Quantitative Sobolev regularity of quasiregular maps

We quantify the Sobolev space norm of the Beltrami resolvent $(I- \mu \mathcal S)^{-1}$, where $\mathcal S$ is the Beurling-Ahlfors transform, in terms of the corresponding Sobolev space norm of the dilatation $\mu$ in the critical and supercrticial ranges. Our estimate entails as a consequence quantitative self-improvement inequalities of Caccioppoli type for quasiregular distributions with dilatations in $W^{1,p}$, $p \ge 2$. Our proof strategy is then adapted to yield quantitative estimates for the resolvent $(I-\mu \mathcal S_\Omega)^{-1}$ of the Beltrami equation on a sufficiently regular domain $\Omega$, with $\mu\in W^{1,p}(\Omega)$. Here, $\mathcal S_\Omega$ is the compression of $\mathcal S$ to a domain $\Omega$. Our proofs do not rely on the compactness or commutator arguments previously employed in related literature. Instead, they leverage the weighted Sobolev estimates for compressions of Calder\'on-Zygmund operators to domains, recently obtained by the authors, to extend the Astala-Iwaniec-Saksman technique to higher regularities

Researching Bradford: A review of social research on Bradford District

A synthesis of findings from social research on the District of Bradford. This report synthesises the findings from a wide range of social research undertaken on the District of Bradford, primarily between 1995 and 2005. The researchers reviewed almost 200 pieces of work. The key results are summarised under thematic headings: - The social, economic and institutional context - Community cohesion - Housing, neighbourhoods and regeneration - Business and enterprise - Health, disability and social care - Children and young people - Education, skills and the labour market - Crime and community safety It also identifies a future research agenda. The main purpose of the review was to provide the Joseph Rowntree Foundation and local organisations in Bradford with a firm basis upon which to build future work in the District

Chains of N=2, D=4 heterotic/type II duals

We report on a search for $N=2$ heterotic strings that are dual candidates of type II compactifications on Calabi-Yau threefolds described as $K3$ fibrations. We find many new heterotic duals by using standard orbifold techniques. The associated type II compactifications fall into chains in which the proposed duals are heterotic compactifications related one another by a sequential Higgs mechanism. This breaking in the heterotic side typically involves the sequence $SU(4)\rightarrow SU(3)\rightarrow$ $SU(2)\rightarrow 0$, while in the type II side the weights of the complex hypersurfaces and the structure of the $K3$ quotient singularities also follow specific patterns.Comment: Latex, 21 pages, 2 table

A model for the future: Ecosystem services provided by the aquaculture activities of Veta la Palma, Southern Spain

© 2015 Elsevier B.V. The lack of space and opportunity for development has been identified as key reasons behind the stagnation of the European aquaculture industry. With the historical loss and degradation of current European wetlands there is an opportunity for harnessing the commercial investment of the aquaculture industry in construction of dual purpose wetlands that incorporate both conservation and extensive aquaculture activities. These wetlands can be used to expand the area available to suitable aquaculture into ecologically sensitive areas, such as Natura 2000 sites. Veta la Palma (VLP) situated in the Doñana Natural Park (and a Natura 2000 site) is an example of such an aquaculture development and a possible model for future opportunities. In the current study some of the important ecosystem services that are provided by VLP are assessed. The provisioning services of VLP were the economic rationale for the investment and more than 820tonnesyr-1 of fish and shrimp is produced, through a mixture of semi-extensive and extensive aquaculture. The regulating services include nutrient absorption, and the flow of river water through VLP and high primary production results in the absorption of 377tonnes of dissolved inorganic nitrogen yr-1, and 516tonnes of Cyr-1. Supporting services include the provision of habitat for more than 94 bird and 21 fish species. The primary production that supports the birds, extensive and semi-extensive aquaculture production was also estimated to be 167,000tonnes, 50,000tonnes and 133,000tonnesyr-1, respectively. The losses to birds are substantial and these estimates indicate that almost half of the primary production supports the wetland birds which directly consume 249tonnes of fish and 2578tonnes of invertebrates per annum. However it is the ecological credentials of the farm that enable premium prices and hence ensure the economic viability of the farm. The study demonstrates the possibility of using aquaculture to mitigate the historical loss of wetlands, provide significant ecosystem services and contribute to achievement of the European environmental legislative goals, and furthers the opportunity for the expansion of aquaculture into sensitive but impacted habitats.Peer Reviewe

Improved Oil Recovery in Fluvial Dominated Deltaic Reservoirs of Kansas Near Term

