7,134 research outputs found

    Report of the Education and Development Group of the National Midwifery Recruitment and Retention Six Point Action Plan

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    Final report of the Education Group written for the Chief Nursing Officer for England, Dame, Professor Christine Beasley. Paul Lewis chaired the Education Group and also co-wrote the publication

    Comparative analysis of the seismic hazard of Central China

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    Seismic hazard assessment is globally recognised as a tool in identifying levels of earthquake ground shaking within an area. However, methodologies for seismic hazard calculation are wide ranging and produce variations in results and maps. As a case study seismic hazard and results from Gumbel’s method of extremes are determined for the area of greatest intraplate seismicity in China covering the provinces of Gansu, Sichuan and Yunnan. This area is termed the North-South Seismic Zone. Devastating earthquakes in this zone include the 8.4 MS 1920 Haiyuan earthquake causing over 220,000 deaths and the 1996 Lijiang earthquake. Most recently the 2008 Wenchuan earthquake caused over 69,000 deaths with more than 18,000 people missing. These results and seismic hazard maps are compared with the publicly available maps of GSHAP and the national seismic hazard map of China at the level of 10% probability of exceedance in a 50 year period. The distributions of high and low hazard areas are similar and adjacent to the major thrust and strike-slip faults dominating in this area. However, results from the Gumbel method of extremes suggest that the hazard levels within certain areas are slightly different compared to the other two models. This is primarily because the Gumbel methodology is based on determining hazard from earthquakes that have already taken place whereas the other two models determine maximum hazard levels in areas which may exhibit no previous strong hazard. Additionally the Chinese national hazard map does not indicate levels of ground shaking intensity greater than IX in detail, whereas such zones are identified using the extreme value method. This work should be used to strengthen the seismic hazard analysis of this area of China

    Characteristics of the low-energy reporters in a longitudinal national dietary survey

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    The aim of the present study was to establish whether the characteristics of members of a large national birth cohort study who submitted diet diaries with implausibly low-energy intake differed from those whose recorded energy intake was more plausible. Survey members (n 1898) recorded their diets in a 7 d diary in household measures. Those whose reported energy intake (EI) as a fraction of their estimated BMR was less than 1.10, here termed low-energy reporters (LER) but often called under-reporters, constituted 20.6 % of the study population. None of the variables describing dietary, smoking or exercise behaviour bore a significant relationship with low EI/BMR (<1.10), neither did those describing region of residence, subjective adequacy of income, current social class, social relations or the social environment of the subjects. Results of logistic regression analysis showed that the only independently significant characteristic for men was higher BMI. In women, in addition to higher BMI, having been overweight or obese as an adult independently, but less significantly, predicted low EI/BMR, while membership as a child of social class III (nonmanual), having more children in the household and having a paid job marginally but independently decreased the probability of reporting low EI/BMR. Submission of a diary with EI/BMR <1.10 7 years earlier in the same survey was an even more powerful predictor of current low EI/BMR than higher BMI in both sexes. The average reported diet-composition of LER was more micronutrient- and protein-rich than that of the others, indicating different dietary, or diet-recording, behaviour in this group of subjects. LER are not a random sample of the survey population, and their characteristics, definable to some extent, put them at risk for lower health status. Although EI/BMR cut-off points can be used to identify LER, the problem of how to use their data is still unresolved

    Asymptotic Solutions for Mean-Field Slab Dynamos

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    We discuss asymptotic solutions of the kinematic αω\alpha\omega-dynamo in a thin disc (slab). Focusing upon the strong dynamo regime, in which the dynamo number DD satisfies ∣D∣≫1|D|\gg1, we resolve uncertainties in the earlier treatments and conclude that some of the simplifications that have been made in previous studies are questionable. Comparing numerical solutions with asymptotic results obtained for ∣D∣≫1|D|\gg1 and ∣D∣≪1|D|\ll1 we find that the asymptotic solutions give a reasonably accurate description of the dynamo even far beyond their formal ranges of applicability. Indeed, our results suggest a simple analytical expression for the growth rate of the mean magnetic field that remains accurate in the range −200<D<−10-200< D< -10 (which is appropriate for dynamos in spiral galaxies and accretion discs). Finally, we analyse the role of various terms in the dynamo equations to clarify the fine details of the dynamo process.Comment: "This is an Author's Original Manuscript of an article submitted for consideration in Geophysical and Astrophysical Fluid Dynamics [copyright Taylor & Francis]; Geophysical and Astrophysical Fluid Dynamics is available online at http://www.tandfonline.com/gafd

