Sökning: "Björn Palm"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden Björn Palm.

  1. 1. Studien über Konstruktionstypen und Entwicklungswege des Embryosackes der Angiospermen

    Författare :Björn Palm; Stockholms högskola; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 2. The influence of national curricula and national assessments on teachers’ beliefs about the goals of school mathematics

    Författare :Björn Palmberg; Torulf Palm; Ole Björkqvist; Umeå universitet; []
    Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; mathematical competence; competency goals; policy; reform; national curriculum; national assessment; teachers’ goals; teachers’ belief change; didactics of mathematics; matematikdidaktik;

    Sammanfattning : What students should learn in school and therefore also what teachers should teach is an important issue worldwide. Mathematics teaching (and teaching in other subjects) is often regulated by some form of governing text in a written curriculum communcating a set of standards. LÄS MER

  4. 3. Magnetic Refrigeration for Near Room-Temperature Applications

    Författare :Behzad A Monfared; Björn Palm; Joachim Claesson; Andrew Rowe; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic Refrigeration; Magnetic; Cooling; Magnetocaloric; Life Cycle Assessment; Modeling; Simulation; Optimization; Regeneration; Active Magnetic Regeneration; Bonded Regenerator; Heat Switch; Thermal Diode; Peltier; Solid-State; Prototype; Magnetisk Kylteknik; Magnetisk; Kylning; Magnetokalorisk; Livscykela-nalys; Modellering; Simulering; Optimering; Regenerering; Aktiv Mag-netisk Regenerering; Bunden Regenerator; Värmebrytare; Termodiod; Peltier; Solid-State; Prototyp; Energy Technology; Energiteknik;

    Sammanfattning : Refrigeration plays a crucial role in many different sectors and consumes about 17% of the electricity produced globally. This significant energy consumption implies large share of refrigeration in primary energy consumption and other environmental impacts. LÄS MER

  5. 4. Distributed thermal response tests : New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes

    Författare :José Acuña; Björn Palm; Jeffrey Spitler; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Borehole heat exchangers; Distributed Thermal Response Test; Ground Source Heat Pumps; Coaxial; U-pipe; Multi-pipe; Pipe-in-pipe; Multi-chamber; Groundwater; Thermosyphon; SRA - Energy; SRA - Energi;

    Sammanfattning : U-pipe Borehole Heat Exchangers (BHE) are widely used today in ground source heating and cooling systems in spite of their less than optimal performance. This thesis provides a better understanding on the function of U-pipe BHEs and Investigates alternative methods to reduce the temperature difference between the circulating fluid and the borehole wall, including one thermosyphon and three different types of coaxial BHEs. LÄS MER

  7. 5. Improvements of U-pipe Borehole Heat Exchangers

    Författare :José Acuña; Björn Palm; Signhild Gehlin; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Borehole Heat Exchanger; Distributed Thermal Response Test; Ground Source Heat Pumps; Environmental engineering; Miljöteknik; Earth sciences; Geovetenskap; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

    Sammanfattning : The sales of Ground Source Heat Pumps in Sweden and many other countries are having a rapid growth in the last decade. Today, there are approximately 360 000 systems installed in Sweden, with a growing rate of about 30 000 installations per year. LÄS MER