Vortex configurations and metastability in mesoscopic superconductors

The vortex dynamics in mesoscopic superconducting cylinders with rectangular cross section under an axially applied magnetic field is investigated in the multivortex London regime. The rectangles considered range from a square up to an infinite slab. The flux distribution and total flux carried by a vortex placed in an arbitrary position of the sample is calculated analytically by assuming Clem's solution for the vortex core. The Bean-Livingston energy barrier is also analytically calculated in this framework. A Langevin algorithm simulates the flux penetration and dynamical evolution of the vortices as the external field is slowly cycled. The simulated magnetization process is governed by metastable states. The magnetization curves are hysteretic, with paramagnetic response in part of the downward branch, and present a series of peaks corresponding to the entry or expulsion of a single vortex. For elongated rectangles, the vortices arrange themselves into parallel vortex chains and an additional modulation of the magnetization, corresponding to creation or destruction of a vortex chain, comes out.Comment: 7 pages, 4 figures. Presented on the III European Conference on Vortex Matter in Superconductors, Crete, 2003. To appear in Physica

Vortex-Antivortex annihilation dynamics in a square mesoscopic superconducting cylinder

The dynamics of the annihilation of a vortex-antivortex pair is investigated. The pair is activated magnetically during the run of a simulated hysteresis loop on a square mesoscopic superconducting cylinder with an antidot inserted at its center. We study the nucleation of vortices and antivortices by first increasing the magnetic field, applied parallel to the axis of the sample, from zero until the first vortex is created. A further increase of the field pulls the vortex in, until it reaches the antidot. As the polarity of the field is reversed, an antivortex enters the scene, travels toward the center of the sample and eventually the pair is annihilated. Depending on the sample size, its temperature, and Ginzburg-Landau parameter, the vortex-antivortex encounter takes place at the antidot or at the superconducting sea around it. The position and velocity of the vortex and antivortex singularities were evaluated as a function of time. The current density, magnetization and order parameter topology were also calculated.Comment: One REVTeX file and 5 EPS figure

Development of Ontology Aware of Information Quality for the Improvement of Situational Awareness in the Field of Emergency Management

Artigo apresentado no I Workshop de Informação, Dados e Tecnologia, realizado entre nos dias 04 e 06 de setembro de 2017, na cidade de Florianópolis (SC), no Auditório do Espaço Físico Integrado (EFI) da Universidade Federal de Santa Catarina (UFSC).Uma questão desafiadora na comunidade da Avaliação da Situação é determinar como o processo de avaliação pode ser redesenhado para o aprimoramento da Consciência da Situação (SAW), que pode ser severamente degradada se dados de baixa qualidade propagarem pelo processo comprometendo assim a tomada de decisões. Em sistemas de gerenciamento de emergências o grande desafio de adquirir e manter a SAW em operadores humano, é o consumo em excesso de dados em um ambiente dinâmico. O presente trabalho tem por objetivo o desenvolvimento de uma ontologia de domínio para o gerenciamento de emergências mais especificamente sobre incêndios florestais visando contribuir para a representação de informações, contribuindo assim com processos de avaliação de situações de fogo. Para tal, foram desenvolvidas entrevistas com especialistas, modelagem conceitual das tarefas e objetivos e o emprego de ferramentas e metodologias para a construção da ontologia que ao final será incorporada ao sistema “Distrito Federal Sem Fogo” (DF100Fogo).A challenging issue in the Situation Assessment community is to determine how the assessment process can be redesigned to improve Situation Awareness (SAW), which can be severely degraded if poor quality data propagate through the process, thereby compromising decision-making. In emergency management systems, the great challenge of acquiring and maintaining SAW in human operators is consuming too much data in a dynamic environment. The present work has the objective of developing a domain ontology for the emergencies management, more specifically about forest fires, aiming to contribute to the representation of information in this domain, thus contributing to fire assessment processes. To this end, interviews with specialists, conceptual modeling of tasks and objectives and the use of tools and methodologies for the construction of the ontology were developed, which in the end will be incorporated into the Distrito Federal Sem Fogo (DF100Fogo) system

Vortices in superconducting strips: interplay between surface effects and the pinning landscape

Vortices in a narrow superconducting strip with a square array of pinning sites are studied. The interactions of vortices with other vortices and with external sources (applied magnetic field and transport current) are calculated via a screened Coulomb model. The edge barrier is taken into account and shown to have an important role on the system dynamics. Numerical simulations in this approach show that the field dependent magnetic moment presents peaks corresponding to history dependent configurations of the vortex lattice. Some effects of the edge barrier on the I-V characteristics are also reported.Comment: 4 pages, 3 figure

