Search for dissertations about: "electrical activity"

Showing result 1 - 5 of 284 swedish dissertations containing the words electrical activity.

2. 1. Electrical Characterisations of Bearings

   Author : Abhishek Joshi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ball bearing; Equivalent circuit model; Lubricants; Bearing Capacitance; Spherical bearing; Mechanical bearing; Bearing currents; Electrical conduction; Electrical characterisation;

   Abstract : Mechanical bearings are an integral part of industry, and are used in various places in order to reduce friction between two interacting surfaces and are used to transmit power and loads. Mechanical bearings are one of the most extensively used components within the wind industry, but on the other hand they are also one of the most dominantly failing failed components. READ MORE

4. 2. Aspects of Electrical Bioimpedance Spectrum Estimation

   Author : Farhad Abtahi; Kaj Lindecrantz; Fernando Seoane; Mart Min; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Bioimpedance Spectroscopy; Thoracic Bioimpedance Spectroscopy; Sub-Nyquist Sampling; Undersampling; Aliasing in Electrical Bioimpedance; Bioimpedance Estimation Error.; Medicinsk teknologi; Medical Technology; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Electrical bioimpedance spectroscopy (EBIS) has been used to assess the status or composition of various types of tissue, and examples of EBIS include body composition analysis (BCA) and tissue characterisation for skin cancer detection. EBIS is a non-invasive method that has the potential to provide a large amount of information for diagnosis or monitoring purposes, such as the monitoring of pulmonary oedema, i. READ MORE

5. 3. Mechanisms of Electrical Ageing of Oilimpregnated Paper due to Partial Discharges

   Author : Mohamad Ghaffarian Niasar; Hans Edin; Ernst Gockenback; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharges; oil-impregnated paper; oil; transformer insulation; dielectric frequency response; breakdown strength; ion mobility; thermal ageing; electrical ageing; moisture in paper; life time; thermal breakdown.; Electrical Engineering; Elektro- och systemteknik;

   Abstract : In this thesis, partial discharge (PD) phenomenon in oil-impregnated paper (OIP) is investigated under accelerated electrical stress. The thesis is mainly focused on the characteristic of PD activity and the influence it has on the insulation properties of OIP. READ MORE

6. 4. Characterization of Electrical Insulation Exposed to Arbitrary Voltage Waveforms

   Author : Björn Sonerud; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; arbitrary voltage waveforms; partial discharge; diagnostics; dielectric response measurement; signal processing; electrical treeing; dielectric heating.;

   Abstract : The extensive use of power electronics in power systems today gives rise to other voltage waveforms than the conventional 50/60 Hz sinusoidal and consequently other types of electric stress act on high voltage insulating materials. Previous studies has shown that Pulse Width Modulated (PWM) voltages and similar waveforms increase stress in Adjustable Speed Drives (ASD) as compared with sinusoidal waveforms and it has also been shown that partial discharge (PD) activity is intensified during PWM voltages and that rise time of square like pulses affect PD inception voltage. READ MORE

7. 5. Studies of sympathetic nerve activity in cutaneous nerves in healthy subjects using intraneural microneurography : The relationship between nerve activity and effector organ response

   Author : Pirkko Hynninen; Anna Rostedt Punga; Roland Flink; Kristin Ørstavik; Uppsala universitet; []
   Keywords : Human; microneurography; neurophysiology; sympathetic nerve activity;

   Abstract : The aim of the research presented in this thesis is to gain new knowledge of the characteristic features of sympathetic nerve activity of cutaneous nerves in healthy adult humans using intraneural microneurography. One further goal is to study the relationship between nerve activity and effector organ response. READ MORE