Ensayo para calcular tensiones y deformaciones en la estructura del techo de un silo metálico de 18,34 m de diámetro

Los silos metálicos requieren la disposición de una estructura en su parte superior para permitir la fijación de las chapas que forman la cubierta del silo y así soportar las cargas para las que ha sido diseñada. Esta estructura está formada por un sistema reticular de vigas radiales y circunferenciales que desempeñan diversas funciones. Los modelos de cálculo que se emplean asumen la existencia de ciertos supuestos de comportamiento que luego deben verificarse en la práctica. Por esta razón, se diseñó un experimento para obtener las tensiones y desplazamientos verticales producidos en distintos elementos de la estructura del techo de un silo de 18,34 m de diámetro, con objeto de validar los resultados proporcionados por modelos de cálculo numérico. La instrumentación de un silo de estas dimensiones resulta bastante compleja, y requiere tener en cuenta numerosos factores como la selección representativa de los puntos de carga aplicados sobre el techo, la comprobación de las cargas transmitidas o la instalación de los dispositivos adecuados para poder registrar las mediciones necesarias. En los distintos ensayos realizados llegaron a aplicarse simultáneamente cargas sobre la estructura hasta en 54 puntos, mediante el uso de cintas tensoras (eslingas). La comprobación de la carga aplicada se realizó con el uso de 8 dinamómetros. Por otro lado, los desplazamientos verticales sufridos por la estructura, sometida a carga, se comprobaron en 3 puntos alineados con el uso de flexímetros ASM tipo A-WS10-100-R1K-L10, y las tensiones se infirieron a partir de las deformaciones registradas mediante el uso de 8 galgas extensométricas en 4 vigas opuestas de la estructura. Las lecturas procedentes de las galgas extensométricas y de los flexímetros fueron registrados mediante el uso de dataloggers. Los resultados obtenidos con los ensayos fueron comparados con los obtenidos con un programa de cálculo de estructuras mediante el cual se realizó un modelo tridimensional de la estructura. Se observó una buena concordancia en los resultados, siempre que se cumplieran las hipótesis de partida del modelo. El ensayo permitió detectar la presencia de ciertas anomalías en el funcionamiento de algunos elementos del silo, que fueron corroboradas con los modelos de cálculo.

Influência do diâmetro da coroa de mudas de morangueiro das cultivares aromas e albion na precocidade da produção de frutas.

2015

Uso de banda dendrométrica na definição de padrões de crescimento individual em diâmetro de árvores da bacia do Rio Cuieiras.

Este trabalho tem como objetivo analisar padrões de crescimento individual de diversas árvores que ocorrem em duas toposseqüências (direções Norte-Sul e Leste-Oeste), de uma amostra representativa da floresta de terra-firme na Amazônia Central.

Tree structure and richness in an Atlantic Forest fragment: distance from anthropogenic and natural edges

Approximately 7.2% of the Atlantic rainforest remains in Brazil, with only 16% of this forest remaining in the State of Rio de Janeiro, all of it distributed in fragments. This forest fragmentation can produce biotic and abiotic differences between edges and the fragment interior. In this study, we compared the structure and richness of tree communities in three habitats - an anthropogenic edge (AE), a natural edge (NE) and the fragment interior (FI) - of a fragment of Atlantic forest in the State of Rio de Janeiro, Brazil (22°50'S and 42°28'W). One thousand and seventy-six trees with a diameter at breast height > 4.8 cm, belonging to 132 morphospecies and 39 families, were sampled in a total study area of 0.75 ha. NE had the greatest basal area and the trees in this habitat had the greatest diameter:height allometric coefficient, whereas AE had a lower richness and greater variation in the height of the first tree branch. Tree density, diameter, height and the proportion of standing dead trees did not differ among the habitats. There was marked heterogeneity among replicates within each habitat. These results indicate that the forest interior and the fragment edges (natural or anthropogenic) do not differ markedly considering the studied parameters. Other factors, such as the age from the edge, type of matrix and proximity of gaps, may play a more important role in plant community structure than the proximity from edges.

