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.

Bargaining for Productivity: Comparative Report

Productivity growth was at the heart of the economic development in the Afterwar period – the so called ‘trentes glorieuses’. These years were characterised by a strong coordination of labour markets, collective agreements that were mainly set at the sectoral level and wage constraint. At this time, the most relevant objectives were a strong competitive economy, a hard currency, low inflation and full employment. It seems that this glorious era has come to an end. Many EU and non-EU countries, such as the UK and the USA, have experienced a labour productivity stagnation or slowdown over the last decade. Academics, policy makers and business leaders are concerned to reverse this trend since “productivity is the ultimate engine of growth in the global economy” (OECD 2015). As the working population is projected to decline with the ageing population, labour productivity growth becomes the sole source for potential average output growth in both the EU and the euro area starting from 2028 (European Commission, 2012). This projection includes both the quantitative and qualitative dimensions of growth. Directly linked to productivity stagnation is the issue of inequality and, precisely, wage inequality (Keune, Tomassetti 2016). There is mounting evidence that “increasing inequality may be one of the causes of declining growth, as inequality both impedes improvements in productivity and weakens demand. Low growth, in turn, reinforces inequality by intensifying distributional conflict” (Streeck 2014, 37). Inequality is also likely to increase even more in the years ahead as a consequence of the impact of Industry 4.0 and the digital evolution of the economy on labour markets and societies (Blasi et al 2013; Etui 2016). On the brink of a new extraordinary age of change – i.e. the so-called Fourth Industrial Revolution (Shwab 2016) –, many scholars still disagree over what current technological innovations imply for the future of work and employment relations (Katz et al. 2015). Along with opportunities, new challenges appear in different forms than previous waves of technological change: hybridization between humans and robots; dematerialisation of boundaries between industries; working and doing business anytime, anywhere; labour market polarisation; marginal cost reduction and productivity slowdown. These factors are compounded by an increasingly diverse workforce where tensions exists between inclusion and diversity, impacting on employment relations. There is consensus that investments in technological innovation, research and skills are key drivers for labour productivity. It is also clear that – beside these factors – work organisation plays an important role in enhancing labour productivity and making growth sustainable. Productivity figures (GDP/GVA per hour worked and GDP/GVA per capita) are linked to the output of production and the input of labour. Collective bargaining and other aspects of labour and employment relations play a major role in these figures. Dialogue on productivity issues is important both in terms of consensual labour-management cooperation and as a regulator of wages and conditions of work. Coordination of collective bargaining has a positive impact on economic performance, because it impedes wage competition and enforces companies to increase productivity in order to being able to pay the given wages. At the company level, productivity agreements can result in innovation and enhance performance through compensation and benefits, working time flexibility, Work-life Balance, skills improvements and workers involvement. Furthermore, collective bargaining, especially firm-level bargaining, has always been conceived as a means both to facilitate and react to technological changes. This project is set against a background of institutionalist research which investigates the role of central institutions and actors in the setting and maintenance of employment relations. Drawing on key theories such as regulatory space, varieties of capitalism, regulation theory and coordination theory this research places the productivity bargaining in a theoretical arena to understand the role of productivity bargaining and the coordination of collective bargaining across key European countries. Against this background, this report aims to shed light on the reasons behind labour productivity slowdown or weak growth in some countries, by focusing on the role that employment relations plays behind such a trend. Our goal is to analyse the potential and effective implication of collective bargaining and employment relations on labour productivity, as well as to analyse public policies and social partners’ attitude towards labour productivity in Germany, Italy, the Netherlands, Poland, Spain and the UK A note of caution is, however, needed because the relationship between employment relations and the input of labour is at best complex and, if worse, dubious. While the connotation of high productivity and hard work is a very basic one, the actual relationship is likely to be much more complex with influence from smarter working, new technology and research and development investment. Therefore, when comparing figures of productivity GDP growth between countries and sectors, such complexities should be kept in mind. The ‘productivity paradox’ furthermore points to the question to what extent productivity growth gives an accurate figure of productivity as such. The quality of production output may not be taken into account accurately and services that are for free, like some of the services with ICT, do not count to productivity but may still add to prosperity

Torsion in strain-gradient plasticity: energetic scale effects

Abstract. We study elasto-plastic torsion in a thin wire within the framework of the strain-gradient plasticity theory elaborated by Gurtin and Anand in 2005. The theory in question envisages two material scales: an energetic length-scale, which takes into account the so-called “geometrically-necessary dislocations” through a dependence of the free energy on the Burgers tensor, and a dissipative length-scale. For the rate-independent case with null dissipative length-scale, we construct and characterize a special class of solutions to the evolution problem. With the aid of such characterization, we estimate the dependence on the energetic scale of the ratio between the torque and the twist. Our analysis confirms that the energetic scale is responsible for size-dependent strain-hardening, with thinner wires being stronger. We also detect, and quantify in terms of the energetic length-scale, both a critical twist, after which the wire becomes fully plastified, and two boundary layers near the external boundary of the wire and near the boundary of the plastified region, respectively. The research that led to the present paper was partially supported by a grant of the group GNFM of INdA

Carbonate factory of Pietra di Finale coastal wedge (Miocene): the unusual abundance of stylasterids (Cnidaria, Hydrozoa)

