Non-parabolic hydrodynamic formulations for the simulation of inhomogeneous semiconductor devices

Hydrodynamic models are becoming prevalent design tools for small scale devices and other devices in which high energy effects can dominate transport. Most current hydrodynamic models use a parabolic band approximation to obtain fairly simple conservation equations. Interest in accounting for band structure effects in hydrodynamic device simulation has begun to grow since parabolic models can not fully describe the transport in state of the art devices due to the distribution populating non-parabolic states within the band. This paper presents two different non-parabolic formulations of the hydrodynamic model suitable for the simulation of inhomogeneous semiconductor devices. The first formulation uses the Kane dispersion relationship (hk)(exp 2)/2m = W(1 + alpha(W)). The second formulation makes use of a power law ((hk)(exp 2)/2m = xW(sup y)) for the dispersion relation. Hydrodynamic models which use the first formulation rely on the binomial expansion to obtain moment equations with closed form coefficients. This limits the energy range over which the model is valid. The power law formulation readily produces closed form coefficients similar to those obtained using the parabolic band approximation. However, the fitting parameters (x,y) are only valid over a limited energy range. The physical significance of the band non-parabolicity is discussed as well as the advantages/disadvantages and approximations of the two non-parabolic models. A companion paper describes device simulations based on the three dispersion relationships: parabolic, Kane dispersion, and power low dispersion

An acoustic charge transport imager for high definition television applications

The primary goal of this research is to develop a solid-state high definition television (HDTV) imager chip operating at a frame rate of about 170 frames/sec at 2 Megapixels per frame. This imager offers an order of magnitude improvement in speed over CCD designs and will allow for monolithic imagers operating from the IR to the UV. The technical approach of the project focuses on the development of the three basic components of the imager and their integration. The imager chip can be divided into three distinct components: (1) image capture via an array of avalanche photodiodes (APD's), (2) charge collection, storage and overflow control via a charge transfer transistor device (CTD), and (3) charge readout via an array of acoustic charge transport (ACT) channels. The use of APD's allows for front end gain at low noise and low operating voltages while the ACT readout enables concomitant high speed and high charge transfer efficiency. Currently work is progressing towards the development of manufacturable designs for each of these component devices. In addition to the development of each of the three distinct components, work towards their integration is also progressing. The component designs are considered not only to meet individual specifications but to provide overall system level performance suitable for HDTV operation upon integration. The ultimate manufacturability and reliability of the chip constrains the design as well. The progress made during this period is described in detail in Sections 2-4

Theoretical study of the effect of an AlGaAs double heterostructure on metal-semiconductor-metal photodetector performance

The sizing and efficiency of an aircraft is largely determined by the performance of its high-lift system. Subsonic civil transports most often use deployable multi-element airfoils to achieve the maximum-lift requirements for landing, as well as the high lift-to-drag ratios for take-off. However, these systems produce very complex flow fields which are not fully understood by the scientific community. In order to compete in today's market place, aircraft manufacturers will have to design better high-lift systems. Therefore, a more thorough understanding of the flows associated with these systems is desired. Flight and wind-tunnel experiments have been conducted on NASA Langley's B737-100 research aircraft to obtain detailed full-scale flow measurements on a multi-element high-lift system at various flight conditions. As part of this effort, computational aerodynamic tools are being used to provide preliminary flow-field information for instrumentation development, and to provide additional insight during the data analysis and interpretation process. The purpose of this paper is to demonstrate the ability and usefulness of a three-dimensional low-order potentialflow solver, PMARC, by comparing computational results with data obtained from 1/8 scale wind-tunnel tests. Overall, correlation of experimental and computational data reveals that the panel method is able to predict reasonably well the pressures of the aircraft's multi-element wing at several spanwise stations. PMARC's versatility and usefulness is also demonstrated by accurately predicting inviscid threedimensional flow features for several intricate geometrical regions

Solvent Dependence of Lateral Charge Transfer in a Porphyrin Monolayer

Lateral charge transport in a redox-active monolayer can be utilized for solar energy harvesting. A model porphyrin system was chosen to study the influence of the solvent on lateral hole hopping, which plays a crucial role in the charge-transfer kinetics. We examined the influence of water, acetonitrile, and propylene carbonate as solvents. Hole-hopping lifetimes varied by nearly three orders of magnitude among solvents, ranging from 3 ns in water to 2800 ns in propylene carbonate, and increased nonlinearly as a function of added acetonitrile in aqueous solvent mixtures. These results elucidate the important roles of solvation, molecular packing dynamics, and lateral charge-transfer mechanisms that have implications for all dye-sensitized photoelectrochemical device designs

