Vortex-antivortex annihilation in mesoscopic superconductors with a central pinning center

In this work we solved the time-dependent Ginzburg-Landau equations, TDGL, to simulate two superconducting systems with different lateral sizes and with an antidot inserted in the center. Then, by cycling the external magnetic field, the creation and annihilation dynamics of a vortex-antivortex pair was studied as well as the range of temperatures for which such processes could occur. We verified that in the annihilation process both vortex and antivortex acquire an elongated format while an accelerated motion takes place.Comment: 4 pages, 5 figures, work presented in Vortex VII

Public Health England's recovery tools: potential teaching resources?

The file attached to this record is the author's final peer reviewed version.Training to combat chemical and radiation accidents, incidents or attacks is critical for health professionals due to recent events involving these hazards or their use as unconventional weapons, such as the use of the nerve agent novichok in Salisbury, UK. Health professionals need to have appropriate knowledge and skills to effectively respond to future events involving any of these substances, which requires a rapid and coordinated response from different professionals to protect the environment and minimise the number of people exposed and reduce morbidity and mortality. However, despite chemical and radiation incidents becoming increasingly prevalent, literature reviews have shown that there is a lack of teaching of appropriate competences to face future crises in Europe, particularly amongst clinicians and other health professionals that would be part of the initial response. Thus, De Montfort University (DMU, UK) in collaboration with different academics from the University of Alcalá (Spain) and researchers from Public Health England (PHE) with comprehensive experience in environmental decontamination and restoration, have created a short training course for providing undergraduate/postgraduate students with basic skills to respond to chemical incidents, basic skills that are based on the major competences recently identified by the European Commission [1]. This novel training has been tested with students from different backgrounds in various European universities, recording high degrees of acquisition of the various basic competences that we developed to initially respond to chemical events [2]. To develop the practical part of this chemical training, we have incorporated the novel guidance and methodology developed by PHE to successfully tailor a protection and recovery response to any incident involving chemical substances, which is available in the “UK Recovery Handbook for Chemical Incidents” [3] and its web-based tools: “Chemical Recovery Navigation Tool” (CRNT, [4]) and “Chemical Recovery Record Form” (CRRF, [5]). These innovative resources aid the user to select effective protection, decontamination and restoration techniques or strategies from a pool of up-to-date options applicable to different environments according to the physicochemical properties of the chemical(s) involved and the area affected. The CRNT is accompanied by the CRRF, which facilitates collection and analysis of the necessary data to inform decisions, and an e-learning resource named “Chemical Recovery: Background” (CRB, [6]), which could facilitate the learning of environmental decontamination and restoration. We are currently developing a short training course to cover minor radiation incidents; this radiation training will follow the same methods used to develop the chemical training, but with the specific PHE recovery tools to tackle such events, specifically the “UK Recovery Handbooks for Radiation Incidents” [7] and its associated web-based tools “Radiation Recovery Navigation Tool” (Rad RNT, [8]), one for each environment: food production systems, inhabited areas and drinking water supplies. This communication will explore the use of the PHE’s Recovery Navigation Tools as potential resources to facilitate the acquisition of basic knowledge to tailor protection and recovery interventions for minor chemical and radiation incidents to protect the public

Primeiro registro de Aetalion reticulatum (Auchenorrhyncha: Aethalionidae) em açaizeiro (Euterpe oleracea) no estado do Acre.

