A VHDL-AMS Based Time Domain Skin Depth Model for Edge Coupled Lossy Transmission Stripline

This contribution presents a time-domain model of the skin depth effect in a lossy transmission line. The model was developed and implemented in VHDL-AMS for a two wire edge coupled line but it is general and can be used for other types of lossy transmission line and high-frequency applications with skin depth effect. The salient feature of the model is the use of signal variation rate instead of frequency in the signal dependent resistance that models the skin depth losses. VHDL-AMS simulation experiments are presented to validate the model

An Improved Rotary Singulator

A new operating approach for a previously existing rotary singulator was developed which improves the versatility of the device. This was accomplished by the implementation of a modular mechanism that performed the basic functions of agitation, gating, pocket formation, and exit, all inherent in this type of singulation device

The effect of host structure on the selectivity and mechanism of supramolecular catalysis of Prins cyclizations.

The effect of host structure on the selectivity and mechanism of intramolecular Prins reactions is evaluated using K12Ga4L6 tetrahedral catalysts. The host structure was varied by modifying the structure of the chelating moieties and the size of the aromatic spacers. While variation in chelator substituents was generally observed to affect changes in rate but not selectivity, changing the host spacer afforded differences in efficiency and product diastereoselectivity. An extremely high number of turnovers (up to 840) was observed. Maximum rate accelerations were measured to be on the order of 105, which numbers among the largest magnitudes of transition state stabilization measured with a synthetic host-catalyst. Host/guest size effects were observed to play an important role in host-mediated enantioselectivity

Battery-Operated Atomic Force Microscope

The design of a battery-operated atomic force microscope (AFM) using a piezoresistive cantilever is described. The AFM is designed so that all power to drive the scanning tube and detection electronics comes from a self-contained battery. The prototype AFM uses a 6 V, Ni–Cd, camcorder battery, however, any battery that supplies between 6 and 12 V may be used. Scanner control and data acquisition are implemented using commercially available software running on an external computer. The prototype AFM achieves a scan area of 53 by 53 μm, consumes 1.8 W of power, and can scan continuously for about 7 h on a single battery charge

User perceptions of multi-source feedback tools for junior doctors

Context:  The effectiveness of multi-source feedback (MSF) tools, which are increasingly important in medical careers, will be influenced by their users’ attitudes. This study compared perceptions of two tools for giving MSF to UK junior doctors, of which one provides mainly textual feedback and one provides mainly numerical feedback. We then compared the perceptions of three groups, including: trainees; raters giving feedback, and supervisors delivering feedback. Methods:  Postal questionnaires about the usability, usefulness and validity of a feedback system were distributed to trainees, raters and supervisors across the north of England. Results:  Questionnaire responses were analysed to compare opinions of the two tools and among the different user groups. Overall there were few differences. Attitudes towards MSF in principle were positive and the tools were felt to be usable, but there was little agreement that they could effectively identify doctors in difficulty or provide developmental feedback. The text-oriented tool was rated as more useful for giving feedback on communication and attitude, and as more useful for identifying a doctor in difficulty. Raters were more positive than other users about the usefulness of numerical feedback, but, overall, text was felt to be more useful. Some trainees expressed concern that feedback was based on insufficient knowledge of their work. This was not supported by raters’ responses, although many did use indirect information. Trainees selected raters mainly for the perceived value of their feedback, but also based on personal relationships and the simple pragmatics of getting a tool completed. Discussion:  Despite positive attitudes to MSF, the perceived effectiveness of the tools was low. There are small but significant preferences for textual feedback, although raters may prefer numerical scales. Concerns about validity imply that greater awareness of contextual and psychological influences on feedback generation is necessary to allow the formative benefits of MSF to be optimised and to negate the risk of misuse in high-stakes contexts

Data Management Guide: Integrated Baseline System (IBS). Version 2.1

The Integrated Baseline System (IBS) is an emergency management planning and analysis tool that is being developed under the direction of the US Army Nuclear and Chemical Agency (USANCA). The IBS Data Management Guide provides the background, as well as the operations and procedures needed to generate and maintain a site-specific map database. Data and system managers use this guide to manage the data files and database that support the administrative, user-environment, database management, and operational capabilities of the IBS. This document provides a description of the data files and structures necessary for running the IBS software and using the site map database

Stressors in the pharmacy: An observational of interruptions in pharmacy

Errors in the healthcare field are a significant problem. Interruptions leading to distractions can cause errors as these interruptions can distract the pharmacy workers from their tasks. Hence it is important to study interruptions, their types, how they are caused, where they come from, when they occur, how long they last, and how pharmacists and technicians feel about them. The objectives of this observational study were to: 1) classify interruptions based on the type of interruption and cause, time, location, and duration, 2) identify differences in interruption types, duration and frequency across days of the week or time of day, and the analysis of these stressors can aid in improving the processes and increasing safety within the pharmacy. Poster originally presented at the MU Spring 2011 Undergraduate Research and Creative Achievements Forum

Ocean urea fertilization for carbon credits poses high ecological risks

The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved