Sökning: "environmentally friendly"

Visar resultat 1 - 5 av 310 avhandlingar innehållade orden environmentally friendly.

1. 1. Towards Environmentally Friendly Aero Engines

   Författare :Rickard Avellan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; geared turbofan; energy efficiency; turbofan; environmentally friendly; DDTF; aero engines; GTF; aircraft;

   Sammanfattning : Since the introduction of subsonic jet driven commercial aircraft, incremental improvements in overall efficiency has been a driving requirement as well as a selling argument for the engine industry. The historical overall efficiency improvement is the result of continuous advances in aerodynamic design, increase of overall pressure ratios, turbine inlet temperatures and propulsive efficiencies in parallel with the development of stronger and lighter materials. LÄS MER

3. 2. Characterization of dye-sensitized solar cells : Components for environmentally friendly photovoltaics

   Författare :Hanna Ellis; Anders Hagfeldt; Gerrit Boschloo; Erik Johansson; Maria Hahlin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solar cells; dye-sensitized solar cells; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

   Sammanfattning : As fossil fuels, the major source of energy used today, create the greenhouse gas carbon dioxide which causes global warming, alternative energy sources are necessary in the future. There is a need for different types of renewable energy sources such as hydropower, windpower, wave- power and photovoltaics since different parts of the world have different possibilities. LÄS MER

4. 3. Environmentally friendly utilization of biomass

   Författare :Alejandro Grimm; Emilia Björkbom; Mats Westermark; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; Kemiteknik;

   Sammanfattning : The thesis deals with various ways of utilization of biomass. Chapter 1 compares three biomass types: birch wood Betula sp., marine brown alga Fucus vesiculosus, and terrestrial moss Pleurozium schreberi, as precursors for preparation of biosorbents for removal of copper ions from diluted water solutions. Small sample doses (0. LÄS MER

5. 4. Environmentally Friendly Plasticizers for PVC : Improved Material Properties and Long-term Performance Through Plasticizer Design

   Författare :Annika Lindström; Minna Hakkaraninen; Anders Södergård; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; poly butylene adipate ; poly vinyl chloride ; plasticizers; miscibility; mechanical properties; surface segregation; migration; degradation products; Polymer chemistry; Polymerkemi;

   Sammanfattning : Linear and branched poly(butylene adipate) polyesters with number-average molecular weights ranging from 700 to 10 000 g/mol, and degrees of branching ranging from very low to hyperbranched were solution cast with PVC to study the effects of chemical structure, molecular weight, end-group functionality, and chain architecture on plasticizing efficiency and durability. Miscibility was evaluated by the existence of a single glass transition temperature and a shift of the carbonyl group absorption band. LÄS MER

7. 5. Environmentally Friendly Construction Processes Under Uncertainty : Assessment, Optimisation and Robust Decision-Making

   Författare :Kailun Feng; Weizhuo Lu; Thomas Olofsson; Geoffrey Qiping Shen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Construction processes; environmental impacts; uncertain factors; decision-making; Byggproduktion och teknik; Construction Management and Building Technology;

   Sammanfattning : The construction processes of building and civil infrastructure are broadly recognised as large contributors to the environmental degradation, which cause environmental impacts directly and indirectly by massive energy use, intensive greenhouse emissions, and significant resources consumption. The report from Royal Swedish Academy of Engineering Sciences (IVA) and the Swedish Construction Federation (Byggföretagen) shows that the total carbon dioxide equivalents emitted per year from construction processes are the same size as emissions from all of the cars in Sweden, and more than that is generated by all lorries and busses. LÄS MER