Sökning: "electric resistance"

Visar resultat 21 - 25 av 108 avhandlingar innehållade orden electric resistance.

  1. 21. Run-Up Transient Analysis for Salient Pole Wound Field Synchronous Motors : Field winding and power electronics implications for a smoother and cooler asynchronous start

    Författare :Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Nyckelord :apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency; asynchronous start; run-up; torque ripple; reluctance torque; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Salient Pole Wound Field Synchronous Machines have better efficiency at full load than asynchronous machines of the same capability. Moreover, where asynchronous machines need inherently to draw a magnetizing current from the grid, Salient Pole Wound Field Synchronous Machines can work efficiently at unity power factor. LÄS MER

  3. 22. Distributions Of Fiber Characteristics As A Tool To Evaluate Mechanical Pulps

    Författare :Sofia Reyier Österling; Per Engstrand; Hans Höglund; Olof Ferritsius; Rita Ferritsius; Hans Ersson; Per Gradin; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fiber; fibre; fiber characteristics; fiber dimension; fiber properties; mechanical pulp; FiberLab; raw data; distribution; fiber wall thickness; BIN; bonding ability influence; bonding indicator; bonding ability; fiber width; fibrillation; collapse resistance; laboratory sheet; fiber analyzer; optical analyzer; TMP; CTMP; SGW; sheet model; prediction; fiber characterization; hydrocyclone; fractionation; kernel density estimation; KDE; diffusion mixing; acoustic emission; F0.90; Norway spruce; Picea abies;

    Sammanfattning : Mechanical pulps are used in paper products such as magazine or news grade printing papers or paperboard. Mechanical pulping gives a high yield; nearly everything in the tree except the bark is used in the paper. This means that mechanical pulping consumes much less wood than chemical pulping, especially to produce a unit area of printing surface. LÄS MER

  4. 23. Filtration of Cellulosic material - the impact of ionic strength and electric field

    Författare :Anna Lidén; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electro-assisted; microfibrillated cellulose; ionic strength; microcrystalline cellulose; dead-end filtration;

    Sammanfattning : It is crucial that dewatering technology is considered if an economically feasible production of cellulosic materials is to be achieved. Cellulosic materials are often produced in dilute streams and therefore require great amounts of water to be removed to allow for reasonable transportation costs and/or further modifications. LÄS MER

  5. 24. Filtration of Microcrystalline and Microfibrillated Cellulose: The impact of ions and electric field

    Författare :Anna Hjorth; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microfibrillated cellulose; microcrystalline cellulose; ions; filtration; electro-assisted;

    Sammanfattning : Dewatering plays an essential role in the processing of microcrystalline cellulose (MCC) and microfibrillated cellulose (MFC), as their commercial attractiveness in many applications is limited by the high water content of the products. Filtration is the most common mechanical dewatering technique, but the filtration of these materials results in filter cakes with high filtration resistance. LÄS MER

  7. 25. Characterising Resistance to Electrical Treeing in New XLPE-Based Materials for High-Voltage Cables

    Författare :Anette Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electrical treeing; partial discharge; cross-linked polyethylene; voltage stabiliser; degradation; power cables;

    Sammanfattning : This work looks into electrical treeing in cross-linked polyethylene-based materials (XLPE), where the ability to resist tree development is considered as an indicator of improved applicability for insulation in high voltage power cables. The thesis presents results of a twin PhD project involving joint work of two students. LÄS MER