New generation of high-efficiency solar cells: Development,processing and marketing

In 1985, BP Solar Australia (BPSA) licensed and began commercialization of the high-efficiency buried-contact solar cell technology developed and patented by the University of New South Wales.⁻¹ Small-area cells of 18% efficiency were soon produced in BPSA's Brookvale laboratory, leading on to a 5-year development period in Australia and the establishment of a pilot production facility within the BP Solar España facility in Madrid in 1989. This paper looks at the current technical and commercial situation within BPSA for this novel technology, and how its future is viewed relative to other processing technologies.     

In vivo and in vitro testing of microelectronically fabricated planar sensors designed for applications in cardiology

Summary Ion-sensitive, planar micro-electrode arrays were fabricated by photolithographic microelectronics technology on a flexible polyimide substrate. The steps of the microelectronics processing are summarized. The electrodes were tested in blood serum, whole blood and in the hamstring muscle of anesthetized rabbits. The performance characteristics of planar pH-sensors are compared with commercial glass electrodes. The close correlation of the data are encouraging for further acute and later chronic applications.Dedicated to Professor Dr. Wilhelm Fresenius     

Sum frequency generation by intersubband transition in step quantumwells

Using two CO₂ lasers, sum frequency generation was achieved in step quantum wells via intersubband transition processes. The power from each continuous wave (CW) CO₂ lasers was kept low such that the total power onto the sample was below 2 W. The observed sum frequency signal obeyed the polarization selection rule predicted by the simple effective mass envelope function model. The experimentally determined and calculated second order susceptibility values are in reasonable agreement     

Theory of the dielectric constant of ice

The first result of this paper is to show that the Onsager—Slater theory of the dielectric constant is consistent for some reasoable model of ice in the limit of no intrinsic defects. Accordingly, a model is presented, called the unit model, which has unit cells with no dipole moments for which the Onsager—Slater theory is exact. The second result of this paper is to show that the unit model is physically and chemically realistic. Bjerrum defects are introduced into the model and the relation between the dielectric constant and the Bjerrum defect charge found by Onsager and Dupuis for a less realistic model continues to hold and is satisfied by the experimental values. In a simple point charge approximation the charge distribution determined by the model requirements and the experimentally determined Bjerrum fault charge are found and seem reasonble. Higher order multipole interaction energies are consistent with eviations from pure 1/T dependence of the dielectric constant of real ice with intrinsic defects, can be derived in the context of the unit model. This formula interpolates between the Onsager—Slater formula in the limit of no intrinsic defects and the Kirkwood—Frohlich formula in the limit of many intrinsic defects. For the concentration of defects in real ice the interpolation formula is practically the same as the Onsager—Slater formula and differs from the Kirkwood—Frohlich formula by a factor of nearly $\text{3}\text{2}$.     

Observation of infrared intersubband emission in optically pumpedquantum wells

Mid-infrared intersubband emission is investigated in GaAs/AlGaAs asymmetric coupled quantum wells exhibiting an energy separation between the ground and first excited subbands close to the LO-phonon energy. The authors show that an infrared emission occurs between excited subbands under intersubband optical pumping     

Absence of a vestigial vapor pressure paradox

The enigmatic but much accepted vapor pressure paradox for oriented lipid bilayer samples was recently justified theoretically. Subsequently, recent experiments have shown that there is no vapor pressure paradox. The first result of this paper is to consider another degree of freedom that reverses the previous theoretical conclusion, so that theory and experiment are now in agreement that there is no vapor pressure paradox. However, this analysis also suggests the possibility of a vestigial vapor pressure paradox that would rationalize why the vapor pressure paradox was historically so persistent and that would have led to an improved protocol for obtaining bilayer structure. This vestigial vapor pressure paradox would involve a phase transition as a function of applied osmotic pressure. We test this possibility experimentally using combined neutron and x-ray scattering data. The conclusion from these experiments is that there is not even a vestigial vapor pressure paradox. However, this negative result validates an improved method for calibrating osmotic pressure in x-ray studies of oriented samples.     

Evaluation of discrete cellulase enzyme activities from anaerobic digester sludge fed a municipal solid waste feedstock

Applied Biochemistry and Biotechnology -     

SSF comparison of selected woods from southern sawmills

Applied Biochemistry and Biotechnology - Simultaneous saccharification and fermentation (SSF) is recognized as an efficient approach to the cost-effective conversion of biomass to fuel ethanol....