102,097 research outputs found
Excavations at Jalarne Site of a Glass Factory in Late Roman Palestine, G. Davidson Weinberg ed., 1988
No full textNenna Marie-Dominique. Excavations at Jalarne Site of a Glass Factory in Late Roman Palestine, G. Davidson Weinberg ed., 1988. In: Topoi, volume 1, 1991. pp. 79-82
Bragg extraction of light in 2D photonic Thue-Morse quasicrystals patterned in active CdSe/CdS nanorod-polymer nanocomposites
No full textIn this paper two-dimensional (2D) photonic Thue-Morse quasicrystals (ThMo-PQCs) in active CdSe/CdS nanorod (NR) doped polymer nanocomposites are proposed and experimentally demonstrated. Active PQCs and undoped lattices have been prepared in a one-step fabrication process by an electron beam lithography technique (EBL) and the effects on light extraction and emission directionality are studied experimentally. Vertical extraction of light was found to be strongly dependent on both the geometric parameters of the ThMo-PQCs and the presence of NR dopants. By changing the geometrical parameters of the photonic structures, the resonance peak could be tuned from a narrow bluish green emission at 543 nm up to a red-NIR emission at 711 nm with a full width at half-maximum of 22 nm which is in good agreement with Bragg's diffraction theory and free photon band structure. Angular resolved measurements revealed a directional profile in the far-field distribution with guided mode extraction in both doped and undoped PQCs and an enhancement as high as 6.5-fold in light extraction was achieved in the doped photonic structures. These experimental results indicate the critical role of the CdSe/CdS NRs in improving the light extraction efficiency of 2D ThMo-PQCs for solid-state lighting and lasing. © 2013 The Royal Society of Chemistry
Optical and electrical characterizations of graphene nanoplatelet coatings on low density polyethylene
No full textCoatings of graphene nanoplatelets (GNPs) were deposited on a low density polyethylene (LDPE) substrate by a micromechanical method based on rubbing graphite platelets against the surface of the polymer. Transmission electron microscopy measurements reveal that the coatings were composed of nanoplatelets containing 13-30 graphene layers. Thermal gravimetric analysis shows that the investigated GNP coatings on LDPE (GNP/LDPE) samples are thermally stable up to 250 °C. Optical spectra of these samples, compared to those of pristine LDPE in the ultraviolet-visible-near-infrared range, indicate an increase in both reflectance and absorptance. On the other hand, the coating is able to markedly improve the surface conductivity of the polymeric substrate, indeed in the case of electrical contacts in the coplanar configuration (1 cm long and spaced 1 mm), the resistance of LDPE is 1015Ω, while that of GNP/LDPE is 670 Ω. Electrical measurements under white light illumination point out a decrease in the conductance and a linear behavior of the photoconductance as a function of the optical power density. GNP/LDPE materials can be used for their optical, electrical, thermal, and flexibility properties in large area plastic electronics and optoelectronics. © 2017 Author(s)
Multiband PIFA for WLAN mobile terminals
No full textA novel compact planar inverted-F antenna (PIFA)
to be mounted on laptop computers is presented. The proposed
multiband single-feed PIFA simultaneously operates in the IEEE
802.11a, IEEE 802.11b/g, and HIPERLAN2 frequency bands. The
multiband behavior is obtained by combining a trapezoidal feed
plate with two different resonance paths in the radiating structure.
The overall size of the antenna renders it suitable to be installed at
the border of the display of a notebook. Simulation results are compared
with measurements performed on an antenna prototype
Insights into thermal degradation of organic light emitting diodes induced by glass transition through impedance spectroscopy
No full textSafety and efficacy of non-vitamin K antagonist oral anticoagulants versus warfarin in diabetic patients with atrial fibrillation: A study-level meta-analysis of phase III randomized trials
No full textFunctional polymeric coatings for csi(Tl) scintillators
Get PDFThe handling of inorganic scintillators (e.g., alkali metal halides) can benefit from the availability of polymeric materials able to adhere to their surface. Polymeric materials, such as epoxy resins, can act as protective coatings, as adhesives for photodiodes to be connected with the scintillator surface, and as a matrix for functional fillers to improve the optical properties of scintillators. Here, the optical properties of two epoxy resins (E-30 by Prochima, and Technovit Epox by Heraeus Kulzer) deposited on the surface of a scintillator crystal made of CsI(Tl) were investigated, in order to improve the detection of high-energy radiation. It is found that these resins are capable of adhering to the surface of alkali metal halides. Adhesion, active at the epoxy–CsI(Tl) interface, can be explained on the basis of Coulomb forces acting between the ionic solid surface and an ionic intermediate of synthesis generated during the epoxy setting reaction. Technovit Epox showed higher transparency, and it was also functionalized by embedding white powdered pigments (PTFE or BaSO4) to achieve an optically reflective coating on the scintillator surface
From research question to dissemination: How to design, analyse and present study results
No full textThe key for the success of a study lies in the careful design of all its different phases, from the statement of the objectives to the dissemination of the results
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