277 research outputs found
Landscape as mediator, landscape as commons: an introduction
Il contributo propone una trattazione dei due temi chiavi che si intersecano nel volume, andando a costituire non solo una introduzione ai saggi ivi contenuti, ma una pi\uf9 ampia trattazione delle questioni attorno a cui questi si muovono: le potenzialit\ue0 del concetto di paesaggio considerato come intermediario/mediatore e come bene comune/commons. Il volume raccoglie i migliori contributi internazionali presentati nelle sessioni sul paesaggio del congresso Eugeo 2013 (Roma) coordinate dai curatori dell'opera, e si conclude con una approfondita postfazione redatta da Kenneth R. Olwig, che ha partecipato come discussant ai lavori congressuali
Chemical chain termination resolves the timing of ketoreduction in a partially reducing iterative type I polyketide synthase
Synthetic chain terminators were used to capture the biosynthetic intermediates from a partially reducing iterative type I polyketide synthase, which is integrated into a multimodular biosynthesis enzyme. The off-loaded metabolites clarified the timing of ketoreduction and aromatization in the assembly of the antibiotic micacocidin
3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds
Aim: To develop a methodology for producing patient-specific scaffolds that mimic the annulus fibrosus (AF) of the human intervertebral disc (IVD) by means of combining magnetic resonance imaging (MRI) and 3D bioprinting. Methods: In order to obtain the AF 3D model from patientâ s volumetric MRI dataset, the RheumaSCORE segmentation software was used. Polycaprolactone scaffolds with three different internal architectures were fabricated by 3D bioprinting, and characterized by micro-computed tomography.
Results: The demonstrated methodology of a geometry reconstruction pipeline enabled to successfully obtain an accurate AF model and 3D print patient-specific scaffolds with different internal architectures.
Conclusion: The results guide us towards patient-specific IVD tissue engineering as demonstrated a way of manufacturing personalized scaffolds using patient's MRI data.The authors would like to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAPEXPL/BBB-ECT/0050/2014),
funded in the Framework of the ‘International Collaboratory for Emerging Technologies, CoLab’, UT
justin|Portugal Program. FCT is also acknowledged for the PhD scholarship attributed to IF Cengiz (SFRH/
BD/99555/2014) and the financial support provided to J Silva-Correia (SFRH/BPD/100590/2014 and IF/00115/2015).
JM Oliveira also thanks the FCT for the funds provided under the program Investigador FCT (IF/00423/2012 and IF/01285/2015). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.info:eu-repo/semantics/publishedVersio
Oscillations above the barrier in the fusion of 28Si + 28Si
Fusion cross sections of 28Si + 28Si have been measured in a range above the
barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular
oscillations have been observed, best evidenced in the first derivative of the
energy-weighted excitation function. For the first time, quite different
behaviors (the appearance of oscillations and the trend of sub-barrier cross
sections) have been reproduced within the same theoretical frame, i.e., the
coupled-channel model using the shallow M3Y+repulsion potential. The
calculations suggest that channel couplings play an important role in the
appearance of the oscillations, and that the simple relation between a peak in
the derivative of the energy-weighted cross section and the height of a
centrifugal barrier is lost, and so is the interpretation of the second
derivative of the excitation function as a barrier distribution for this
system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters
Electronics design of the RPC system for the OPERA muon spectrometer
The present document describes the front-end electronics of the RPC system that instruments the magnet muon spectrometer of the OPERA experiment. The main task of the OPERA spectrometer is to provide particle tracking
information for muon identification and simplify the matching between the Precision Trackers. As no trigger has been foreseen for the experiment, the spectrometer
electronics must be self-triggered with single-plane readout capability. Moreover, precision time information must be added within each event frame for off-line reconstruction. The read-out electronics is made of three different stages: the Front-End Boards (FEBs) system, the Controller Boards (CBs) system and the Trigger Boards(TBs) system. The FEB system provides discrimination of the strip incoming signals; a FAST-OR output of the input signals is also available for trigger plane signal generation. FEB signals are acquired by the CB system that provides the zero suppression and manages the communication to the DAQ and Slow Control. A Trigger Board allows to operate in both self-trigger mode (the FEB’s FAST-OR signal starts the plane acquisition) or in external-trigger mode (different conditions can be set on the FAST-OR signals generated from different planes)
LATEST DEVELOPMENTS ON MICROMORPH TANDEM CELLS AT IMT
