93 research outputs found
First investigation of a novel 2D position-sensitive semiconductor detector concept
This paper presents a first study of the performance of a novel 2D
position-sensitive microstrip detector, where the resistive charge division
method was implemented by replacing the metallic electrodes with resistive
electrodes made of polycrystalline silicon. A characterization of two
proof-of-concept prototypes with different values of the electrode resistivity
was carried out using a pulsed Near Infra-Red laser. The experimental data were
compared with the electrical simulation of the sensor equivalent circuit
coupled to simple electronics readout circuits. The good agreement between
experimental and simulation results establishes the soundness of resistive
charge division method in silicon microstrip sensors and validates the
developed simulation as a tool for the optimization of future sensor
prototypes. Spatial resolution in the strip length direction depends on the
ionizing event position. The average value obtained from the protype analysis
is close to 1.2% of the strip length for a 6 MIP signal.Comment: 14 pages, 12 figure
A convenient band-gap interpolation technique and an improved band line-up model for InGaAlAs on InP
The band-gap energy and the band line-up of InGaAlAs quaternary compound material on InP are essential information for the theoretical study of physical properties and the design of optoelectronics devices operating in the long-wavelength communication window. The band-gap interpolation of In1-x-y Ga (x) Al (y) As on InP is known to be a challenging task due to the observed discrepancy of experimental results arising from the bowing effect. Besides, the band line-up results of In1-x-y Ga (x) Al (y) As on InP based on previously reported models have limited success by far. In this work, we propose an interpolation solution using the single-variable surface bowing estimation interpolation method for the fitting of experimentally measured In1-x-y Ga (x) Al (y) As band-gap data with various degree of bowing using the same set of input parameters. The suggested solution provides an easier and more physically interpretable way to determine not only lattice matched, but also strained band-gap energy of In1-x-y Ga (x) Al (y) As on InP based on the experimental results. Interpolated results from this convenient method show a more favourable match to multiple independent experiment data sets measured under different temperature conditions as compared to those obtained from the commonly used weighted-sum approach. On top of that, extended framework of the model-solid theory for the band line-up of In1-x-y Ga (x) Al (y) As/InP heterostructure is proposed. Our model-solid theory band line-up result using the proposed extended framework has shown an improved accuracy over those without the extension. In contrast to some previously reported works, it is worth noting that the band line-up result based on our proposed extended model-solid theory has also shown to be more accurate than those given by Harrison's mode
CHARACTERIZATION AND VALORIZATION OF MAIZE LANDRACES FROM VALLE D'AOSTA
During 1949-1950 in Italy begun a formal investigation to characterize
maize (Zea mays L.) cultivation. In 1954, started a project for the
sampling of all Italian maize landraces; this work ended with the
collection of 562 different accessions collected in all regions with the
exception of Valle d’Aosta, even if historical cultivation of maize in this
Region is well documented.
In Italy maize landraces have been extensively grown until the mid of the
XX century when the cultivation of hybrid took place due to their
significant agronomic performances. Despite that, being Valle d’Aosta a
mountain region where intensive maize cultivation never started, it was
possible to preserve the presence of some landraces. These local materials,
which are still cultivated, mainly at domestic level, have high importance
from a genetic and historical point of view. Recently, 5 maize landraces
from Valle d’Aosta and 2 landraces from the adjacent Canavese (Piedmont)
have been collected and subjected to historic, morphologic and genetic
characterization. These landraces were named after the sampling location as
it follows: Arnad, Arnad-Crest, Chatillon, Entrebin, Perloz, Bianco
Canavese, and Rostrato Canavese.
Firstly, on these 6 varieties the historic characterization has been
carried out. Information and photographs have been searched in local
archives and this was crucial to prove their long presence in all the
sampling sites under study. From this historic reconstruction, the variety
Entrebin resulted as the one that is better historically characterized.
