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Visar resultat 1 - 5 av 162 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Structured Metallic Films for Enhanced Light Transmission and Absorption

    Författare :Reyhaneh Soltanmoradi; Min Yan; Sanshui Xiao; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : Photonic devices such as light emitters, detectors, solar cells etc. are playing increasingly important roles in modern society. Yet their structures and designs are still under constant improvement, driven mostly by advances in material science and progress in integration techniques. LÄS MER

  3. 2. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

    Författare :Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. LÄS MER

  4. 3. Relation Between Drug Exposure and Selection of Antibiotic Resistant Bacteria

    Författare :Sara K. Olofsson; Otto Cars; Dan I. Andersson; Diarmaid Hughes; George G. Zhanel; Uppsala universitet; []
    Nyckelord :Microbiology; Pharmacokinetics; Pharmacodynamics; Antibiotic resistance; Selection; Transmission; Mathematical model; Escherichia coli; Mikrobiologi;

    Sammanfattning : The worldwide increase in antibiotic resistance is a concern for public health. When the appropriate antibiotic dosage is determined, the priorities are efficacy and toxicity. The aim of this thesis was to gain knowledge about the most efficient dosing regimens in order to minimize the emergence and selection of antibiotic-resistant mutants. LÄS MER

  5. 4. Dispersion Engineering : Negative Refraction and Designed Surface Plasmons in Periodic Structures

    Författare :Zhichao Ruan; Min Qiu; Henri Benisty; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photonic crystal; dispersion property; negative refraction; surface plasmon polariton; designed surface plasmon; negative index material; layer-KKR method; finite-difference time-domain method; plane wave method; subwavelength imaging; open cavity; enhanced transmission; slowing light; Photonics; Fotonik;

    Sammanfattning : The dispersion property of periodic structures is a hot research topic in the last decade. By exploiting dispersion properties, one can manipulate the propagation of electromagnetic waves, and produce effects that do not exist in conventional materials. LÄS MER

  7. 5. Layered optical networks : implications to switching and transmission

    Författare :Stefan Larsson; KTH; []
    Nyckelord :;

    Sammanfattning : With the aim of supporting and enhancing high-capacitycommunication networks, such as telephony, Internet and others,this work has investigated:· transmission gains withtime-slotted optical communication, · performance ofoptical add/drop multiplexers (OADMs) and optical crossconnects(OXCs), · OXC networks serving Internet Protocol(IP)-routers, · packet hop reductions in IP-controlledoptical networks, · a simple optical neighbour discoverymethod, · economics of complementing a client network withan optical express layer.Time-slotting was shown to enable bi-directionaltransmission at the same frequency and multiwavelengthtransmission over dispersion-shifted fibre. LÄS MER