Sökning: "point impedance"

Visar resultat 1 - 5 av 53 avhandlingar innehållade orden point impedance.

  1. 1. Mathematical Models for Investigation of Performance, Safety, and Aging in Lithium-Ion Batteries

    Författare :Tommy Georgios Zavalis; Göran Lindbergh; Mårten Behm; Yann Bultel; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lithium-ion battery; modeling; electrochemical processes; impedance; polarization; performance; safety; aging; power optimized battery; litiumjonbatteri; modellering; elektrokemiska processer; impedans; polarisation; prestanda; säkerhet; åldring; effektoptimerat batteri;

    Sammanfattning : Rechargeable lithium-ion batteries have both the power and energy capabilities to be utilized in hybrid electric vehicles and other power demanding applications. However, there are obstacles primarily related to reliability in safety and lifetime. Additionally, there is still room for improvement in the battery performance. LÄS MER

  3. 2. Investigation of electrochemical properties and performance of stimulation/sensing electrodes for pacemaker applications

    Författare :Anna Norlin; Jinshan Pan; Dieter Scharnweber; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; pacemaker electrode; interfacial property; biomaterial; electrostimulation charge transfer mechanism; electrochemical impedance spectroscopy; transient processes; plasma electrolysis anodisation; porous niobium oxide; ruthenium oxide; nano-porous carbon; iridium oxide; titanium nitride; platinum; surface roughness; porous electrode; pacing impedance; electrode polarisation; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : People suffering from certain types of arrhythmia may benefit from the implantation of a cardiac pacemaker. Pacemakers artificially stimulate the heart by applying short electrical pulses to the cardiac tissue to restore and maintain a steady heart rhythm. By adjusting the pulse delivery rate the heart is stimulated to beat at desired pace. LÄS MER

  4. 3. Monitoring alveolar recruitment in the critically ill - Patient studies using electric impedance tomography and volume-dependent compliance

    Författare :Karin Lowhagen; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ALI; ARDS; compliance; end-expiratory lung volume; EELV; EIT; electric impedance tomography; lung recruitment; morbid obesity; PEEP; recruitment manoeuvre; regional ventilation; volume-dependent compliance;

    Sammanfattning : Background: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with a high mortality rate and poor long term outcome in terms of quality of life, for those who survive. Similarly, patients with morbid obesity are at risk for respiratory complications when subjected to anaesthesia and surgery. LÄS MER

  5. 4. Analysis, Control, and Design Optimization of Engineering Mechanics Systems

    Författare :Esubalewe Lakie Yedeg; Martin Berggren; Eddie Wadbro; Anton Evgrafov; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topology optimization; Helmholtz equation; acoustic impedance; anisotropic filter; thin structures; finite element method; Nitsche-type method; interface problem; Optimal control; adjoint method; business data processing; administrativ databehandling;

    Sammanfattning : This thesis considers applications of gradient-based optimization algorithms to the design and control of some mechanics systems. The material distribution approach to topology optimization is applied to design two different acoustic devices, a reactive muffler and an acoustic horn, and optimization is used to control a ball pitching robot. LÄS MER

  7. 5. Vibration exposure of the glabrous skin of the human hand

    Författare :Ronnie Lundström; Ludwik Liszka; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Vibration; hand; skin; mechanical impedance; mechanoreceptors; tactile perception; high-frequency;

    Sammanfattning : An occupational exposure to hand-arm vibration can cause a complex of neurological, vascular and musculo-skeletal disturbances, known as the 'vibration syndrome'. However, the underlying pathophysiological mechanisms are not at all clear. LÄS MER