3,208 research outputs found
Synthesis and characterization of plasmonic nanostructures with controlled geometry for photonic applications
No full textThe purpose of the present thesis is the study of the interaction of plasmonic and pre-plasmonic nanostructures with an emitter in close proximity. The investigation was carried out following different approaches but always with the aim of inserting the experimental results in the frame- work of new or existing theoretical models in order to better understand the photophysical nature of the interaction. To this aim in the framework of this thesis different nanoarchitectures have been synthesised and coupled to Er-doped silica layers. The choice of Erbium as emitting source was driven by the great technological importance of this rare earth in photonics and optoelectronics, connected to the characteristic emission at 1540 nm that matches the window of minimum transmission loss for silica. For this reason the first step of the research activity was devoted to the optimization of the Erbium photoluminescent properties in silica.
When an emitter is placed near an interface, its optical properties will be modified. To describe this variation different contributions have to be taken into account: the variation of the local density of state due to the reflection from the interface, the coupling of the emitted radiation with propagating surface plasmons on the metal-dielectric interface and the dissipation in the overlayer. All these aspects have been studied in detail for different overlayer materials demonstrating that the strong control of the excited state lifetime of the emitter can be obtained by tailoring the dielectric properties of the overlayer and the separation distance from the interface.
Nanostructuring the overlayer offers further opportunities for changing the optical properties of a nearby emitter. Among different plasmonic nanostructures, nanohole arrays (NHAs) can represent the ideal candidate for this purpose due to their extraordinary optical transmission (EOT): at specific frequencies determined by the hole periodicity, the light transmitted through the NHA is orders of magnitude higher than the one predicted with the classical diffraction theory. When the EOT peak was tailored with the emission wavelength of the emitter strong plasmonic coupling was demonstrated, leading to lifetime shortening with almost no dissipation in the overlayer.
The improvement of the optical performances of an emitter can be obtained not only acting on the decay from the excited state but also increasing the excitation efficiency. For this purpose, an interesting possibility that has been explored is the sensitization by of ultra-small molecular-like metal nanoclurters (NCs) produced by ion implantation. Noble metal NCs can indeed efficiently absorb light through broad-band interband transitions and transfer energy to a nearby emitter, acting as efficient nanoantennae for excitation of the emitter. Such interaction leads to the increase of the effective excitation cross-section by several orders of magnitude.
Finally, all the obtained results allowed the development of predictive models that can be used in the design of novel devices for different photonic application
Letter of concern from Boris Drasin, President of the Jersey Homesteads Industrial Cooperative Association
No full textJersey Homesteads (later renamed the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whome had emigrated from Europe. In this letter, Boris Drasin, a community leader who was the President of the Jersey Homesteads Industrial Cooperative Association, expresses his concerns to their management corporation (Consumers Wholesale Clothiers, Inc.) about how financial losses will impact the lives of Roosevelt's residents, three-fourths of whom depended on the garment factory for their livelihoods. He makes suggestions as to how the situation might be improved
Widespread Expression of BORIS/CTCFL in Normal and Cancer Cells
No full textThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Boris Smolar papers, undated, 1913-1985.
