7,602 research outputs found
Micropropagation of Ailanthus altissima and in vitro heavy metal tolerance
Ailanthus altissima, a fast?growing and contamination?resistant species is investigated for its use in areas contaminated by heavy metals. A micropropagation protocol for A. altissima was developed, cultured shoots were tested for in vitro heavy metals tolerance. Proliferation rate and shoot length were affected by 6?benzylaminopurine (BAP) and Murashige and Skoog\u27s (MS) salt concentrations, best results were obtained in full strength MS medium supplemented with 1.32 or 2.64 μM BAP. Rooting percentage was strongly influenced by indole?3?butyric acid. Cultures of A. altissima exposed to heavy metals demonstrated a tolerance comparable to species already utilized in phytoremediation
Dimensionality of the spatio-temporal entanglement of PDC photon pairs
In this work the Schmidt number of the two-photon state generated by
parametric-down conversion (PDC) is evaluated in the framework of a fully
spatio-temporal model for PDC. A comparison with the results obtained in either
purely spatial or purely temporal models shows that the degree of entanglement
of the PDC state cannot be trivially reduced to the product of the Schmidt
numbers obtained in models with lower dimensionality, unless the detected
bandwidth is very narrow. This result is a consequence of the non-factorability
of the state in the spatial and temporal degrees of freedoms of twin photons.
In the limit of a broad pump beam, we provide a geometrical interpretation of
the Schmidt number, as the ratio between the volume of the phase matching
region and of a correlation volume.Comment: 17 pages, 10 figures. Submitted to Phys. Rev.
Experimental observation of the X-shaped near field spatio-temporal correlation of ultra-broadband twin beams
In this work we present the experimental observation of the non factorable
near field spatio-temporal correlation of ultra-broadband twin beams generated
by parametric down conversion (PDC), in an interferometric-type experiment
using sum frequency generation, where both the temporal and spatial degrees of
freedom of PDC light are controlled with very high resolution. The revealed
X-structure of the correlation is in accordance with the predictions of the
theory.Comment: 5 pages, 3 figure
The synthesis of boron carbide filaments final report
Synthesis, strength, crystal structure, and composite material formation of boron carbide whisker
High-sensitivity imaging with multi-mode twin beams
Twin entangled beams produced by single-pass parametric down-conversion (PDC)
offer the opportunity to detect weak amount of absorption with an improved
sensitivity with respect to standard techniques which make use of classical
light sources. We propose a differential measurement scheme which exploits the
spatial quantum correlation of type II PDC to image a weak amplitude object
with a sensitivity beyond the standard quantum limit imposed by shot-noise.Comment: 13 pages, 8 figure
"Credit Cycle" in an OLG Economy with Money and Bequest
In the late '90s Kiyotaki and Moore (KM) put forward a new framework (Kiyotaki and Moore,1997) to explore the Financial Accelerator hypothesis. The original model was framed in an Infinitely Lived Agent context (ILA-KM economy). As in KM we develop a dynamic model in which the durable asset ("land") is not only an input but also collateralizable wealth to secure lenders from the risk of borrowers' default. In this paper, however, we model an OLG-KM economy whose novel feature is the role of money as a store of value and of bequest as a vehicle of resources to be "invested" in landholding. The dynamics generated by the model are complex. Not only cyclical patterns are routinely generated but the periodicity and amplitude are irregular. A route to chaotic dynamics is open.
- …