Experimental study of vapor-cell magneto-optical traps for efficient trapping of radioactive atoms

We have studied magneto-optical traps (MOTs) for efficient on-line trapping of radioactive atoms. After discussing a model of the trapping process in a vapor cell and its efficiency, we present the results of detailed experimental studies on Rb MOTs. Three spherical cells of different sizes were used. These cells can be easily replaced, while keeping the rest of the apparatus unchanged: atomic sources, vacuum conditions, magnetic field gradients, sizes and power of the laser beams, detection system. By direct comparison, we find that the trapping efficiency only weakly depends on the MOT cell size. It is also found that the trapping efficiency of the MOT with the smallest cell, whose diameter is equal to the diameter of the trapping beams, is about 40% smaller than the efficiency of larger cells. Furthermore, we also demonstrate the importance of two factors: a long coated tube at the entrance of the MOT cell, used instead of a diaphragm; and the passivation with an alkali vapor of the coating on the cell walls, in order to minimize the losses of trappable atoms. These results guided us in the construction of an efficient large-diameter cell, which has been successfully employed for on-line trapping of Fr isotopes at INFN's national laboratories in Legnaro, Italy.Comment: 9 pages, 7 figures, submitted to Eur. Phys. J.

Preliminary findings from a survey on the MD state of the practice

In the context of an Italian research project, this paper reports on an on-line survey, performed with 155 software professionals, with the aim of investigating about their opinions and experiences in modeling during software development and Model-driven engineering usage. The survey focused also on used modeling languages, processes and tools. A preliminary analysis of the results confirmed that Model-driven engineering, and more in general software modeling, are very relevant phenomena. Approximately 68% of the sample use models during software development. Among then, 44% generate code starting from models and 16% execute them directly. The preferred language for modeling is UML but DSLs are used as wel

Algorithms for the Sum of Discrete Random Variables. Actuarial Applications

In literature, the sum of discrete random variables becomes a problem of heavy (and often impracticable) computation no sooner does the number of convolutions exceed few units (at most in actuarial applications). In this paper, we show how this problem can be easily overcome when using random variables with integer (positive, negative, or null) or referable to integer numerical realizations but not necessarily identically distributed. Under the above-mentioned condition, we illustrate in particular two exact methods and an approximated one for calculating convolution: - the first exact method is based on the well-known Fast Fourier Transform (FFT); - the second exact method is derived from the classical approach using Discrete Fourier Transform (DFT) by means of algebraic manipulations; - the third method is derived from the definition of convolution and it is approximated by neglecting the probabilities less than a given bound ? =10-h (51?h?100)**. As for the error bounds of the approximated method, it is worth noting that the results obtained by this method differ in relative terms from the corresponding exact values of less than 10-9. This can be tested by comparing the convoluted probability distribution obtained by the approximated method with the one obtained by the other two methods and by also comparing the first four moments with those computed directly on the original random variables. The results (in particular the exact and the approximated probability distribution) are identical in practice. It does not exist therefore the problem of a difference along the tail. As a consequence, although the proposed method is an “approximated method” under a mathematical point of view, it can be considered an “exact method” in the actuarial applications. As for the efficiency of calculation, we have to distinguish between the simple sum of discrete random variables and the calculation of compound distributions with prefixed counting distributions (i.g. Poisson, Negative Binomial, Pareto): - in the first case, the approximated method and the second exact method are similar but the approximated method gives further information about the random variables (for instance, the information about the independence using some properties of the characteristic functions); - in the second case, only the approximated method is applicable in practice. Finally, in the conditions of interest, the exact method using FFT is less efficient than the other methods and it has a more limited application field

Coral assemblages and bioconstructions adapted to the depositional dynamics of a mixed carbonate-siliciclastic setting: the case study of the Burdigalian Bonifacio Basin (South Corsica)

