Further exploring the dynamicity, situatedness, and emergence of the self: The key role of context

Drawing on theoretical insights from a complex dynamic systems framework, this work explores the ways that learner selves, as they relate to learning and using languages, manifest across different contexts and timescales and emerge in interaction with various factors. First, a broad overview of dynamically-oriented L2 motivation research is provided before critically considering the need for research that aligns with conceptual advances made under the dynamic turn in SLA. In particular, this critical overview highlights a crucial need for more research employing dynamic methods capable of revealing how learner perceptions of self emerge in relation to their interlocutors and in interaction with external factors, including language ideologies that may uniquely characterize sociocultural contexts where target languages other than English are learned. The chapter concludes by discussing ways to implement dynamically oriented methodology that can provide much needed insights into the inherent dynamic, emergent, and contextually and socially embedded nature of learner selves

Multiple Exciton Generation in Nanostructures for Advanced Photovoltaic Cells

This paper reviews both experimental and theoretical work on nanostructures showing high quantum yields due to the phenomenon of multiple exciton generation. It outlines the aims and barriers to progress in identifying further such nanostructures, and also includes developments concerning solar devices where nanostructures act as the light-absorbing component. It reports on both semiconductor and carbon structures, both monocomposite (of various dimensionalities) and heterogeneous. Finally, it looks at future directions that can be taken to push solar cell efficiency above the classic limit set by Shockley and Queissier in 1961.Comment: 13 pages, 10 figure

Distributed First Order Logic

Distributed First Order Logic (DFOL) has been introduced more than ten years ago with the purpose of formalising distributed knowledge-based systems, where knowledge about heterogeneous domains is scattered into a set of interconnected modules. DFOL formalises the knowledge contained in each module by means of first-order theories, and the interconnections between modules by means of special inference rules called bridge rules. Despite their restricted form in the original DFOL formulation, bridge rules have influenced several works in the areas of heterogeneous knowledge integration, modular knowledge representation, and schema/ontology matching. This, in turn, has fostered extensions and modifications of the original DFOL that have never been systematically described and published. This paper tackles the lack of a comprehensive description of DFOL by providing a systematic account of a completely revised and extended version of the logic, together with a sound and complete axiomatisation of a general form of bridge rules based on Natural Deduction. The resulting DFOL framework is then proposed as a clear formal tool for the representation of and reasoning about distributed knowledge and bridge rules

Female entrepreneurship in perspective: a methodological issue

A methodological approach to the concept of female entrepreneurship concept has not yet been treated: is female entrepreneurship an individual or collective concept? Is it considered a social or natural variable? The purpose of this research is to clear up these alternatives, which are preparatory questions for any research into female entrepreneurship that wishes to measure its features and effects. The article starts with the proposal of an identification procedure, necessary to identifying the variables of female entrepreneurship. It proceeds by classifying the concept of female entrepreneurship into four different modes and discussing their characteristics. The originality of this research consists in its fourfold classification of the concept of female entrepreneurship, intended as a preparatory step prior to the analysis of its characteristics and measures

Standard forms and entanglement engineering of multimode Gaussian states under local operations

We investigate the action of local unitary operations on multimode (pure or mixed) Gaussian states and single out the minimal number of locally invariant parametres which completely characterise the covariance matrix of such states. For pure Gaussian states, central resources for continuous-variable quantum information, we investigate separately the parametre reduction due to the additional constraint of global purity, and the one following by the local-unitary freedom. Counting arguments and insights from the phase-space Schmidt decomposition and in general from the framework of symplectic analysis, accompany our description of the standard form of pure n-mode Gaussian states. In particular we clarify why only in pure states with n<=3 modes all the direct correlations between position and momentum operators can be set to zero by local unitary operations. For any n, the emerging minimal set of parametres contains complete information about all forms of entanglement in the corresponding states. An efficient state engineering scheme (able to encode direct correlations between position and momentum operators as well) is proposed to produce entangled multimode Gaussian resources, its number of optical elements matching the minimal number of locally invariant degrees of freedom of general pure n-mode Gaussian states. We demonstrate that so-called "block-diagonal" Gaussian states, without direct correlations between position and momentum, are systematically less entangled, on average, than arbitrary pure Gaussian states.Comment: 14 pages, 2 figures, IOP style. Published in J. Phys. A, Special Issue on Quantum Information, Communication, Computation and Cryptography (the arXiv version has an extra note added