Search for dissertations about: "electromagnetic pulses"

Showing result 1 - 5 of 26 swedish dissertations containing the words electromagnetic pulses.

  2. 1. Intentional electromagnetic interference (IEMI) : Susceptibility investigations and classification of civilian systems and equipment

    Author : Daniel Månsson; Rajeev Thottappillil; Mats Bäckström; William Radasky; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; Intentional electromagnetic interference; High power electromagnetic; Other engineering physics; Övrig teknisk fysik;

    Abstract : This PhD thesis addresses the threat posed to society by sources that can produce high power electromagnetic pulses (HEPM) and be used maliciously to disturb or damage electronic equipment. The vulnerability from intentional electromagnetic interference (IEMI) has increased in the recent decades due to the widespread dependence of the civil society on sensitive electronic systems and proliferation of radiation sources. READ MORE

  4. 2. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes

    Author : Mohd Muzafar Ismail; Vernon Cooray; Farhad Rachidi; Uppsala universitet; []
    Keywords : negative cloud-to-ground lightning flashes; HF and VHF radiation; chaotic pulse trains; lightning initiation; zero-crossing time; electromagnetic fields; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Abstract : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. READ MORE

  5. 3. Response of Civilian Facilities and Systems to High Power Electromagnetic (HPEM) Pulses and the Threat of Intentional Electromagnetic Interference (IEMI)

    Author : Daniel Månsson; Rajeev Thottappillil; Uppsala universitet; []
    Keywords : EMC; Intentional EMI;

    Abstract : .... READ MORE

  6. 4. Transient electromagnetic pulse propagation in temporally dispersive materials

    Author : Igor Egorov; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Green functions; direct scattering; time domain; wave propagation; bi-gyrotropic; chiral; bi-isotropic; Forerunner; precursor; Green dyadics; Electronics and Electrical technology; Elektronik och elektroteknik;

    Abstract : This thesis treats the problem of transient electromagnetic pulse propagation in temporally dispersive media. The analysis is performed using time-domain techniques. In particular, the dispersive wave splitting which decouples the Maxwell equations both in vacuum and inside the medium is utilized. READ MORE

  7. 5. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Author : Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. READ MORE