A OFERTA DE TRABALHO NO BRASIL NA PERSPECTIVA DO TEMPO DE ESTUDO DOS TRABALHADORES

The present article aims to identify the main transformations of the Brazilian labor force in the perspective of its qualification by means of the conclusion of years of studies between the years of 2001 to 2015. For this, it analyzes the data of the base of the National Survey by Sample of Domiciles (PNAD) for the period. It notes that the intense process of raising the level of education of the country's workforce does not translate into meeting socially established expectations during the last century, that dedication to studies is the basis for a better insertion in the labor market.O presente artigo objetiva identificar as principais transformações da força de trabalho do Brasil na perspectiva da sua qualificação mediante a conclusão de anos de estudos entre os anos de 2001 a 2015. Para tanto, são analisados dados disponibilizados pela Pesquisa Nacional por Amostra de Domicílios (PNAD) para o mencionado período. Nele se observa que o intenso processo de elevação da escolaridade dos trabalhadores do país não se traduz em atendimento às expectativas socialmente estabelecidas durante o século passado, de que a dedicação aos estudos são a base para uma melhor inserção no mercado de trabalho

Bulbos úmidos a partir da irrigação por gotejamento subsuperficial com água de abastecimento e efluente de esgoto tratado

The use of treated sewage effluent (TSE) combined with the subsurface drip irrigation (SDI) method in agriculture can decrease the costs of agricultural production, in attempts to fertigate crops more efficiently. In this study it was compared the dimensions of the wet bulb formed by the application of TSE and municipal water supply (MWS) in an Oxisoil. We have evaluated the effect of water quality and discharge between drippers used in sugarcane crop. Three trenches were opened and 21 three-rod TDR probes were setup in a mesh and a dripper was buried at 0.30 m, for each constant discharge of 1.0 L h-1and 1.6 L h-1. Comparing results from different wetted soil profiles it was observed that the vertical and horizontal dimensions of the wet bulb are similar for both MWS and TSE, being peculiars according to the discharges used and volume applied. Regardless the water quality, an increase of 60% in discharge decreased the deepest infiltration.352242253O uso de efluente de esgoto tratado (EET), combinado com o método de irrigação por gotejamento subsuperfical (IGS) na agricultura, pode reduzir os custos de produção agrícola, fertirrigando de maneira eficiente as culturas. Neste artigo, compararam-se as dimensões do bulbo úmido formado pela aplicação de EET e água de abastecimento municipal (AAM), em um Latossolo Vermelho distroférrico. Avaliou-se o efeito da qualidade da água e da vazão entre gotejadores utilizados na cultura da cana-de-açúcar. Três trincheiras foram abertas e 21 sondas de TDR com três hastes foram instaladas em malha, e um gotejador foi enterrado a 0,30 m, para cada vazão constante de 1,0 Lh-1 e 1,6 Lh-1. Comparando os resultados de diferentes perfis de umidade do solo, sugere-se que as dimensões vertical e horizontal do bulbo úmido sejam similares para a AAM e para o EET, sendo peculiares de acordo com as vazões utilizadas e o volume aplicado. Independentemente da qualidade da água, o aumento de 60% na vazão reduziu a infiltração em profundidade

New segregates from the Neotropical genus Stryphnodendron (Leguminosae, Caesalpinioideae, mimosoid clade)

Non-monophyly is a prominent issue in mimosoid legumes, even in some of the less speciose genera such as the neotropical genus Stryphnodendron. This genus includes 35 species occurring from Nicaragua to Southern Brazil mostly in humid forests and savannas. Previous taxonomic studies of Stryphnodendron have highlighted morphologically distinct groups within the genus, recognized by differences on leaves (number of pinnae and size of leaflets), inflorescences (a simple or compound thyrse), and fruit types (legume, nucoid legume or follicle). Recent phylogenetic analyses have confirmed the non-monophyly of Stryphnodendron, supporting the recognition of three independent and morphologically well-delimited genera. Here we re-circumscribe Stryphnodendron and propose the two new genera Gwilymia and Naiadendron. In addition, we also provide an updated taxonomic account of the closely related genus Microlobius, including the proposal of a lectotype for the single species in the genus