Sökning: "Shell theory."

Visar resultat 1 - 5 av 86 avhandlingar innehållade orden Shell theory..

1. 1. Multiconfigurational perturbation theory

   Författare :Kerstin Andersson; Karlstads universitet; []
   Nyckelord :Electron correlation; CASSCF; multiconfigurational second-order perturbation theory; CASPT2; ozone; C; N; O; F; Si; P; S; Cl; Ni; benzene; pyridine; pyrazine; pyrimidine; pyridazine; s-triazine; electric properties; excited states; spectroscopic data;

   Sammanfattning : The aim of the thesis is to analyze a method which describes the electron correlation in atoms and molecules. The method is based on Rayleigh-Schrödinger perturbation theory with a partitioning of the Hamiltonian into a fairly simple zeroth-order operator and a perturbation operator. LÄS MER

3. 2. Dynamic Equations foe Spherical and Cylindrical Shells Using Power Series Method

   Författare :Reza Okhovat; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power series.; surface differential operators; shell equations; eigenfrequency; anisotropy; Spherical shell; cylindrical shell; dynamics;

   Sammanfattning : Shells are commonly used in many branches of engineeringand have therefore beeninvestigated for a number of different types of shells.A shell can be considered as a curved plate having small thickness compared to the other geometrical dimensions as well as to the wavelengths of importance. LÄS MER

4. 3. Dynamic Equations for Spherical, Orthotropic and Piezoelectric Cylindrical Shells Using the Power Series Method

   Författare :Reza Okhovat; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shell equations; cylindrical shell; eigenfrequency.; piezoelectricity; Shells; Hamilton’s principle; surface differential operators; recursion relations; spherical shell; orthotropic; dynamics;

   Sammanfattning : Shells are commonly used in many branches of engineering, and have therefore beeninvestigated for a number of different types of shells. A shell is considered to be curved aplate with small thickness compared both to the other geometrical dimensions as well asto the wavelengths of importance. LÄS MER

5. 4. Theory and Modelling of Functional Materials

   Författare :Vancho Kocevski; Jan Rusz; Christophe Delerue; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanocrystals; graphene; alloys; density functional theory; optical properties; electronic properties; core-shell structures; semiconductors;

   Sammanfattning : The diverse field of material research has been steadily expanding with a great help from computational physics, especially in the investigation of the fundamental properties of materials. This has driven the computational physics to become one of the main branches of physics, allowing for density functional theory (DFT) to develop as one of the cornerstones of material research. LÄS MER

7. 5. Mixture Effects in Shell-and-Tube Condensers. Theory and Calculations

   Författare :Tord Karlsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shell-and-tube; heat transfer; zeotropic; condensation; mass transfer; mixture;

   Sammanfattning : Zeotropic mixtures have come into more frequent use as working fluids (refrigerants) in heat pumps and air conditioning equipment due to the phase-out of ozone-depleting substances. Substantial drop in performance for shell-side condensation in shell-and-tube condensers when replacing a pure fluid with a mixture has been reported in the literature. LÄS MER