No description available.

No description available.

An AA5083 aluminium alloy sensitized in service after 40 years exposure to ground atmosphere temperature is studied. Nitric acid mass loss test (NAMLT) is used to determine the susceptibility to intergranular corrosion (IGC). The degree of sensitization in various areas through the alloy thickness was found different, which can be associated with non-homogeneous Mg distribution through the alloy plate thickness. Structure characterisation confirmed that the in-service sensitization is associated with the formation of the ' phase and a cubic Al-Mg transition phase with magnesium content between the GP zones and the '' phase at the grain boundaries. In order to simulate the in-service sensitization process and to gain insight into the sensitization mechanism, the sensitization of AA5083 alloy at relatively low temperatures, namely 70 and 100°C, is studied. For the AA5083 alloy sensitized at 70°C, although the mass loss value is below 15 mg/cm2, ' phase is observed as individual precipitates at grain boundaries. The AA5083 alloy after exposure to 100°C for 240 hours is susceptible to IGC since the ' precipitates have grown continuously at the grain boundaries. Additionally, the effect of sensitization in AA5083 alloy on stress corrosion cracking (SCC) is also investigated using constant displacement double cantilever beam (DCB) testing. It is found that the cracking length increases with the degree of sensitization. The population density of the crack branches also increases with the degree of sensitization. The metal between different small branches is known as ligament. And with high degree of sensitization, the ligaments between crack branches have become brittle. Therefore, small branches became connected to form a continuous crack with the crack propagating.

Modern synthetic chemistry is unimaginable without transition metal catalysis. Yet the often high cost, toxicity and scarcity of many transition metals is driving attempts to find sustainable alternatives. Thus, the development of catalytic processes using main-group catalysts is now of broad interest. This thesis reports the development of a facile protocol for the aluminium-catalysed hydroboration of alkynes, alkenes and polar bonds using commercially-available catalysts. The catalytic hydroboration is proposed to occur by hydroalumination followed by product release through σ-bond metathesis with pinacol borane. An alternative route to alkenyl boranes is the 1,1-carboboration of alkynes using stoichiometric B(C6F5)3. A zwitterionic intermediate in the Piers' borane-catalysed hydroboration and 1,1-carboboration of alkynes with B(C6F5)3 has been characterised and its divergent reactivity identified. This has led to the development of a B(C6F5)3 - catalysed hydroboration of alkynes using HBpin.

No description available.

No description available.

Idag finns det i Sverige fyra olika miljöcertifieringssystem. Miljöbyggnad, GreenBuilding, LEED och BREEAM. BREEAM är det som är bäst lämpat för vår studie. Rapporten kommer att undersöka om BREEAM är tillräckligt omfattande för att avgöra den verkliga energiåtgången och miljöpåverkan för aluminium-, PVC- och träfönster.  Rapporten visar att BREEAM är tillräckligt omfattande vid materialbedömningar, dock finns det en risk att man får ett sämre betyg då BREEAM vanligtvis arbetar med att göra en genomsnittlig bedömning av olika fönstermaterial. Därför kan man som individuell leverantör få ett sämre betyg än vad man kanske förtjänar. Efter jämförelse mellan de olika materialen visar det att aluminium har mest miljöpåverkan vid en primärtillverkning. Beroende på hur mycket som återvinns kan detta dock komma att ändras.

Universiẗat, Diss.--Bremen, 2007.

Thèse de doctorat : Génie des Matériaux : Villeurbanne, INSA : 2002. / Titre provenant de l'écran-titre. Bibliogr. p.151-159. Index.

Thèse doctorat : Génie des Matériaux : Villeurbanne, INSA : 2005. / Titre provenant de l'écran-titre. Bibliogr. p. [193]-202.