No full textThis collection contains materials pertaining to the life and career of Boris Smolar, a journalist and editor-in-chief of the Jewish Telegraphic Agency and an author of children's books.Gift of Leivy Smolar
Emission Rate Modification and Quantum Efficiency Enhancement of Er3+Emitters by Near-Field Coupling with Nanohole Arrays
No full textThe control of the spontaneous emission properties of quantum emitters with limited losses by near-field coupling with plasmons-supporting nanostructures is one of the keys for next-generation high-efficiency and high-coherence plasmonic devices. In the present work, gold nanohole arrays are demonstrated to be an effective plasmonic system for controlling radiative rate and quantum efficiency of the 1540 nm emission of Er3+ ions embedded in silica. Finite element method electrodynamic simulations were used to describe the interaction between dipolar Er3+ emitters and the nanohole arrays. The results are in agreement with those of photoluminescence measurements performed in different coupling configurations. Particularly, we demonstrated that owing to the combination of strong emission enhancement and low level of ohmic losses in the metal, nanohole arrays are able to enhance the far-field photon yield up to 74%. This in turn is related to an extremely high far-field quantum efficiency: more than 90% of the emitted photons reach the far-field for the most efficient configurations investigated in which the extraordinary optical transmission peak of the nanohole array is matched with the Er3+ emission
Maxwell's color box: Retracing the path of color matching experiments
No full textIn his 1860 paper On the theory of compound colours, James Clerk Maxwell described an
instrument used to obtain a direct comparison between daylight and a mixture of three selected
spectral colors. This investigation was part of Maxwell’s study of human color vision, color
perception, and color representation, and it encompasses his main achievements in the field. The
working principle underlying this device provided the basis from which color diagrams have been
derived, beginning with the standard chromaticity diagram proposed by the International
Commission on Illumination in 1931. We describe a reconstruction of Maxwell’s original version
of the color box. Constructing and analyzing data obtained with such a replica could serve as a
semester project for advanced optics students
Long-Run Development and the New Cultural Economics
No full textThis paper reviews recent economics literature on culture, with an emphasis on its relation to the field of long-run growth and development. It examines the key issues debated in the new cultural economics: causal effects of culture on economic outcomes, the origins and social costs of culture, as well as cultural transmission, persistence, and change. Some of these topics are illustrated in application to the economic analysis of envy-related culture
Enhanced optical functionalities in silica by doping with Au-based nanostructures
No full textThe sensitization mechanism of Er3+ ions by sub-nanometric AuN aggregates formed in silica by sequential ion implantation has been investigated by room temperature photoluminescence characterizations. Er–Au co-implanted samples with different Au and Er relative concentrations have been studied. The results allowed to point out a correlation between the luminescence properties of the molecule-like AuN nanoclusters and the Er sensitization effect and to definitely prove the short-range nature of the energy-transfer process
Making Enterprise Information Systems Resilient Against Disruptive Events: A Conceptual View
No full textEnterprise Information Systems (EIS) are designed to deal with normal variability in their inputs and data. Empowered by CONTEXT-AWARENESS, some EIS even count on sensors and/or data analytics for capturing changes outside of the system. Nevertheless, context-awareness would often fail when EIS are affected by (large-scale) disruptive events, such as disasters, virus outbreaks, or military conflicts. Hence, in the current paper, we take a step forward, by considering context-awareness for disruptive events. We combine context-awareness with risk management techniques, such as FMECA and FTA, that are useful for defining and mitigating risk events. To avoid having to define the likelihood for such very-low-probability disruptive risks, we use CONSEQUENCE-BASED RISK MANAGEMENT rather than traditional risk management. We augment this approach with the context-awareness paradigm, delivering a contribution that is two-fold: (i) We propose context-awareness-related measures and consequence-based-risk-management-related measures, to address disruptive events; (ii) We reflect this in a method featuring the application of context-awareness and risk management for designing robust and resilient EIS.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Policy Analysi
Illustrated book of fiction, Boris Vian-Froth on the Daydream
No full textBakalářká práce Ilustrovaná kniha beletrie se v praktické části zaměřuje na koncepci ilustrací a jejich následnou kresbu pro knihu Pěna dní autora Borise Viana. V teoretické části práce je detailně sledován proces vzniku od prvotních idejí až po hlavní koncepční řešení celku. Text zde dále zkoumá formu díla skrze technologický proces výroby až po konečnou realizaci knihy a dalšího příslušenství, které kniha nabízí. Krom procesu vzniku a tvorby text obsahuje také kontextové srovnání, autorčinu osobní výpověď a zhodnocení výsledného díla.OVUObhájenoBachelor´s thesis Illustrated book of fiction in it´s practical part is aimed at conception of illustrations with following realisation of drawings for the book Froth on the Daydream by Boris Vian. In theoretical part the creation process of the book is observed there closely from the first ideas up to whole piece solution. Next part of the thesis is focused on technological process of manufacturing and final realisation of the book and it´s other accessories. Also the context comparison is described there as well as personal statement of the author and evaluation of the final work
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