Lateral resistance of log timber walls subjected to horizontal loads

The present works intends to represent a further step in the knowledge of timber log-houses through an experimental approach, from which only few information is available. The main part of the experimental work is based on in-plane static tests conducted on timber log walls with distinct transversal stiffness, two vertical compression levels and two values of slenderness. Monotonic and cyclic tests were performed according to EN 12512:2001. The formers were performed to define the elastic slip values and assessment of the failure mechanisms while the lasts allowed evaluating impairment of strength, to measure the ductility and to quantify the energy dissipation. In a first step research, an extensive characterization of the timber logs was made. The connection between the first timber log and the basement was also evaluated.(undefined

Comportamento sísmico de um sistema log-house

O presente trabalho pretende contribuir para o conhecimento do sistema construtivo “Log-house” através de uma vasta análise experimental e de análises numéricas. A campanha experimental, realizada previamente, teve por objectivo de estudar o comportamento no plano das paredes em troncos de madeira quando sujeitas a acções monotónicas e cíclicas, de acordo com a EN 12512:2001. Apresenta-se ainda um caso de estudo, relativo a uma moradia produzida e comercializada pela empresa “Rusticasa”, no qual se considera a distribuição das forças sísmicas em função: a) da área de influência de cada parede e, b) da rigidez de cada parede. As análises efectuadas contemplam algumas verificações de resistência, nomeadamente ao nível da ligação à fundação e no cruzamento entre paredes ortogonais, as quais não são verificadas na totalidade pelo que se apresentam algumas sugestões a implementar no sistema construtivo com vista à verificação da segurança.This paper aims to contribute to the knowledge of the building system "Log-house” through an extensive experimental analysis and numerical analysis. The experimental campaign, performed previously, aimed of studying the in-plane behavior of log walls when subjected to monotonic and cyclic loads, in accordance with EN 12512:2001. Moreover, a case study concerning a house characteristic of the "Rusticasa" system was analyzed considering the distribution of seismic forces according to: a) the area of influence of each wall, and b) the stiffness of each wall. Analyses carried out include some resistance checks, particularly in terms of the connection to the foundation and at the crossing between orthogonal walls, which are not checked for all walls and, therefore, some suggestions are presented to improve the safety of the structural system.Rusticas

Structural behaviour of log timber walls under lateral in-plane loads

The present works intends to represent a further step in the knowledge of timber loghouses through an experimental approach, from which only few information is available. The main part of the experimental work is based on in-plane static tests conducted on timber log walls with distinct transversal stiffness, two vertical compression levels and different values of slenderness. Monotonic and cyclic tests were performed according to EN 12512:2001. The former were performed to define the elastic slip values and assessment of the failure mechanisms while the latter allowed for the evaluation of the impairment of strength, the measurement of the ductility and the quantification the energy dissipation. Previously to the full-scale tests of walls, an extensive characterization of the timber logs was made. Due to its importance, the connection between the first timber log and the basement was also evaluated through tests. In a second step of the research, a case study was used to develop a numeric analysis. Using FEM, the in-plane stiffness of timber logs walls was quantified, thus allowing to compare the result of distributing the horizontal loads by the walls according to their area of influence or their in-plane stiffness. Finally, improvements to the log system analyzed were suggested

On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

In this report, a successful thermodynamical model was employed to understand the structural transition in Er$_5$Si$_4$, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a $\Delta F_0 = -$0.262 eV. Finally, it was achieved a variation of Seebeck coefficient ($\sim$ 6 $\mu$V) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

Congruences on direct products of transformation and matrix monoids

Malcev described the congruences of the monoid Tn of all full transformations on a finite set Xn={1,…,n}. Since then, congruences have been characterized in various other monoids of (partial) transformations on Xn, such as the symmetric inverse monoid Inn of all injective partial transformations, or the monoid PTn of all partial transformations. The first aim of this paper is to describe the congruences of the direct products Qm×Pn, where Q and P belong to {T,PT,In}. Malcev also provided a similar description of the congruences on the multiplicative monoid Fn of all n×n matrices with entries in a field F, our second aim is provide a description of the principal congruences of Fm×Fn. The paper finishes with some comments on the congruences of products of more than two transformation semigroups, and a fairly large number of open problems

Seasonal distribution and sex ratio of eleven noctuid species (Insecta, Lepidoptera) captured in blacklight traps on Terceira Island (Azores)

