A numerical study of non structural masonry walls with bed joint reinforcement subject to flexure

This paper presents a numerical investigation of a non structural small masonry wall submitted to a flexion effort in its plan and constructed with ceramic blocks. The effort is due to an excessive deformation of the structural elements. The small walls of ceramic blocks (named here mini-walls) were analyzed under two different situations: without bed joint reinforcement (for reference) and with bed joint reinforcement. In order to evaluate the improvement of structural performance with the proposed strengthening (reinforcement masonry walls) the arrows were measured in the middle of the mini-walls, cracking degree and the steel bars deformation. The program employed to carry out the numerical analyses was DIANA (version 9.1), that uses Finet Element Method (FEM). The strategy adopted was macromodelling and non linear phisical behaviour. The results obtained from the numerical research proved that masonry walls with bed joint showed an increased load at first cracking, better performance in service, increased capacity and more resistant arrow at break. Improvements also in relation to the ultimate limit state, which indicates that it is profit and that bed joint reinforcement can be used in non structural and structural mansory walls

Geometric singular perturbartion theory for non-smooth dynamical systems

In this article we deal with singularly perturbed Filippov systems Zε: (1) ˙x = ( F(x, y, ε) if h(x, y, ε) ≤ 0, G(x, y, ε) if h(x, y, ε) ≥ 0, εy˙ = H(x, y, ε), where ε ∈ R is a small parameter, x ∈ Rn, n ≥ 2, and y ∈ R denote the slow and fast variables, respectively, and F, G, h, and H are smooth maps. We study the effect of singular perturbations at typical singularities of Z0. Special attention will be dedicated to those points satisfying q ∈ {h(x, y, 0) = 0} ∩ {H(x, y, 0) = 0} where F or G is tangent to {h(x, y, 0) = 0}. The persistence and the stability properties of those objects are investigated.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Satellite Star Tracker Breadboard with Space Debris Detection Capability for LEO

This paper evaluates the possibility of having a star tracker device running space debris algorithms. A simple star tracker breadboard was developed to evaluate the possibility of having a device running both stellar identification and space debris algorithms. The breadboard was built with commercial off-the-shelf components, representing the current star tracker resolution and field of view. A star tracker device and space debris algorithms were implemented and tested, respectively: Tetra and ASTRiDE. The device concept was tested by taking pictures of the night sky with satellite streaks. Seeking to overcome such limitations, a dual-purpose star tracker with stars detection and optical debris detection capability is proposed. Star trackers are usually used in satellites for attitude determination and therefore have a vast potential to be a major tool for space debris detection. The rapid increase of space debris poses a risk to space activities, so it is vital to detect it. Ground-based radar and optical telescope techniques used for debris detection are limited by a size threshold, detecting only a tiny amount of the total, reason why evaluating the possibility of detecting them in space is of major importance.info:eu-repo/semantics/publishedVersio

Association of radio polar cap brightening with bright patches and coronal holes

Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet. We propose that small magnetic loops are the source of these bright patches, and present modeling results that reproduce the main observational characteristics of the polar brightening within coronal holes at 17 GHz. The simulations were carried out by calculating the radio emission of the small loops, with several temperature and density profiles, within a 2D coronal hole atmospheric model. If located at high latitudes, the size of the simulated bright patches are much smaller than the beam size and they present the instrument beam size when observed. The larger bright patches can be generated by a great number of small magnetic loops unresolved by the NoRH beam. Loop models that reproduce bright patches contain denser and hotter plasma near the upper chromosphere and lower corona. On the other hand, loops with increased plasma density and temperature only in the corona do not contribute to the emission at 17 GHz. This could explain the absence of a one-to-one association between the 17 GHz bright patches and those observed in extreme ultraviolet. Moreover, the emission arising from small magnetic loops located close to the limb may merge with the usual limb brightening profile, increasing its brightness temperature and width.Comment: 8 pages, 6 figures, 1 table. Accepted for publication in The Astrophysical Journa

Monitoramento da população do besouro Rhynchophorus palmarum em dendezais no município de Igarapé-Açu, Pará.

bitstream/item/60313/1/CPATU-PA198.pd

Avaliação de iscas e armadilhas para captura de Rhynchophorus palmarum em dendezais.

bitstream/item/57488/1/CPATU-BP200.pd

Photonic sensors based on flexible materials with FBGs for use on biomedical applications

This chapter is intended for presenting biomedical applications of FBGs embedded into flexible carriers for enhancing the sensitivity and to provide interference-free instrumentation.This work was fully supported by the Algoritmi’s Strategic Project UI 319-2011-2012, under the Portuguese Foundation for Science and Technology grant Pest C/EEI/UI0319/2011

Influence of ageing on the properties of bitumen from asphalt mixtures with recycled concrete aggregates

The reuse of recycled concrete aggregates in new hot-mix asphalt can be a more sustainable method of production, but these mixtures may need a heat treatment before compaction to improve their water sensitivity performance. A direct consequence of this treatment is an increase in the hot-mix asphalt resilient modulus. The aim of this paper is to analyse the effect of ageing on the stiffness of asphalt mixtures with different amounts of recycled concrete aggregates, before and after a heat treatment, which was analysed through the assessment of its bitumen properties. Moreover, this paper also aims to analyse whether the rolling thin-film oven test is able to simulate the ageing effect of the heat treatment. In the laboratory work, a paving grade bitumen B50/70 has been used to produce asphalt mixtures with 0% and 30% recycled concrete aggregates, and the bitumen was later characterised (using penetration, softening point, dynamic viscosity and dynamic shear rheometer tests) in various situations, such as when using virgin bitumen, short-term aged bitumen, aged bitumen after heat treatment (simulated with 4 h of rolling thin-film oven test) and bitumen samples recovered from asphalt mixtures with different production mixes (0% and 30% recycled concrete aggregate) and heat treatment conditions (0 and 4 h of curing time in the oven). Based on the results obtained, it could be concluded that the ageing resulting from the heat treatment is the primary cause of the hot-mix asphalt's increased stiffness, while recycled concrete aggregate content has a small influence. Moreover, it could be concluded that when there is no curing time, the recycled concrete aggregate protects the bitumen against ageing. Additionally, it could be stated that the rolling thin-film test is able to adequately simulate the ageing effect of the heat treatment. Thus, this test is useful for determining the ageing suffered by the bitumen when the recycled concrete aggregate mixture is manufactured using a heat treatment.The authors would like to acknowledge the Spanish Ministry of Education and Science for sponsoring this research through Project BIA2010-17751