1,354 research outputs found

    Numerical and analytical investigation of load transfer through eccentric columns with different cross sections

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    Eccentric columns are not a common feature in concrete building structures. However, late changes in floor layouts and constraints due to available spaces may enforce structural designers to use eccentric columns to transfer vertical load. The load paths of the eccentric column connections can create complications. Due to the sudden changes in geometry, additional stresses are developed at the slab- column connection and a discontinuity region is created in which the strain distribution becomes highly nonlinear and unpredictable. The strut and tie method has been extensively used in analysing such complicated structural elements over the years. This method has its own limitations and is based on simplifications including the definition of the load path. This simplified method can under or over predict the design capacities of such columns, which can be inefficient or inadequate for current design requirements. The objective of this study is to comprehensively investigate the load transfer mechanism for vertical loads of eccentric columns using an advanced finite element approach. Clear identification of the load path, effective cross-sectional area for load transfer and alternative design guidelines for column-slab joint are evaluated and the preliminary work is presented in this paper.ARC DE15010170

    Rotating Dilaton Solutions in 2+1 Dimensions

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    We report a three parameter family of solutions for dilaton gravity in 2+1 dimensions with finite mass and finite angular momentum. These solutions are obtained by a compactification of vacuum solutions in 3+1 dimensions with cylindrical symmetry. One class of solutions corresponds to conical singularities and the other leads to curvature singularities.Comment: Accepted to be published in Gen. Rel. Grav., added reference

    Kinetics and thermodynamics of poly (9,9-dioctylfluorene) beta-phase formation in dilute solution

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    Poly(9,9-dioctylfluorene) (PFO) adopts a particular type of conformation in dilute solutions of the poor solvent methylcyclohexane (MCH) below 273 K, which is revealed by the appearance of a red-shifted absorption peak at 437−438 nm. The formation of this ordered conformation depends on the temperature but is independent of polymer concentration over the range studied (3−25 μg/mL). On the basis of absorption, steady-state, and time-resolved fluorescence data, the new absorption peak at 437−438 nm is assigned to a highly ordered conformation of PFO chains, analogous to the so-called β-phase first identified in PFO films. From the study of PFO solutions in MCH as a function of temperature, we conclude that these ordered segments (β-conformation) coexist with less ordered domains in the same chain. When the ordered domains are present, they act as efficient energy traps and the fluorescence from the disordered regions is quenched. The transition between the disordered and the ordered PFO conformations is adequately described by a mechanism that involves two steps:  a first, essentially intramolecular, one from a relatively disordered (α) to an ordered conformation (β), followed by aggregation of chains containing β-conformation into anisotropic ordered domains. From the temperature dependence of the 437−438 nm peak intensity, the transition temperature Tβ = 261 K, enthalpy ΔHβ = −18.0 kcal mol-1, and entropy ΔSβ = −68.4 cal K-1 mol-1 were obtained. The formation of the β-conformation domains were also followed as a function of time at 260 K. The rate constants at 260 K were determined, showing an order of magnitude around 10-3 s-1 (kα→β = 5.9 × 10-4 s-1; kβ→α = 9 × 10-4 s-1; kagg = 2.3 × 10-3 M-1 s-1; kdiss = 4.4 × 10-4 s-1). This small magnitude explains the long times required for a “complete” conversion to the β-conformation

    Video analysis of left and right breaking putts

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    The aim of this study was to investigate how a player responds to external constraints (slope and angle) in a golf putting task. The sample consisted of 10 adult male (33.8 ± 11.89 years), right handed and highly skilled golfers (average handicap of 10.82). The participants performed 30 putts at a distance of two meters with 25 degrees to the left of the hole (Angle 1) and 30 putts at a distance of two meters with 25 degrees to the right of the hole (Angle 2), with a constraint imposed by a slope. The data suggests that the performance of the golf putting may be improved if different situations and difficulty degrees are employed and exploited. In that sense, the manipulation of task related constraints forced the appearance of solutions uniquely adjusted to each player. This brings implications to the area of sports coaching and training, considering that the athlete can optimize his performance if he explores different couplings of information-movement, in different levels of complexity.info:eu-repo/semantics/publishedVersio

    Video summary - Neptus, command and control infrastructure for heterogeneous teams of autonomous vehicles

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    This video shows a brief overview over Neptus, a command and control infrastructure for heterogeneous teams of autonomous vehicles. Having different,types of vehicles at our laboratory and from our partners, there was an increasing need to create a common infrastructure to all these systems. Additionally, a tool to support the entire mission life cycle (Planning, Execution, Review and Dissemination) was lacking. Neptus was created to provide vehicle independence and seamless inter-systems communications. Currently, Neptus has been already tested with Remotely Operated Vehicles, Autonomous Underwater Vehicles, Unmanned Air Vehicles, Autonomous Surface Vehicles and Wireless Sensor Networks. Some of these systems were operated simultaneously by various operating consoles that were sharing the same communication infrastructure. The received data was being relayed to a web server that allowed for the real-time mission following by using a common web browser

