Double-injection, deep-impurity switch development

The overall objective of this program is the development of device design and process techniques for the fabrication of a double-injection, deep-impurity (DI)(2) silicon switch that operates in the 1-10 kV range with conduction current of 10 and 1A, respectively. Other major specifications include a holding voltage of 0 to 5 volts at 1 A anode current, 10 microsecond switching time, and power dissipation of 50 W at 75 C. This report describes work that shows how the results obtained at the University of Cincinnati under NASA Grant NSG-3022 have been applied to larger area and higher voltage devices. The investigations include theoretical, analytical, and experimental studies of device design and processing. Methods to introduce deep levels, such as Au diffusion and electron irradiation, have been carried out to "pin down' the Fermi level and control device-switching characteristics. Different anode, cathode, and gate configurations are presented. Techniques to control the surface electric field of planar structures used for (DI)(2) switches are examined. Various sections of this report describe the device design, wafer-processing techniques, and various measurements which include ac and dc characteristics, 4-point probe, and spreading resistance

Development of superconducting YBa2Cu3O(x) wires with low resistance electrical contacts

Materials exhibiting superconductivity above liquid nitrogen temperatures (77 K) will enable new applications of this phenomena. One of the first commercial applications of this technology will be superconducting magnets for medical imaging. However, a large number of aerospace applications of the high temperature superconducting materials have also been identified. These include magnetic suspension and balance of models in wind tunnels and resistanceless leads to anemometers. The development of superconducting wires fabricated from the ceramic materials is critical for these applications. The progress in application of a patented fiber process developed by Clemson University for the fabrication of superconducting wires is reviewed. The effect of particle size and heat treatment on the quality of materials is discussed. Recent advances made at Christopher Newport College in the development of micro-ohm resistance electrical contacts which are capable of carrying the highest reported direct current to this material is presented

Attitudes and barriers to incident reporting: a collaborative hospital study

Copyright © 2006 by the BMJ Publishing Group Ltd.ObjectivesTo assess awareness and use of the current incident reporting system and to identify factors inhibiting reporting of incidents in hospitals.Design, setting and participantsAnonymous survey of 186 doctors and 587 nurses from diverse clinical settings in six South Australian hospitals (response rate = 70.7% and 73.6%, respectively).Main outcome measuresKnowledge and use of the current reporting system; barriers to incident reporting.ResultsMost doctors and nurses (98.3%) were aware that their hospital had an incident reporting system. Nurses were more likely than doctors to know how to access a report (88.3% v 43.0%; relative risk (RR) 2.05, 95% CI 1.61 to 2.63), to have ever completed a report (89.2% v 64.4%; RR 1.38, 95% CI 1.19 to 1.61), and to know what to do with the completed report (81.9% v 49.7%; RR 1.65, 95% CI 1.27 to 2.13). Staff were more likely to report incidents which are habitually reported, often witnessed, and usually associated with immediate outcomes such as patient falls and medication errors requiring corrective treatment. Near misses and incidents which occur over time such as pressure ulcers and DVT due to inadequate prophylaxis were least likely to be reported. The most frequently stated barrier to reporting for doctors and nurses was lack of feedback (57.7% and 61.8% agreeing, respectively).ConclusionsBoth doctors and nurses believe they should report most incidents, but nurses do so more frequently than doctors. To improve incident reporting, especially among doctors, clarification is needed of which incidents should be reported, the process needs to be simplified, and feedback given to reporters.S M Evans, J G Berry, B J Smith, A Esterman, P Selim, J O’Shaughnessy, M DeWi

Symptom Levels in Care-Seeking Bangladeshi and Nepalese Adults With Advanced Cancer

Purpose Three-fourths of patients with advanced cancer are reported to suffer from pain. A primary barrier to provision of adequate symptom treatment is failure to appreciate the intensity of the symptoms patients are experiencing. Because data on Bangladeshi and Nepalese patients’ perceptions of their symptomatic status are limited, we sought such information using a cell phone questionnaire. Methods At tertiary care centers in Dhaka and Kathmandu, we recruited 640 and 383 adult patients, respectively, with incurable malignancy presenting for outpatient visits and instructed them for that single visit on one-time completion of a cell phone platform 15-item survey of questions about common cancer associated symptoms and their magnitudes using Likert scales of 0 to 10. The questions were taken from the Edmonton Symptom Assessment System and the Brief Pain Inventory instruments. Results All but two Bangladeshi patients recruited agreed to study participation. Two-thirds of Bangladeshi patients reported usual pain levels ≥ 5, and 50% of Nepalese patients reported usual pain levels ≤ 4 (population differences significant at P \u3c .001). Conclusion Bangladeshi and Nepalese adults with advanced cancer are comfortable with cell phone questionnaires about their symptoms and report high levels of pain. Greater attention to the suffering of these patients is warranted

