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171.
There has been a decline in the population of some bird species at Morecambe Bay and the Solway Firth Special Protected Areas in North-West England during the last fifty years. It was suggested that the declines were caused, in part, by contaminants in the food and environment, primarily from the radioactive effluent discharge from the Sellafield Ltd nuclear fuel reprocessing plant in Cumbria. This study analysed bird feathers and tissues, vegetation and sediment for radionuclides, metals and persistent organic compounds. The non-radionuclide results were all low compared to relevant action limits. The ERICA model was used with field data to estimate the radiological dose to birds from exposure to 137Cs and 241Am with results between 1.26 to 3.83 μGy h− 1, below the ERICA screening level of 10 μGy h− 1 and within the IAEA 40 μGy h− 1 guideline value below which potential adverse impacts on biota are unlikely. The study showed no link between bird population decline and anthropogenic discharges to the SPAs. 相似文献
172.
Jethro Akroyd Alastair J. Smith Laurence R. McGlashan Markus Kraft 《Chemical engineering science》2010,65(6):1915-1924
This paper investigates a mean reaction rate closure for turbulent reacting flows called the Direct Quadrature Method of Moments using the Interaction by Exchange with the Mean micromixing model (DQMoM-IEM). The method was first introduced for reacting flows by Fox (Computational Models for Turbulent Reacting Flows, Cambridge University Press, 2003). We present a systematic study that considers several important new aspects of the method. In particular we introduce a new analytic expression for the DQMoM-IEM source terms. We present a rigourous numerical investigation and discuss problems of boundedness and singularity in detail. We introduce a filter function to overcome these issues in the general case and present analytic integrals for special cases of specific terms. We extend the methodology to take advantage of these developments and show details of the implementation in a commercial computational fluid dynamics (CFD) code. We present an extensive set of numerical experiments and validation. The method is proven for a problem known from the literature which includes an isothermal dimerisation process. Experimental and transported probability density function (PDF) data compare reasonably well. The method is discussed critically and areas for further research are suggested to make the method more practical. 相似文献
173.
Ali Z. Khokhar Graham Hubbard Douglas S. Macintyre David Massoubre Nigel P. Johnson Ian M. Watson Martin D. Dawson Martin D.B. Charlton 《Microelectronic Engineering》2010,87(11):2200-3239
We describe a comparison of nanofabrication technologies for the fabrication of 2D photonic crystal structures on GaN/InGaN blue LEDs. Such devices exhibit enhanced brightness and the possibility of controlling the angular emission profile of emitted light. This paper describes three nano lithography techniques for patterning photonic crystal structures on the emitting faces of LEDs: direct-write electron beam lithography, hard stamp nanoimprint lithography and soft-stamp nanoimprint lithography with disposable embossing masters. In each case we describe variations on the technique as well as its advantages and disadvantages. Complete process details have been given for all three techniques. In addition, we show how high performance GaN dry etch techniques, coupled with optical process monitoring can transfer resist patterns into underlying GaN material with high fidelity. 相似文献
174.
175.
Victoria Watson 《The Journal of Architecture》2013,18(1):99-112
This paper looks at two theoretical statements about ‘space’, both of which are grounded in a vitalist philosophy. The first is Henri Lefebvre's formulation of ‘spatial architectonics’, a structure of concepts which he develops in The Production of Space; the second is Mies van der Rohe's intuition of something he termed ‘authentic form’, a means of triggering new experiences and understandings through sensual engagement with space. Since there are other philosophers and other architects whose thinking about space has been influenced by vitalist philosophy, the discussion will begin with an explanation as to why Lefebvre and van der Rohe have been selected for reciprocal examination. 相似文献
176.
177.
