694 research outputs found
Testing Ultrafast Two-Photon Spectral Amplitudes via Optical Fibres
We test two-dimensional TPSA of biphoton light emitted via ultrafast
spontaneous parametric down-conversion (SPDC) using the effect of
group-velocity dispersion in optical fibres. Further, we apply this technique
to demonstrate the engineering of biphoton spectral properties by acting on the
pump pulse shape
Perspective: Polarizable continuum models for quantum-mechanical descriptions
Polarizable continuum solvation models are nowadays the most popular approach to describe solvent effects in the context of quantum mechanical calculations. Unexpectedly, despite their widespread use in all branches of quantum chemistry and beyond, important aspects of both their theoretical formulation and numerical implementation are still not completely understood. In particular, in this perspective we focus on the numerical issues of their implementation when applied to large systems and on the theoretical framework needed to treat time dependent problems and excited states or to deal with electronic correlation. Possible extensions beyond a purely electrostatic model and generalizations to environments beyond common solvents are also critically presented and discussed. Finally, some possible new theoretical approaches and numerical strategies are suggested to overcome the obstacles which still prevent a full exploitation of these models
Performance of the diamond active target prototype for the PADME experiment at the DANE BTF
The PADME experiment at the DANE Beam-Test Facility (BTF) is designed
to search for the gauge boson of a new interaction in the process
ee+, using the intense positron beam hitting a
light target. The , usually referred as dark photon, is assumed to
decay into invisible particles of a secluded sector and it can be observed by
searching for an anomalous peak in the spectrum of the missing mass measured in
events with a single photon in the final state. The measurement requires the
determination of the 4-momentum of the recoil photon, performed by a
homogeneous, highly segmented BGO crystals calorimeter. A significant
improvement of the missing mass resolution is possible using an active target
capable to determine the average position of the positron bunch with a
resolution of less than 1 mm. This report presents the performance of a real
size PADME active target made of a thin (50 m) diamond
sensor, with graphitic strips produced via laser irradiation on both sides. The
measurements are based on data collected in a beam test at the BTF in November
2015.Comment: 7 pages, 10 figure
Realization and characterization of graphitic contacts on diamond by means of laser
This work deals with the realization and characterization of integrated graphitic contacts on diamond by means of laser irradiation (graphitization), in order to obtain good quality ohmic electrodes for nuclear radiation detectors to be used in high energy physics experiments. Unlike the conventional method used for the electrode production, which requires numerous steps and very well controlled environmental conditions, this alternative technique presents many advantages: the contacts are realized in air at room temperature in a single step. In this study, the characteristics of several graphitic structures realized on a diamond surface by changing the radiation-matter interaction parameters have been evaluated in order to define the best experimental conditions to create graphitic electrodes with low resistivity. The obtained results are promising: contacts perfectly adherent, with good charge collection properties, stable and resistant to ionizing radiation
Radiation Damage of Polycrystalline CVD Diamond with Graphite Electrical Contacts
In this work we show preliminary results of radiation damage for a polycrystalline diamond with graphite contacts in terms of time response after 62 MeV protons irradiation for a total fluence of (2.0±0.08)×1015 protons/cm2. In addition, we describe the realization of a new type of device made with graphite micro-strips by laser micro-writing on diamond surface. In this way we made 20 graphite micro-strips of width about 87 m and spacing between each other of about 60 m
Diamond detectors with electrodes graphitized by means of laser
In the last years there has been an increase of interest in diamond devices because of the promising applications in different field, such as high-energy physics, radiotherapy and biochemical applications. In particular, a new frontier is represented by the realization of full-carbon detectors characterized by graphite electrodes, which give to the devices considerable advantages like high radiation hardness, perfect mechanical adhesion and good charge collection properties. In this paper the manufacturing of full-carbon devices and their detection performances are illustrated and compared to a reference diamond detector characterized by traditional electrodes
A five-year survey for plastic surgery malpractice claims in Rome, Italy
(1) Introduction: Medical malpractice claims against both health institutions and physicians are a crucial topic in Italy, as well as in other countries, particularly regarding civil proceedings. Our study reports an analysis of all of the malpractice judgments concerning plastic surgery decided in the Civil Court of Rome between 2012 and 2016. (2) Methods: the database of the Observatory Project on Medical Responsibility (ORMe) was analyzed, which collects all of the judgments of the Civil Court of Rome, that is, the first instance district court. Therefore, neither the jurisprudence of the second level court nor that of the Supreme Court was taken into account. (3) Results: 144 judgments concerning plastic surgery were delivered in the five-year period of 2012–2016 (corresponding to 10.6% of total professional liability verdicts of the Civil Court of Rome in the same period). In 101/144 cases (70.14%), the claim was accepted. A total of €4,727,579.00 was paid in compensation for plastic surgery malpractice claims, with a range from a minimum amount of €1555.96 to a maximum amount of €1,425,155.00 and an average compensation of €46,807.71 per claim that was significantly lower compared to other surgical disciplines. (4) Conclusions: Our data confirm that the analyzed branch has a high litigation rate, with a prevalence of convictions for cosmetic procedures over reconstructive ones, both for malpractice and for violation of the informed consent. Plastic surgery is also confirmed among those branches in which the professionals are more frequently sued compared to health institutions
Stereospecific generation of homochiral helices in coordination polymers built from enantiopure binaphthyl-based ligands
The novel enantiopure spacer 2,2′-dimethoxy-1,1′-binaphthyl-3,3′-bis(4-pyridyl-amido) has been designed to prepare helical coordination polymers here investigated by means of experimental and theoretical data
Study of a metal-halide perovskite CsPbBr3 thin film deposited on a 10B layer for neutron detection
Metal halide perovskite materials have received significant attention in recent years due to their
promising properties and potential applications, particularly their use as scintillator detectors,
which is rapidly emerging due to their promising advantages as detectors, such as low costs, fast
response, high quantum yield, strong absorption, scalability, flexibility, and emission
wavelength tunability. Given the effectiveness of perovskites as α particle detectors and the
potential of 10B as a neutron converter, in this paper a 10B converting layer was coupled with an
all-inorganic lead halide perovskite (CsPbBr3) layer aiming to create a thermal neutron detector.
Specifically, a 1 μm thin film of 10B and a 1 μm thin layer of CsPbBr3 were deposited on a
suitable substrate using a laser ablation process. The fabricated detector was subjected to a
comprehensive characterization, including structural, morphological, and detection properties.
As output, the films exhibit macroscopically uniform behavior and good adhesion to the
substrate. In terms of thermal neutron efficiency, an efficiency of (7.9 ± 0.3)% was determined
with respect to a commercial detector (EJ-426), which corresponds to an intrinsic efficiency of
(2.5 ± 0.1)%. Also, Monte Carlo simulations were conducted, and the optimum value of the 10B
layer thickness was found to be 2.5 μm
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