Qualidade da classificação do tomate de mesa em unidades de beneficiamento

Quality evaluation of classification was done in two fresh market tomatoes packing house, using electronically and mechanical equipments in two harvest periods, summer and winter seasons. The main goal of this work was to evaluate size and color grading conformity with the standards proposed by the Brazilian Program for Horticulture Modernization and size grading obtainded with the one established by the packer. The cultivar studied was Carmen. The results showed that there was no grade conformity with the fresh tomato quality standards proposed by the Brazilian Program for Horticulture Modernization. The grade conformity obtained when compared with the one programmed by the packer, was only for large sizes, in both equipments. The electronically equipment has presented better performance, over the mechanical, considering grading quality and fruits post-harvest quality. However, the electronically equipment must be constantly monitored to achieve efficiency and investment return. On the other side, for mechanical equipment it will be necessary to review the actual system of size grading, in order to follow the fresh tomato quality standards.

Avaliação de linhas de beneficiamento e impactos de queda na qualidade de caqui Rama Forte

Excessive and inadequate handling of fruits and vegetables provides high incidences of physical damage, consequently, post harvest losses. The main goal of this work was to evaluate the impact magnitude in persimmon packing lines, Rama Forte, and to determine, at the laboratory, its impact limits. For evaluating the critical points it was used an instrumented sphere of 76 mm of diameter (Technmark, Inc, Lansing, USA), which registered the impact magnitude in seven distinctive impact lines located in four packing houses. For determining physical damages, tests were carried out at the laboratory, where fruit drop was related to impact magnitude, physical damage incidence and fruit post harvest losses. At the packing lines, the values found varied from 21 to 87 G on the transfer points and the majority of registered impacts (over 94%) were down 50G. Drops from 20 cm caused an increase in weight losses after six days of storage at room temperature. Drops from 20 and 30 cm caused skin darkness (low L values), associated to a decrease in color intensity (chroma). Impact drop did not affect pulp fruit chemical features.

Estimativa de parâmetros biofísicos de plantios de café a partir de imagens orbitais de alta resolução espacial

Remote sensing data are each time more available and can be used to monitor the vegetal development of main agricultural crops, such as the Arabic coffee in Brazil, since that the relationship between spectral and agronomical data be well known. Therefore, this work had the main objective to assess the use of Quickbird satellite images to estimate biophysical parameters of coffee crop. Test area was composed by 25 coffee fields located between the cities of Ribeirão Corrente, Franca and Cristais Paulista (SP), Brazil, and the biophysical parameters used were row and between plants spacing, plant height, LAI, canopy diameter, percentage of vegetation cover, roughness and biomass. Spectral data were the reflectance of four bands of QUICKBIRD and values of four vegetations indexes (NDVI, GVI, SAVI and RVI) based on the same satellite. All these data were analyzed using linear and nonlinear regression methods to generate estimation models of biophysical parameters. The use of regression models based on nonlinear equations was more appropriate to estimate parameters such as the LAI and the percentage of biomass, important to indicate the productivity of coffee crop.

Fisionomia e organização da vegetação do carrasco no planalto da Ibiapaba, estado do Ceará

Is the carrasco on the Ibiapaba plateau a unique plant formation? To answer this question the vertical height (except of climbers) and the stem basal diameter (from 3cm on) of woody plants were measured, and soil extracts (0-50 and 50-100cm depth) were taken from 100 random plots (10x10m) at Jaburuna (3º54'34S and 40º59'24W, altitudes near 830m), municipality of Ubajara, Ceará State. Data on climate, soil, diameter height, density, basal area, and physiognomy were compared with those surveyed by other researchers from the carrasco, caatinga, and cerrado in Northeastern Brazil. The carrasco occurs under an annual rainfall of between 668 and 1,289mm and temperatures from 22 to 24ºC, on alic Quartz Sand soils, at altitudes between 700 and 900m: it has a larger density and a smaller basal area than the caatinga and the cerrado, small and similar diameters, and an average vertical height between 3,7 and 5,4m. It differs from the caatinga, cerrado (and cerradão) and secondary forest in many items of lhe ecotope, organization and physiognomy, thus being a unique plain formation, which can be characterized as a deciduous, high, closed, and unistratified shrubland intermingled by lianas, with an irregular canopy and sparse, emergent trees.

