Search for dissertations about: "periodic operation"

Showing result 1 - 5 of 44 swedish dissertations containing the words periodic operation.

  2. 1. On the use of periodic operation for improvning chemical processes

    Author : Lennart Vamling; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic operation; di-; ammonia; and triethanolamine production; ethylene oxide; zeolites; Mono-; yield; adiabatic packed-bed reactor; selectivity;

    Abstract : In this thesis, some methods of improving the product distribution from chemical processes are compared. The first two parts contain an experimental investigation of how the product distribution of a process is influenced by the choice of catalyst. READ MORE

  4. 2. Twist-Symmetric Periodic Structures : Properties and Applications

    Author : Oskar Zetterström; Oscar Quevedo-Teruel; Martin Norgren; Nelson Fonseca; Jorge Ruiz-Cruz; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In this thesis, periodic structures with higher symmetries symmetries are discussed. The main focus of the thesis is on twist symmetries. Importantly, the attractive properties of twist symmetries for the control of electromagnetic wave propagation are demonstrated. READ MORE

  5. 3. Periodic Structures with Higher Symmetries: Analysis and Applications

    Author : Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. READ MORE

  6. 4. Transient Phenomena in CO and Hydrocarbon Oxidation over Supported Platinum Catalysts

    Author : Per-Anders Carlsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; mean-field kinetics simulations; ignition; environmental heterogeneous catalysis; flow-reactor studies; periodic operation; extinction; low-temperature activity; transient methods; in situ spectroscopy;

    Abstract : The aim with this thesis work was to better understand transient phenomena involved in the low-temperature oxidation of CO and hydrocarbons by oxygen over typical oxidation catalysts. Supported platinum catalysts were prepared and carefully studied under transient conditions by means of flow-reactor experiments, different in situ spectroscopic (FTIR and XANES) methods in combination with mass spectrometry and mean-field kinetics simulations. READ MORE

  7. 5. Interaction of CO and methane with platinum, Low-temperature oxidation and sensor response mechanisms

    Author : Elin Becker; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CO; Low-temperature activity; XAS; In situ spectroscopy; Environmental catalysis; Support material; Periodic operation; XANES; Chemical sensors;

    Abstract : The aim of this thesis project was to increase the understanding of the mechanisms for low-temperature oxidation of carbon monoxide and methane over supported platinum catalysts. In situ spectroscopic methods together with mass spectrometry were used to study the catalysts during both steady state and transient conditions. READ MORE