Revista Jurídica Digital UANDES
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Commentary on: Chou AIW, Wang Y-C, Lin C-L, Kao C-H. Female schizophrenia patients and risk of breast cancer: A population-based cohort study. Schizophrenia Research 2017;188:165–171.
No full textComparison of stochastic frontier approaches for estimating national efficiency:an application to sub-Saharan African countries
No full textIn this paper, we attempt to estimate pure national (technical) efficiency for 19 SSA countries over the 1960-2010 periods. In doing this, we compare conventional stochastic frontier models for panel data with a number of recently developed models which seek to control for unobserved heterogeneity in the inefficiency component. We find that the ‘true’ random effects model that treats unobserved heterogeneity in our national dataset generates more reasonable efficiency estimates. Moreover the results confirm that most SSA countries operate far from the efficient frontier
Diffusion NMR Characterization of Catalytic Silica Supports:A Tortuous Path
No full textMesoporous silicas have found widespread application within the field of heterogeneous catalysis. Acid functionalization of such materials, through one-pot or postsynthetic grafting of sulfonic acid groups, imparts activity for fatty acid esterification, with the studious choice of pore geometry facilitating significant rate enhancements. Diffusion NMR has been utilized for the first time to characterize the structure of mesoporous silicas through the transport behavior of systematically related carboxylic acids confined within their mesopore networks. A reduced diffusion coefficient is obtained for species constrained within the 3-dimensional interconnected pores of KIT-6 relative to the 2-dimensional noninterconnected pore channels of SBA-15. The effective tortuosity of both porous silicas increases with the acid chain length, with the diffusion behavior of long-chain acids dominated by the alkyl chain and silica architecture. Carboxylic acid diffusion within these two pore networks is unlikely to be rate-limiting in catalytic esterification over sulfonic acid silica analogues. Physicochemical insights from diffusion NMR will aid the future design of optimal silica architectures for catalytic applications.</p
Acceptor levels of the carbon vacancy in 4H-SiC:combining Laplace deep level transient spectroscopy with density functional modeling
No full textWe provide direct evidence that the broad Z1/2 peak, commonly observed by conventional DLTS in as-grown and athigh concentrations in radiation damaged 4H-SiC, has two components, namely Z1 and Z2, with activation energies for electron emission of 0.59 and 0.67 eV, respectively. We assign these components to Z=1/2 →Z−1/2 +e− → Z01/2+2e−transition sequences from negative-U ordered acceptor levels of carbon vacancy (VC) defects at hexagonal/pseudo-cubic sites, respectively. By employing short filling pulses at lower temperatures, we were able to characterize the first acceptor level of VC on both sub-lattice sites. Activation energies for electron emission of 0.48 and 0.41 eV were determined for Z1(−/0) and Z2(−/0) transitions, respectively. Based on trap filling kinetics and capture barrier calculations, we investigated the two-step transitions from neutral to doubly negatively charged Z1 and Z2. Positions of the first and second acceptor levels of VC at both lattice sites, as well as (=/0) occupancy levels were derived from the analysis of the emission and capture data
MANTIS:The Mid-Frequency Aperture Array Transient and Intensity-Mapping System
No full textThe objective of this paper is to present the main characteristics of a wide-field MFAA precursor that we envisage to be built at the SKA site in South Africa. Known as MANTIS (the Mid-Frequency Aperture Array Transient and Intensity-Mapping System), this ambitious instrument will represent the next logical step towards the MFAA based SKA telescope. The goal is to use innovative aperture array technology at cm wavelengths, in order to demonstrate the feasibility of deploying huge collecting areas at modest construction and operational cost. Such a transformative step is required in order to continue the exponential progress in radio telescope performance, and to make the ambitious scale of the SKA Phase 2 a realistic near-time proposition
ASTERICS:Addressing Cross-Cutting Synergies and Common Challenges for the Next Decade Astronomy Facilities
No full textThe large infrastructure projects for the next decade will allow a new quantum leap in terms of new possible science. ESFRI, the European Strategy Forum on Research Infrastructures, a strategic initiative to develop the scientific integration of Europe, has identified four facilities (SKA, CTA, KM3Net and E-ELT) deserving priority in support. The ASTERICS project aims to address the cross-cutting synergies and common challenges shared by the various Astronomy ESFRI and other world-class facilities. The project (22 partners across Europe) is funded by the EU Horizon 2020 programme with 15 MEuro in 4 years. It brings together for the first time the astronomy, astrophysics and particle astrophysics communities, in addition to other related research infrastructures
Feature-oriented Component-based Development of Software Product Families: A Case Study
No full textFeature-oriented Software Development (FOSD) is widely used in Software Product Line Engineering (SPLE). FOSD constructs product families by incremental feature implementations. In this paper, we introduce a feature-oriented componentbasedapproach, which implements features as an encapsulated components for further family modelling. A case study of elevator systems is also presented to describe the use of our approach