Radiolinkkipäätteen laajakaistainen paikallisoskillaattori 150-1500 MHz:lle

Radiolinkkipäätteen välitaajuuden paikallisoskillaattori on eräs keskeisistä kiinnostuksen kohteista, kun halutaan toteuttaa laajakaistaisia yleiskäyttöisiä lohkoja. Tässä diplomityössä tutkitaan hyvin laajakaistaisen (150...1500 MHz) välitaajuisen jänniteohjatun oskillaattorin (VCO) toteutusmahdollisuuksia osana digitaalisen radiolinkkipäätteen taajuussyntesointipiiristöä. Perinteisen heijastustyyppisen transistorioskillaattorin lisäksi on simuloitu ja vertailtu erilaisia oskillaattoripankkirakenteita sekä hyvin laajakaistaisia oskillaattorirakenteita. Osa rakenteista on toteutettu ja mitattu. Yhä lisääntyvän integrointitarpeen vuoksi on suunnittelu toteutettu BiCMOS-prosessiin perustuen, ja lisäksi on pohdittu oskillaattorin eri osien integrointimahdollisuuksia

Sleepiness and the risk of car crash : a case control study

Driver sleepiness is believed to be a strong contributing factor to road traffic crashes. Acute sleepiness risk factors, such as driving during early morning hours or having insufficient sleep, was observed in 15% to 25% of the car crash injuries in New Zealand. Most studies are observational and describe the information about the crashes, whereas controlled studies are rare. One exception is the study by Connor et al. (2002), which used a case-control design and compared 571 car drivers involved in crashes (in which at least one driver was admitted to hospital or killed - "cases") with 588 representative drivers (controls) recruited while driving on public roads. The results showed a strong association between indicators of acute sleepiness and the risk of an injury crash, whereas measures of chronic sleepiness showed no association with injury risk. The aim of the present study was to carry out a similar study in Sweden and examine the relationship between acute and chronic sleepiness characteristics, including disturbed sleep and other factors that may contribute to driver sleepiness, with the risk of crashes in which the driver was admitted to hospital

Influence of kaolin addition on the dynamics of oxygen mass transport in polyvinyl alcohol dispersion coatings

The permeability of dispersion barriers produced from polyvinyl alcohol (PVOH) and kaolin clay blends coated onto polymeric supports has been studied by employing two different measurement methods: the oxygen transmission rate (OTR) and the ambient oxygen ingress rate (AOIR). Coatings with different thicknesses and kaolin contents were studied. Structural information of the dispersion-barrier coatings was obtained by Fourier transform infrared spectroscopy (FTIR) spectroscopy and scanning electron microscopy (SEM). These results showed that the kaolin content influences both the orientation of the kaolin and the degree of crystallinity of the PVOH coating. Increased kaolin content increased the alignment of the kaolin platelets to the basal plane of the coating. Higher kaolin content was accompanied by higher degree of crystallinity of the PVOH. The barrier thickness proved to be less important in the early stages of the mass transport process, whereas it had a significant influence on the steady-state permeability. The results from this study demonstrate the need for better understanding of how permeability is influenced by (chemical and physical) structure.Ingår i lic.uppsats Structural Studies and Modelling of Oxygen Transport in Barrier Materials for Food Packaging som manuskript med titeln: Influence of kaolin addition in polyvinyl alcohol dispersion coating on the dynamics of oxygen mass transport.</p