    Permian carbonate facies Southern Big Horn Basin -Owl Creek Mountains area north central Wyoming

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    High resolution mass spectrometry for molecular characterization of pyrolysis products and kinetics

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    In recent decades, thermochemical conversion of biomass, such as pyrolysis, has gained popularity as a source for renewable materials. Pyrolysis generates three products: biochar that has shown promise as a soil amendment and carbon sequestration agent, bio-oil that could supplement petroleum-based products and transportation fuel, and syngas that is useful for ammonia, methanol, or hydrocarbon/aromatic production. At the molecular level, these samples are complex and difficult to analyze, which creates a bottleneck for thorough understanding. This dissertation utilizes high-resolution mass spectrometry (HRMS) to overcome the sample complexity and improve understanding at the molecular level. HRMS was applied to understanding organic molecules entrapped in biochar during pyrolysis and gasification of switchgrass. Extraction of organic molecules used toluene and a mixture of water/methanol for hydrophobic aromatic compounds and hydrophilic polar compounds, respectively. Orbitrap mass spectrometric data acquisition revealed that molecular compounds previously known in bio-oils were observed for fast pyrolysis biochar, whereas polycyclic aromatic hydrocarbons (PAHs) with various ring sizes were observed for gasification and slow pyrolysis biochars. Bio-oils from fast pyrolysis of switchgrass harvested at various times throughout the year were studied using high-resolution mass spectrometry. Nearly three hundred total nitrogen-containing species were detected through efficient ionization and accurate mass information. Nitrogen-containing species, particularly N2 compounds, were highly abundant for early summer bio-oils, but decrease significantly in later harvest times. Contour plots of double bond equivalent (DBE) versus carbon number and tandem mass spectrometric analysis were utilized to determine the major structural motif for N1 and NO class compounds as pyridine and N2 class compounds as imidazole. The dramatic decrease in nitrogen compounds correlates to the decomposition of proteins as the perennial plant senesces. Catalytic deoxygenation of cellulose pyrolysis was evaluated using micropyrolyzer-gas chromatography (µPy-GC) coupled to dopant-assisted atmospheric pressure chemical ionization (dAPCI) time-of-flight mass spectrometry (TOF MS). A vast majority of compounds produced via catalysis and/or pyrolysis cannot be found in the database. However, dAPCI-TOF MS produces soft ionization and accurate mass measurement for direct chemical composition analysis of GC-separated molecules. This analytical technique demonstrated the ability to evaluate catalytic efficiency and monitor the change in reaction products. A total of 142 compounds could be analyzed with this approach compared to 38 compounds in traditional Py-GC-EI-MS analysis. Finally, HRMS is utilized for the real-time monitoring of fast pyrolysis products of glucose-based carbohydrates. The soft ionization and rapid-scanning capabilities provided new insights into molecular-level understanding of pyrolysis chemistry. Comparing time evolution profiles and yields for individual products revealed that hydrogen bonding may play a larger role in degradation of cellulose and that cyclodextrin does not appear to be a good surrogate for understanding cellulose pyrolysis. More work is necessary to piece together all the information, but the first steps have been taken toward unraveling the complex network of elementary reactions

    The volcaniclastic deposits of the main caldera and the evolution of the Galluccio Tuff of Roccamonfina volcano, Southern Italy