Coral bioconstructions associated with mixed carbonate-siliciclastic settings are known to be strongly controlled by coastal morphology and paleotopography. A striking example is represented by the different types of coral bioconstructions and coral-rich deposits of the Cala di Labra Formation deposited in the coastal environment of the Bonifacio Basin (Corsica, France) during the Early Miocene. Detailed mapping on photomosaics allowed accurate documentation of the internal organization of coral deposits as well as lateral and vertical facies relationships. Four types of coral bioconstructions (CB) and one reworked coral deposits (RCD) have been recognized. The CB are represented by sigmoidal cluster reefs, coral carpets and skeletal conglomerates rich in corals. The RCD occurs in lens-shaped bodies intercalated within clinoforms composed of bioclastic loatstones and coarse packstones. The investigated bioconstructions can be contextualised in a coastal environment. In the upper shoreface corals developed in association with the oyster Hyotissa, above bioclastic conglomerates sourced by ephemeral streams and erosion of the granitic coastline. In the lower shoreface corals formed sigmoidal bioconstructions interpreted as cluster reefs, whereas coral carpets developed during a relative sea-level rise related to the middle Burdigalian transgressive phase. The reworked coral deposits can be interpreted as lobe-shaped deposits of coarse-grained bioclastic submarine fans formed at the base of the depositional slope of an infralittoral prograding wedge system

EFFECT OF AN INNOVATIVE ISOLATION SYSTEM ON THE SEISMIC RESPONSE OF CULTURAL HERITAGE BUILDING CONTENTS

An experimental study was conducted at the University of Pavia and at the EUCENTRE Foundation (Pavia, Italy) to assess the effectiveness of an innovative seismic isolation device at protecting cultural heritage building contents. The recently patented isolator, named “Kinematic Steel Joint (KSJ)”, is based on a multiple articulated quadrilateral mechanism and is entirely made of steel components obtained by simply cutting, folding, and pinning metal sheets, eventually employing stainless steel to limit corrosion issues. The trajectory imposed by the KSJ isolator to the supported mass combines horizontal with increasing vertical displacements, resulting in a pendulum-type motion with self-centering behavior. The friction developing within the pinned joints can be exploited to grant energy dissipation capacity to the device. The KSJ isolator can be manufactured with different sizes, payloads, and displacement ranges. In fact, seismic isolation can be applied at a global building level as an integrated system or as a retrofit solution in new or existing construction, respectively, or at a local scale as a passive protection technique for non-structural components. Despite their undeniable effectiveness in reducing the seismic accelerations transmitted to the isolated structure and to its content, currently available isolation devices may add significantly to the construction cost of buildings, and may require particular maintenance to preserve a stable performance over time. The proposed KSJ solution will allow for a reduction in manufacturing and maintenance burdens compared to established technologies. This paper discusses the main results of a shake-table test conducted at the EUCENTRE Foundation laboratories on an assembly with four prototypes of the KSJ device. The experimental setup included a 19-t rigid mass supported by the isolators, simulating the building superstructure, and four marble blocks installed above the rigid mass, representing non-structural rocking components such as parapets, pinnacles, statues, or other architectural ornaments. Moreover, a museum showcase with a small-scale replica of Michelangelo’s David was mounted above the rigid block, while two clay vases completed the setup, to encompass additional cultural heritage features. Accelerometers and potentiometers were deployed at several locations to monitor the kinematic response of the individual isolators, as well as their effect on the dynamic response of the rigid mass and of the different non-structural elements. The experiment was conducted first with the KSJ devices allowed to displace freely, then after fastening the rigid mass to the shake-table through post-tensioning rods, following the same incremental dynamic test sequence. This allowed comparing the response of the non-structural components with and without seismic isolation, to better understand the effect of the proposed isolation devices on the overall test assembly and on each sub-component

Thermally driven circulation in a region of complex topography: comparison of wind-profiling radar measurements and MM5 numerical predictions