The latest developments on micromorph tandem cells in small area laboratory and large area industrial PE-CVD systems are reviewed. We report on a 13.3% initial efficiency micromorph tandem cell deposited in our small area system. The development of an in-situ silicon oxide based intermediate reflector layer (SOIR) was essential in order to achieve such high efficiencies. We describe its detailed material structure and discuss optical management aspects for different cell configurations. In our large area industrial R&D reactor the highest efficiency so far obtained is a 11.0% initial efficiency micromorph tandem cell. We discuss in detail the role of pressure and silane depletion on the cell parameters of single junction microcrystalline cells and present efficiency trends decreasing from 8.2% to 7.0% with deposition rates increasing from 0.3 nm/s to 1.2 nm/s
Development of Micromorph Cells in Large-Area Industrial Reactor
The influences of the deposition pressure and silane depletion on the efficiency of single-junction microcrystalline silicon solar cells has been investigated. The efficiency is found to correlate with the ion energy which affects the density of states in the absorber material. Cell with efficiency of 7.3% at a deposition rate of 1 nm/s, and, respectively, 7.8% at 0.35 nm/s were deposited in R&D KAI M industrial reactor. Silicon oxide based intermediate reflector layers were developed in KAI reactor for incorporation in micromorph devices. Material with an index of refraction of 1.7 at 600 nm and low lateral conductivity were deposited. Micromorph devices incorporating these intermediate reflector layers were fabricated with initial efficiency of 12.3% at a deposition rate of 0.35 nm/s and 10.8% at 1 nm/s
Fusion Hindrance and Quadrupole Collectivity in Collisions of A≃50 Nuclei: The Case of 48Ti + 58Fe
International audience; The fusion excitation function of Ti-48 + Fe-58 has been measured in a wide energy range around the Coulomb barrier, covering 6 orders of magnitude of the cross sections. We present here the preliminary results of this experiment, and a full comparison with the near-by system Ni-58 + Fe-54 where evidence of fusion hindrance shows up at relatively high cross sections. The sub-barrier cross sections of Ti-48 + Fe-58 are much larger than those of Ni-58 + Fe-54. Significant differences are also observed in the logarithmic derivatives, astrophysical S-factors and fusion barrier distributions. The influence of low-energy nuclear structure on all these trends is pointed out and commented. Coupled-channels calculations using a Woods-Saxon potential are able to reproduce the experimental results for Ti-48 + Fe-58. The logarithmic derivative of the excitation function is very nicely fit, and no evidence of hindrance is observed down to around 1 mu b. The fusion barrier distribution is rather wide, flat and structureless. It is only in qualitative agreement with the calculated distribution
The MU-RAY project: Volcano radiography with cosmic-ray muons
Cosmic-ray muon radiography is a technique for imaging the variation of density inside the top few 100m of a volcanic cone. With resolutions up to 10s of meters in optimal detection conditions, muon radiography can provide images of the top region of a volcano edifice with a resolution that is considerably better than that typically achieved with conventional methods. Such precise measurements are expected to provide us with information on anomalies in the rock density distribution, like those expected from dense lava conduits, low density magma supply paths or the compression with depth of the overlying soil. The MU-RAY project aims at the construction of muon telescopes and the development of new analysis tools for muon radiography. The telescopes are required to be able to work in harsh environment and to have low power consumption, good angular and time resolutions, large active area and modularity. The telescope consists of two X–Y planes of 2x2 square meters area made by plastic scintillator strips of triangular shape. Each strip is read by a fast WLS fiber coupled to a silicon photomultiplier. The readout electronics is based on the SPIROC chip.Published120-1231.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveJCR Journalrestricte
Fusion of 28Si + 28Si: oscillations above the barrier and the behavior down to 1μb
Fusion excitation functions of light heavy-ion systems show oscillatory structures above the Coulomb barrier, caused by resonances or due to the penetration of successive centrifugal barriers well separated in energy. In heavier systems, the amplitude of oscillations decreases and the peaks get nearer to each other. This makes the measurements very challenging. We have performed a first experiment for 28Si + 28Si, by measuring fusion cross sections (σ) in an energy range of ≃15 MeV above the barrier, with a small ΔElab = 0.5 MeV step. Three regular oscillations are clearly observed, which are best revealed by plotting the energy-weighted derivative of the excitation function. The excitation function has been recently measured down to cross sections ≤1μb with larger energy steps. Coupled-channel (CC) calculations based on a shallow potential in the entrance channel are able to reproduce the oscillations. A further analysis will provide a stringent test for the calculations, in particular for the choice of the ion-ion potential, because the subbarrier excitation function has to be reproduced as well. Coupled-channel (CC) calculations based on a shallow potential in the entrance channel are able to reproduce the oscillations. A further analysis will provide a stringent test for the calculations, in particular for the choice of the ion-ion potential, because the subbarrier excitation function has to be reproduced as well
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