Durability of enamel bonding using two-step self-etch systems on ground and unground enamel

This study examined the early and long-term microtensile bond strengths (mu TBS) and interfacial enamel gap formation (IGW) of two-step selfetch systems to unground and ground enamel. Resin composite (Filtek Z250) buildups were bonded to proximal enamel surfaces (unground, bur-cut or SiC-treated enamel) of third molars after the application of four self-etch adhesives: a mild (Clearfil SE Bond [SE]), two moderate (Optibond Solo Plus Self-Etch Primer [SO] and AdheSE [AD]) and a strong adhesive (Tyrian Self Priming Etchant + One Step Plus [TY]) and two etch-and-rinse adhesive systems (Single Bond [SB] and Scotchbond Multi-Purpose Plus [SBMP]). Ten tooth halves were assigned for each adhesive. After storage in water (24 hours/37 degrees C), the bonded specimens were sectioned into beams (0.9 mm(2)) and subjected to mu TBS (0.5 mm/minute) or interfacial gap width measurement (stereomicroscope at 400x) either immediately (IM) or after 12 months (12M) of water storage. The data were analyzed by three-way repeated measures ANOVA and Tukey`s test (alpha=0.05). No gap formation was observed in any experimental condition. The mu TBS in the Si-C paper and diamond bur groups were similar and greater than the unground group only for the moderate self-etch systems (SO and AD). No reductions in bond strength values were observed after 12 months of water storage, regardless of the adhesive evaluated.

Canal transportation and centring ability of RaCe rotary instruments

Evaluate, through computerized tomography, canal transportation and centring ability of RaCe rotary instruments after preparation of mesiobuccal root canals in maxillary molar teeth. Twenty-seven teeth were submitted to three cone beam tomographic analyses, one preoperatively, and two after preparation with file size 35, .02 taper and size 50, .02 taper. Canal transportation and centring ability were measured with reference to the distance between the noninstrumented portion of the root canals and the mesial and distal periphery of the root, compared with images obtained after the preparation with size 35 and 50 instruments. Canal transportation after preparation with the size 35 file was 0.030 +/- 0.253 mm and after the size 50 file was 0.057 +/- 0.317 mm. The centring ratio values after preparation with the size 35 file was 0.42 +/- 0.32 and after the size 50 file was 0.54 +/- 0.29, with no significant statistical difference between the groups. RaCe instruments allowed the preparation of curved root canals with preparation diameters larger than those normally used with minimal canal transportation and adequate centring ability.

Exploring through cover - the integrated interpretation of high resolution aeromagnetic, airborne electromagnetic and ground gravity data from the Grant's Patch area, Eastern Goldfields Province, Archaean Yigarn Craton Part B; Gravity inversion as a

The cost and risk associated with mineral exploration in Australia increases significantly as companies move into deeper regolith-covered terrain. The ability to map the bedrock and the depth of weathering within an area has the potential to decrease this risk and increase the effectiveness of exploration programs. This paper is the second in a trilogy concerning the Grant's Patch area of the Eastern Goldfields. The recent development of the VPmg potential field inversion program in conjunction with the acquisition of high-resolution gravity data over an area with extensive drilling provided an opportunity to evaluate three-dimensional gravity inversion as a bedrock and regolith mapping tool. An apparent density model of the study area was constructed, with the ground represented as adjoining 200 m by 200 m vertical rectangular prisms. During inversion VPmg incrementally adjusted the density of each prism until the free-air gravity response of the model replicated the observed data. For the Grant's Patch study area, this image of the apparent density values proved easier to interpret than the Bouguer gravity image. A regolith layer was introduced into the model and realistic fresh-rock densities assigned to each basement prism according to its interpreted lithology. With the basement and regolith densities fixed, the VPmg inversion algorithm adjusted the depth to fresh basement until the misfit between the calculated and observed gravity response was minimised. The resulting geometry of the bedrock/regolith contact largely replicated the base of weathering indicated by drilling with predicted depth of weathering values from gravity inversion typically within 15% of those logged during RAB and RC drilling.

