Sökning: "natural experiments"

Visar resultat 21 - 25 av 3117 avhandlingar innehållade orden natural experiments.

  1. 21. Static and time-dependent mechanical behaviour of preserved archaeological wood : Case studies of the seventeenth century warship Vasa

    Författare :Alexey Vorobyev; Kristofer Gamstedt; Eiichi Obataya; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; archaeological wood; compression test; cubic samples; elastic constants; oak wood; barrelling formation; quasi-static loading; resonant ultrasound spectroscopy RUS ; Vasa ship; creep; 3D laser scanning; Time-dependent behaviour;

    Sammanfattning : Wooden objects have been widely used in the history of humanity and play an important role in our cultural heritage. The preservation of such objects is of great importance and can be a challenging task. This thesis investigates the static and time-dependent mechanical behaviour of archaeological oak wood from the Vasa warship. LÄS MER

  3. 22. The Invisible Tools of a Timber Framer - A survey of principles, situations and procedures for marking

    Författare :Ulrik Hjort Lassen; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; timber framing; marking; procedures; procedural description; scribing; craft skills; craft research; working methods; layout; developed drawing; compound joinery; invisible tools; practice-led;

    Sammanfattning : My thesis focuses on the marking procedures when building timber frames, from the idea of a construction to the cutting of the timbers. The marking procedures are essential parts of the building process, and without markings you don’t know where to cut. LÄS MER

  4. 23. Dynamic glucose enhanced chemical exchange saturation transfer MRI : Optimization of methodology and characterization of cerebral transport kinetics

    Författare :Anina Seidemo; Lund Medicinsk strålningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical exchange saturation transfer CEST ; Dynamic glucose enhanced DGE MRI; GlucoCEST; MRI; D-glucose; Fysicumarkivet A:2023:Seidemo;

    Sammanfattning : Dynamic glucose enhanced (DGE) chemical exchange saturation transfer (CEST) MRI is an emerging imaging technique that provides a molecular-specific type of image contrast, based on magnetic labelling of exchangeable protons. The technique enables the use of biodegradable sugars as contrast agents, and such compounds are believed to have less side effects than conventional MRI contrast agents. LÄS MER

  5. 24. Fighting flameless fires : Initiating and extinguishing self-sustainedsmoldering fires in wood pellets

    Författare :Ragni Fjellgaard Mikalsen; Vidar Frette; Bjarne C. Hagen; Ulrich Krause; Anne Steen-Hansen; Ulrich Krause; Nieves Fernandez-Anez; RISE; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fuel storage safety; Industrial fire; Biofuels; Smoldering; Extinguishment; Fire suppression; Fire growth; Fire spread; Heat transfer; Nonlinear dynamics; Complex systems; Combustion; Biomass energy; Synchronization; Oscillations; EMRIS;

    Sammanfattning : Smoldering fires represent domestic, environmental and industrial hazards. This flameless form of combustion is more easily initiated than flaming, and is also more persistent and difficult to extinguish. The growing demand for non-fossil fuels has increased the use of solid biofuels such as biomass. LÄS MER

  7. 25. Analyses of voice and glottographic signals in singing and speech

    Författare :Andreas Selamtzis; Sten Ternström; Paavo Alku; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; voice ; singing ; electroglottography ; clustering ; dysphonia ; sample entropy ; ; Tal- och musikkommunikation; Speech and Music Communication;

    Sammanfattning : Recent advances in machine learning and time series analysis techniques have brought new perspectives to a great number of scientific fields. This thesis contributes applications of such techniques to voice analysis, in an attempt to extract information on the vibration of the vocal folds as such, as well as on the radiated acoustic signal. LÄS MER