Sökning: "material degradation"

Visar resultat 1 - 5 av 591 avhandlingar innehållade orden material degradation.

1. 1. Deterioration of Polyethylene Exposed to Chlorinated Species in Aqueous Phases : Test Methods, Antioxidants Consumption and Polymer Degradation

   Författare :Wenbin Yu; Ulf Gedde; Sahar Al-Malaika; KTH; []
   Nyckelord :Antioxidants; Polyethylene pipes; Chlorine dioxide; Degradation;

   Sammanfattning : This thesis presents a study of antioxidant depletion in water containing chlorinated species (water containing 10 ppm either Cl2 or ClO2, buffered to pH = 6.8), the degradation products in the aqueous phase, and polyethylene pipe degradation scenarios. LÄS MER

3. 2. Long-Term Tracheostomy : Outcome, Cannula care, and Material Wear

   Författare :Gunilla Björling; Unn-Britt Johansson; Claes Frostell; Agneta Markström; Bengt Midgren; Sophiahemmet Högskola; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Long-term tracheostomy; Respiratory failure; Hospital care; Tracheostomy care; Decontamination; Trachestomy tube; Material degradation; Polymeric material; Health-related quality of life; Nursing; Omvårdnad; Long-term tracheostomy; respiratory failure; hospital care; tracheostomy care; decontamination; tracheostomy tube; material degradation; polymeric material; and health-related quality of life;

   Sammanfattning : Do people with long-term tracheostomy need hospital care? Which cleaning method is most appropriate for decontamination of inner cannulae? Are tracheostomy tubes changed for rational reasons? There is clearly a lack of evidence based research in this field and the clinical guidelines available are often based on local practice. A tracheostomy is a created opening in trachea to facilitate breathing. LÄS MER

4. 3. Determination of Material Properties for Fire Modelling

   Författare :Ulf Göransson; Avdelningen för Brandteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material properties; Material degradation; Measurements; Fire test data; Byggnadsteknik; Building construction; Teknik; Technological sciences; Fire; Surface temperature; Mathematical modelling;

   Sammanfattning : Fire and flame spread are very complex phenomenon to study. Several aspects need to be considered and treated. In order to be able to do a correct analysis of the flame spread phenomenon, which is necessary to be able to predict flame spread, knowledge of material properties are needed. Material properties can be obtained in different ways. LÄS MER

5. 4. Controlling Polylactide Degradation through Stereocomplexation and Lactic Acid Based Additives

   Författare :Sofia Regnell Andersson; Minna Hakkarainen; Ann-Christine Albertsson; Marek Kowalczuk; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polylactide; stereocomplex; plasticizer; degradation; degradation products; ESI-MS;

   Sammanfattning : The successful use of degradable materials in new applications depends on our ability to control the degradation process. A number of aspects need to be evaluated including degradation rate, the onset of degradation and the nature, formation and release of degradation products. LÄS MER

7. 5. Powder degradation during powder bed fusion processing

   Författare :Ahmad Raza; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser-based powder bed fusion; Alloy 718; Powder degradation; Oxidation; Electron beam powder bed fusion; Additive manufacturing; AlSi10Mg; Residual oxygen; Spatter particles; Sublimation.;

   Sammanfattning : Powder bed fusion (PBF) techniques, including laser-based powder bed fusion (LB-PBF) and electron beam powder bed fusion (EB-PBF), are two rapidly growing additive manufacturing (AM) processes due to their ability to produce complex geometries in near-net shapes. To attain reproducibility and repeatability in PBF processes, a consistent set of powder properties is vital. LÄS MER