Sökning: "Leif Abrahamsson"

Hittade 5 avhandlingar innehållade orden Leif Abrahamsson.

  1. 1. Tuning of the Excited State Properties of Ruthenium(II)-Polypyridyl Complexes

    Författare :Maria Abrahamsson; Leif Hammarström; Hans-Christian Becker; Russell Schmehl; Uppsala universitet; []
    Nyckelord :Physical chemistry; Artificial photosynthesis; Ruthenium II ; Bistridentate complexes; Excited state lifetime; Linear donor-photosenstizer-acceptor arrays; Temperature dependence; Excited state decay; Fysikalisk kemi;

    Sammanfattning : Processes where a molecule absorbs visible light and then converts the solar energy into chemical energy are important in many biological systems, such as photosynthesis and also in many technical applications e.g. photovoltaics. LÄS MER

  3. 2. Arbetsmiljö och säkerhet : Praktikgemenskaper på könade byggarbetsplatser

    Författare :Maria Johansson; Lena Abrahamsson; Leif Berglund; Björn Samuelson; Lotta Dellve; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Human Work Sciences; Arbetsvetenskap;

    Sammanfattning : Trots att många insatser genomförs är fortfarande anställda på byggarbetsplatser överrepresenterade i arbetsskadestatistiken. Avhandlingens övergripande syfte är att bidra till kunskap om varför byggarbetsplatser fortsätter att drabbas av en hög andel arbetsskador. LÄS MER

  4. 3. Numerical Techniques for Acoustic Modelling and Design of Brass Wind Instruments

    Författare :Daniel Noreland; Bertil Gustafsson; Leif Abrahamsson; Björn Sjögreen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acoustic horn; brass wind instrument; loudspeaker; optimization; hybrid method; Numerical Analysis; Numerisk analys;

    Sammanfattning : Acoustic horns are used in musical instruments and loudspeakers in order to provide an impedance match between an acoustic source and the surrounding air. The aim of this study is to develop numerical tools for the analysis and optimisation of such horns, with respect to their input impedance spectra. LÄS MER

  5. 4. High Order Symmetric Finite Difference Schemes for the Acoustic Wave Equation

    Författare :Abraham Zemui; Bertil Gustafsson; Leif Abrahamsson; Per Weinerfelt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; mass lumping; high order; finite difference method; wave equation; Numerical Analysis; Numerisk analys;

    Sammanfattning : When someone speaks, or when a piano is played, sound waves are spread through the room. Physically the propagation of sound is governed by the acoustic wave equation. This thesis deals with the problem of finding solutions to this equation by numerical methods. LÄS MER

  7. 5. Estimation of Machining System Dynamic Properties - Measurement and Modelling

    Författare :Tomas Österlind; Andreas Archenti; Mihai Nicolescu; Leif Kari; Amir Rashid; Thomas Abrahamsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machining system; Operational dynamic parameters; Displacement map; Contactless excitation and response system; SRA - Production; SRA - Produktion; Production Engineering; Industriell produktion;

    Sammanfattning : Dynamic characteristics of machining systems are analysed for improved understanding of both structural and process properties. The thesis stresses the use of testing methods under operational like conditions as these are more representative of closed loop systems, such as machining systems, as compared to conventional testing methods. LÄS MER