First time III-nitride photonic crystals

AbstractThe development of compound semiconductor photonic crystals (PCs) based on infrared devices (wavelengths longer than 700nm) has been quite rapid during the last few years, mostly focused on Indium Phosphide materials for optical communication uses in the 1.3 and 1.55nm transmission windows. The property being exploited is the ability of lattices of varying refractive index to form photonic bandgaps in which the propagation of specific light wavelengths is prohibited or modified. This property can be used to control or enhance the spontaneous emission and or light extraction efficiencies from both active and passive devices (including LEDs)

Polyominoes which tile rectangles

Pericas, Enric;Ordóñez, Estrell

The contragredient equivalence for several matrices: a set of invariants

AbstractIn this paper, the contragredient equivalence is extended to several matrices and a reduced form of the cyclically multiplicable n-tuples of matrices under this equivalence is defined and constructed. An invariant set of elementary divisors (the spectrum of divisors) is found. This set describes completely the reduced form of a given cyclically multiplicable n-tuple

Assessing the Effects of Trade-induced Technology Imitation on Economic Growth in Africa

AbstractThe study aims at quantifying the effects of trade-induced technology imitation (proxied by the share of imports in the “easy imitation” SITC category) on economic growth in Africa, using a production function approach in a panel system-GMM estimator. Indicators of trade-induced technology imitation have been built on the Standard International Trade Classification (SITC) using raw data from the United Nations’ COMTRADE Statistics. Findings suggest that economic growth tends to be greater in countries with higher ratios of technology imitation, since technology imitation requires creative effort on the part of a firm's employees and will consequently develop capabilities such as skills and efficiency. Another finding is that the lower the level of GDP per capita, the higher the growth effects of technology imitation relative to other forms of technology progress

Erratum

Llauradó Grau, José María;Llopis Manlleu, Juan Manue

A live test of automated facies prediction at wells for CO2 storage projects

AbstractAt least 900 m of image log data have been interpreted in detail through the Late Cretaceous and Cenozoic succession intersected at two purpose-drilled injection wells of the CO2CRC Otway Project. Interpretations have been calibrated against core observations where possible. Natural clusters for the combined signature of a common suite of coincident well log data were determined using an unsupervised Naïve Bayesian classification algorithm called Autoclass. A deterministic relationship between these modelled clusters and interpreted image log facies provides a two-step facies prediction algorithm that can be applied using well log data acquired at other wells intersecting sedimentary successions prospective for CO2 storage.Earlier this year the Division of Resources & Energy, Department of Trade & Investment, of the Australian state of New South Wales drilled a new stratigraphic test well within the Pondie Range Trough of the Darling Basin. The new well, Mena Murtee-1, was drilled close to a 2D seismic tie line linking the Pondie Range Trough depocenter with an old petroleum exploration well, Pondie Range-1, that is sited on a flanking high. Analyses and interpretation of data acquired at Mena Murtee-1 is the latest step in reducing the uncertainty surrounding CO2 storage potential within the Darling Basin. Interpretation of core and image log data acquired at the new well has provided a means by which to test facies predictions made on the basis of the models developed within the Otway Basin

Society News

Tarrasó, Olga;Fuente Fuente, Carlos;Reventós, Manue

Discussion

Pericas, Enri

Editorial Board

Farrando Sicilia, Jordi; Lecea, Ignasi de; Fuente Fuente, Carlos; Ribas Seix, Anna; Masana Padrós, Judit; Delgado, José L

IBM and Stanford's SpinAps Center

Sagnier Villavechhia, Enric;Pruna, Pere;Salvador, MarinaPla de detall de la vitrina de de la façana de la Capella de les Mares Reparadores, actual Espai Cultural Pere Pruna