Implications of HGV charging for the UK

Road transport taxation in Europe is undergoing a major and radical shift away from fixed charges and fuel duties towards pricing according to distance travelled and externalities produced. Implementation is underway in some states, change being led by national schemes for the freight sector only. The UK is considering such a system for implementation by 2008, to use global positioning system technology. The paper reviews the current developments and considers charging scenarios, including a scenario for covering the full external costs of the UK freight industry. Implications for taxation policy are considered, including whether the doctrine of revenue neutrality is consistent with 'sustainable mobility'. Consideration is given to a transition strategy which could bridge between the current level and structure of prices and a future, more economically efficient approach

Statistical Filtering of Space Navigation Measurements

Statistical filtering of space navigation measurement

Optimization of midcourse velocity corrections

Optimum time to apply single midcourse velocity correction and optimum schedule for corrections in variable time-of-arrival guidance - geometrical mode

The western blue groper (Achoerodus gouldii), a protogynous hermaphroditic labrid with exceptional longevity, late maturity, slow growth, and both late maturation and sex change

The western blue groper (Achoerodus gouldii) is shown to be a temperate protogynous hermaphrodite, which spawns between early winter and mid-spring. Because A. gouldii changes body color at about the time of sex change, its color can be used as a proxy for sex for estimating the size and age at sex change and for estimating growth when it is not possible to use gonads for determining the sex of this fish. The following characteristics make A. gouldii highly susceptible to overfishing: 1) exceptional longevity, with a maximum age (70 years) that is by far the greatest yet estimated for a labrid; 2) slow growth for the first 15 years and little subsequent growth by females; and 3) late maturation at a large total length (TL50 = 653 mm) and old age (~17 years) and 4) late sex change at an even greater total length (TL50 = 821 mm) and age (~35 years). The TL50 at maturity and particularly at sex change exceeded the minimum legal total length (500 mm) of A. gouldii and the lengths of many recreationally and commercially caught fish. Many of these characteristics are found in certain deep-water fishes that are likewise considered susceptible to overfishing. Indeed, although fishing effort for A. gouldii in Western Australia is not particularly high, per-recruit analyses indicate that this species is already close to or fully exploited

Prognostic significance of short-term blood pressure variability in acute stroke

Background and Purpose— Blood pressure variability (BPV) may be an important prognostic factor acutely after stroke. This review investigated the existing evidence for the effect of BPV on outcome after stroke, also considering BPV measurement techniques and definitions. Methods— A literature search was performed according to a prespecified study protocol. Two reviewers independently assessed study eligibility and quality. Where appropriate, meta-analyses were performed to assess the effect of BPV on poor functional outcome. Results— Eighteen studies from 1359 identified citations were included. Seven studies were included in a meta-analysis for the effect of BPV on functional outcome (death or disability). Systolic BPV was significantly associated with poor functional outcome: pooled odds ratio per 10-mm Hg increment, 1.2; confidence interval (1.1–1.3). A descriptive review of included studies also supports these findings, and in addition, it suggests that systolic BPV may be associated with increased risk of intracranial hemorrhage in those treated with thrombolytic therapy. Conclusions— This systematic review and meta-analysis suggest that greater systolic BPV, measured early from ischemic stroke or intracerebral hemorrhage onset, is associated with poor longer-term functional outcome. Future prospective studies should investigate how best to measure and define BPV in acute stroke, as well as to determine its prognostic significance. </jats:sec

1999 Quadrantids and the lunar Na atmosphere

Enhancements of the Na emission and temperature from the lunar atmosphere were reported during the Leonids meteor showers of 1995, 1997 and 1998. Here we report a search for similar enhancement during the 1999 Quadrantids, which have the highest mass flux of any of the major streams. No enhancements were detected. We suggest that different chemical-physical properties of the Leonid and Quadrantid streams may be responsible for the difference.Comment: 5 pages, 1 figure, accepted for publication in MNRA

Solar Assisted Power Systems

Except for hydroelectric power, solar electric generation has not been widely used in the past to assist power system generation because of its relatively high cost. This situation has now started to change with the advent of the energy crisis as exemplified by decreasing natural gas supplies and increasing fossil fuel prices. One possible response to this situation which appears to have a relatively good chance for economic success is the utilization of wind and solar thermal energy for space and water heating loads served by natural gas or electric power. Unfortunately, a large portion of the energy collected in a typical solar heating system is lost because the received solar energy is variable and, in most cases, is not well correlated with collection site loads. This paper examines the feasibility of using the excess energy available from solar heating systems for electric power production so that power system peaking capacity and total fossil fuel consumption can be reduced. As solar electric generation becomes larger, energy storage systems will be needed to assure power system stability and reliability. At the solar collection site, thermal energy and chemical storage units in battery form are preferred. For large central energy storage facilities pumped hydro, compressed air, liquid ammonia, storage batteries, and liquid hydrogen systems are possible choices. The liquid ammonia storage system is considered the best overall choice when pumped hydro or compressed air are not feasible

Analysis of programs and procedures designed to mitigate F/A-18 mishaps caused by Out of Control Flight

In 1983 the F/A-18 \u27Hornet\u27 was introduced into the United States Navy fleet. Since that time, Out-of-Control Flight (OOCF) has been the number three cause of F/A- 18 losses, third only to Controlled Flight Into Terrain (CFIT) and midair collisions. To mitigate crashes due to sustained OOCF modes, a pilot training program was developed and new recovery procedures were implemented. Begun in 2000, the Full Aft Stick Recovery Controls flight test program began-evaluating alternate recovery procedures for the most common OOCF mode, falling leaf. This program resulted in improved OOCF recovery procedures for the fleet and suggested a technique that has the potential of substantially reducing altitude loss. One year later, the Naval Air Systems Command (NAVAIR) Departure Training Program was formally introduced to provide academic lectures, a simulation session, and in-flight OOCF training to F/A-18 fleet pilots. The effectiveness of these programs is attributed to the quality of instructional materials, the hands-on instructional techniques, and the exploration of radically altered emergency procedures. These programs and procedures are likely to substantially reduce the number of aircraft lost to OOCF