Inertial Imaging with Nanomechanical Systems

Mass sensing with nanoelectromechanical systems has advanced significantly during the last decade. With nanoelectromechanical systems sensors it is now possible to carry out ultrasensitive detection of gaseous analytes, to achieve atomic-scale mass resolution and to perform mass spectrometry on single proteins. Here, we demonstrate that the spatial distribution of mass within an individual analyte can be imaged—in real time and at the molecular scale—when it adsorbs onto a nanomechanical resonator. Each single-molecule adsorption event induces discrete, time-correlated perturbations to all modal frequencies of the device. We show that by continuously monitoring a multiplicity of vibrational modes, the spatial moments of mass distribution can be deduced for individual analytes, one-by-one, as they adsorb. We validate this method for inertial imaging, using both experimental measurements of multimode frequency shifts and numerical simulations, to analyse the inertial mass, position of adsorption and the size and shape of individual analytes. Unlike conventional imaging, the minimum analyte size detectable through nanomechanical inertial imaging is not limited by wavelength-dependent diffraction phenomena. Instead, frequency fluctuation processes determine the ultimate attainable resolution. Advanced nanoelectromechanical devices appear capable of resolving molecular-scale analytes

A mean-field kinetic lattice gas model of electrochemical cells

We develop Electrochemical Mean-Field Kinetic Equations (EMFKE) to simulate electrochemical cells. We start from a microscopic lattice-gas model with charged particles, and build mean-field kinetic equations following the lines of earlier work for neutral particles. We include the Poisson equation to account for the influence of the electric field on ion migration, and oxido-reduction processes on the electrode surfaces to allow for growth and dissolution. We confirm the viability of our approach by simulating (i) the electrochemical equilibrium at flat electrodes, which displays the correct charged double-layer, (ii) the growth kinetics of one-dimensional electrochemical cells during growth and dissolution, and (iii) electrochemical dendrites in two dimensions.Comment: 14 pages twocolumn, 17 figure

Autonomous clustering using rough set theory

This paper proposes a clustering technique that minimises the need for subjective human intervention and is based on elements of rough set theory. The proposed algorithm is unified in its approach to clustering and makes use of both local and global data properties to obtain clustering solutions. It handles single-type and mixed attribute data sets with ease and results from three data sets of single and mixed attribute types are used to illustrate the technique and establish its efficiency

Quantum Optics and Photonics

Contains table of contents for Part II, table of contents for Section 1, and reports on six research projects.Charles S. Draper Laboratories Contract DL-H-418468U.S. Air Force - Electronic Systems Division Contract F19628-89-K-0300U.S. Navy - Office of Naval Research Grant N0014-91-J-1808U.S. Air Force - Electronic Systems Division Contract F19628-89-K-003

Quantum Optics and Photonics

Contains table of contents for Part II, table of contents for Section 1 and reports on six research projects.U.S. Air Force - Electronic Systems Division Contract F19628-92-K-0013U.S. Navy - Office of Naval Research Grant N0014-91-J-1808Ballistic Missile Defense Organization Grant NG0921-94-C-0101MIT Plasma Fusion Cente

White Paper: Shifting the goal post - from high impact journals to high impact data

The purpose of this white paper is to provide an overview of the ongoing initiatives at center level to respond to changing public expectations and to the challenge of improving the conduct of science by making research data widely available. We also attempt to provide a framework for implementing open access for research data to maximize CGIAR’s impact on development. The remainder of this paper proceeds as follows; firstly a summary of the diversity of research data produced by the centers is given, followed by an overview of the existing infrastructure for data management for each Center. Secondly, some of the limitations and barriers faced by the centers in their process to mainstream research data publishing are addressed. The paper concludes with recommendations for how these limitations and barriers can be tackled