To study the variability and differentiation of landraces from Valle
d’Aosta, the genetic characterization was performed by the means of 10 SSR
markers tested on 20 samples from each landrace. This study highlighted a
significant genetic variability among the landraces and, especially, a good
level of differentiation between the accessions under investigation. This
last result may be explained by the long reproductive isolation experienced
by these materials. Complete morphological characterization is actually
ongoing. Preliminary morphological observations revealed that these
landraces have, generally, flint kernels with the exception of Bianco
Canavese (dent) whose color is variable from white (Bianco Canavese) to
dark red (Chatillon). Arnad landrace showed 8 kernel rows, probably being
an Eight-rowed Flint while the others presented more rows, like many
Derived Races. Interestingly, Perloz and Rostrato Canavese showed kernels
with an apical beak which was more pronounced in the latter. This suggest
that these two landraces belong to the “Rostrata” group, which is common in
mountain areas.
The present work confirms the importance of mountain areas in conserving
biodiversity and increases the rich Italian maize germplasm with materials
well adapted to marginal areas. Such new genetic variability may be used to
breed new materials for a more resilient agriculture
Infrastructure for Detector Research and Development towards the International Linear Collider
The EUDET-project was launched to create an infrastructure for developing and
testing new and advanced detector technologies to be used at a future linear
collider. The aim was to make possible experimentation and analysis of data for
institutes, which otherwise could not be realized due to lack of resources. The
infrastructure comprised an analysis and software network, and instrumentation
infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture
Epitaxial Catalyst-Free Growth of InN Nanorods onc-Plane Sapphire
We report observation of catalyst-free hydride vapor phase epitaxy growth of InN nanorods. Characterization of the nanorods with transmission electron microscopy, and X-ray diffraction show that the nanorods are stoichiometric 2H–InN single crystals growing in the [0001] orientation. The InN rods are uniform, showing very little variation in both diameter and length. Surprisingly, the rods show clear epitaxial relations with thec-plane sapphire substrate, despite about 29% of lattice mismatch. Comparing catalyst-free with Ni-catalyzed growth, the only difference observed is in the density of nucleation sites, suggesting that Ni does not work like the typical vapor–liquid–solid catalyst, but rather functions as a nucleation promoter by catalyzing the decomposition of ammonia. No conclusive photoluminescence was observed from single nanorods, while integrating over a large area showed weak wide emissions centered at 0.78 and at 1.9 eV
Comparison of bioresorbable vs durable polymer drug-eluting stents in unprotected left main (from the RAIN-CARDIOGROUP VII Study)
International audienceAbstract Background There are limited data regarding the impact of bioresorbable polymer drug eluting stent (BP-DES) compared to durable polymer drug eluting stent (DP-DES) in patients treated with percutaneous coronary intervention using ultrathin stents in left main or bifurcations. Methods In the RAIN registry (ClinicalTrials NCT03544294, june 2018 retrospectively registered) patients with a ULM or bifurcation stenosis treated with PCI using ultrathin stents (struts thinner than 81 μm) were enrolled. The primary endpoint was the rate of target lesion revascularization (TLR); major adverse cardiovascular events (MACE, a composite of all-cause death, myocardial infarction, TLR and stent thrombosis) and its components, along with target vessel revascularization (TVR) were the secondary ones. A propensity score with matching analysis to compare patients treated with BP-DES versus DP-DES was also assessed. Results From 3001 enrolled patients, after propensity score analysis 1400 patients (700 for each group) were selected. Among them, 352 had ULM disease and 1048 had non-LM bifurcations. At 16 months (12–22), rates of TLR (3.7% vs 2.9%, p = 0.22) and MACE were similar (12.3% vs. 11.6%, p = 0.74) as well as for the other endpoints. Sensitivity analysis of outcomes after a two-stents strategy, showed better outcome in term of MACE (20.4% vs 10%, p = 0.03) and TVR (12% vs 4.6%, p = 0.05) and a trend towards lower TLR in patients treated with BP-DES. Conclusion In patients with bifurcations or ULM treated with ultrathin stents BP-DES seems to perform similarly to DP-DES: the trends toward improved clinical outcomes in patients treated with the BP-DES might potentially be of value for speculating the stent choice in selected high-risk subgroups of patients at increased risk of ischemic events. Trial registration ClinicalTrials.gov Identifier: NCT03544294 . Retrospectively registered June 1, 2018
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