The objective of this project is to address waterflood problems of the type found in Morrow sandstone reservoirs in southwestern Kansas and Cherokee Group reservoirs in southeastern Kansas. Two demonstration sites operated by different independent oil operators are involved in this project. The Stewart Field is located in Finney County, Kansas and is operated by North American Resources Company. The Nelson Lease is located in Allen County, Kansas, in the N.E. Savonburg Field and is operated by James E. Russell Petroleum, Inc. General topics to be addressed are (1) reservoir management and performance evaluation, (2) waterflood optimization, and (3) the demonstration of recovery processes involving off-the-shelf technologies which can be used to enhance waterflood recovery, increase reserves, and reduce the abandonment rate of these reservoir types. In the Stewart Project, the reservoir management portion of the project conducted during Budget Period I involved performance evaluation. This included (1) reservoir characterization and the development of a reservoir database, (2) volumetric analysis to evaluate production performance, (3) reservoir modeling, (4) laboratory work, (5) identification of operational problems, (6) identification of unrecovered mobile oil and estimation of recovery factors, and (7) identification of the most efficient and economical recovery process. To accomplish these objectives the initial budget period was subdivided into three major tasks. The tasks were (1) geological and engineering analysis, (2) laboratory testing, and (3) unitization. Due to the presence of different operators within the field, it was necessary to unitize the field in order to demonstrate a field-wide improved recovery process. This work was completed and the project moved into Budget Period 2. Budget Period 2 objectives consisted of the design, construction, and operation of a field-wide waterflood utilizing state-of-the-art, off-the-shelf technologies in an attempt to optimize secondary oil recovery. To accomplish these objectives the second budget period was subdivided into five major tasks. The tasks were (1) design and construction of a waterflood plant, (2) design and construction of a water injection system, (3) design and construction of tank battery consolidation and gathering system, (4) initiation of waterflood operations and reservoir management, and (5) technology transfer. In the Savonburg Project, the reservoir management portion involves performance evaluation. This work included (1) reservoir characterization and the development of a reservoir database, (2) identification of operational problems, (3) identification of near wellbore problems such as plugging caused from poor water quality, (4) identification of unrecovered mobile oil and estimation of recovery factors, and (5) preliminary identification of the most efficient and economical recovery process i.e., polymer augmented waterflooding or infill drilling (vertical or horizontal wells). To accomplish this work the initial budget period was subdivided into four major tasks. The tasks included (1) geological and engineering analysis, (2) waterplant optimization, (3) wellbore cleanup and pattern changes, and (4) field operations. This work was completed and the project has moved into Budget Period 2. The Budget Period 2 objectives consisted of continual optimization of this mature waterflood in an attempt to optimize secondary and tertiary oil recovery. To accomplish these objectives the second budget period was subdivided into six major tasks. The tasks were (1) waterplant development, (2) profile modification treatments, (3) pattern changes, new wells and wellbore cleanups, (4) reservoir development (polymer flooding), (5) field operations, and (6) technology transfer

Improved oil recovery in fluvial dominated reservoirs of Kansas--near-term. Annual report

Common oil field problems exist in fluvial dominated deltaic reservoirs in Kansas. The problems are poor waterflood sweep efficiency and lack of reservoir management. The poor waterflood sweep efficiency is due to (1) reservoir heterogeneity, (2) channeling of injected water through high permeability zones or fractures, and (3) clogging of injection wells due to solids in the injection water. In many instances the lack of reservoir management results from (1) poor data collection and organization, (2) little or no integrated analysis of existing data by geological and engineering personnel, (3) the presence of multiple operators within the field, and (4) not identifying optimum recovery techniques. Two demonstration sites operated by different independent oil operators are involved in this project. The Stewart Field is located in Finney County, Kansas and is operated by North American Resources Company. This field was in the latter stage of primary production at the beginning of this project and is currently being waterflooded as a result of this project. The Nelson Lease (an existing waterflood) is located in Allen County, Kansas, in the N.E. Savonburg Field and is operated by James E. Russell Petroleum, Inc. The objective is to increase recovery efficiency and economics in these type of reservoirs. The technologies being applied to increase waterflood sweep efficiency are (1) in situ permeability modification treatments, (2) infill drilling, (3) pattern changes, and (4) air flotation to improve water quality. The technologies being applied to improve reservoir management are (1) database development, (2) reservoir simulation, (3) transient testing, (4) database management and (5) integrated geological and engineering analysis. Results of these two field projects are discussed

6D Effective Action of Heterotic Compactification on K3 with nontrivial Gauge Bundles

We compute the six-dimensional effective action of the heterotic string compactified on K3 for the standard embedding and for a class of backgrounds with line bundles and appropriate Yang-Mills fluxes. We compute the couplings of the charged scalars and the bundle moduli as functions of the geometrical K3 moduli from a Kaluza-Klein analysis. We derive the D-term potential and show that in the flux backgrounds U(1) vector multiplets become massive by a Stuckelberg mechanism.Comment: 41 pages, typos corrected, references adde

Effects of air pollution and the introduction of the London Low Emission Zone on the prevalence of respiratory and allergic symptoms in schoolchildren in East London: a sequential cross-sectional study

The adverse effects of traffic-related air pollution on children’s respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8–9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00–1.02), NO2 (1.03, 1.00–1.06), PM10 (1.16, 1.04–1.28) and PM2.5 (1.38, 1.08–1.78), all per μg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions

X-Ray Spectral Variability in NGC 3783

NGC 3783 was observed for approximately 210 ks by Suzaku and in this time showed significant spectral and flux variability at both short (20 ks) and long (100 ks) timescales. The full observation is found to consist of approximately six "spectral periods" where the behavior of the soft (0.3-1.0 keV) and hard (2-10 keV) bands are somewhat distinct. Using a variety of methods we find that the strong warm absorber present in this source does not change on these timescales, confirming that the broadband variability is intrinsic to the central source. The time-resolved difference-spectra are well modeled with an absorbed power law below 10 keV, but show an additional hard excess at ##IMG## [http://ej.iop.org/icons/Entities/ap.gif] {≈ 20 keV in the latter stages of the observation. This suggests that, in addition to the variable power law, there is a further variable component that varies with time but not monotonically with flux. We show that a likely interpretation is that this further component is associated with variations in the reflection fraction or possibly ionization state of the accretion disk a few gravitational radii from the black hole.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98537/1/0004-637X_745_1_93.pd