2,696 research outputs found
The determination of the momentum dependence of the ionisation loss of fast cosmic-ray particles in neon
Not availabl
Annona muricata (graviola): toxic or therapeutic
This paper examines annona muricata (graviola): toxic or therapeutic
Chemical signatures of the Anthropocene in the Clyde Estuary, UK: sediment hosted Pb, 207/206 Pb, Total Petroleum Hydrocarbons (TPH), Polyaromatic Hydrocarbon (PAH) and Polychlorinated Bipheny (PCB) pollution records
The sediment concentrations of total petroleum hydrocarbons (TPHs), polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), Pb and 207/206Pb isotope ratios were measured in seven cores from the middle Clyde estuary (Scotland, UK) with an aim of tracking the late Anthropocene. Concentrations of TPHs ranged from 34 to 4386 mg kg−1, total PAHs from 19 to 16 163 μg kg−1 and total PCBs between less than 4.3 to 1217 μg kg−1. Inventories, distributions and isomeric ratios of the organic pollutants were used to reconstruct pollutant histories. Pre-Industrial Revolution and modern non-polluted sediments were characterized by low TPH and PAH values as well as high relative abundance of biogenic-sourced phenanthrene and naphthalene. The increasing industrialization of the Clyde gave rise to elevated PAH concentrations and PAH isomeric ratios characteristic of both grass/wood/coal and petroleum and combustion (specifically petroleum combustion). Overall, PAHs had the longest history of any of the organic contaminants. Increasing TPH concentrations and a concomitant decline in PAHs mirrored the lessening of coal use and increasing reliance on petroleum fuels from about the 1950s. Thereafter, declining hydrocarbon pollution was followed by the onset (1950s), peak (1965–1977) and decline (post-1980s) in total PCB concentrations. Lead concentrations ranged from 6 to 631 mg kg−1, while 207/206Pb isotope ratios spanned 0.838–0.876, indicative of various proportions of ‘background’, British ore/coal and Broken Hill type petrol/industrial lead. A chronology was established using published Pb isotope data for aerosol-derived Pb and applied to the cores
NMR quantum computation with indirectly coupled gates
An NMR realization of a two-qubit quantum gate which processes quantum
information indirectly via couplings to a spectator qubit is presented in the
context of the Deutsch-Jozsa algorithm. This enables a successful comprehensive
NMR implementation of the Deutsch-Jozsa algorithm for functions with three
argument bits and demonstrates a technique essential for multi-qubit quantum
computation.Comment: 9 pages, 2 figures. 10 additional figures illustrating output spectr
Implementation of a Deutsch-like quantum algorithm utilizing entanglement at the two-qubit level, on an NMR quantum information processor
We describe the experimental implementation of a recently proposed quantum
algorithm involving quantum entanglement at the level of two qubits using NMR.
The algorithm solves a generalisation of the Deutsch problem and distinguishes
between even and odd functions using fewer function calls than is possible
classically. The manipulation of entangled states of the two qubits is
essential here, unlike the Deutsch-Jozsa algorithm and the Grover's search
algorithm for two bits.Comment: 4 pages, two eps figure
Using goal directed task analysis to identify situation awareness requirements of advanced paramedics
Advanced paramedics, known in the UK as emergency care practitioners (ECPs) are employed by ambulance services to meet the demand for urgent care in the community. The role has been evaluated in terms of patient outcomes. To further
understand and evaluate the role, Goal Directed Task Analysis (GDTA) was conducted. Based on the analysis, situation awareness requirements among ECPs were identified. The results of the GDTA are presented and their implication discussed in terms of goal hierarchy structure, patient as source of information, and sociotechnical system. We discuss recommendations for the role with regard to the ECPs' SA. Further SA studies to evaluate and develop the ECP role are also outlined
The High Resolution Airborne Resource and Environmental Survey- (Phase 1) (HiRES-1): background, data processing and dissemination and future prospects
This report provides an overview of the HiRES-1 airborne
geophysical survey of Central England. The BGS and World
Geoscience (UK) Ltd. carried out the survey jointly in 1998.
