Towards agent-based crowd simulation in airports using games technology

We adapt popular video games technology for an agent-based crowd simulation in an airport terminal. To achieve this, we investigate the unique traits of airports and implement a virtual crowd by exploiting a scalable layered intelligence technique in combination with physics middleware and a socialforces approach. Our experiments show that the framework runs at interactive frame-rate and evaluate the scalability with increasing number of agents demonstrating navigation behaviour

Branching in fluidic networks with permeable walls: an extension of Hess-Murray’s law

The branching of fluidic networks becomes a subject of great interest due to its importance in understanding the behavior of branching networks in biology (cardiovascular and bronchial systems, river basins, the structure of plants and trees, etc..), as well as for the biomimetic design of engineering systems [1, 2]. The successive division of tubes and their hierarchical structure are distinctive features of tree-shaped networks. As the network progresses, tubes become smaller, both in length and diameter with the successive division of tubes. The design of these networks is generally assumed as being described by the Hess-Murray’s law. This paper addresses a fundamental issue of distributing a fluid flow in a network of vessels with permeable walls

Age-related changes in anatomical and morphological leaf traits of Wollemia nobilis

The results highlight significant variations of Wollemia nobilis leaf traits which reflect age-related changes of the subsequent growth units along the branches. Age-related changes appear in a gradual increase of leaf size from young leaves to old leaves. The LMA increasing from 13.75 g/cm(2) in current year leaves to 24.84 g/cm(2) in 7 year leaves is associated with an increment of the number of lignified elements (vascular tissues, astrosclereids), of hypodermal and epidermal-cuticle structures (cuticle, wax layer) and of oil bodies abundance, which may increase resistance to stress factors. These characteristics highlight that W. nobilis leaves can adapt to variable environmental conditions with a return rate on a larger time-scale since leaves on a branch stay alive for a long time until the branch dies

The Spitzer search for the transits of HARPS low-mass planets - II. Null results for 19 planets

Short-period super-Earths and Neptunes are now known to be very frequent around solar-type stars. Improving our understanding of these mysterious planets requires the detection of a significant sample of objects suitable for detailed characterization. Searching for the transits of the low-mass planets detected by Doppler surveys is a straightforward way to achieve this goal. Indeed, Doppler surveys target the most nearby main-sequence stars, they regularly detect close-in low-mass planets with significant transit probability, and their radial velocity data constrain strongly the ephemeris of possible transits. In this context, we initiated in 2010 an ambitious Spitzer multi-Cycle transit search project that targeted 25 low-mass planets detected by radial velocity, focusing mainly on the shortest-period planets detected by the HARPS spectrograph. We report here null results for 19 targets of the project. For 16 planets out of 19, a transiting configuration is strongly disfavored or firmly rejected by our data for most planetary compositions. We derive a posterior probability of 83% that none of the probed 19 planets transits (for a prior probability of 22%), which still leaves a significant probability of 17% that at least one of them does transit. Globally, our Spitzer project revealed or confirmed transits for three of its 25 targeted planets, and discarded or disfavored the transiting nature of 20 of them. Our light curves demonstrate for Warm Spitzer excellent photometric precisions: for 14 targets out of 19, we were able to reach standard deviations that were better than 50ppm per 30 min intervals. Combined with its Earth-trailing orbit, which makes it capable of pointing any star in the sky and to monitor it continuously for days, this work confirms Spitzer as an optimal instrument to detect sub-mmag-deep transits on the bright nearby stars targeted by Doppler surveys.Comment: Accepted for publication in Astronomy and Astrophysics. 23 pages, 21 figure

Experimental and theoretical study on bond behavior of GFRP bars in steel fiber reinforced self compacting concrete

To estimate the cracking and the deformational behavior of steel fiber reinforced selfcompacting concrete (SFRSCC) beams reinforced with glass fiber reinforced polymer (GFRP) bars, it is fundamental to understand the interfacial bond behavior of embedded bars. Hence, the evaluation of the bond behavior between GFRP and (SFRSCC) was investigated in this study. A closed-form formulation was derived, adopting a new local bond stress-slip relationship. Furthermore, an experimental program composed of pullout bending tests was carried out in order to assess the influence of the following parameters on the bond behavior: bar diameter, bar surface treatment, embedment length and SFRSCC cover thickness. Finally, a numerical simulation was performed with a FEM-based computer program in order to simulate the bond behavior between GFRP bar and SFRSCC by means of a non-linear bond-slip relationship assigned to the interface finite element. The predictive performance of the theoretical models was appraised by comparing experimental and numerical results

Experimental study on bond performance of GFRP bars in self-compacting steel fiber reinforced concrete

