A study of nano-particle based silane consolidants for Globigerina limestone

This STEPS funded study focuses on the application of hybrid and nanoparticle loaded hybrid silane consolidants for the treatment of 'Franka' type Globigerina Limestone. Consolidants act by gluing the deteriorated stone material to the underlying healthy stone (Dukes, 1972; Gutt, 1973; Alessandrini et al., 1975; Garrod, 2001). The consolidants evaluated in this work were a laboratory prepared hybrid silane based on a mixture of tetraethylorthosilicate (TEOS) and 3-(glycidoxypropyl) trimethoxysilane (GPTMS), the same hybrid consolidant loaded with silica nanoparticles and GPTMS-modified silica nanoparticles. In addition, a consolidant based on the hydrolysis product of TEOS was also tested. Prepared consolidants were applied to Globigerina Limestone test blocks by complete immersion. Untreated stone block were used as benchmarks. Following application of the consolidants, half of the treated limestone blocks were subjected to accelerated weathering. Non-weathered and weathered limestone blocks were then characterised by optical and electron microscopy and the stone colour before and after treatment with consolidants was assessed by a colorimetric technique. The pore size distribution before and after application of the different consolidant treatments was assessed by Mercury Intrusion Porosimetry. A water absorption by capillarity technique was also carried out to assess how the water uptake rate into the limestone alters with the different treatments. The mechanical properties of the consolidated limestone blocks were assessed by resistance to sodium sulfate crystallisation. Microscopy observations showed that the consolidants penetrated the stone to different extents depending on the consolidant and the method of application. The hybrid consolidant on its own led to yellowing of the limestone but the addition of nanoparticles to the hybrid (modified or not) appeared to help restore the original colour of the stone. The porosity of the limestone was only marginally affected by the different treatments but the somewhat hydrophobic nature of the consolidants led to a disruption in the capillary flow of water into the limestone.peer-reviewe

Consecuencias legales derivadas de un accidente laboral

Traballo fin de grao (UDC.DER). Dereito. Curso 2014/201

The unique continuation property for a nonlinear equation on trees

In this paper, we study the game p-Laplacian on a tree, that is, u(x) = α / 2 max y∈S(x) u(y) + min y∈S(x) u(y) + β m y∈S(x) u(y);here x is a vertex of the tree and S(x) is the set of successors of x. We study the family of the subsets of the tree that enjoy the unique continuation property, that is, subsets U such that u |U = 0 implies u ≡ 0.Fil: del Pezzo, Leandro Martin. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mosquera, Carolina Alejandra. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rossi, Julio Daniel. Universidad de Alicante; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Existence, uniqueness and decay rates for evolution equations on trees

We study evolution equations governed by an averaging operator on a directed tree, showing existence and uniqueness of solutions. In addition we find conditions of the initial condition that allows us to find the asymptotic decay rate of the solutions as $t\to \infty$. It turns out that this decay rate is not uniform, it strongly depends on how the initial condition goes to zero as one goes down in the tree.Fil: del Pezzo, Leandro Martin. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mosquera, Carolina Alejandra. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rossi, Julio Daniel. Universidad de Alicante; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Investigación del virus de importancia médica y veterinaria transmitidos por culicoides

The first paper comprises the study of the Bluetongue virus (BTV) and Epizootic Hemorrhagic Virus (EHDV), two orbiviruses transmitted by Culicoides biting midges, and causative agents of disease in wild and domestic ruminants. In Ecuador, alarming serological evidence of the presence of both viruses in cattle has recently been found, but the vector species are still unknown...El primer artículo comprende el estudio del virus de la lengua azul (BTV) y el virus de la enfermedad epizoótica hemorrágica (EHDV), dos orbivirus transmitidos por Culicoides, y agentes causales de enfermedades en rumiantes salvajes y domésticos. En Ecuador, se encontró evidencia serológica alarmante sobre la presencia de ambos virus en ganado vacuno, pero las especies vectores todavía no se conocen..

Registro isotópico de δ13 C y δ15 N de 12.000 años de antigüedad de Amboromena (Macizo de Andringitra, Madagascar)

[Abstract] Profiles of percent carbon, nitrogen and phosphorus, carbon/nitrogen (C/N) ratios, percent organic matter and carbonates, and stable carbon (δ13C) and nitrogen (δ15N) from a 176 cm core were used to reconstruct environments of deposition in the Amboromena basin (Madagascar)during last 12,000 yr BP. From these profiles three distinctively different stages in the basin evolution were apparent, which could have been result from the response to changes in the climatic conditions. Similar changes has been observed in other works about climate evolution in Madagascar and the African Tropics during the Late Quaternary

The precise center of a crossed module

The final publication is available at www.degruyter.com[EN] We generalize the definition of the precise center of a group to the crossed modules context. We construct the Ganea map for the homology of crossed modules, and we study the connections between the precise center of a crossed module and the Ganea map. We extend some other known notions from group theory such as capable and relatively capable groups, capable pairs and unicentral groups with the definitions of capable and unicentral crossed modules. Finally we show how to apply these constructions to solve some open questions in the theory of crossed modules.SIMinisterio de Educación y CienciaXunta de GaliciaThe authors were supported by Ministerio de Ciencia e Innovación (European FEDER support included), grant MTM2009-14464-C02-01, and by Xunta de Galicia, grant Incite09 207 215 PR. We also thank the referee and the editor for providing several constructive comments that were very helpful for improving the contents of this paper

Central Extensions of Precrossed Modules

This version of the article has been accepted for publication, after peer review and is subject to Springer Nature's AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1023/B:APCS.0000040555.48968.64[EN] We classify the precrossed module central extensions using the second cohomology group of precrossed modules. We relate these central extensions to the relative central group extensions of Loday, and to other notions of centrality defined in general contexts. Finally we establish a Universal Coefficient Theorem for the (co)homology of precrossed modules, which we use to describe the precrossed module central extensions in terms of the generalized Galois theory developed by Janelidze.SIMinisterio de Ciencia y TecnologíaXunta de GaliciaWork partially supported by PGIDT01PXI20702PR and by MCYT, project BFM20000523 and BFM2003-04686-C02-01. Spai

Baer Invariants and Cohomology of Precrossed Modules

This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s10485-013-9307-x[EN] In this paper we study Baer invariants of precrossed modules relative to the subcategory of crossed modules, following Fröhlich and Furtado-Coelho's general theory on Baer invariants in varieties of Ω-groups and Modi's theory on higher dimensional Baer invariants. Several homological invariants of precrossed and crossed modules were de fined in the last two decades. We show how to use Baer invariants in order to connect these various homology theories. First, we express the low-dimensional Baer invariants of precrossed modules in terms of a new non-abelian tensor product of a precrossed module. This expression is used to analyze the connection between the Baer invariants and the homological invariants of precrossed modules de ned by Conduché and Ellis. Specifi cally we prove that the second homological invariant of Conduché and Ellis is in general a quotient of the first component of the Baer invariant we consider. The defi nition of classical Baer invariants is generalized using homological methods. These generalized Baer invariants of precrossed modules are applied to the construction of fi ve term exact sequences connecting the generalized Baer invariants with the cohomology theory of crossed modules considered by Carrasco, Cegarra and R.-Grandjeán and the cohomology theory of precrossed modules.SIMinisterio de Ciencia e InnovaciónXunta de GaliciaWork partially supported by PGIDT01PXI20702PR and by MCYT, project BFM20000523, Spai