We demonstrate quantitative functional imaging using image-guided near-infrared spectroscopy (IG-NIRS) implemented with the boundary element method (BEM) for reconstructing 3-D optical property estimates in breast tissue in vivo. A multimodality MRI-NIR system was used to collect measurements of light reflectance from breast tissue. The BEM was used to model light propagation in 3-D based only ...

In functional brain imaging there is controversy over which hemodynamic signal best represents neural activity. Intrinsic signal optical imaging (ISOI) suggests that the best signal is the early darkening observed at wavelengths absorbed preferentially by deoxyhemoglobin (HbR). It is assumed that this darkening or "initial dip" reports local conversion of oxyhemoglobin (HbO) to HbR, i.e., oxyge...

The Georgia Tech team developed state-of-the-art GaN heterojunction bipolar transistor (HBT) technology in this NSF program. Throughout the project period, baseline device fabrication and material growth techniques were actively studied and significant technological advancement was achieved in III-Nitride (III-N) HBT research. We successfully demonstrated high-current gain (> 100) InGaN HBT on ...

We used near-infrared spectroscopy (NIRS) to study noninvasively the influence of aging on changes in the local concentration of oxygenated hemoglobin ([HbO2]), reduced hemoglobin ([HbR]), and total hemoglobin ([HbT] = [HbR] + [HbO2]) during activation of brain function. Young subjects (n = 12; age, 28 +/- 4 years) performing calculation tasks showed an increase in [HbO2] [mean (arbitrary units...

The performance capabilities of Pnp InGaAsN-based heterojunction bipolar transistors (HBT) for use in complementary HBT technology have been theoretically addressed with a twodimensional simulation program based on the drift-diffusion model. Simulation results closely reproduce the DC characteristics experimentally observed from the first demonstrated Pnp AIGaAsAnGaAsN HBT with a current gain o...

Technical progress in bringing SiGe heterojunction bipolar transistor (HBT) technology to reality has been exceptionally rapid. The first functional SiGe HBT was demonstrated in December 1987, only fifteen years ago. In this fifteen years, since the first demonstration of a functional transistor, SiGe HBT technology has emerged from the research laboratory, entered manufacturing on 200-mm wafer...

The CERN SPS lead beam program has covered for the first time with high statistics all HBT radius parameters of the full three-dimensional parametrization over a wide region in rapidity and transverse momentum (for data, see Ref. [1]). Theory provides by now a detailed data analysis strategy and interpretation (for a review, see Ref. [2]) . In this talk, I summarize the conclusions which we can...

Twenty-three infants and children aged 21 months to 13 years with chronic diarrhoea and 6 patients without diarrhoea were investigated for lactose malabsorption with the hydrogen breath test (HBT) adapted for use in young infants and children. A further 8 children with proven or suspected coeliac disease were also investigated. The HBT was compared with the histology of the jejunal mucosa, muco...

This paper gives an overview of the physics and modeling of noise in SiGe HBT devices and circuits, including RF broadband noise, low-frequency noise, and oscillator phase noise. The ability to simultaneously achieve high cutoff frequency (fT ), low base resistance (rb), and high current gain (β) using Si processing underlies the low levels of low frequency 1/f noise, RF noise and phase noise o...