The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent

Peer reviewedPublisher PD

Modelling spatial and inter-annual variations of nitrous oxide emissions from UK cropland and grasslands using DailyDayCent

This work contributes to the Defra funded projects AC0116: ‘Improving the nitrous oxide inventory’, and AC0114: ‘Data Synthesis, Management and Modelling’. Funding for this work was provided by the UK Department for Environment, Food and Rural Affairs (Defra) AC0116 and AC0114, the Department of Agriculture, Environment and Rural Affairs for Northern Ireland, the Scottish Government and the Welsh Government. Rothamsted Research receives strategic funding from the Biotechnology and Biological Sciences Research Council. This study also contributes to the projects: N-Circle (BB/N013484/1), U-GRASS (NE/M016900/1) and GREENHOUSE (NE/K002589/1).Peer reviewedPublisher PD

Many-body localization and thermalization in the full probability distribution function of observables

We investigate the relation between thermalization following a quantum quench and many-body localization in quasiparticle space in terms of the long-time full distribution function of physical observables. In particular, expanding on our recent work [E. Canovi {\em et al.}, Phys. Rev. B {\bf 83}, 094431 (2011)], we focus on the long-time behavior of an integrable XXZ chain subject to an integrability-breaking perturbation. After a characterization of the breaking of integrability and the associated localization/delocalization transition using the level spacing statistics and the properties of the eigenstates, we study the effect of integrability-breaking on the asymptotic state after a quantum quench of the anisotropy parameter, looking at the behavior of the full probability distribution of the transverse and longitudinal magnetization of a subsystem. We compare the resulting distributions with those obtained in equilibrium at an effective temperature set by the initial energy. We find that, while the long time distribution functions appear to always agree {\it qualitatively} with the equilibrium ones, {\it quantitative} agreement is obtained only when integrability is fully broken and the relevant eigenstates are diffusive in quasi-particle space.Comment: 18 pages, 11 figure

Incorporação de resíduos cerâmicos vidrados em argamassas bastardas: estudo de propriedades físicas e mecânicas

Dissertação de Natureza Científica para obtenção do grau de Mestre em Engenharia Civil Perfil de EdificaçõesA conservação do património edificado constitui no presente, a memória de uma civilização. O conhecimento da composição e comportamento dos revestimentos antigos é importante para garantir a conservação do património edificado através das intervenções de conservação e reabilitação. A presente dissertação tem como objetivo o estudo do desempenho de argamassas bastardas de cal aérea e cimento com substituição de cal aérea por resíduo cerâmico vidrado. As argamassas formuladas foram sujeitas a cura laboratorial. Realizou-se a caracterização física, e mecânica de modo a avaliar o seu desempenho ao longo do tempo. O sector da construção pauta a sua atividade por elevados impactos ambientais ao nível da extração de elevadas quantidades de matérias-primas não renováveis, de elevados consumos energéticos e das consequentes e elevadas emissões de gases responsáveis por efeito de estufa. Além dos enormes excedentes que provem da indústria que normalmente seguem para aterro. De forma a aproveitar esses excedentes de algumas indústrias, nomeadamente da cerâmica procedeu-se à transformação de produtos excedentes em resíduo, de forma a ser possível a sua incorporação argamassas, uma vez que na antiguidade, no império romano já se efetuava esta incorporação. A produção de cimento tem elevados impactos ambientais, deste modo a redução da sua utilização através da incorporação de outros ligantes de natureza natural (cal aérea) e a possível substituição desses recursos naturais por excedentes irá aumentar a sustentabilidade do sector.In the present, the conservation of the built heritage constitutes the memory of a civilization. The knowledge of composition and performance of the old coverings is crucial to ensure the preservation of the built heritage through intervention of conservation and rehabilitation. This thesis aims to study the performance of aerial lime based mortars and cement with replacement of the aerial lime with glazed ceramic waste. The bastard mortars have characteristics well-suited for these functions, once incorporates the best features of air lime and cement. The construction sector bases its activity by high environmental impacts, because of the extraction of non-renewable raw material, high energy consumption and high emission of gases responsible for the greenhouse effect. In addition to huge surpluses that comes from the industry and that usually goes to landfill. In order to take advantage of the surpluses in some industries, including ceramics, it was proceeded the transformation of surpluses in residue. In this way was possible to incorporate the residues in mortars, as the Roman Empire in ancient time proceeded. The production of cement has high environmental impacts, thereby reducing their use by incorporating other ligands with natural source (air lime) and the possible replacement of these natural resources by surpluses will increase the sustainability of the sector. The incorporation of residues leads to the study of new mortars formulations. The formulated mortars were subject to a process of laboratory cure. It was reported over time, the performance, the physical and mechanical characterization of the mortars. In the properties studied was recorded a good performance of the mortars, due to the placement of the ceramic powder

Manipulation and removal of defects in spontaneous optical patterns

Defects play an important role in a number of fields dealing with ordered structures. They are often described in terms of their topology, mutual interaction and their statistical characteristics. We demonstrate theoretically and experimentally the possibility of an active manipulation and removal of defects. We focus on the spontaneous formation of two-dimensional spatial structures in a nonlinear optical system, a liquid crystal light valve under single optical feedback. With increasing distance from threshold, the spontaneously formed hexagonal pattern becomes disordered and contains several defects. A scheme based on Fourier filtering allows us to remove defects and to restore spatial order. Starting without control, the controlled area is progressively expanded, such that defects are swept out of the active area.Comment: 4 pages, 4 figure

"LUDO" - Kids playing Distributed Denial of Service

Distributed denial of service attacks pose a serious threat to the availability of the network infrastructures and services. GE̿ANT, the pan-European network with terabit capacities witnesses close to hundreds of DDoS attacks on a daily basis. The reason is that DDoS attacks are getting larger, more sophisticated and frequent. At the same time, it has never been easier to execute DDoS attacks, e.g., Booter services offer paying customers without any technical knowledge the possibility to perform DDoS attacks as a service. Given the increasing size, frequency and complexity of DDoS attacks, there is a need to perform a collaborative mitigation. Therefore, we developed (i) a DDoSDB to share real attack data and allow collaborators to query, compare, and download attacks, (ii) the Security attack experimentation framework to test mitigation and response capabilities and (iii) a collaborative mitigation and response process among trusted partners to disseminate security event information. In addition to these developments, we present and would like to discuss our latest research results with experienced networking operators and bridging the gap between academic research and operational business

Проблема правової культури в історії філософсько-педагогічної думки

(uk) Стаття присвячена проблемі правової культури в історії філософсько-педагогічної думки

Western Indian Ocean marine and terrestrial records of climate variability: a review and new concepts on land-ocean interactions since AD 1660

We examine the relationship between three tropical and two subtropical western Indian Ocean coral oxygen isotope time series to surface air temperatures (SAT) and rainfall over India, tropical East Africa and southeast Africa. We review established relationships, provide new concepts with regard to distinct rainfall seasons, and mean annual temperatures. Tropical corals are coherent with SAT over western India and East Africa at interannual and multidecadal periodicities. The subtropical corals correlate with Southeast African SAT at periodicities of 16–30 years. The relationship between the coral records and land rainfall is more complex. Running correlations suggest varying strength of interannual teleconnections between the tropical coral oxygen isotope records and rainfall over equatorial East Africa. The relationship with rainfall over India changed in the 1970s. The subtropical oxygen isotope records are coherent with South African rainfall at interdecadal periodicities. Paleoclimatological reconstructions of land rainfall and SAT reveal that the inferred relationships generally hold during the last 350 years. Thus, the Indian Ocean corals prove invaluable for investigating land–ocean interactions during past centuries