Resistively loaded helical antennas for ground-penetrating radar

Resistively loaded helical antennas, used in the normal mode and horizontally polarised, are modelled using the moment method above typical lossy ground. The distributed resistive loading was adjusted to maintain a two octave bandwidth. The centre frequency of 1 m dipoles was reduced from 250 MHz for the straight resistive wire to 50 MHz for a helix of pitch 2.5 cm and diameter 5 cm. The reduction in efficiency required to maintain the bandwidth for this helix was 12 dB. This agrees reasonably with the theory for small antennas in free space. The results were also verified by comparing measurements performed on a monopole resistively loaded helical antenna in a watertank with the numerical model used elsewhere.

An investigation into the possible inhibitory effects of white cypress pine (Callitris glaucophylla) litter on the germination and growth of associated ground cover species

White cypress-pine stands typically support sparse densities of shrubs and grasses. The commonly held opinion is that leaching of allelopathic chemical compounds from cypress-pine litter partly facilitates this exclusion. Germination and growth of cypress pine seedlings do not appear to be similarly affected. This study set out to determine whether cypress litter had a differential effect on germination and growth of cypress-pine seedlings and on associated ground-cover species. Glasshouse trials comparing seedling emergence under cypress- and artificial-litter layers were undertaken. Cypress-pine litter did not have an inhibitory effect on the germination or growth of ground-cover species. In most cases, seedling emergence was facilitated by the application of cypress-pine litter due to its ability to increase the water holding capacity of the underlying soil. Cypress litter did not promote growth of its own seedlings over its competitors except on coarse-textured soils where it provided an ameliorative function to water stress due to the soil's reduced water holding capacity. The inhibition of ground-cover species' germination and growth in pure cypress stands was suggested to be the result of high below-ground resource competition due to the pine's expansive root morphology.

An investigation of magnetic antennas for ground penetrating radar

For ground penetrating radar (GPR), smaller antennas would provide considerable practical advantages. Some of which are: portability; ease of use; and higher spatial sampling. A theoretical comparison of the fundamental limits of a small electric field antenna and a small magnetic field antenna shows that the minimum Q constraints are identical. Furthermore, it is shown that only the small magnetic loop antenna can be constructed to approach, arbitrarily closely, the fundamental minimum Q limit. This is achieved with the addition of a high permeability material which reduces energy stored in the magnetic fields. This is of special interest to some GPR applications. For example, applications requiring synthetic aperture data collection would benefit from the increased spatial sampling offered by electrically smaller antennas. Low frequency applications may also benefit, in terms of reduced antenna dimensions, by the use of electrically small antennas. Under these circumstances, a magnetic type antenna should be considered in preference to the typical electric field antenna. Numerical modeling data supports this assertion.

Estudo do transporte atmosférico de Mp10 e SO2 com os Modelos WRF/CMAQ em regiões costeiras urbanas

