bonding; power penetration depth; shear strength; delamination; acetylation; pH; bending strength; dielectric properties; stability;

   Sammanfattning : The influence of acetylation on selected wood properties has been determined for Scandinavian pine and spruce wood, in order to predict the behavior of acetylated wood when it is used in different applications. Only minor differences in both bending strength and the modulus of elasticity were obtained for acetylated wood when compared with unmodified wood, and can, for practical applications, be considered unaltered. LÄS MER

4. 3. Striderna i Rosenbad : Om trettio års försök att förändra Regeringskansliet

   Författare :Magnus Erlandsson; Rune Premfors; Shirin Ahlbäck Öberg; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; bureaucratic politics; political institutions; institutional change; institutional stability; public administration; government; political executive; state organisation; Political science; Statsvetenskap; Political Science; statsvetenskap;

   Sammanfattning : This dissertation examines the last thirty years of internal reforms in the Swedish Government Offices. Analysis of the evolution of personnel politics, the formation of one agency and the attempts to introduce a collective activity planning model, show that the immediate problems of the early 1970’s – an over dimensioned staff, territory battles and unclear division of responsibility for personnel and organisation – remains to this day, notwithstanding the many reforms to approach them. LÄS MER

5. 4. Selective conversion of alcohols to aldehydes over metal oxide catalysts

   Författare :Mariano Massa; Avdelningen för kemiteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Nowadays, transition metal oxide catalysts are employed to a large extent in many chemical processes for the selective production of chemicals and intermediates. Although metal oxides are mostly known as oxidation catalysts, they can successfully catalyze a wide range of reactions, such as dehydration. LÄS MER

7. 5. Engineering of lignin in wood towards functional materials

   Författare :Gabriella G. Mastantuoni; Qi Zhou; Lars Berglund; Jean-Marie Raquez; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose; wood; nanotechnology; sulfonation; biocomposite; cross-linking; densification; transparent film; wood foam; conductivity; Cellulosa; trä; nanoteknologi; sulfonering; biokomposit; tvärbindning; förtätning; transparent film; poröst trämaterial; konduktivitet; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Through 270 million years of evolution, the finely tuned hierarchical structure of wood has been optimized for efficient nutrient transport and exceptional mechanical stability. Its distinctive orthotropic constitution can provide inspiration and design opportunities for the development of novel functional materials. LÄS MER