The adult flight periods of Agrotis segetum (DENNIS & SCHIFFERMÜLLER), Noctua pronuba (LINNAEUS), Noctua atlantica (WARREN), Peridroma saucia (HÜBNER), Xestia c-nigrum (LINNAEUS), Mythimna loreyi (DUPONCHEL), Phlogophora meticulosa (LINNAEUS), Phlogophora interrupta(WARREN), Mesapamea storai (REBEL), Autographa gamma (LINNAEUS), and Trichoplusia orichalcea (FABRICIUS) (Lepidoptera: Noctuidae) were studied between November 1992 and November 1993, at Terra Chã (110 m), Granja (310 m), Fajãs (310 m) and Santa Bárbara (525 m) on the island of Terceira, Azores archipelago, using Pennsylvania blacklight traps. While there was evidence of considerable fluctuations in abundance, A. segetum, P. saucia, X. c-nigrum, M. loreyi and P. meticulosa were present continuously at Santa Bárbara. In contrast N. pronuba, N. atlantica, M. storai, P. interrupta, A. gamma, and T. orichalcea were generally captured from Spring to beginning of Autumn. For any given species both sexes were captured simultaneously. Males of X. c-nigrum, P. meticulosa (Santa Bárbara), A. segetum and M. storai (Fajãs) were more frequent than females, while in the other species females were more abundant. However, in no case does the sex ratio deviates entirely from 1:1. Under an integrated pest management perspective, blacklight trap is an important technique for agricultural warning services, allowing to forecast the outbreaks of agricultural pests

Unveiling the Influence of Non-Toxic Fluorinated Ionic Liquids Aqueous Solutions in the Encapsulation and Stability of Lysozyme

Proteins are bioactive compounds with high potential to be applied in the biopharmaceutical industry, food science and as biocatalysts. However, protein stability is very difficult to maintain outside of the native environment, which hinders their applications. Fluorinated ionic liquids (FILs) are a promising family of surface-active ionic liquids (SAILs) that have an amphiphilic behavior and the ability to self-aggregate in aqueous solutions by the formation of colloidal systems. In this work, the protein lysozyme was selected to infer on the influence of FILs in its stability and activity. Then, the cytotoxicity of FILs was determined to evaluate their biocompatibility, concluding that the selected compounds have neglected cytotoxicity. Therefore, UV–visible spectroscopy was used to infer the FIL-lysozyme interactions, concluding that the predominant interaction is the encapsulation of the lysozyme by FILs. The encapsulation efficiency was also tested, which highly depends on the concentration and anion of FIL. Finally, the bioactivity and thermal stability of lysozyme were evaluated, and the encapsulated lysozyme keeps its activity and thermal stability, concluding that FILs can be a potential stabilizer to be used in protein-based delivery systems.publishersversionpublishe

Isolated Taylor Bubbles in Co-Current with Shear Thinning CMC Solutions in Microchannels—A Numerical Study

Slug flow is a multiphase flow pattern characterized by the occurrence of long gas bubbles (Taylor bubbles) separated by liquid slugs. This multiphase flow regime is present in many and diversified natural and industrial processes, at macro and microscales, such as in eruption of volcanic magmas, oil recovery from pre-salt regions, micro heat exchangers, and small-sized refrigerating systems. Previous studies in the literature have been mostly focused on tubular gas bubbles flowing in Newtonian liquids. In this work, results from several numerical simulations of tubular gas bubbles flowing in a shear thinning liquid in microchannels are reported. To simulate the shear thinning behavior, carboxymethylcellulose (CMC) solutions with different concentrations were considered. The results are compared with data from bubbles flowing in Newtonian liquids in identical geometric and dynamic conditions. The numerical work was carried out in computational fluid dynamics (CFD) package Ansys Fluent (release 16.2.0) employing the volume of fluid (VOF) methodology to track the volume fraction of each phase and the continuum surface force (CSF) model to insert the surface tension effects. The flow patterns, the viscosity distribution in the liquid, the liquid film thickness between the bubble and the wall, and the bubbles shape are analyzed for a wide range of shear rates. In general, the flow patterns are similar to those in Newtonian liquids, but in the film, where a high viscosity region is observed, the thickness is smaller. Bubble velocities are smaller for the non-Newtonian cases.</jats:p