Oxygen challenge magnetic resonance imaging in healthy human volunteers

Oxygen challenge imaging involves transient hyperoxia applied during deoxyhaemoglobin sensitive (T2*-weighted) magnetic resonance imaging and has the potential to detect changes in brain oxygen extraction. In order to develop optimal practical protocols for oxygen challenge imaging, we investigated the influence of oxygen concentration, cerebral blood flow change, pattern of oxygen administration and field strength on T2*-weighted signal. Eight healthy volunteers underwent multi-parametric magnetic resonance imaging including oxygen challenge imaging and arterial spin labelling using two oxygen concentrations (target FiO2 of 100 and 60%) administered consecutively (two-stage challenge) at both 1.5T and 3T. There was a greater signal increase in grey matter compared to white matter during oxygen challenge (p < 0.002 at 3T, P < 0.0001 at 1.5T) and at FiO2 = 100% compared to FiO2 = 60% in grey matter at both field strengths (p < 0.02) and in white matter at 3T only (p = 0.0314). Differences in the magnitude of signal change between 1.5T and 3T did not reach statistical significance. Reduction of T2*-weighted signal to below baseline, after hyperoxia withdrawal, confounded interpretation of two-stage oxygen challenge imaging. Reductions in cerebral blood flow did not obscure the T2*-weighted signal increases. In conclusion, the optimal protocol for further study should utilise target FiO2 = 100% during a single oxygen challenge. Imaging at both 1.5T and 3T is clinically feasible

Induction of fibroblast senescence generates a non-fibrogenic myofibroblast phenotype that differentially impacts on cancer prognosis

Cancer-associated fibroblasts (CAF) remain a poorly characterized, heterogeneous cell population. Here we characterized two previously described tumor-promoting CAF sub-types, smooth muscle actin (SMA)-positive myofibroblasts and senescent fibroblasts, identifying a novel link between the two. Analysis of CAF cultured ex vivo, showed that senescent CAF are predominantly SMA-positive; this was confirmed by immunochemistry in head & neck (HNSCC) and esophageal (EAC) cancers. In vitro, we found that fibroblasts induced to senesce develop molecular, ultrastructural and contractile features typical of myofibroblasts and this is dependent on canonical TGF-? signaling. Similar to TGF-?1-generated myofibroblasts, these cells secrete soluble factors that promote tumor cell motility. However, RNA-sequencing revealed significant transcriptomic differences between the two SMA-positive CAF groups, particularly in genes associated with extracellular matrix (ECM) deposition and organization, which differentially promote tumor cell invasion. Notably, second harmonic generation imaging and bioinformatic analysis of SMA-positive human HNSCC and EAC showed that collagen fiber organization correlates with poor prognosis, indicating that heterogeneity within the SMA-positive CAF population differentially impacts on survival. These results show that non-fibrogenic, SMA-positive myofibroblasts can be directly generated through induction of fibroblast senescence and suggest that senescence and myofibroblast differentiation are closely linked processes

Crop Updates - 2003 Oilseeds

This session covers fifteen papers from different authors ACKNOWLEDGMENTS VARIETIES Large scale canola varietal evaluation in WA, Peter Nelson, Oilseeds WA Performance of IT and TT canola varieties in the medium and high rainfall agzones of WA 2001-02, Graham Walton, Hasan Zaheer and Paul Carmody, Department of Agriculture QUALITY Reproductive biology, cotyledon development and oil accumulation in canola, J.A. Fortescue and D.W. Turner, School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia Plant and environmental factors affecting oil concentration in canola – a mini-review, D.W. Turner, School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia Potential benefits from interspecific crosses between canola and ‘near canola’ quality Indian mustard, Janet Wroth, School of Plant Biology, The University of Western Australia (UWA), Wallace Cowling, School of Plant Biology, UWA and CBWA Pty Ltd, Anh-Van Pham, School of Mathematics and Statistics, UWA NUTRITION, AGRONOMY AND MACHINERY Timing of nitrogen application for producing canola grain and oil, R. F. Brennan, Department of Agriculture Managing canola for soil type and moisture stress, Paul Carmody and Hasan Zaheer Department of Agriculture Machinery lessons from 2002 – canola establishment, Glen Riethmuller, Greg Hamilton and Jo Hawksley, Department of Agriculture Machinery lessons from 2002 – harvesting short crops, Glen Riethmuller, Department of Agriculture Does increasing canola seeding rate reduce the competitiveness of grass weeds? Zaicou-Kunesch, C.M., Zaheer, S.H. and Eksteen, D, Department of Agriculture PESTS AND DISEASES Aphid damage to canola – not all cultivars are equal, Françoise A. Berlandier and Christiaan Valentine, Department of Agriculture Should we be worried about developing insecticide resistance in aphids? Owain Edwards, CSIRO Entomology Benefits provided by treating canola seed with imidacloprid seed dressing, Roger Jones, Brenda Coutts, Lisa Smith and Jenny Hawkes, Department of Agriculture, and Centre for Legumes in Mediterranean Agriculture Blackleg levels in canola in 2002, Ravjit Khangura1, Moin Salam1, Art J Diggle1 and Martin J Barbetti1,2 1Department of Agriculture, 2University of Western Australia DBM in canola, Kevin Walden, Department of Agricultur

