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Visar resultat 26 - 30 av 66 avhandlingar som matchar ovanstående sökkriterier.

1. 26. Maximum a posteriori deconvulution of ultrasonic data with applications in nondestructive testing : Multiple transducer and robustness is

   Författare :Tomas Olofsson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Ultrasonic pulse-echo testing; nondestructive testing; maximum a posteriori estimation; linear minimum mean squared error estimation; robust filtering; multivariable filtering; sparse deconvolution; Materialvetenskap; Materials science; Teknisk materialvetenskap; Signal Processing; signalbehandling;

   Sammanfattning : In the thesis, various aspects of deconvolution of ultrasonic pulse-echo signals in nondestructive testing are treated. The deconvolution problem is formulated as estimation of a reflection sequence which is the impulse characteristic of the inspected object and the estimation is performed using either maximum a posteriori (MAP) or linear minimum mean square error (MMSE) estimators. LÄS MER

3. 27. Interactions between polymers and the environment

   Författare :Nazanin Alipour; Mikael S. Hedenqvist; Antal Boldizar; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deltamethrin; piperonyl butoxide; polyethylene; migration; multilayer film; EVOH; n-hexane; crystallization; mechanical properties; X-ray scattering; swelling; larvae; protein; lipid; moisture sorption; release; nanoclay; polypropylene; degradation; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : This dissertation addresses the structure and properties of a number of polymer-based materials when they come into contact with specific environments. The first part describes the migration and depletion of active substances from insecticide-impregnated polyethylene sheets in water and air at different humidity levels and higher temperatures. LÄS MER

4. 28. Coronal restoration in root-filled and non root-filled teeth : studies on periapical status, tooth survival, subsequent treatments and treatment decisions

   Författare :Victoria Dawson; Malmö universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Endodontics; Coronal restoration; Indirect restoration; Direct restoration; Root canal treatment; Decision process; Apical periodontitis; Qualitative Content Analysis;

   Sammanfattning : The overall aim of this thesis was to study the following aspects ofdirect and indirect coronal restoration, primarily of root-filled teeth, withspecial reference to:• periapical health• the natural course of root-filled teeth, particularly furtherclinical intervention• the dentist´s decision-making process for root-filled teeth.The aims of coronal restoration are to restore the function and aestheticsof the tooth, with a tight marginal seal as protection from microbialleakage. LÄS MER

5. 29. Adolescent mental health : time trends and validity of self-report measures

   Författare :Ida Blomqvist; Eva Henje; Inga Dennhag; Anne Hammarström; Lotte Haverman; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Adolescent; classical test theory; computer adaptive testing; cross-sectional; differential item functioning; graded response model; item banks; item response theory; measurement invariance; mental health; Patient-Reported Outcomes Measurement Information System; Reynolds Adolescent Depression Scale second edition; self-report measures; time trends; barn- och ungdomspsykiatri; Child and Youth Psychiatry;

   Sammanfattning : Background: Studies of time trends of adolescent self-reported mental health suggest an increase of mental health symptoms globally. Unfortunately, several studies within the field have methodological problems, such as short time-period between measurements and different mental health measures over time. LÄS MER

7. 30. Unveiling the nature of blue compact galaxies

   Författare :Genoveva Micheva; Göran Östlin; Evan Skillman; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; blue compact galaxies; starbursts; host galaxy; stellar populations; surface photometry; optical and NIR broadband; Astronomy; astronomi;

   Sammanfattning : Blue compact galaxies (BCGs) are gas-rich star-forming low redshift galaxies with low metallicities. In some cases the relative strength of the starburst can be so high that it completely dominates the light output of the galaxy, an obstacle which has been countered by deeper optical imaging data and observations in the near infra-red (NIR) regime. LÄS MER