Sökning: "length effect"

Visar resultat 11 - 15 av 833 avhandlingar innehållade orden length effect.

1. 11. The effect of scale on the morphology, mechanics and transmissivity of single rock fractures

   Författare :Nader Fardin; KTH; []
   Nyckelord :Anisotropy; Aperture; Asperity degradation; Contact area; Finite Element Method FEM ; Flow analysis; Fractals; Fracture morphology; Heterogeneity; Stress-deformation; Surface roughness; Roughness-Length method; Scale dependency; Stationarity; Transm;

   Sammanfattning : This thesis investigates the effect of scale on themorphology, mechanics and transmissivity of single rockfractures using both laboratory and in-situ experiments, aswell as numerical simulations. Using a laboratory 3D laserscanner, the surface topography of a large silicon-rubberfracture replica of size 1m x 1m, as well as the topography ofboth surfaces of several high-strength concrete fracturereplicas varying in size from 50mmx50mm to 200mm x 200mm, werescanned. LÄS MER

3. 12. Impact of adjacent dielectrics on the high-frequency performance of graphene field-effect transistors

   Författare :Muhammad Asad; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-frequency electronics; Graphene; transit frequency; contact resistance; MOGFETs; drift velocity; field-effect transistors; saturation velocity; maximum frequency of oscillation; diamond;

   Sammanfattning : Transistors operating at high frequencies are the basic building blocks of millimeter wave communication and sensor systems. The high velocity and mobility of carriers in graphene can open ways for development of ultra-fast group IV transistors with similar or even better performance than that achieved with III-V based semiconductors. LÄS MER

4. 13. Hospital length stay : register-based studies on breast cancer surgery

   Författare :Rikard Lindqvist; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Length of stay; breast cancer; breast surgery; social factors;

   Sammanfattning : The present investigation focused on three main questions: what factors can determine length of stay for primary surgery for breast cancer? Can these factors be attributed to the decreasing trend in mean length of stay for primary breast-cancer surgery? And can there be any adverse effect of declining length of stay, such as prolonged sick leave, following breast-cancer surgery? For the four studies of the thesis, routinely collected data was used. In study I the Swedish Hospital Discharge Register was used to describe the trend in mean length of stay of women surgically treated for breast cancer and to investigate the effect of the increasing use of breast-conserving surgery on the decreasing trend in mean length of stay. LÄS MER

5. 14. Heterostructure Field-Effect Transistors for Millimeter Wave Applications

   Författare :Christer Karlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This thesis deals with the development of low-noise heterostructure field-effect transistors (HFETs) on III-V materials. The emphasis is on devices for high gain and low noise applications. Fabrication processes have been developed and transistors have been fabricated and characterized. LÄS MER

7. 15. Vertical III-V Nanowire Tunnel Field-Effect Transistor

   Författare :Elvedin Memisevic; Nanoelektronik; []
   Nyckelord :Transistor; TFET; Steep slope; Nanowire; III-V materials; HSQ; Vertical; InAs; GaSb; MOSFET;

   Sammanfattning : In this thesis fabrication and optimization of vertical III-V Tunneling Field-Effect transistors was explored. Usage of vertical nanowires, allows for combination of materials with large lattice mismatch in the same nanowire structure. LÄS MER