1,721,631 research outputs found
Lasers for health
Full text linkThanks to its spatial and temporal coherence properties, laser light lends itself to a wealth of biomedical applications. We review the use of lasers in medical sciences, from microscopy for understanding the origin of diseases, to diagnostics for enhancing the accuracy of therapies to surgery of almost any organ of the human body
Ultrafast lasers: From femtoseconds to attoseconds
No full textWe review the capability of lasers to generate light pulses of incredibly short duration, from a few femtoseconds (1 fs = 10 -15 s) in the visible down to a few tens of attoseconds (1 as = 10 -18 s) in the extreme-ultraviolet, reaching peak powers up to several petawatts (1 PW = 10 15 W)
Efficient Supply Chain Management: Traceability and Transparency
No full textThe development of SCM systems is a difficult activity, since it involves integrating critical business flows both within and among participating companies. The inherently difficulty of the problem is exacerbated by the business constraint (that almost invariably applies in the real world) that the investments made by individual companies throughout the years must be preserved. This maps to major design constraints, since SCM systems must be built around the preexisting ICT infrastructures of the individual companies and- A lso importantly-without affecting the local policies. We propose a federation-based approach to seamless and effective integration of legacy enterprise information systems into a unified SCM system. The proposed solution is implemented using a combination of Open Source BPM and cloud computing platform, and validated with respect to a real world use case taken from a research activity (namely: The GLOB-ID project) conducted cooperatively by academic and industrial parties
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Ultrafast Spectroscopy: State of the Art and Open Challenges
Full text linkUltrafast spectroscopy techniques use sequences of ultrashort light pulses (with femto- to attosecond durations) to study photoinduced dynamical processes in atoms, molecules, nanostructures, and solids. This field of research has experienced an impetuous growth in recent years, due to the technological progress in the generation of ultrashort light pulses and to the development of sophisticated spectroscopic techniques, which greatly increase the amount of information on the process under study. This paper aims at providing a non-exhaustive overview of the state of the art of the field and at pointing out future challenges. We first review the progress in ultrafast optics, which has enabled the generation of broadly tunable light pulses with duration down to a few optical cycles; we then discuss the pump-probe technique, showing examples of its capability to combine very high time resolution, down to the attosecond regime, with broad spectral coverage; we introduce two-dimensional spectroscopy and present results that demonstrate the additional information content provided by the combination of temporal and spectral resolution. Next, we review the achievements of ultrafast X-ray and electron diffraction, which provide time-dependent structural information on photochemical processes, and we conclude with a critical analysis of the future open challenges in the field
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Ultrabroadband pulse shaping with a push-pull deformable mirror
No full textWe report the programmable pulse shaping of ultrabroadband pulses by the use of a novel design of electrostatic deformable mirror based on push pull technology. We shape few-optical pulses from near-IR and visible optical parametric amplifiers, and demonstrate strong-field control of excited state population transfer in a dye molecule
Ultrafast dynamics of a charge-transfer dimer as a model for the photoinduced phase transition of charge-transfer compounds
No full textBy applying ultrafast pump-probe spectroscopy with 15 fs temporal resolution to TMTTF2 dimers
we provide a full picture of the structural relaxation following photoexcitation of their CT transition. Both
population and coherent phonon dynamics allow tracking wave packet motion onto the multidimensional
excited state potential energy surface, as obtained by density functional theory calculations. We show that
the vibrations that are strongly coupled to the charge-transfer transition of the dimer correspond to those
driving the photoinduced phase transition occurring in charge-transfer crystalline solids
- …