Crop Updates 2002 - Oilseeds

This session covers twenty seven papers from different authors: 1. Forward and acknowledgements, Dave Eksteen, ACTING MANAGER OILSEEDS PRODUCTIVITY AND INDUSTRY DEVELOPMENT Department of Agriculture PLENARY SESSION 2. GMO canola - Track record in Canada, K. Neil Harker and George W. Clayton,Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, R. Keith Downey, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan 3. GMO canola – Prospects in Western Australia farming systems, Keith Alcock, Crop Improvement Institute, Department of Agriculture 4. Diamondback moth (DBM) in canola, Kevin Walden, Department of Agriculture CANOLA AGRONOMY 5. Getting the best out of canola in the low rainfall central wheatbelt, Bevan Addison and Peter Carlton, Elders Ltd 6. Canola variety performance in Western Australia, Kevin Morthorpe, Stephen Addenbrooke and Alex Ford, Pioneer Hi-Bred Australia P/L 7. Relative performance of new canola varieties in Department of Agriculture variety trials in 2000 and 2001, S. Hasan Zaheer, GSARI, Department of Agriculture, G. Walton, Crop Improvement Institute, Department of Agriculture 8. Which canola cultivar should I sow? Imma Farré, CSIRO Plant Industry, Floreat, Bill Bowden,Western Australia Department of Agriculture 9. The effect of seed generation and seed source on yield and quality of canola, Paul Carmody, Department of Agriculture 10. The accumulation of oil in Brassica species, J.A. Fortescue and D.W. Turner, Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, B. Tan, PO Box 1249, South Perth 11. Potential and performance of alternative oilseeds in WA, Margaret C. Campbell, Centre for Legumes in Mediterranean Agriculture 12. Comparison of oilseed crops in WA, Ian Pritchard and Paul Carmody, Department of Agriculture, Centre for Cropping Systems, Margaret Campbell, Centre for Legumes in Mediterranean Agriculture 13. Identifying constraints to canola production, Dave Eksteen, Canola Development Officer, Department of Agriculture 14. Boron – should we be worried about it? Richard W. BellA, K. FrostA, Mike WongB, and Ross BrennanC , ASchool of Environmental Science, Murdoch University, BCSIRO Land and Water, CDepartment of Agriculture PEST AND DISEASE 15. Yield losses caused when Beet Western Yellows Virus infects canola, Roger Jones and Jenny Hawkes, Department of Agriculture, and Centre for Legumes in Mediterranean Agriculture 16. Influence of climate on aphid outbreaks and virus epidemics in canola, Debbie Thackray, Jenny Hawkes and Roger Jones, Centre for Legumes in Mediterranean Agriculture and Department of Agriculture 17. The annual shower of blackleg ascospores in canola: Can we predict and avoid it? Moin U. Salam, Ravjit K. Khangura, Art J. Diggle and Martin J. Barbetti, Department of Agriculture 18. Environmental influences on production and release of ascospores of blackleg and their implications in blackleg management in canola, Ravjit K. Khangura, Martin J. Barbetti , Moin U. Salam and Art J. Diggle, Department of Agriculture 19. WA blackleg resistance ratings on canola varieties form 2002, Ravjit Khangura, Martin J. Barbetti and Graham Walton, Department of Agriculture 20. Bronzed field beetle management in canola, Phil Michael, Department of Agriculture 21. DBM control in canola: Aerial versus boom application, Paul Carmody, Department of Agriculture 22. Effect of single or multiple spray trearments on the control of Diamondback moth (Plutella xylostella) and yield of canola at Wongan Hills, Françoise Berlandier, Paul Carmody and Christiaan Valentine, Department of Agriculture ESTABLISHMENT 23. GrainGuardÔ - A biosecurity plan for the canola industry, Greg Shea, Department of Agriculture 24. Large canola seed is best, particularly for deep sowing, Glen Riethmuller, Rafiul Alam, Greg Hamilton and Jo Hawksley, Department of Agriculture 25. Canola establishment with seed size, tines and discs, with and without stubble, Glen Riethmuller, Rafiul Alam, Greg Hamilton and Jo Hawksley, Department of Agriculture WEEDS 26. Role of Roundup ReadyÒ canola in the farming system, Art Diggle1, Patrick Smith2, Paul Neve3, Felicity Flugge4, Amir Abadi5, Stephen Powles3 1Department of Agriculture, 2CSIRO, Sustainable Ecosystems, 3Western Australian Herbicide Resistance Initiative, University of Western Australia, 4Centre for Legumes in Mediterranean Agriculture, University of Western Australia, 5Touchstone Consulting, Mt Hawthorn FEED 27. Getting value from canola meals in the animal feed industries: Aquaculture, Brett Glencross and John Curnow, Department of Fisheries - Government of Western Australia and Wayne Hawkins, Department of Agricultur