O açaizeiro (Euterpe oleracea) é uma palmeira nativa da várzea da região amazônica e pode ser indicada como a espécie de maior valor econômico do gênero. Dos seus frutos é extraída a polpa, largamente consumida no mercado nacional, quanto internacional. Com a expansão da área plantada, muitos fatores podem comprometer a produção e limitar o cultivo, destacando-se a ocorrência de insetos-praga que causam prejuízos à produção. Diversos insetos são relatados, associados ao açaizeiro, desde a fase de sementeira até a fase adulta. Portanto, torna-se necessário que sejam conhecidas as pragas que atacam esta palmeira, a fim de que se façam recomendações seguras de controle das mesmas. Em março de 2014 foram observadas colônias de cigarrinhas em plantas de E. oleracea, em plantio localizado no Campo Experimental da Embrapa Acre (10°01’26’’S; 67°41’39’’W), município de Rio Branco, Acre. As colônias se encontravam nas ráquilas de inflorescências e infrutescências, e a infestação se encontrava distribuída de forma não homogênea no talhão (reboleira). Insetos adultos foram coletados manualmente nas ráquilas das inflorescências e infrutescências, acondicionados em frascos de vidro contendo álcool etílico (70%) e levados até o Laboratório de Entomologia da Embrapa Acre, onde foram triados, montados e etiquetados. Os insetos foram identificados como Aetalion reticulatum (Auchenorrhyncha: Aethalionidae), espécie polífaga, associada principalmente às frutíferas. Este relato configura o primeiro registro de ocorrência desta cigarrinha em açaizeiro e no estado do Acre. Esta informação aumenta a lista de hospedeiros desta cigarrinha no Brasil e reforça a necessidade de estudos de dinâmica populacional, levantamento de inimigos naturais, níveis de dano e métodos de controle, a fim de antecipar possíveis surtos populacionais e prejuízos pelo ataque desta praga em plantios comerciais de açaí no Estado

A Method to Tackle First Order Differential Equations with Liouvillian Functions in the Solution - II

We present a semi-decision procedure to tackle first order differential equations, with Liouvillian functions in the solution (LFOODEs). As in the case of the Prelle-Singer procedure, this method is based on the knowledge of the integrating factor structure.Comment: 11 pages, late

Statistical mixing and aggregation in Feller diffusion

We consider Feller mean-reverting square-root diffusion, which has been applied to model a wide variety of processes with linearly state-dependent diffusion, such as stochastic volatility and interest rates in finance, and neuronal and populations dynamics in natural sciences. We focus on the statistical mixing (or superstatistical) process in which the parameter related to the mean value can fluctuate - a plausible mechanism for the emergence of heavy-tailed distributions. We obtain analytical results for the associated probability density function (both stationary and time dependent), its correlation structure and aggregation properties. Our results are applied to explain the statistics of stock traded volume at different aggregation scales.Comment: 16 pages, 3 figures. To be published in Journal of Statistical Mechanics: Theory and Experimen

Oferta e comercializacao de melancia na CEASA-PI(1991-1996).

bitstream/item/96038/1/CT710001.pd

In vitro toxin production by fusarium solani f. sp. piperis.

Fusarium solani f. sp. piperis (teleomórfico: Nectria haematococca f. sp. piperis) agente causal da podridão-das-raízes e do secamento-dos-ramos da pimenteira-do-reino (Piper nigrum) produz metabólitos secundários com propriedades tóxicas capazes de induzir descoloração das nervuras em folhas destacadas e murcha em micro-estacas. A produção de metabólitos tóxicos alcançou o pico após 25 dias de incubação, sob iluminação. Variações no pH do filtrado da cultura não aumentaram o efeito tóxico, entretanto, quando o pH foi ajustado antes da esterilização do meio de cultura, uma resposta biológica mais intensa foi observada, atingindo o máximo em pH 6,0. Isolados que produziram pigmentos vermelhos no meio de cultura foram mais eficientes em produzir filtrados biologicamente ativos do que aqueles que produziram filtrados de coloração rósea ou branca sugerindo que estes pigmentos podem estar relacionados com atividade toxigênica. Folhas destacadas de sete cultivares de pimenta-do-reino e Piper betle exibiram sintomas de descoloração das nervuras após imersão em filtrados autoclavado e não autoclavado indicando a natureza termoestável destes metabólitos tóxicos

Oscillatory dynamics of a superconductor vortex lattice in high amplitude ac magnetic fields

In this work we study by ac susceptibility measurements the evolution of the solid vortex lattice mobility under oscillating forces. Previous work had already shown that in YBCO single crystals, below the melting transition, a temporarily symmetric magnetic ac field (e.g. sinusoidal, square, triangular) can heal the vortex lattice (VL) and increase its mobility, but a temporarily asymmetric one (e.g. sawtooth) of the same amplitude can tear the lattice into a more pinned disordered state. In this work we present evidence that the mobility of the VL is reduced for large vortex displacements, in agreement with predictions of recent simulations. We show that with large symmetric oscillating fields both an initially ordered or an initially disordered VL configuration evolve towards a less mobile lattice, supporting the scenario of plastic flow.Comment: 5 pages, 4 figures. To appear in Phys. Rev.