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Visar resultat 1 - 5 av 111 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Analysis of Planar and Circular Cylindrical Multilayer Structures with Application to Soft and Hard Surfaces

   Författare :Zvonimir Sipus; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antennas; periodic surfaces; integral equations; approximate boundary conditions; soft and hard surfaces; Green s functions; corrugated surfaces; moment method; periodic metal strips; multilayer structures; EFIE; microstrip antennas; spectral domain analysis; group representation theory; strip scatterers;

   Sammanfattning : This thesis deals with the analysis of planar and circular cylindrical multilayer structures, such as strip-loaded dielectric layers, corrugated surfaces and microstrip antennas. In particular, we study corrugations and strip-loaded grounded dielectric slabs when they are used to realize soft and hard surfaces. LÄS MER

3. 2. Dynamiskt belastade tribologiska system under plastisk formning, del II --- analyserade genom akustisk emission

   Författare :Thomas Skåre; Industriell Produktion; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; supervision; wear; waves; vibrations; tribology; surfaces; stick-slip; sliding; sheet metal; quality check; plastic forming; monitoring; galling; machining; deep drawing; friction; cracking; contact surfaces; Acoustic emission AE ; contact pressure; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Material technology; Materiallära; materialteknik; Production technology; Produktionsteknik;

   Sammanfattning : The dynamic friction process and contact surface between tool and working material in a plastic forming process is hard to describe in mathematical form and hard to monitor and control in real time. High production speed and highly optimised forming operations result in great demands on the control equipment. LÄS MER

4. 3. Microengineered CVD Diamond Surfaces : Tribology and Applications

   Författare :Joakim Andersson; Staffan Jacobson; Arto Alahelisten; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Diamond; DLC; Tribology; Friction; Environment; Microengineering; Materialvetenskap; Materials science; Teknisk materialvetenskap;

   Sammanfattning : Recent developments in thin film synthesis of diamond have facilitated a host of new technical applications. These are motivated by the many attractive properties of diamond, for example high hardness, chemical inertness, transparency and heat conductivity. Unfortunately, these properties also make it difficult to fashion complex geometries. LÄS MER

5. 4. Miniaturized Hard Waveguides in Multifunction Array Antennas

   Författare :Malcolm Ng Mou Kehn; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interlaced arrays; Floquet theorem; reflector antennas; focal plane array; multifunction antennas; miniaturized waveguides; multilayer structures; spectral domain technique; periodic structures; aperture reuse; method of moments; soft and hard surfaces; array antennas;

   Sammanfattning : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. LÄS MER

7. 5. Atomic-scale modelling of interfaces in cemented carbides: wetting and strength

   Författare :Martin Gren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; adhesion; density functional theory; hardmetals; cemented carbides; WC-Co; surfaces; interfaces; grain boundaries; wetting; phase boundaries;

   Sammanfattning : Cemented carbides are composite materials of great technological and industrial importance. They have a unique combination of hardness and toughness and are therefore used widely as tool materials in applications where both high hardness and toughness are demanded. These applications include among others: mining, turning, cutting and milling. LÄS MER