This work focuses on the carbonate factories constituting the Pietra di Finale Fm cropping out in the Ligurian Alps. This unit constituted a mixed carbonate-siliciclastic coastal wedge developed during the Middle Miocene. The carbonate factories characterizing the coastal wedge of the Pietra di Finale clearly differ from those of the coastal mixed systems and carbonate platforms developing during the Miocene elsewhere in the Mediterranean area. Here, in the Ligurian Alps, the euphotic carbonate factory does not show any evidence of seagrass meadows and coral bioconstructions. Zooxanthellate corals are present only as skeletal debris associated with abundant stylasterids. In the mesophotic and oligophotic zones, the typical oligophotic biota of red algae and larger benthic foraminifers are strongly reduced. The coastal wedge of the Pietra di Finale shows an unusual abundance of stylasterids, classically interpreted as deep-water biota. However, in this example, the absence of low-energy textures and other skeletal components suggest a shallow-water origin, probably in the eu- or mesophotic zone. The stylasterids colonized the hard substrates available and were successively removed and resedimented to form the skeletal fraction of the coastal wedge of the Pietra di Finale. The abundance of stylasterids is restricted to particular and limited situations in the Miocene of the Mediterranean, thus suggesting that their abnormal development is controlled by local rather than global factors

Shape programming of a magnetic elastica

We consider a cantilever beam which possesses a possibly non-uniform permanent magnetization, and whose shape is controlled by an applied magnetic field. We model the beam as a plane elastic curve and we suppose that the magnetic field acts upon the beam by means of a distributed couple that pulls the magnetization towards its direction. Given a list of target shapes, we look for a design of the magnetization profile and for a list of controls such that the shapes assumed by the beam when acted upon by the controls are as close as possible to the targets, in an averaged sense. To this effect, we formulate and solve an optimal design and control problem leading to the minimization of a functional which we study by both direct and indirect methods. In particular, we prove that minimizers exist, solve the associated Lagrange-multiplier formulation (besides non-generic cases), and are unique at least for sufficiently low intensities of the controlling magnetic fields. To achieve the latter result, we use two nested fixed-point arguments relying on the Lagrange-multiplier formulation of the problem, a method which also suggests a numerical scheme. Various relevant open question are also discussed

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

A superoxide dismutase biosensor for measuring the antioxidant capacity of blueberry based integrators

The antioxidant capacity of capsules containing blueberry based products which are included among the group of integrators owing to their antioxidant capacity and produced by various films was investigated. The results of the investigation are compared to rank these products in order to their antioxidant capacity. In order to measure antioxidant capacity, our laboratory has recently developed a special electrochemical method based on a superoxide dismutase (SOD) biosensor to determine the superoxide radical. The results obtained by applying the SOD biosensor method to various blueberry based integrators were compared with the results obtained with the spectrophotometric (FRAP) method based on N,N-dimethyl-p-phenylendiamine (DMPD-FeCl3) and with those obtained also using the ORAC fluorimetric (TRAP) method. One of the more interesting aspect of the article is the good agreement it evidences of the results of the three methods for measuring antioxidant capacity. The three methods differ among themselves: an Electron Transfer (ET) method, a Hydrogen Atom Trasnfer Metod (HAT) and an electrochemical based biosensor method of the Morning Superoxide Radical (MSR) type. It is also shown how the antioxidant capacity of the fresh vegetable is in any case always greater then of any food supplement obtained from the same type of vegetable

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

A comparison of acute phase proteins and traditional risk factors as markers of combined plaque and intima-media thickness and plaque density in carotid and femoral arteries

AbstractObjectives: to test the hypothesis that some acute phase proteins may be better independent predictors of objective measures of arterial wall impairment than traditional risk factors. Design: cross-sectional study. Materials and Methods: C-reactive protein (CRP), fibrinogen, C3 complement and traditional risk factors were measured in 288 men aged 55-64 years, randomly chosen from the local registry lists. By ultrasound assessment of the bifurcations of carotid and femoral arteries, maximum combined plaque/intima-media thickness (CPIMTmax) and mean plaque density (MPD, in a grey scale from 0 to 255) were also measured. Results: in multivariate analysis only traditional risk factors remained associated with the overall CPIMTmax: smoking (r = 0.35, p < 0.0001), cholesterol (r = 0.23, p = 0.0001), age (r = 0.22, p = 0.0002), glucose (r = 0.18, p = 0.002) and systolic blood pressure (r = 0.13, p = 0.02). However, with regard to carotid disease only, fibrinogen was the strongest covariate of CPIMT (r = 0.18, p = 0.002). The overall MPD was independently associated with CRP (r = 0.25, p = 0.0008), physical activity (r = 0.19, p = 0.009), triglycerides (r = −0.18, p = 0.02) and body mass index (r = 0.15, p = 0.04). CRP was mainly associated with femoral MPD, while triglycerides were the major (inverse) covariate of carotid MPD. Conclusions: traditional risk factors are the main determinants of CPIMTmax, although fibrinogen seems to play a role in carotids. CRP was associated with high density femoral plaques. Finally, no acute phase protein was independently associated with low density, potentially vulnerable, plaques.Eur J Vasc Endovasc Surg 26, 81-87 (2003