O objetivo principal deste trabalho foi o estudo do transporte atmosférico de PM10 e SO2 em regiões costeiras urbanas usando modelos WRF/CMAQ. Duas regiões foram contempladas neste estudo. Uma é a Região da Grande Vitória (RGV), no estado do Espírito Santo, Brasil; a outra é a Região da Grande Dunkerque (RGD), no Departamento Nord Pas-de-Calais, França. A RGV é cercada por uma cadeia de montanhas paralela à costa, resultando num topografia complexa e acidentada. Já a RGD possui uma topografia muito mais suave. As entradas de dados para os modelos WRF/CMAQ englobaram o inventário de emissões de poluentes atmosféricos do IEMA-ES para a RGV, e o inventário de emissões no nível do solo de Nord Pas-de-Calais denominado ―Cadastre_totaux_3km_A2008 _M2010_V2_SNAPN2‖ para a RGD. Ambos os inventários apresentaram restrições, todavia. O inventário da RGV apresentou valores de ressuspensão em vias de tráfego elevados, em comparação com diversos estudos, e teve esses dados modificados. Os dados no nível do solo e a grande área de das células da grade (9 km2) do inventário da RGD não permitiram resultados satisfatórios de modelagem. A validação dos modelos foi realizada por comparação com resultados obtidos em duas campanhas experimentais: uma na cidade de Dunkerque, no norte da França, em setembro de 2009; a outra na cidade de Vitória, no sudeste do Brasil, em julho de 2012. Esses dados foram obtidos pelo uso de sistemas de Light Detection and Ranging (LIDAR) e Sonic Detection and Ranging (SODAR), bem como de Estações Meteorológicas de Superfície (EMS) e de monitoramento atmosférico. Os resultados deste trabalho mostraram que: a) existe uma necessidade de melhorias contínuas nos inventários regionais de emissões, adaptando-os para condições locais específicas e focando na obtenção de parâmetros necessários para modelagem fotoquímica; b) os valores de módulo e direção das velocidades obtidas na modelagem meteorológica influenciam fortemente os resultados da modelagem de concentração de poluentes; c) a qualidade do ar tanto na RGV quanto na RGD merece atenção, sobretudo no que diz respeito às concentrações de MP10. De acordo com os dados das estações de monitoramento, a situação parece mais crítica na RGD; d) a modelagem da RGV apresentou resultados mais satisfatórios do que a da RGD, de acordo com os resultados das validações; e) a entrada da brisa do mar provocou alterações significativas na concentração dos poluentes, o que pôde ser observado na análise da dinâmica da dispersão de MP10 e SO2. Esse fenômeno foi mais marcante na RGV, onde a entrada da brisa marítima provocou um movimento oscilatório na pluma de poluição, levando-a para os bairros mais densamente povoados do conglomerado urbano. Na RGD, a entrada da brisa não foi cotidiana e, no dia em que ela aconteceu, houve uma alteração de quase 180º na direção do movimento da pluma de poluição. Além do aumento da turbulência vertical, o qual já foi estudado por diversos autores, este estudo focou também na influência brisa do mar na dinâmica da pluma de dispersão de poluentes atmosféricos em regiões costeiras.

Decomposition of ground biomass of secondary forest and yield of annual crops in no tillage

ABSTRACT The objective of this work was to evaluate the dynamics of decomposition process of chopped secondary forest system, previously enriched with legumes Inga velutina Willd. and Stryphnodendron pulcherrimum (Willd.) Hochr. and the contribution of this process to the nutrient input to the cultivation of corn and bean under no-tillage. The experimental design was a randomized block, split plot with four replications. The plots were two species (I. velutina and S. pulcherrimum) and the subplots were seven times of evaluation (0, 7, 28, 63, 189, 252, 294 days after experiment installation). There was no difference (p ≥ 0.05) between the secondary forest systems enriched and no interaction with times for biomass waste, decomposition constant and half-life time. The waste of S. pulcherrimum trees had higher (p < 0.05) C/N ratio than that I. velutina. However, this one was higher (p < 0.05) in lignin content. Nevertheless, the dynamics of residue decomposition was similar. The corn yield was higher (p < 0.05) in cultivation under I.velutina waste. Meanwhile, the beans planted after corn, shows similar (p > 0.05) yield in both areas, regardless of the waste origin.

Porto: cidade amiga das pessoas idosas. Um estudo centrado na perspectiva de idosos das freguesias de S. Nicolau e Sé