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    A thesis submitted in partial fulfilment of the requirements of the Council for National Academic Awards for the degree of Doctor of PhilosophyThe south-west portion of the main caldera was mapped and a stratigraphy for the caldera-fill was constructed. The exact timing of formation of the main caldera is unclear; However, caldera collapse either predates or was synchronous with the eruption of the Campagnola Tuff. The proximal facies of the Campagnola Tuff exists as a complex relation of ignimbrite, lithic breccia and pyroclastic surge deposits. Overlying this the Galluccio Tuff a compound ignimbrite, ~6 km3 D.R.E, forms the base of the exposed caldera fill. Caldera lakes then became well established and following activity was predominantly phreatomagmatic. Pyroclastic surge deposits possess sand wave structures of several types and their migration direction was apparently controlled by the velocity/flow regime of the surge rather than the moisutre content. The morphology of juvenile clasts from phreatomagmatic deposits indicates that the eruptions were driven by a combination of vesiculation and magma/water interaction. The uppermost pyroclastic deposits are thought to represent the early phase of dome building where water still had access to the vent. The construction of the lava domes brought activity to a close within the main caldera. The Galluccio Tuff on the flanks of the volcano may be divided into three compositionally distinct eruptive units. The Lower Galluccio Tuff, correlated with the bulk of the Galluccio Tuff filling the main caldera. The Middle Galluccio Tuff commenced with the eruption of pumice-rich pyroclastic flows followed by flows enriched in both the size and amount of lithic fragments forming lithic-rich ignimbrite and co-ignimbrite lithic breccias of which several types exist. The Upper Galluccio Tuff is composed of lithic-rich ignimbrite which possess dense pumice fragments and are thought to be the product of a combination of both vesiculation and magma water interaction. Field relations indicate that pyroclastic flows were sometimes generated in quick succession and may have overrun earlier slower moving flows. Occasionally internal shear may have caused the overriding of portions of the same flow, these often coincide with lithic breccias and represent the climax of the eruptive phases. The grading of lithic fragments indicates that the expansion and fluidization decreased and yield strength increased with time in a pyroclastic flow

    Modulated cycles in an illustrative solar dynamo model with competing alpha effects

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    The large-scale magnetic field in the Sun varies with a period of approximately 22 years, although the amplitude of the cycle is subject to long-term modulation with recurrent phases of significantly reduced magnetic activity. It is believed that a hydromagnetic dynamo is responsible for producing this large-scale field, although this dynamo process is not well understood. Within the framework of mean-field dynamo theory, our aim is to investigate how competing mechanisms for poloidal field regeneration (namely a time delayed Babcock-Leighton surface alpha-effect and an interface-type alpha-effect), can lead to the modulation of magnetic activity in a deep-seated solar dynamo model. We solve the standard alpha-omega dynamo equations in one spatial dimension, including source terms corresponding to both of the the competing alpha-effects in the evolution equation for the poloidal field. This system is solved using two different methods. In addition to solving the one-dimensional partial differential equations directly, using numerical techniques, we also use a local approximation to reduce the governing equations to a set of coupled ordinary differential equations (ODEs), which are studied using a combination of analytical and numerical methods. In the ODE model, it is straightforward to find parameters such that a series of bifurcations can be identified as the time delay is increased, with the dynamo transitioning from periodic states to chaotic states via multiply periodic solutions. Similar transitions can be observed in the full model, with the chaotically modulated solutions exhibiting solar-like behaviour.Comment: Reproduced with permission from Astronomy & Astrophysic

    C32, A Young Star Cluster in IC 1613

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    The Local Group irregular galaxy IC 1613 has remained an enigma for many years because of its apparent lack of star clusters. We report the successful search for clusters among several of the candidate objects identified many years ago on photographic plates. We have used a single HST WFPC2 pointing and a series of images obtained with the WIYN telescope under exceptional seeing conditions, examining a total of 23 of the previously published candidates. All but six of these objects were found to be either asterisms or background galaxies. Five of the six remaining candidates possibly are small, sparse clusters and the sixth, C32, is an obvious cluster. It is a compact, young object, with an age of less than 10 million years and a total absolute magnitude of M_V = -5.78+/-0.16 within a radius of 13 pc.Comment: 5 pages, 5 figures, to be published in the May 2000 issue of the PAS
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