    The effect of artificial side wind on the serve ofcompetitive tennis players

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    In tennis, the serve is the shot ofgreatest importance.The servedependsmainly on the player’stechnique, however,environmental factorscan influencethe accuracy of the serve. This study highlights the effect of side wind on the serve of 12 experienced tennis players. The players were asked to hit the intersection point betweenthe centralandthe service line at maximum speed while awind effect was artificially generated by a ventilator setup with various speed of Induced Aerodynamic Flow (IAF).Each player’s serve was then analyzed using error ellipsesas a statistical measure. Thismethod allowed us toevaluate theeffect of "random wind"in comparison to“constant wind” on the accuracy of the serves.The truncated Fourier series analysis showedthat there was an adaptive pattern in the accuracy of the serve dependingon therandom wind. However in four players,the more unpredictablethe impact of the wind the more accurate they becamewith the serve. The fact that there was not a linear trend in the accuracy of serveswhen IAFincreased shows that each playeradapts differentlytothe windinfluence.info:eu-repo/semantics/publishedVersio

    First in situ observations of soft bottom megafauna from the Cascais Canyon head

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    We report the first in situ observations of soft bottom megafauna from the Cascais Canyon head. Observations were collected opportunistically during three technical dives with the ROV Luso between 460-805 m at two locations distanced 1,230 m. The habitats were clas-sified as upper bathyal fine mud. The soft bottom fauna was dominated by burrows of Nephrops norvegicus reaching up to 2.9 burrows/m2, a common habitat along the Portu-guese continental margin. To our knowledge, densities are the highest ever reported for depths below 300 m. The ichthyofauna at the upper Cascais Canyon is a mixture of lower shelf and upper bathyal species, including Phycis blennoides, Scyliorhynus canicula, Coe-lorhynchus labiatus/occa and Chimaera monstrosa. Bait release attracted Myxine glutinosa. Surveys in other geological settings of the Cascays Canyon are required to understand more comprehensively the diversity of its sessile and vagile biodiversity

    Therapeutic drug monitoring of CT-P13: a comparison of four different immunoassays

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    Background: The commercialization of CT-P13, an infliximab (IFX) biosimilar, has the potential to decrease health-related costs and enhance access to biological therapies. This study aimed to address the accuracy and inter-assay agreement of the CT-P13 quantification using four different assays initially developed to assess IFX. Methods: The four different methods, one in-house method and three commercially available kits, were used to quantify exogenously-spiked samples and the sera from 185 inflammatory bowel disease (IBD) patients on CT-P13 therapy. Results: The quantification of the spiked samples unveiled a consistent and accurate behaviour of three of the tested methods, with average percentage recoveries of 90%, 102% and 109%. Results from the clinical samples demonstrated that these three assays were also highly correlated, both concerning Spearman's rank coefficients (range 0.890-0.947) and intraclass correlation coefficients (range 0.907-0.935). There were a few systematic deviations among them, but their impact in the clinical stratification of the patients using different cut-offs was minimal, particularly when these cut-offs were in the 3-4 mu g/ml range, for which the strength of agreement (as assessed by the Kappa statistics that ranged from 0.732 to 0.902) was substantial to almost perfect. Conclusions: Our results indicate that three of the tested IFX quantification methods can be used to accurately quantify CT-P13 without any adjustments.Portuguese IBD Group (GEDII, Grupo de Estudo da Doenca Inflamatoria Intestinal)Portuguese IBD Group (GEDII, Grupo de Estudo da Doença Inflamatória Intestinal

    Nutritional Properties of Baobab Pulp from Different Angolan Origins

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    Publisher Copyright: © 2022 by the authors.The baobab tree (Adansonia digitata L.) is found widely in the forests and savannas of sub-Saharan Africa. The baobab fruit has a sour and slightly sweet taste and is widely consumed by the natives, thus containing a high nutritional value and providing a source of income for rural people. This study aimed to compare the nutritional composition of baobab fruit pulp from different localities in the Namibe province (Angola). Twenty samples of baobab pulp were collected in markets of the four municipalities of Namibe. The results obtained showed that there is some geographic location dependence on nutritional and functional composition. The municipality of Camucuio showed samples with higher fibre content (56.62 g/100 g) and vitamin C (288.9 mg/100 g). Samples from the Virei municipality stood out for their antioxidant activity (1936 mmol TE/100 g), high K content (42.4 mg/g) and higher values of protein (2.42 g/100 g). The samples collected in the municipality of Bibala stood out for their high contents of carbohydrates (28.1 g/100 g), total phenolic compounds (972 mg GAE/100 g) and Ca (3.80 mg/g). Despite the differences in origin, the high nutritional value of baobab fruit has the potential to improve the diet of thousands of people in Africa qualitatively.publishersversionpublishe
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