Sökning: "periodiska systemet"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden periodiska systemet.

  1. 1. Ultracold atoms in optical potentials : from noise-induced transport to superfluidity

    Författare :Martin Zelan; Claude Dion; Sile Nic Chormaic; Umeå universitet; []
    Nyckelord :Brownian motors; noise-induced transport; superfluidity; ultracold atoms; optical potentials; optical lattices; laser coooling; fysik; Physics;

    Sammanfattning : In this thesis, both experimental studies and numerical simulations of ultracold atoms in optical potentials are presented in a collection of nine scientific papers. In particular, noise-induced transport in dissipative optical lattices and superfluid properties of Bose-Einstein condensates have been studied. LÄS MER

  3. 2. A Study of the Swirling Flow Pattern when Using TurboSwirl in the Casting Process

    Författare :Haitong Bai; Mikael Ersson; Pär Jönsson; Yogeshwar Sahai; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow pattern; swirling flow; TurboSwirl; CFD; turbulence models; water model; flödesmönster; roterandeflöde; TurboSwirl; CFD; turbulensmodeller; vattenmodell; Metallurgical process science; Metallurgisk processvetenskap;

    Sammanfattning : The use of a swirling flow can provide a more uniform velocity distribution and a calmer filling condition according to previous studies of both ingot and continuous casting processes of steel. However, the existing swirling flow generation methods developed in last decades all have some limitations. LÄS MER

  4. 3. Studies of optical properties of lanthanide upconversion nanoparticles for emerging applications

    Författare :Qingyun Liu; Hans Ågren; Haichun Liu; Patricia Haro Gonzalez; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Upconversion nanoparticles; solar cells sensitization; near infrared photodetector; multiplex imaging; optical encoding; information technology; bioimaging; rate equation models; Theoretical Chemistry and Biology; Teoretisk kemi och biologi;

    Sammanfattning : YTTERBY, a small village very close to Stockholm where I live, is the place in the world which has lent its name to the largest number of elements in the periodic table, namely four - YTTRIUM, YTTERBIUM, ERBIUM and TERBIUM. Three more lanthanide elements were discovered from the now empty quarry located in this village. LÄS MER

  5. 4. Electron Tunneling and Field-Effect Devices in mm-Wave Circuits

    Författare :Mikael Egard; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; negative differential conductance oscillator; resonant tunneling diode; ultra-wideband; impulse radio; Wavelet generator; MOSFET; nanowire; high frequency characterization; Fysicumarkivet A:2012:Egard;

    Sammanfattning : Short high-frequency electromagnetic pulses, also referred to as wavelets, are considered for use in various short-range impulse based ultra-wideband applications, such as communication, imaging, radar, spectroscopy, and localization. This thesis investigates field-effect and tunneling based semiconductor devices and their operation in millimeter-wave (mm-wave) impulse transceivers. LÄS MER

  7. 5. On steady waves in two-layer fluids and ferrofluids

    Författare :Dag Nilsson; Partiella differentialekvationer; []
    Nyckelord :Internal waves; ferrofluids; partial differential equation; nonlinear waves; travelling waves; solitary waves; dynamical systems; Hamiltonian systems; non-local equations;

    Sammanfattning : This thesis concerns travelling waves in a two-layer fluid and on a ferrofluid jet. We prove existence of several types of such waves by reformulating the corresponding governing equation as an infinite dimensional dynamical system, where an unbounded spatial coordinate is used as time. LÄS MER