Poluição por partículas. Um estudo de magnetismo ambiental com biocolectores em Braga, Porto, Valongo e Trancoso (Norte de Portugal)

This work presents an assessment on the pollution levels in plant leaves from 5 selected sites, 4 in urban areas and one in a rural area. It was used an environmental magnetism study with particle biological collectors (Nerium oleander L., Quercus spp., Tilia spp. e Platanus spp.). The results pointed out the contrast between sites with high traffic and the countryside. When comparing the biological collectors, Quercus leaves had higher efficiency to accumulate particles, while Platanus leaves showed the lowest value

On spin-1 massive particles coupled to a Chern-Simons field

We study spin one particles interacting through a Chern-Simons field. In the Born approximation, we calculate the two body scattering amplitude considering three possible ways to introduce the interaction: (a) a Proca like model minimally coupled to a Chern-Simons field, (b) the model obtained from (a) by replacing the Proca's mass by a Chern-Simons term and (c) a complex Maxwell-Chern-Simons model minimally coupled to a Chern-Simons field. In the low energy regime the results show similarities with the Aharonov-Bohm scattering for spin 1/2 particles. We discuss the one loop renormalization program for the Proca's model. In spite of the bad ultraviolet behavior of the matter field propagator, we show that, up to one loop the model is power counting renormalizable thanks to the Ward identities satisfied by the interaction vertices.Comment: 14 pages, 5 figures, revte

OS RELEVOS CALCÁRIOS DA REGIÃO CENTRAL DO BARROCAL ALGARVIO (SUL DE PORTUGAL) - UM MODELO TECTÓNICO The limestones reliefs of the Algarve Barrocal (south Portugal) – a tectonic model

Several Mesozoic limestone elevations of E-W elongated shape rise up in the central region of the Algarve Barrocal (Portuguese southwestern margin). Tectonic geomorphology suggests that these reliefs correspond to right lateral strike-slip contractional duplexes of a large, NW-SE trending, shear zone, with a pronounced topographic expression, whose southern boundary, located southeast of the Serra de Monchique hill, is defined by the São Marcos–Quarteira Fault Zone

Fabric magnético em red beds da Formação de Conraria, Portugal Central

The main goal of this study was to quantify the magnetic fabric on rock samples of the upper subunit of the Conraria Formation, Silves Group, in the region of Coimbra. Studies of Anisotropy of Magnetic Susceptibility (AMS) were carried out on 50 samples from 11 sites in order to characterise the magnetic fabric. The general parallelism between an oblate fabric and stratification may indicate a combination between the primary sedimentary arrangement and another one with origin in the diagenesis or even in components of earlier tectonic origi

Relationship between polymorphism of growth hormone and precocity traits in Nellore heifers

Avaliaram-se as relações entre o polimorfismo do gene do hormônio do crescimento (GH) e as características de precocidade, em novilhas da raça Nelore. Amostras de sangue periférico foram obtidas de 181 animais de três rebanhos distintos do estado da Bahia, nas quais foi realizada a extração de DNA e a amplificação por PCR, seguidas por digestão com enzima de restrição AluI. Os fragmentos resultantes da digestão enzimática foram analisados em gel de agarose 2% para determinação dos respectivos genótipos. A frequência do alelo Leu nas amostras analisadas foi estimada em 100%. Em decorrência da alta incidência de homozigose para o alelo Leu, sugere-se que o restriction fragment lenght polymorphism AluI do gene GH não possa ser considerado como marcador molecular para precocidade sexual em novilhas Nelore nesses rebanhos.The relationships between polymorphism of growth hormone gene (GH) and precocity traits in Nellore heifers were evaluated. A total of 181 animals from three different farms of Bahia state, Brazil, were blood sampled. The DNA of each animal was extracted, amplified by PCR, and digested by "AluI" restriction enzyme, and the resultant fragments were analyzed in 2% agarose gel for genotype identification. The frequency of Leu allele in the analyzed samples was estimated in 100%. Due to the high incidence of homozygose for the Leu allele, it is suggested that the restriction fragment lenght polymorphism AluI of GH gene can not be considered as a molecular marker for sexual precocity in Nellore heifers of those herds.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Hysteresis in the Mott Transition between Plasma and Insulating Gas

We show that hysteresis can occur in the transition between a neutral plasma and the insulating gas consisting of neutral pairs bound by Coulomb attraction. Since the transition depends sensitively on the screening length in the plasma, regions of bistability occur in density--temperature phase space. We present numerical results which indicate where these regions occur for systems such as spin-polarized hydrogen, positronium gas, and excitons in a semiconductor.Comment: 9 pages (Latex/RevTex), 6 postscript figures which are in compressed and uuencoded file, prepared using the utility "uufiles" and separately submitted. They should be automatically included with the text when it is downloaded. Figures also available in hard copy from the authors ([email protected]; [email protected]); paper submitted to Phys. Rev.

Distributed situation awareness in nuclear, chemical, and maritime domains

The increase in size, automation and complexity of modern sociotechnical systems changed the dynamics of work environments and calls for new methodologies and metaphors towards safety of complex systems. Chemical, nuclear, and transportation (i.e. road, maritime, and aviation) industries are composed of various nested sub-systems where smooth coordination and communication are essential features to achieve continuous and safe operations. Even though such sub-systems exist since the industrial revolution, fewer studies have been conducted in these domains: to understand the work as it is done (rather than it is imagined), which is the only way to shed light about the variability in work performance and how these subsystems can combine to generate dangerous and unexpected outcomes. The theoretical framework of Distributed Situation Awareness provides a firm background to investigate the sub-systems that constitute the chemical, nuclear, and maritime industries/domains. This paper unfolds the key sub-systems (e.g., operators, human-computer interfaces, communication tools, and distant/different locations) that play a critical role in normal and abnormal situations in these industries. The complex interconnections among various artifacts are explained and their significance is assessed