Boron nanobelts grown under intensive ion bombardment

High-quality α-tetragonal crystalline boronnanobelts with [001] growth axis were synthesized using a novel method combining e-beam evaporation and plasma ion bombardment techniques. Intensive ion bombardment of the growingboronnanobelts at a high substrate temperature (∼1200°C) was found to be effective in increasing the atomic density, reducing the crystal disorder, and improving the yield of the nanobelts.This work was supported by the Australian Research Council ARC

Space Station/Shuttle Orbiter dynamics during docking

Mathematical models of a reference space station configuration (Power Tower) and a Space Shuttle Orbiter are developed and used to study the dynamic behavior of the Space Station/Orbiter system just prior to and subsequent to an impulsive docking of the two spacecraft. The physical model of the space station is a collection of rigid and flexible bodies. The orbiter is modeled as a rigid body. An algorithm developed for use in digitally simulating the dynamics of the system is described and results of its application are presented

A comparison of A-level performance in economics and business studies: how much more difficult is economics?

This paper uses ALIS data to compare academic performance in two subjects often viewed as relatively close substitutes for one another at A-level. The important role of GCSE achievement is confirmed for both subjects. There is evidence of strong gender effects and variation in outcomes across Examination Boards. A counterfactual exercise suggests that if the sample of Business Studies candidates had studied Economics nearly 40% of those who obtained a grade C or better in the former subject would not have done so in the latter. The opposite exercise uggests that 12% more Economics candidates would have achieved a grade C or better if they had taken Business Studies. In order to render a Business Studies A-level grade comparable to an Economics one in terms of relative difficulty, we estimate that a downward adjustment of 1.5 UCAS points should be applied to the former subject. This adjustment is lower than that suggested by correction factors based on conventional subject pair analysis for these two subjects

Gonzalo de Berceo in Spanish Literary Criticism before 1780

In Spanish literature the first poet whose name we know with certainty is Gonzalo de Berceo, who flourished in the first half of the thirteenth century. The first complete edition of his works did not appear until toward the end of the eighteenth century. What happened to them and what was thought of them during the five centuries that intervened between the death of the poet and the year 1780, when the learned Librarian of the King, Don Tomás Antonio Sánchez, published the second volume of his Collección de Poesías Castellanas Anteriores al Siglo XV giving it the subtitle of Poesías de Don Gonzalo de Berceo? The question is not without interest; neither are the results of the investigations that lead us toward the possibility of answering it. Consequently, I propose setting forth with the utmost brevity the results that I have so far been able to obtain from my investigations. In citing the texts that speak of Berceo, I shall not stop to comment on them, nor even to correct the errors–sometimes rather serious-they may contain

Finite element models of wire rope for vibration analysis

The usefulness of wire rope in shock and vibration isolation is briefly reviewed and its modeling for the purpose of vibration analysis is addressed. A model of a nominally straight segment of wire rope is described in which the rope structure is represented by a maiden, or central, strand of wire with one (or more) strand(s) wrapped around it in a helix (helices). The individual strands are modeled using finite elements and MSC NASTRAN. Small linear segments of each wire are modeled mathematically by dividing them lengthwise into triangular prisms representing each prism by a solid NASTRAN element. To model pretensioning and allow for extraction of internal force information from the NASTRAN model, the wound strands are connected to the maiden strand and each other using spring (scalar elastic) elements. Mode shapes for a length of wire rope with one and fixed to a moving base and the other attached to a point mass, are presented. The use of the NASTRAN derived mode shapes to approximate internal normal forces in equations of motion for vibration analyses is considered

Borman Expressway Point-to-Point Wireless Modem

The Federal Highway Administration has a nationwide allocation of five frequency pairs in the 220-222 MHz Narrowband Radio Services band which are intended for application in Intelligent Transportation Systems. These frequencies are available for use by state DOTs (subject to FHWA approval) and provide an attractive solution for certain low to medium bit rate data communications applications. However, given the limited bandwidth available in these channels, very efficient modems will be required to make maximum beneficial use of this resource. The goal of this project was to design, field test, and deploy a digital radio which uses the 220-222 MHz spectral allocation and is suitable for stationary point-to-point data communications applications. The target application for this project was the control (pan, tilt, and zoom) of a video camera located at the interchange of I-65 and the Borman Expressway. The wireless link extends from the camera location to the traffic operations center (approximately 1.5 miles). There were three main tasks needed to produce a deployable modem: 1) interface circuitry was required between the 220 MHz modem and the camera control keypad and the camera pan/tilt/zoom receiver, 2) the fabrication of a compact and rugged transmitter was required, and 3) the fabrication of a compact and rugged receiver was required. The receiver size constraints were more exacting than those of the transmitter as the receiver is deployed in a roadside cabinet, while the transmitter is deployed in the traffic management center. The work plan was divided into a set of twelve tasks. The 220 MHz modem can serve INDOT as a general purpose link for low to medium rate data communications in a wide variety of applications. The most significant issue outstanding with regard to widespread implementation of the technology is the mass production cost and the availability of a reliable source of production versions of the device. Efforts are continuing at both Purdue and Ohio State toward further simplifications aimed at complexity reduction in the receiver. As topics for further study, the following should be considered: 1) a detailed cost/benefit analysis should be made comparing the 220 MHz technology to other alternative technologies, and 2) a preliminary design study of interoperability issues should be performed for the 220 MHz technology in transportation applications

Assessing Vulnerability of Selected Sectors Under Environmental Tax Reform: The Issue of Pricing Power. ESRI WP222. October 2007

This paper investigates pricing power, an important criterion for identifying sectors that would be vulnerable under environmental tax reform. Environmental tax reform, defined here as introduction of carbon taxes alongside reductions in labour taxes, could bear heavily on sectors that are energy intensive and highly traded, in particular if their options for adapting technology are limited. However, a sector with pricing power has less to fear as, rather than having to conform to the world price, it can set its price to accommodate a tax mark-up

ENVIRONMENTAL ACCOUNTS: TIME SERIES + ECO-TAXES

This study was commissioned by the European Commission in cooperation with Eurostat with the objective of improving and extending the scope of the environmental accounts for Ireland. It follows two previous studies, Pilot Environmental Accounts published by the Central Statistics Office and the Satellite Environmental Accounts for Ireland 1996, unpublished report to Eurostat (2000). As indicated in the title, this study presents time series, which in some cases are of considerable length, and provides information on what could loosely be called eco-taxes. Additionally, where feasible the study relates environmental information to the underlying economic magnitudes and movements, and broadens the information considerably. The report consists of three self-contained sections. The sections cover (1) emissions to air, (2) discharges to water and (3) disposals of solid waste and these three types of releases to the environment are disaggregated according to NACE Rev 1 by five major economic sectors: Agriculture/forestry/fishing Energy transformation Industry Transport Services Households though in some areas the breakdown is unavoidably less detailed and it is more detailed in others. Section 1 on emissions to air concentrates on greenhouse gases and on improving the underlying information on energy use. Behavioural analyses have been hampered in the past by inadequate time-series of energy-related prices and taxes so that a large effort was devoted here to presenting coherent time-series of these items