Sökning: "Phase-out"

Visar resultat 21 - 25 av 40 avhandlingar innehållade ordet Phase-out.

  1. 21. Steel Beyond Coal : Socio-Technical Change and the Emergent Politics of Steel Decarbonisation

    Författare :Valentin Vogl; Miljö- och energisystem; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel; coal; climate change; decarbonisation; socio-technical transitions; sustainability;

    Sammanfattning : The steel industry is responsible for 8% of all anthropogenic greenhouse gas emissions and is the second largest user of coal after the power sector. The main emission source in steel production is the blast furnace, which converts iron ore and metallurgical coal into pig iron that is then further refined into steel. LÄS MER

  3. 22. Relativa betyg : några empiriska studier och en teoretisk genomgång i ett historiskt perspektiv

    Författare :Håkan Andersson; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Group-referenced marks; norm-referenced marks; criterion-referenced marks; marks; grades; grading; selection; employment qualifications; merits; Relativa betyg; grupprelaterade betyg; normrelaterade betyg; målrelaterade betyg; kriterierelaterade betyg; betyg; urval; anställningsmeriter; meriter;

    Sammanfattning : Denna avhandling, som i huvudsak är resultatet av ett projekt finansierat av Skolöverstyrelsen, består av fem delstudier (I-V) utförda under åren 1977-1991 samt en sammanfattande analysdel (VI). Avhandlingens syfte är att studera det unika svenska relativa betygssystemet, som infördes på försök i folkskolan i början av 1940-talet för att senare permanentas och även införas i enhets- och grundskolan samt slutligen även i gymnasiet. LÄS MER

  4. 23. Mixture Effects in Shell-and-Tube Condensers. Theory and Calculations

    Författare :Tord Karlsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shell-and-tube; heat transfer; zeotropic; condensation; mass transfer; mixture;

    Sammanfattning : Zeotropic mixtures have come into more frequent use as working fluids (refrigerants) in heat pumps and air conditioning equipment due to the phase-out of ozone-depleting substances. Substantial drop in performance for shell-side condensation in shell-and-tube condensers when replacing a pure fluid with a mixture has been reported in the literature. LÄS MER

  5. 24. Modelling the Role of Nuclear Power and Variable Renewables in Climate Change Mitigation

    Författare :Mariliis Lehtveer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; energy system model; nuclear power; multi-criteria analysis; variable renewables; climate change; optimisation;

    Sammanfattning : As the number of people on Earth and our energy needs have increased the system for providing this energy has become ever more complex and complicated and thus the need for more systematic understanding of it has grown. However, change in energy system is slow and many of the challenges that we face such as mitigating climate change need global solutions. LÄS MER

  7. 25. Coordinated Frequency Control Between Interconnected AC/DC Systems

    Författare :Danilo Obradovic; Mehrdad Ghandari; Robert Eriksson; Jonas Persson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System Dynamics; Frequency Stability; Small Signal Stability; HVDC Supplementary Power Control; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : With ambitions of reducing the environmental pollution, power systems integrate larger shares of Renewable Energy Sources (RES) to phase out conventional thermal and nuclear generators. Since RES (such as wind and solar power) are connected to the grid through power electronics devices, they do not inherently contribute to system inertia. LÄS MER