The diurnal variation of regional wind patterns in the complex terrain of Central Italy was investigated for summer fair-weather conditions and winter time periods using a radar wind profiler. The profiler is located on a site where interaction between the complex topography and land-surface produces a variety of thermally and dynamically driven wind systems. The observational data set, collected for a period of one year, was used first to describe the diurnal evolution of thermal driven winds, second to validate the Mesoscale Model 5 (MM5) that is a three-dimensional numerical model. This type of analysis was focused on the near-surface wind observation, since thermally driven winds occur in the lower atmosphere. According to the valley wind theory expectations, the site – located on the left sidewall of the valley (looking up valley) – experiences a clockwise turning with time. Same characteristics in the behavior were established in both the experimental and numerical results. <P style="line-height: 20px;"> Because the thermally driven flows can have some depth and may be influenced mainly by model errors, as a third step the analysis focuses on a subset of cases to explore four different MM5 Planetary Boundary Layer (PBL) parameterizations. The reason is to test how the results are sensitive to the selected PBL parameterization, and to identify the better parameterization if it is possible. For this purpose we analysed the MM5 output for the whole PBL levels. The chosen PBL parameterizations are: 1) Gayno-Seaman; 2) Medium-Range Forecast; 3) Mellor-Yamada scheme as used in the ETA model; and 4) Blackadar

Penetrating particle ANalyzer (PAN)

PAN is a scientific instrument suitable for deep space and interplanetary missions. It can precisely measure and monitor the flux, composition, and direction of highly penetrating particles ($> \sim$100 MeV/nucleon) in deep space, over at least one full solar cycle (~11 years). The science program of PAN is multi- and cross-disciplinary, covering cosmic ray physics, solar physics, space weather and space travel. PAN will fill an observation gap of galactic cosmic rays in the GeV region, and provide precise information of the spectrum, composition and emission time of energetic particle originated from the Sun. The precise measurement and monitoring of the energetic particles is also a unique contribution to space weather studies. PAN will map the flux and composition of penetrating particles, which cannot be shielded effectively, precisely and continuously, providing valuable input for the assessment of the related health risk, and for the development of an adequate mitigation strategy. PAN has the potential to become a standard on-board instrument for deep space human travel. PAN is based on the proven detection principle of a magnetic spectrometer, but with novel layout and detection concept. It will adopt advanced particle detection technologies and industrial processes optimized for deep space application. The device will require limited mass (~20 kg) and power (~20 W) budget. Dipole magnet sectors built from high field permanent magnet Halbach arrays, instrumented in a modular fashion with high resolution silicon strip detectors, allow to reach an energy resolution better than 10\% for nuclei from H to Fe at 1 GeV/n

Effects of caspofungin against Candida guilliermondii and Candida parapsilosis.

The in vitro activity of caspofungin (CAS) was investigated against 28 yeast isolates belonging to Candida albicans (n = 5), Candida guilliermondii (n = 10), and Candida parapsilosis (n = 13). CAS MICs obtained by broth dilution and Etest methods clearly showed a rank order of susceptibility to the echinocandin compound with C. albicans > C. parapsilosis > C. guilliermondii. Similarly, time-kill assays performed on selected isolates showed that CAS was fungistatic against C. albicans and C. parapsilosis, while it did not exert any activity against C. guilliermondii. In a murine model of systemic candidiasis, CAS given at doses as low as 1 mg/kg of body weight/day was effective at reducing the kidney burden of mice infected with either C. albicans or C. guilliermondii isolates. Depending on the isolate tested, mice infected with C. parapsilosis responded to CAS given at 1 and/or 5 mg/kg/day. However, the overall CFU reduction for C. guilliermondii and C. parapsilosis was approximately 100-fold less than that for C. albicans. Our study shows that CAS was active in experimental systemic candidiasis due to C. guilliermondii and C. parapsilosis, but this activity required relatively high drug dosages

The transbonchial lung biopsy for diagnosis of diffuse parenchymal lung disease; Pro

The diagnosis of diffuse parenchymal lung disease (DPLD) may require invasive procedures after all noninvasive tools have failed. The clinical context in which these diseases develop and the radiological patterns are crucial for defining the timing and the methods to be used. After the introduction in clinical practice of HRCT scan, the evaluation of imaging patterns, along with the immunological status of the patient and the clinical course of the disease (acute vs. chronic) seem to be crucial to choose the best diagnostic procedure