Sökning: "Performance limitations"

Visar resultat 11 - 15 av 628 avhandlingar innehållade orden Performance limitations.

1. 11. Analysis of Deformation of Gas Diffusion Layers and the Impact on Performance of PEM Fuel Cells

   Författare :Jiatang Wang; Värmeöverföring; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PEM fuel cell; compression ratio; assembly pressure; porosity; deformed GDL; electric resistance; transport phenomena; model; performance; analysis; OpenFOAM;

   Sammanfattning : Proton exchange membrane (PEM) fuel cells have been promoted due to significant breakthroughs in various aspects and increasing public interests. The porous features of the gas diffusion layer (GDL) and the necessary assembly processes generate localized pressure forces on the channel/shoulder structure of the bi-polar plates (BPP). LÄS MER

3. 12. The "New Negro" in the Old World: Culture and Performance in James Weldon Johnson, Jessie Fauset, and Nella Larsen

   Författare :Lena Ahlin; Engelska; []
   Nyckelord :HUMANIORA; HUMANITIES; Europe in African-American literature; English language and literature; Nella Larsen; Jessie Fauset; James Weldon Johnson; minstrelsy; whiteness; performance; cultural authenticity; New Negro; Harlem Renaissance; African Americans in Europe; Engelska språk och litteratur ;

   Sammanfattning : This thesis investigates the relationship between the “New Negro” moment of the early twentieth-century America and the Old World of Europe, as represented in James Weldon Johnson’s The Autobiography of an Ex-Colored Man (1912), Jessie Fauset’s There is Confusion (1924), and Nella Larsen’s Quicksand (1928). In the nineteenth century, Europe functioned as a symbol of freedom, education and art in the African-American literary imagination. LÄS MER

4. 13. Decentralized Control of Networked Systems : Information Asymmetries and Limitations

   Författare :Farhad Farokhi; Karl Henrik Johansson; Jeff S. Shamma; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Networked Control Systems; Decentralized Control; Limited Model Information; Transportation Systems; Sensor Scheduling;

   Sammanfattning : Designing local controllers for networked systems is challenging, because in these systems each local controller can often access only part of the overall information on system parameters and sensor measurements. Traditional control design cannot be easily applied due to the unconventional information patterns, communication network imperfections, and design procedure complexities. LÄS MER

5. 14. Orientalisk dans i Stockholm : Femininiteter, möjligheter och begränsningar

   Författare :Karin Högström; Lena Gerholm; Helena Wulff; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Middle Eastern dance; Oriental dance; belly dance; Egyptian dance; femininity; orientalism; authenticity; respectability; Ethnology; Etnologi; Ethnology; etnologi;

   Sammanfattning : The aim of the dissertation is to describe and analyze the practice and meaning of Middle Eastern dance through the study of a number of performers in Stockholm. In particular, this study emphasises the ways in which the performers seek, create and defend values such as femininity, authenticity, empowerment and respectability in and through their dancing. LÄS MER

7. 15. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

   Författare :Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power system control; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; fundamental control limitations; frequency stability; hydro power; wind power; non-minimum phase; zero dynamics; eigenvalue analysis; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With the transition towards renewable energy and the deregulation of the electricity markets, the power system is changing. Growing electricity demand and more intermittent power production increase the need for transfer capacity. Lower inertia levels due to a higher share of renewables increase the need for fast frequency reserves (FFR). LÄS MER