42,493 research outputs found
Sub-wavelength light confinement in optical fibres and tapers using surface plasmons
No full textLight confinement beyond the diffraction limit is proposed in optical fibres and fibre tapers by exploiting surface plasmons (SPs). To achieve high transmission efficiency, light is converted into SPs at the fibre/taper tip and then converted back into light. Indeed SPs can be confined to dimensions smaller than diffraction limit, but they require stringent conditions for their excitation: the light incidence angle depends on the wavelength (Figure 1a) and it has a strong dependence on the taper diameter (Figure 1b). For this reason fibre/taper nanostructuring needs to be extremely accurate. In this work, optical fibres and fibre tapers (Figure 1c, 1d) have been nanostructured to achieve highly efficient SPs excitation and high transmission efficiency. The effect of different milling shape on transmission has also been analyzed. Transmissivities as high as 7% have been observed
XXIV Congreso Argentino de Hipertensión Arterial en Mendoza : abril de 2017
No full textFil: Renna, Nicolás F..Fil: Miatello, Roberto M.
La investigación en la formación médica
No full textFil: Renna, Nicolás F..
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: Miatello, Roberto M. .
Universidad Nacional de Cuyo. Facultad de Ciencias Médica
M. Renna, S. Vaccari, Commento all’art. 40 c.p.a. (Contenuto del ricorso), in G. Falcon, B. Marchetti, F. Cortese (a cura di), Commentario breve al Codice del processo amministrativo, Padova, Cedam, 2021, p. 433 e ss
No full textCommento all'art. 40 c.p.a. (Contenuto del ricorso
Discussion on “Computing the Trajectory of Free Jets” by T.L. Wahl, K.H. Frizzell and E.A. Cohen
No full textTowards a sub-10nm optical fibre light source
No full textLight sources with sub-10nm spot sizes have a wealth of applications, including optical memories, optical tweezers, SNOM microscopy and photolithography, just to cite a few. Overall, light confinement is limited by diffraction, which can be seen as a direct consequence of Heisenberg's uncertainty principle [1]. Recent results show that "sub-wavelength" light sources can be manufactured using many techniques, including metamaterials and negative refractive index materials [2,3]. Very often these techniques have been proven inefficient, bulky and do not work at short wavelengths. In this paper, light confinement is attained in nanostructured optical fiber tips exploiting surface plasmon polaritons (SPP)
Nappe flow over horizontal stepped chutes
No full textStepped chutes have been frequently used since the 1980s in order to take advantage of their dissipation efficiency, aeration characteristics and relative ease of construction. Two basic flow regimes exist for stepped chutes: nappe flow and skimming flow, with the nappe flow having received less attention in comparison to the skimming flow regime. This work suggests a simple iterative method, valid for sub-to-supercritical approach flow conditions, for predicting the basic nappe flow features on a horizontal multi-step structure. The proposed calculation procedure, if applied along the stepped chute, allows us to calculate the flow depth at each step brink and at each nappe impact point, the thickness of the water cushion beneath the nappe, the jet impact length and the energy dissipation rate. For validating the proposed analytical approach, a comparison between experimental and calculated data is also presented
Yield and quality of greenhouse multi-leaf lettuce cultivars grown in soil and soilless culture under Mediterranean conditions
No full textMulti-leaf lettuce has been proposed as a new type of product to be grown in open field or protected cultivation, especially for ready-to-eat salads. Like Batavia, oak leaf or lollo, multi-leaf lettuce
is more attractive in characteristics such as size, colour, texture, but has smaller, more uniform leaves
attached in a single point at the base. In the current research, we evaluated yield and quality of three
multi-leaf lettuce cultivars (Ezra, Ezabel and Eztoril), in both autumn-winter and winter-spring cycles,
by comparing soilless versus soil cultivation, and within soilless by comparing the supply of 50% nitrogen
as ammonium form instead of sole nitrate fertilization. Soilless cultivation improved crop yield by
about 20%, but only with the limiting environmental conditions of the first cycle. Among cultivars, Ezra
always presented taller leaves than the others. Multi-leaf lettuce had good ammonium tolerance, never
showing symptoms of toxicity. Ammonium nitrogen supply caused a slight increase in dry matter content,
but only at the spring harvests. Simultaneously, it was responsible for a lower nitrate content, compared
to nitrate-fed plants (-11 and -30%, respectively in first and second cycle). Generally, the nitrate
content was quite low (2,470 and 1,000 mg kg-1 fresh weight, respectively in the two cycles), considering
that it was a protected cultivation in winter or winter-spring. Under the operating conditions of our
experiment, the influence of soil cultivation on dry matter and nitrate content was variable in relation to
the cultivars. Mixed ammonium nutrition tended to increase the chlorophyll content in soilless-grown
lettuce, only in the autumn-winter cycle, but this did not cause colour changes
Conclusioni
No full textIl contributo contiene le conclusioni del convegno svoltosi a Messina il 15 e il 16 ottobre del 2016 e offre spunti di riflessione su aspetti legati all'organizzazione e all'attività delle amministrazioni impegnate nella tutela del patrimonio cultural
- …
