Sökning: "lenses"

Visar resultat 1 - 5 av 123 avhandlingar innehållade ordet lenses.


    Författare :Yakir Gagnon; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Multifocal Lens; Adaptation; Dispersion; Spherical lens; Model; Fish; Ray-trace; Longitudinal Chromatic Aberration; Longitudinal Spherical Aberration; Modulation Transfer Function; Point Spread Function; Refractive Index Gradient;

    Sammanfattning : Vision is an important source of information for many animals. The lens plays a central role in the visual pathway and hence the ecology of these animals. Fish have spherically shaped crystalline lenses that contain a gradient of refractive index. Like all refracting elements, lens performance depends on the wavelength of the refracted light. LÄS MER

  2. 2. Fish Lenses : Anatomy and Optics

    Författare :Tomasz M Kozłowski; Funktionell zoologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Plasticity; Development; Cellular structure; Lens fiber cells; Modeling; Laser Scanning; Schlieren photography; Fast Fourier Transform FFT ;

    Sammanfattning : I have investigated some of the biological regulatory mechanisms governing the development of crystalline lenses. I used fish as model animals because they possess optically interesting lenses, while the geometrical simplicity of fish lenses allows for studies that are difficult or impossible with the lenses of other animals. LÄS MER

  3. 3. On millimeter and submillimeter wave focal plane arrays implemented with MEMS waveguide switches

    Författare :Henrik Frid; Joachim Oberhammer; Vessen Vassilev; Mikro- och nanosystemteknik KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Extended Hemispherical Lens; Beam Steering; Focal Plane Array FPA ; Ray-Tracing; RF MEMS; waveguide switch; micromachined waveguide; submillimeter-wave; rectangular waveguide; terahertz; lenses; antenna theory; silicon; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis presents research towards enabling micromachined millimeter and submillimeter wave focal plane arrays (FPAs). The FPAs operate under the following principle: a switch network consisting of microelectromechanical (MEMS) switches, integrated with micromachined waveguides, is used to feed an array of antenna elements, located in the focal plane of a high-gain quasi-optical system. LÄS MER

  4. 4. How visual ergonomics interventions influence health and performance - with an emphasis on non-computer work tasks

    Författare :Hillevi Hemphälä; Ergonomi och aerosolteknologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light; eye; eyestrain; vision; illuminance; spectacles; glasses; lenses; surgery; postal workers; operating theatres; sorting; post; mail; recycling; recycling facilities;

    Sammanfattning : Visual ergonomics evaluations and interventions were performed on non-computer work tasks at recycling facilities, post sorting facilities and operating theatres. The results can to some extent be applicable to other professions and workplaces. LÄS MER

  5. 5. Ocular aberrations and visual quality in aspherical and multifocal contact lenses

    Författare :Anna Lindskoog Pettersson; Karolinska Institutet; Karolinska Institutet; []

    Sammanfattning : Good visual quality and precise accommodation are required to be able to focus objects at distance and near, and are essential in order to be able to perform most tasks in life. Most eyes are not ideal eyes, i.e., they have different refractive errors which distort the produced image. LÄS MER