O Complexo Vegetacional da Zona Litorânea no Ceará: Pecém, São Gonçalo do Amarante

Due to its geographical location, the northeastern Coast of Brazil (Litoral Setentrional do Nordeste - LSN) is a hotter and drier climate than the eastern coast. In addition, because of its proximity to caatinga and cerrado, the LSN contains species from these vegetation biomes and from the restinga on the coast, which comprise different plant formations and creates a vegetation complex. Despite the great importance of this ecotone, there are few studies about its flora. The objective of this work was to contribute to what is known about the floristic and phytosociological composition of this region. We made a floristic survey in the area (between 2007 and 2011), consulted herbaria data from the region and made a phytosociological study in a stretch of coastal semideciduous forest (mata de tabuleiro). The study recorded 382 plant species from 96 families. In the phytosociological survey (0.32 ha) we recorded 2,970 individuals and 52 species. The most abundant plants surveyed were the trees Manilkara triflora, Chamaecrista ensiformis and Guapira nitida and the shrubs Cordiera sessilis and Maytenus erythroxyla (average height 3.8 m, average diameter 6.2 cm, basal area 39.28 m²/ha). The local flora includes floristic elements of caatinga, cerrado and restinga, corroborating the idea that the plant community of the coastal region of Ceará has an ecotonal nature.

Efeitos da constrição pupilar na perimetria de freqüência dupla em olhos normais

Purpose: To study the effects of pupillary constriction on frequency doubling perimetry in a group of normal subjects. Methods: Eighteen healthy volunteers participated in the study. Only one eye per patient (right eye) underwent frequency doubling perimetry (Full Threshold C-20 strategy). For the second session, one drop of 2% pilocarpine was administered to the volunteers' right eye and the examination was repeated after 60 minutes. Results: Sixty minutes after administration of 2% pilocarpine, there was a significant reduction of the pupillary diameter from 4.22 ± 0.17 mm to 1.55 ± 0.51 mm (p<0.05). There was a significant reduction of the mean retinal sensibility after pupillary constriction. The threshold sensitivity of the central 5º worsened by 5.67 ± 2.49 dB; the area between 2.5º and 10º worsened by 4.49 ± 2.73 dB; and the area between 10º and 20º worsened by 5.10 ± 3.55 dB (p<0.01). A reduction of 4.06 ± 2.67 dB was observed in the mean deviation, as well as an increase of 0.64 ± 0.94 dB in the pattern standard deviation (p<0.01). No differences were observed regarding the number of fixation losses, false-positive and false-negatives responses, and duration of the examination. Conclusion: Changes in pupillary diameter may produce significant declines in threshold sensitivities of the 20º visual field tested by frequency doubling perimetry. These results suggest that is important to maintain a constant pupillary diameter in seriate examinations.

Efeito do treinamento e maturação sexual sobre o crescimento, composição corporal e desempenho motor em adolescentes do sexo masculino

Universidade Estadual de Campinas . Faculdade de Educação Física

Processos adaptativos do tecido muscular esqueletico e tecido conjuntivo : repercussões sobre a flexibilidade

Universidade Estadual de Campinas. Faculdade de Educação Física

Proposta de avaliação motora para portadores de deficiencia visual em coordenação, equilibrio e orientação espacial

Universidade Estadual de Campinas . Faculdade de Educação Física