Sökning: "power density"

Visar resultat 36 - 40 av 638 avhandlingar innehållade orden power density.

  1. 36. Multiple Aspects of Dynamic Rating in the Power System

    Författare :Seyede Fatemeh Hajeforosh; Math Bollen; Sarah Rönnberg; Alfredo Vaccaro; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic rating; Transmission lines; Overload Protection; Stochastic analysis; Hosting capacity; Transformers; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Increased consumption and increased use of renewable energy make overhead lines and transformers more often congested. Dynamic rating (DR) uses a time-depending maximum permissible current instead of a long-term-fixed rating; it is an effective solution to upgrade the capacity of existing grid assets to minimize this congestion. LÄS MER

  3. 37. Water-Metal Surfaces : Insights from core-level spectroscopy and density functional theory

    Författare :Theanne Schiros; Anders Nilsson; John Hemminger; Stockholms universitet; []
    Nyckelord :water; hydroxyl; metal; surfaces; x-ray spectroscopy; density functional theory; bonding; fuel cell; kemisk fysik; Chemical Physics;

    Sammanfattning : Computational methods are combined with synchrotron-based techniques to analyze the structure and bonding of water and water plus hydroxyl at metal surfaces under UHV and at near-ambient conditions. Water-metal interaction plays a crucial role in a multitude of cosmic, atmospheric and biological phenomena as well as heterogeneous catalysis, electrochemistry and corrosion. LÄS MER

  4. 38. Quantization and Noise-Shaped Coding for High Efficiency Transmitter Architectures

    Författare :Ulf Gustavsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Software Defined Radio; Quantization; damped Gauss-Newton; Pulse Density Modulation; Noise-Shaped Coding; ΣΔ-Modulators; Power Amplifier;

    Sammanfattning : Three driving parameters in the development of transmitter technologies for wireless communication today is: energy efficiency, flexibility and footprint reduction. This thesis investigates the use of 1-bit oversampled signal representation, mainly as a power efficiency enhancement technique for the transmitter, but also as a path toward reduced footprint and increased flexibility. LÄS MER

  5. 39. Low Power Wireless Technologies for IIoT : Analysis and enhancement of communication delay, reliability and scalability

    Författare :Raúl Rondón; Mikael Gidlund; Fortunato Santucci; Mittuniversitetet; []
    Nyckelord :;

    Sammanfattning : In recent years, the implementation of wireless communication systems in industrial environments has significantly increased. As a result, new applications such as Industrial Internet-of-Things (IIoT) have arisen, reshaping the future of industrial automation. LÄS MER

  7. 40. Thermally Conductive High-Density Polyethylene Composites for Ground Heat Exchangers

    Författare :Adib Kalantar Mehrjerdi; Högskolan i Borås; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-density polyethylene; talc; thermal conductivity; thermal diffusivity; thermal stability; melt rheology; oxidation induction time; α relaxation; strain hardening;

    Sammanfattning : Today, the energy used for the heating and cooling of offices, shopping centres, schools, residential areas, andother buildings is as large as 50% of the total energy consumption in the world. The climate change, globalwarming, and environmental issues have forced high requirements for energy efficiency and clean energyproduction in buildings. LÄS MER