The three main survey data sets acquired were magnetic,
radiometric (gamma ray spectrometry) and Very Low
Frequency (VLF) electromagnetic. The main aim of the report
is to provide information on the acquisition, processing and
storage of the final data and map products produced by the
HiRES-1 project. Additional descriptions of ground truthing
activities, data licensing and dissemination are also provided.
A significant aspect of the project was the assessment of the
potential of, and issues raised by, modern, multi-parameter,
regional-scale airborne geophysical surveys in the UK
context. Some of the main issues outlined in the report are:
• The practical difficulties of conducting extensive low
level, fixed-wing geophysical surveying in the UK.
Issues discussed include CAA regulatory permissions,
flight height adjustments above conurbations and
surveying near areas with dense air traffic.
• The processing challenges introduced by cultural (nongeological)
influences on high resolution airborne
magnetic data sets in the UK.
• The significant amounts of detailed geological and
environmental information contained within the
radiometric data.
• The weak application potential provided by passive
(i.e. VLF) measurements, in contrast to active airborne
electromagnetic techniques.
The future prospects for regional-scale, airborne geophysical
surveys in the UK are considered. Such prospects are also
influenced by a further set of trial airborne data, obtained in
1999, but not described here.
Further detail of the HiRES-1 survey, productivity,
technical specifications and data pre-processing are contained
in the survey logistics report prepared by WGL: ‘British
Geological Survey “Hi-Res Phase One” Airborne Geophysical
Survey (Survey Details, Technical Specifications &
Processing Summary)’ (WGL 2000)
Potential -pH relationships of some metal-metal oxide electrodes
PhD ThesisThe suitability of metal-metal oxide electrodes and the
drawbacks of established pII measuring electrodes are reviewed.
A well-established metal-metal oxide system was chosen for
initial examination and various experimental techniques of evaluation
were developed. This work was extended to include a brief
investigation of certain other systems, bismuth, tungsten, platinum,
rhodium. and gold, Finally, the viability of an electrode prepared
by the electrodeposition of rhodium was established and detailed
studies made.
Further experiments were designed to determine the chemical
and physical nature of the electrode surface, as well as the,
reactions responsible for some of the deviations from the theorctical
pH response. The techniques employed for this purpose included
Energy Dispersive Analysis, Stereoscan Electron Microscopy, X-ray
Photoelectron Spectroscopy as well as various Electrochemical methods.Electronic Instruments Limited (Chertsey, Surrey)
Trial airborne environmental and geological survey: an initial appraisal of relevance to land-use
A series of four trial airborne environmental and geological surveys was flown by the Geological Survey of Finland (GTK) in collaboration with the British Geological Survey (BGS) in June 1999; the trials were co-sponsored by the Department of the Environment, Transport and the Regions and the Environment Agency. The main objective of these surveys was to test the efficiency of the GTK airborne electromagnetic system in the mapping of potential pollution problems in the UK environment. Gamma spectrometric and magnetometric measurements were also collected to see to what extent these techniques provide complementary information.
This report is an initial consideration of the multi-parameter airborne geophysical data in relation to land-use issues. A variety of earth science information for planning and development already exists. The baseline information is reviewed according to scale and resolution. It is noted that the airborne data is of a new type with regard to both information content and spatial continuity. The specific characteristics and advantages of the airborne geophysical data are emphasised.
The trial survey data were obtained at high resolution and a large number of anomalous responses have been observed. Since the information is provided at a local-scale a number of issues concerning the nature of the responses observed and the underlying causes have been raised. It will be necessary to improve our understanding of the data before an unambiguous discussion of their specific relevance to land-use issues can proceed.
In advance of detailed interpretations of the trial data, the data are presented and discussed in relation to their potential relevance to five land-use issues: (i) Waste planning/Planning and pollution control, (ii) Minerals Planning, (iii) Water supply and water resource protection/Coastal zone management, (iv) Urban regeneration/Peripheral development and new communities and (v) Agriculture and Forestry.
It is acknowledged that there are differences between the information needed for planning the use of land, and information which is required for monitoring environmental strategies. The geophysical data appear to have greatest relevance to the latter requirement. Recommendations for ground and subsurface calibration of the data are made
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