Sökning: "natural sources"

Visar resultat 31 - 35 av 1616 avhandlingar innehållade orden natural sources.

  1. 31. Singular Fluxes in Ten and Eleven Dimensions : Sources, Singularities, Fluxes and Spam

    Författare :Johan Blåbäck; Ulf Danielsson; Niels Obers; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical Physics; Teoretisk fysik;

    Sammanfattning : The energy content of our present universe is dominated by the dark-energy, or vacuum energy, which provides accelerated cosmic expansion. Dark energy has a possible effective explanation through a positive cosmological constant. LÄS MER

  3. 32. Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in air

    Författare :Hanna Söderström; Mats Tysklind; Per-Anders Bergqvist; Jochen F. Muller; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; air pollution; alkyl-PAHs; atmosphere; bioavailability; boundary layer; diffusive sampling; emissions; integrative; membrane; monitoring; nitro-PAHs; PAHs; particles; passive samplers; PCBs; plants; PRCs; release rate; sampler design; sources; SPMDs; traffic; uptake rate; wind effect; wood burning; Miljökemi; Environmental chemistry; Miljökemi;

    Sammanfattning : Air pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. LÄS MER

  4. 33. Groundwater defluoridation by natural minerals : Understanding the process of fluoride removal from drinking water sources in Tanzania

    Författare :Vivian Kimambo; Prosun Bhattacharya; Felix Mtalo; Jyoti Prakash Maity; Jan Hoinkis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluoride removal; Groundwater; Natural minerals; Adsorption isotherms; Batch- and Column Experiments; Kinetics and thermodynamics; Drinking water quality; Sustainability; Kuondolewa kwa fluoride; Maji ya chini ya ardhi; Madini ya asili; isotherms za majaribio ya adsorbenti; Majaribio ya Kundi- na Safu; Kinetics na thermodynamics; ubora wa maji ya kunywa; Uendelevu; Fluoridavlägsnande; Grundvatten; Naturliga mineraler; Batch- och kolonnförsök; Adsorptionsisotermer; Kinetik och termodynamik; Dricksvattenkvalitet; Hållbarhet; Mark- och vattenteknik; Land and Water Resources Engineering;

    Sammanfattning : Fluoride (F-) concentration in drinking water is one of the water quality parameters in countries with high concentrations in groundwater sources. Natural minerals have shown considerable effectiveness in F- removal. LÄS MER

  5. 34. Single Photon Sources and Single Quantum System enabled Communication

    Författare :Muhammad Alley Hameedi; Mohamed Bourennane; Nicolas Brunner; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum information; quantum optics; quantum communication; single photon sources; fysik; Physics;

    Sammanfattning : Quantum information is a highly interesting and fast emerging field that involves processing information encoded into quantum systems and their subsequent use in various information tasks. The use of quantum resources such as superposition and entanglement have shown to enhance information processing capabilities beyond classical means in a number of communication, information and computation tasks. LÄS MER

  7. 35. Exploring the Universe Using Neutrinos : A Search for Point Sources in the Southern Hemisphere Using the IceCube Neutrino Observatory

    Författare :Rickard Ström; Allan Hallgren; Olga Botner; Chad Finley; Lawrence R. Sulak; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astroparticle physics; neutrino sources; neutrino telescopes; IceCube; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics;

    Sammanfattning : Neutrinos are the ideal cosmic messengers, and can be used to explore the most powerful accelerators in the Universe, in particular the mechanisms for producing and accelerating cosmic rays to incredible energies. By studying clustering of neutrino candidate events in the IceCube detector we can discover sites of hadronic acceleration. LÄS MER