Theoretical and material studies on thin-film electroluminescent devices

A theoretical study of resonant tunneling in multilayered heterostructures is presented based on an exact solution of the Schroedinger equation under the application of a constant electric field. By use of the transfer matrix approach, the transmissivity of the structure is determined as a function of the incident electron energy. The approach presented is easily extended to many layer structures where it is more accurate than other existing transfer matrix or WKB models. The transmission resonances are compared to the bound state energies calculated for a finite square well under bias using either an asymmetric square well model or the exact solution of an infinite square well under the application of an electric field. The results show good agreement with other existing models as well as with the bound state energies. The calculations were then applied to a new superlattice structure, the variablly spaced superlattice energy filter, (VSSEP) which is designed such that under bias the spatial quantization levels fully align. Based on these calculations, a new class of resonant tunneling superlattice devices can be designed

Civil helicopter wire strike assessment study. Volume 1: Findings and recommendations

Approximately 208 civil helicopter wire strike accidents for a ten year period 1970 to 1979 are analyzed. It is found that 83% of the wire strikes occurred during bright clear weather. Analysis of the accidents is organized under pilot, environment, and machine factors. Methods to reduce the wire strike accident rate are discussed, including detection/warning devices, identification of wire locations prior to flight, wire cutting devices, and implementation of training programs. The benefits to be gained by implementing accident avoidance methods are estimated to be fully justified by reduction in injury and death and reduction of aircraft damage and loss

The emergence of circular economy: a new framing around prolonging resource productivity

In this article we use Hirsch and Levin’s (1999) notion of ‘umbrella concepts’ as an analytical lens, in order to articulate the valuable catalytic function the circular economy concept could perform in the waste and resource management debate. We realize this goal by anchoring the circular economy concept in this broader debate through a narrative approach. This leads to the insight that while the various resource strategies grouped under circular economy’s banner are not new individually, the concept offers a new framing of these strategies by drawing attention to their capacity of prolonging resource use as well as to the relationship between these strategies. As such, circular economy offers a new perspective on waste and resource management and provides a new cognitive unit and discursive space for debate. We conclude by discussing research opportunities for the IE community relating to the concept’s theoretical development and its implementation. Specifically, we pose that reinvigorating and growing the social science aspects of IE is required for both. After all, it is the wide adoption and collective implementation of an idea that shapes our material future

Collide and Conquer: Constraints on Simplified Dark Matter Models using Mono-X Collider Searches

The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an $s$-channel vector mediator with vector or axial-vector couplings, and a $t$-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-$Z$ (leptonic) and mono-$W/Z$ (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant $t$-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.Comment: 32 pages, 8 figures; v2: minor changes, conclusion unchanged, matches published versio

MARKET STRUCTURE AND INNOVATION INTENSITY IN AGRICULTURAL BIOTECH

Consolidations and spin-offs in the agricultural biotechnology industry and the growing links of multinational corporations with the food and feed industry have been the subject of considerable discussion among academics, policy makers, consumers, and farmers. Most of the research by academic and overnment institutions has focused on the reasons for consolidation. Little theoretical or empirical research has examined the impact of this consolidation. We adapt an endogenous growth model of industry structure and R&D to agricultural biotechnology and empirically estimate the model. These empirical estimates, the main focus of the paper, indicate that industry consolidation influences the amount and direction of research, which then feeds back to influence industry structure.Agribusiness, Marketing, Research and Development/Tech Change/Emerging Technologies,

An acoustic charge transport imager for high definition television applications

In this report we present the progress during the second six month period of the project. This includes both experimental and theoretical work on the acoustic charge transport (ACT) portion of the chip, the theoretical program modelling of both the avalanche photodiode (APD) and the charge transfer and overflow transistor and the materials growth and fabrication part of the program

Effect of nitrogen rates on the copper concentration, dry matter production and grain yield of wheat grown on a residual copper trial.

Trial 67E8 Location: Esperance Downs Research Station. The trial was originally designed to measure the residual effectiveness of rates of copper sulphate drilled in 1967

Trace element nutrition. Tissue testing programme 1989. Residual value. Manganese nutrition of lupins.

Evaluation of existing diagnostic procedures for the recommendation of trace element fertilizers. To compare the accuracy and reliability of a range of tissue and soil tests being variously promoted for use to farmers for the diagnosis and prognosis of zinc and copper deficiencies in wheat crops on Western Australian farms. Trial 66N14 Long term copper residual trial at the Newdegate Research Station. To determine the residual value of previously applied copper. Location: Newdegate Research Station. Trial 86N27 Residual value of zinc with high analysis nitrogen and phosphorus fertilizer. To determine the decline in effectiveness of zinc on this soil types using DAP Location: Newdegate Research Station. Trial 86LG34 Residual value of copper, zinc and sulphur with high analysis nitrogen and phosphorus fertilizer under continuous cropping situation. To determine the decline in effectiveness of copper, zinc and sulphur on this soil types using DAP. Location: South Newdegate. Trial 67E8, 67E9 Effects of rates of nitrogen on copper concentrations, dry matter production and grain yield of lupins grown on a residual copper trial. The trial was originally designed to measure the residual effectiveness of rates of copper fertilizer drilled in 1967, Location: Esperance Downs Research Station. Trial 89E46 Manganese for lupins. Residual value of manganese for lupins. To determine the residual value of drilled manganese for lupins. Location: Esperance Downs Research Station. Trial 86E44 The effects of rates of copper and zinc application on wheat plans and grain production. To examine the possibility of copper and zinc deficiency in lupins. Location: Esperance Downs Research Station New land (1986

The effect of rates of nitrogen on the copper and zinc concentration and grain yield of wheat plants

To examine the possibility of rates of nitrogen inducing copper and zinc deficiency in wheat. 87JE2