Uma cidade amiga das pessoas idosas é um meio urbano onde são proporcionadas condições de saúde, segurança e participação que permitem às pessoas mais velhas envelhecerem activamente e viverem com dignidade. A nossa investigação, de natureza qualitativa e exploratória, teve como objectivo verificar se a cidade do Porto possui características de uma cidade amiga das pessoas idosas, na perspectiva de idosos residentes neste meio urbano. Para tal, realizamos dois focus groups com idosos habitantes nas Freguesias de S. Nicolau e Sé, seleccionados a partir de uma amostragem por conveniência, tendo sido utilizado um guião de entrevista constituído pelas categorias: espaços exteriores e edifícios; transportes; habitação; respeito e inclusão social; participação social; participação cívica e emprego; comunicação e informação; apoio comunitário e serviços de saúde. No nosso estudo, foi possível constatar que os participantes, apesar de se manifestarem genericamente satisfeitos com a sua vida na cidade do Porto e identificarem algumas características desse meio urbano que podem ser consideradas como amigas das pessoas idosas, descreveram um vasto conjunto de condições da cidade que limitam o seu quotidiano. Neste sentido, relativamente aos espaços exteriores, para além de os caracterizarem como inseguros quanto ao crime, reconheceram essencialmente limitações à sua mobilidade e segurança física, tais como os declives acentuados e as irregularidades do terreno de certos passeios, o curto período de tempo proporcionado para que sejam atravessadas algumas passadeiras e o aglomerar de lixo e estacionamento de veículos em locais destinados a peões. Adicionalmente, os participantes manifestaram-se insatisfeitos com o número de autocarros e paragens disponíveis na sua freguesia e identificaram nas habitações existentes na cidade do Porto um elevado nível de degradação estrutural e uma falta generalizada de condições de conforto, acessibilidade e protecção face a condições atmosféricas. Em oposição, foi possível verificar que a maior parte dos participantes se sente respeitado e incluído nas actividades e eventos realizados na sua comunidade. Da mesma forma, mostraram-se satisfeitos com a variedade de actividades em que têm oportunidade de participar, incluindo actividades de voluntariado e trabalho não remunerado. Aspectos característicos de uma cidade amiga do idoso, tais como a aglomeração geográfica dos edifícios públicos e lojas e a existência de serviços de apoio comunitário foram também identificados.

Analysis of ground reaction force and electromyographic activity of the gastrocnemius muscle during double support

O documento em anexo encontra-se na versão post-print (versão corrigida pelo editor).

Comparative analysis of the ground reaction forces, during the support phase, in a group of pregnant women on their 3rd trimester of pregnancy and in a group of not pregnant women

PURPOSE: To analyze and compare the Ground Reaction Forces (GRF), during the stance phase of walking in pregnant women in the 3rd trimester of pregnancy, and non pregnant women. METHODS: 20 women, 10 pregnant and 10 non pregnant, voluntarily took part in this study. GRF were measured (1000 Hz) using a force platform (BERTEC 4060-15), an amplifier (BERTEC AM 6300) and an analogical-digital converter of 16 Bits (Biopac). RESULTS: The study showed that there were significant differences among the two groups concerning absolute values of time of the stance phase. In what concerns to the normalized values the most significant differences were verified in the maximums values of vertical force (Fz3, Fz1) and in the impulse of the antero-posterior force (Fy2), taxes of growth of the vertical force, and in the period of time for the antero-posterior force (Fy) be null. CONCLUSIONS: It is easier for the pregnant to continue forward movement (push-off phase). O smaller growth rates in what concerns to the maximum of the vertical force (Fz1) for the pregnant, can be associated with a slower speed of gait, as an adaptation strategy to maintain the balance, to compensate the alterations in the position of her center of gravity due to the load increase. The data related to the antero-posterior component of the force (Fy), shows that there is a significant difference between the pregnant woman’s left foot and right foot, which accuses a different functional behavior in each one of the feet, during the propulsion phase (TS).

An heuristic approach for optimal location of gas supply units in transportation system

The best places to locate the Gas Supply Units (GSUs) on a natural gas systems and their optimal allocation to loads are the key factors to organize an efficient upstream gas infrastructure. The number of GSUs and their optimal location in a gas network is a decision problem that can be formulated as a linear programming problem. Our emphasis is on the formulation and use of a suitable location model, reflecting real-world operations and constraints of a natural gas system. This paper presents a heuristic model, based on lagrangean approach, developed for finding the optimal GSUs location on a natural gas network, minimizing expenses and maximizing throughput and security of supply.The location model is applied to the Iberian high pressure natural gas network, a system modelised with 65 demand nodes. These nodes are linked by physical and virtual pipelines – road trucks with gas in liquefied form. The location model result shows the best places to locate, with the optimal demand allocation and the most economical gas transport mode: by pipeline or by road truck.

Role of the wider Azores region as a nursery ground for North Atlantic blue shark (Prionace glauca)

Tese de Doutoramento, Ciências do Mar (Ecologia Marinha)