Reinforcing bars made of Glass-Fiber-Reinforced Polymers (GFRP) are more and more common as internal reinforcement of concrete structures and infrastructures. Since the design of GFRP reinforced concrete members is often controlled by serviceability limit state criteria (i.e., deflection or crack width control), an accurate knowledge of the GFRP-concrete bond behavior is needed to formulate sound design equations. Furthermore, bond laws currently available and widely accepted for conventional steel rebars cannot be straightforwardly applied for GFRP ones. Hence, an experimental program consisting of 36 pullout bending tests was carried out to evaluate the bond performance between GFRP bars and steel fiber reinforced self-compacting concrete (SFRSCC) by analyzing the influence of the following parameters: GFRP bar diameter, surface characteristics of the GFRP bars, bond length, and SFRSCC cover thickness. Based on the results obtained in this study, pullout failure was occurred for almost all the specimens. SFRSCC cover thickness and bond length plaid important role on the ultimate value of bond stress of GFRP bars. Moreover, the GFRP bars with ribbed and sand-coated surface treatment showed different interfacial bond behaviors.Fundação para a Ciência e a Tecnologia (FCT

Numerical calibration of bond laws for GFRP bars embedded in steel fiber-reinforced self-compacting concrete

An experimental program was carried out at the Laboratory of Structural Division of the Civil Engineering Department of the University of Minho (LEST-UM) to investigate the bond behaviour of glass fibre reinforced polymer (GFRP) bars embedded in steel fibre reinforced self-compacting concrete (SFRSCC) for the development of an innovative structural system. Thirty-six pull-out-bending tests were executed to assess the influence of the bond length, concrete cover, bar diameter and surface treatment on the bond of GFRP bars embedded in SFRSCC. This paper reports the results of a numerical study aiming to identify an accurate GFRP–SFRSCC bond-slip law. Thus, the above mentioned pullout bending tests were simulated by using a nonlinear finite element (FE) constitutive model available in FEMIX, a FEM based computer program. The bond-slip relationship adopted for modelling the FE interface that simulates the interaction between bar and concrete is the key nonlinear aspect considered in the FE analyses, but the nonlinear behaviour of SFRSCC due to crack initiation and propagation was also simulated. The evaluation of the values of the relevant parameters defining such a bond-slip relationship was executed by fitting the force versus loaded end slip responses recorded in the experimental tests. Finally, correlations are proposed between the parameters identifying the bond-slip relationship and the relevant geometric and mechanical properties of the tested specimens.Fundação para a Ciência e a Tecnologia (FCT

Otimização de design do duto ramificado em forma de T com escoamento de fluido newtoniano e paredes impermeáveis

Este artigo apresenta os resultados de escoamentos em dutos em forma de “T”. O problema consiste em encontrar as resistências ao escoamento em estruturas tridimensionais (3D) cujos sistemas têm diferentes relações homotética entre tamanhos (diâmetros e comprimentos) dos dutos de entrada e saída de fluído. O método utilizado é denominado “Constructal Design” e é fundamentado na “Teoria Constructal”. Este método baseia-se na minimização da resistência global sujeito a restrições geométricas, que no presente estudo são o volume e área ocupada pelos dutos considerados constantes. O escoamento nos dutos é considerado tridimensional, laminar, incompressível, e em regime permanente e com propriedades uniformes e constantes. Os resultados obtidos numericamente em geometrias 3D é validado por comparação com os resultados analíticos bidimensional disponíveis na literatura. A geometria será estudada para diferentes relações D1 / D0 e L1 / L0, para diferentes número de Reynolds

Characterization in the archaeological excavation site of heterotrophic bacteria and fungi of deteriorated wall painting of Herculaneum in Italy.

Microbiological characterization of frescos in four different famous locations of excavation sites of Herculaneum (the Collegio degli Augustali, Casa del Colonnato Tuscanico, Casa dello Scheletro and Casa del Gran Portale), were carried out. The use of infrared thermography allowed us to detect sample points on frescos with greatest moisture not visible to the naked eye, resulting in structural damage. The microclimatic conditions provided perfect habitat for bacteria, especially of spore forming and mould. In fact, heterotrophic bacteria were prevalent in all wall paintings monitored, whereas fungi were also detected but at lower levels. Cultural–based methods allowed to obtain a total of 48 bacteria and 23 mould isolates molecularly identified by 16S and 26S rRNA partial sequence analysis. With this approach, Bacillus-related species (B. cereus/B. thuringiensis group, B. simplex/B.muralis group, B. megaterium and B. subtilis) were isolated in all sample points analysed with the exception of the Casa dello Scheletro in which Micrococcus luteus/Arthrobacter sp./Variovorax sp. group and Streptomyces fragilis were found. Mould isolates were closest related to different genera in which predominated Aspergillus, Penicillium and Fusarium together with the unusual genera as Microascus and Coprinus. Sequencing of the 16S ribosomal DNAs, selected on the basis of DGGE profiling, enabled detection of bacterial species closest related to Microbacterium groups in all sample points analysed, also associated with Brevibacterium, Streptomyces and Stenotrophomonas

A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims. We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods. We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 {\mu}m. Adding the high precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar effects on the flux variation. Results. We present a refined radius estimate of RP=4.10 +/- 0.16 R_Earth, mass MP=25.4 +/- 2.1 M_Earth and eccentricity e= 0.162 +/- 0.004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 {\mu}m that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 {\mu}m that are shallower than in previous works, in particular at 3.6 {\mu}m. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO2, although perhaps less than previously thought. We find no evidence for a potential planetary companion, stellar activity, nor for a stellar spin-orbit misalignment. [ABRIDGED]Comment: 25 pages, 26 figures, 8 tables, accepted for publication in A&