Laarnie Tumolva Ji-Yeon Park Jae-suk Kim Arthur L. Miller Judith C. Chow John G. Watson 《Aerosol science and technology》2013,47(3):202-215
The Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDS) were used to determine morphology and elemental composition of a variety of freshly emitted soot particles (acetylene flame, candle flame, kerosene flame, diesel exhaust, electric arc, plastic burning, styrofoam burning, wood burning [white oak and pine bark], and rice straw burning), which can be possible candidate soot in the ambient atmosphere, and ultrafine particles sampled in urban, industrial, and coastal sites during ultrafine particle formation events (combustion and photochemical events). By using mobility-classified non-refractory ((NH 4 ) 2 SO 4 ) and refractory (Polystyrene latex (PSL) and salt (NaCl)) particles, limitation of the TEM was tested. Data showed that the TEM method can be used to examine shapes of both volatile particles such as (NH 4 ) 2 SO 4 (100 nm) at low, but not high magnification (refer to low and high beam intensity, respectively), and non-volatile particles like NaCl (100 nm) and PSL (84 nm) at either low or high magnification. Distinct differences in morphological properties such as primary particle diameter, fractal dimension, and microstructure were observed among the different types of fresh soot particles. The atmospheric ultrafine particles were classified as agglomerates, sulfate mixtures (spherical), metallic oxides (spherical and polygonal), C-rich refractory (not agglomerated), C-rich non-refractory (not agglomerated), Si-rich (spherical), Na-rich (porous), or P-containing (non-spherical) particles. At the urban Gwangju site, a higher fraction of fresh and aged agglomerates was observed than at other sites. The C-rich non-refractory and sulfate mixtures were often observed in the photochemical event. The C-rich refractory particles were abundant at the Gwangju and Yeosu sites. The coastal Taean site had few agglomerates due to limited anthropogenic combustion source. 相似文献
178.
“I drove after drinking alcohol” and other risky driving behaviours reported by young novice drivers
Bridie Scott-Parker Barry Watson Mark J. King Melissa K. Hyde 《Accident; analysis and prevention》2014
Background: Volitional risky driving behaviours such as drink- and drug-driving (i.e. substance-impaired driving) and speeding contribute to the overrepresentation of young novice drivers in road crash fatalities, and crash risk is greatest during the first year of independent driving in particular. Aims: To explore the: (1) self-reported compliance of drivers with road rules regarding substance-impaired driving and other risky driving behaviours (e.g., speeding, driving while tired), one year after progression from a Learner to a Provisional (intermediate) licence; and (2) interrelationships between substance-impaired driving and other risky driving behaviours (e.g., crashes, offences, and Police avoidance). Methods: Drivers (n = 1076; 319 males) aged 18–20 years were surveyed regarding their sociodemographics (age, gender) and self-reported driving behaviours including crashes, offences, Police avoidance, and driving intentions. Results: A relatively small proportion of participants reported driving after taking drugs (6.3% of males, 1.3% of females) and drinking alcohol (18.5% of males, 11.8% of females). In comparison, a considerable proportion of participants reported at least occasionally exceeding speed limits (86.7% of novices), and risky behaviours like driving when tired (83.6% of novices). Substance-impaired driving was associated with avoiding Police, speeding, risky driving intentions, and self-reported crashes and offences. Forty-three percent of respondents who drove after taking drugs also reported alcohol-impaired driving. Discussion and Conclusions: Behaviours of concern include drink driving, speeding, novice driving errors such as misjudging the speed of oncoming vehicles, violations of graduated driver licensing passenger restrictions, driving tired, driving faster if in a bad mood, and active punishment avoidance. Given the interrelationships between the risky driving behaviours, a deeper understanding of influential factors is required to inform targeted and general countermeasure implementation and evaluation during this critical driving period. Notwithstanding this, a combination of enforcement, education, and engineering efforts appear necessary to improve the road safety of the young novice driver, and for the drink-driving young novice driver in particular. 相似文献
179.
The UK government’s framework for regeneration, “Transforming Places, Changing Lives”, seeks to shape the way regeneration is conducted in England. The emphasis on economic transformation should not be unexpected, considering the Index of Multiple Deprivation – a key measure used throughout the UK literature for several years – has an emphasis on economic dimensions of deprivation. The paper critically assesses the manner in which the ‘localism’ of regeneration policy implementation is being promoted in the literature, while simultaneously using a national metric as an evidence base for action. 相似文献
180.
Ward A.G. Watson N.R. Arnold C.P. Turner A.J. Ring B.J. 《Power Systems, IEEE Transactions on》2000,15(4):1197-1203
An increasing number of electricity markets employing some form of spot pricing. However, limited experience of the behavior of spot prices exists. This paper introduces and investigates one particular aspect of pricing behavior observed in the New Zealand spot market, known as “price inversion”. Spot prices are generally calculated using some form of OPF or power-flow software. The phenomena of price inversion is investigated using the DC power-flow implemented in the New Zealand spot market, and using a full AC power-flow. Price inversion is shown to be dependent on the physical characteristics of the power system. The economic implications of price inversion are also discussed 相似文献