On global location-domination in graphs

A dominating set $S$ of a graph $G$ is called locating-dominating, LD-set for short, if every vertex $v$ not in $S$ is uniquely determined by the set of neighbors of $v$ belonging to $S$. Locating-dominating sets of minimum cardinality are called $LD$-codes and the cardinality of an LD-code is the location-domination number $\lambda(G)$. An LD-set $S$ of a graph $G$ is global if it is an LD-set of both $G$ and its complement $\overline{G}$. The global location-domination number $\lambda_g(G)$ is the minimum cardinality of a global LD-set of $G$. In this work, we give some relations between locating-dominating sets and the location-domination number in a graph and its complement.Comment: 15 pages: 2 tables; 8 figures; 20 reference

The 'native speaker' spin: the construction of the English teacher at a language department at a university in central Mexico

This is a study of how teachers, students and administrators in a particular university's language department in Guanajuato, Mexico, construct the English teachers' professional image. The experiences of ten teachers, fourteen students, and two administrators at the Language Department of the University of Guanajuato in Mexico are explored through data obtained from conversations, narratives, critical incidents, e-mail correspondence and field-notes. This thesis began as an investigation of the construction of the 'native/non-native' debate. However, it arrived at a final point which is concerned about the ways in which individual perceptions are constructed and affected through historical or social pressures. From the data collected key areas emerged, such as: identity, labelling and the socio-political relationship between Mexico and the United States and its consequences. The data shows the polarization that exists between 'native speakers' and 'non-native speakers' themselves concerning aspects such as birthplace, ethnicity and nationality. In order to make sense of this data, I decided to employ the concept of spin to explain how images of the English teacher and speaker are constructed and maintained (or rejected) by participants. This is used as a lens to understand the evolution of the creation of the 'native speaker' image and labels. This helps understand how the 'native speaker' image came to play such a critical —and sometimes apparently harmful— role in the construction of the Other and the Self. Specifically, the 'native speaker' spin was not a point of investigation, but emerged as a significant tool for the discussion of the data as the analysis progressed. Overall this study seems to set a precedent that there is no clear-cut division between 'native' and 'non-native speakers'. Rising awareness of how complex labels operate through discourses, institutions and hiring policies may help to bring about more recognition of commonalities of English teachers as professionals

The low temperature Fulde-Ferrell-Larkin-Ovchinnikov phases in 3 dimensions

We consider the nature of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phases in three dimensions at low temperature. We introduce a new method to handle the quasiclassical equations for superconductors with space dependent order parameter, which makes use of a Fourier expansion. This allows us to show that, at T=0, an order parameter given by the linear combination of three cosines oscillating in orthogonal directions is preferred over the standard single cosine solution. The transition from the normal state to this phase is first order, and quite generally the transition below the tricritical point to the FFLO phases is always first order.Comment: 4 pages, revtex, 1 figur

Strongly coupled large-angle stimulated Raman scattering of short laser pulses in plasma-filled capillaries

Strongly coupled large-angle stimulated Raman scattering (LA SRS) of a short intense laser pulse proceeds in a plane plasma-filled capillary differently than in a plasma with open boundaries. Oblique mirror reflections off capillary walls partly suppress the lateral convection of scattered radiation and increase the growth rate of the instability: the convective gain of the LA SRS falls with an angle much slower than in an unbounded plasma and even for the near-forward SRS can be close to that of the direct backscatter. The long-term evolution of LA SRS in the interior of the capillary is dominated by quasi-one-dimensional leaky modes, whose damping is related to the transmission of electromagnetic waves through capillary walls.Comment: 11 pages, 6 figures; to be submitted to Physics of Plasma

Distribution of fibers in SFRC segments for tunnel linings

This paper presents research results regarding the distribution of steel fibers in concrete used to build precast tunnel segments for Line 9 of the Barcelona Metro. The fiber distribution was studied using the actual fiber contents obtained by means of crushed cores drilled from different points of three full-scale tunnel lining segments. A statistical analysis determined that the fiber content in the ends of segments tends to be greater than in the central zone. The way of transporting, pouring and compacting concrete influences the fiber content and the fiber distribution across the thickness of the segment. In addition, cores with a diameter of 150 mm were found to have a lower scatter in the fiber content than smaller diameter specimens. Finally, based on probabilistic approaches, a minimum of 11 cores is proposed to control the fiber content in FRC segments.Peer ReviewedPostprint (author's final draft

Les festes religioses en el regnat de Carles III: el cas particular de Barcelona (1770-1785)

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