Sökning: "Lens"

Visar resultat 11 - 15 av 525 avhandlingar innehållade ordet Lens.

1. 11. Through the coding-lens : community detection and beyond

   Författare :Christopher Blöcker; Martin Rosvall; Juan Carlos Nieves; Jari Saramäki; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; community detection; map equation; Huffman coding; network centrality; link prediction;

   Sammanfattning : We live in a highly-connected world and find networks wherever we look: social networks, public transport networks, telecommunication networks, financial networks, and more. These networks can be immensely complex, comprising potentially millions or even billions of inter-connected objects. LÄS MER

3. 12. Ocular growth and lens size

   Författare :Ulla Kugelberg; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :congenital cataract; lens thickness; intraocular implants; ocular axial length; corneal diameter; infant eye; rabbit eye;

   Sammanfattning : Ocular axial length growth was investigated with special reference to the influence of crystalline lens and different intraocular lens implants, in human infants and three week-old rabbits. First it was concluded, in a retrospective study of children with bilateral congenital cataract, that lensectomy during the first months of life resulted in almost normal visual development. LÄS MER

4. 13. Ascorbate in the ocular lens

   Författare :Vino C Jr Mody; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : Purpose: First, we intended to establish a method for sample preparation for measurement of ascorbate in whole rat and guinea pig lenses utilizing ultrafiltration and high performance liquid chromatography with ultraviolet radiation detection. Then, we aimed to investigate whether, in the albino rat, lens ascorbate concentration depends on solid dietary intake. LÄS MER

5. 14. Photonic terahertz-wave generation, radiation and quasioptical integration

   Författare :Biddut Kumar Banik; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

   Sammanfattning : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. LÄS MER

7. 15. Photonic THz Generation and Quasioptical Integration for Imaging Applications

   Författare :Biddut Kumar Banik; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nondestructive evaluation; semiconductor device modelling; uni-travelling-carrier photodiodes; millimetre wave and submillimetre wave generation; III-V semiconductors; photomixers; terahertz sources.; catadioptric lens; microwave imaging; dielectric loaded antennas; terahertz imaging; lens antennas; millimetre wave and submillimetre wave imaging;

   Sammanfattning : This thesis deals with the analysis and optimisation of the uni-travelling-carrier photodiode (UTC-PD) for continuous-wave generation in terahertz (THz) frequencyrange. Photonic THz generation using UTC-PDs is extremely promising as it offers wide tunability, adequate output power and room temperature operation. LÄS MER