Assessing the volcanic hazard for Rome. 40Ar/39Ar and In-SAR constraints on the most recent eruptive activity and present-day uplift at Colli Albani Volcanic District

We present new 40Ar/39Ar data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36 kyr) overruns the recurrence time (31 kyr) in the last 100 kyr. New interferometric synthetic aperture radar data, covering the years 1993–2010, reveal ongoing inflation with maximum uplift rates (>2 mm/yr) in the area hosting the most recent (<200 ka) vents, suggesting that the observed uplift might be caused by magma injection within the youngest plumbing system. Finally, we frame the present deformation within the structural pattern of the area of Rome, characterized by 50 m of regional uplift since 200 ka and by geologic evidence for a recent (<2000 years) switch of the local stress-field, highlighting that the precursors of a new phase of volcanic activity are likely occurring at the CAVD

Phase noise characterization of injection locked semiconductor lasers to a 250 MHz optical frequency comb

Two lasers are simultaneously injection locked to the same comb mode and the injection locking quality is assessed in terms of phase noise and phase variance (1 kHz-10 MHz) for various injected powers

Mechanical behaviour with temperatures of aluminum matrix composites with CNTs

Aluminum is a very useful structural metal employed in different industrial sectors, in particular it is used in large quantities in automotive, aeronautic and nautical industries. The main reasons of its wide use are: a very good oxidation resistance, excellent ductility, low melting temperature (660 °C) and low density (2.71 g/cm3). However, in order to reduce the emissions and fuel consumption is necessary to reduce the overall weight of vehicles by increasing mechanical properties of the structural material. The improvement of mechanical properties is normally achieved through use of reinforcement in materials, used like matrix, in order to improve some specific characteristics. In this work composites of carbon nanotubes (CNTs) dispersed in aluminum were made. The most difficulties in the preparation of this type of composite are represented by the low wettability between metallic matrix and fillers and the possibility of the oxidation of metal during melting with consequent decreasing of mechanical proprieties. The composite was obtained by three consecutive step: the first one is the functionalization of fillers surface to improve the fillers dispersion, the second one is the dispersion of fillers in the matrix by powder mixing and the third one is the melting and casting of the mix prepared. In particular, fillers used are multi walled carbon nanotubes (MWCNTs) with functionalized surface by treatment with a solfonitric solution. Melting and casting are carried out with the aid of an induction furnace with a controlled atmosphere system and centrifugal casting. Argon is the inert gas used to prevent the oxidation of aluminium during fusion. Young’s modulus was evaluated at different temperature and correlated with the different CNTs percentage. The dispersion rate of fillers and the microstructure of the sample were evaluated by FESEM micrograph

TOWARD A MARKETING STRATEGY FOR FRESH WILD BLUEBERRIES IN THE NORTHEAST

Marketing,

Time Variation of Fine Structure Constant and Proton-Electron Mass Ratio with Quintessence

Recent astrophysical observations of quasar absorption systems indicate that the fine structure constant $\alpha$ and the proton-electron mass ratio $\mu$ may have evolved through the history of the universe. Motivated by these observations, we consider the cosmological evolution of a quintessence-like scalar field $\phi$ coupled to gauge fields and matter which leads to effective modifications of the coupling constants and particle masses over time. We show that a class of models where the scalar field potential $V(\phi)$ and the couplings to matter $B(\phi)$ admit common extremum in $\phi$ naturally explains constraints on variations of both the fine structure constant and the proton-electron mass ratio.Comment: 9 pages, 4 figures, CosPA 2006 Proceeding. 9 pages, 4 figures, CosPA 2006 Proceeding will be published in the Mod. Phys. Lett.

Willingness to Pay for Emission Reductions with E85

This study examines consumers' WTP for reductions in greenhouse gas emissions from E85 as opposed to gasoline. Data were collected via a contingent choice exercise in a 2009 national online survey. As part of the fuel choice exercise, several fuel attributes were allowed to vary including emission reductions, import level, proximity of fuel availability, price, and fuel blend (E85 or regular gasoline). A random parameters model with demographics and attitudes interacted with emission reductions was estimated. The resulting estimates suggest that, overall the WTP for an emission reduction is not statistically significant. However, for some demographic and attitudinal profiles, the WTP is significant. An example profile includes younger age, female, concerned about climate change, not supportive of additional drilling, supportive of farmland being used for fuel, own or are likely to own a FlexFuel vehicle, and primary vehicle not an SUV.Willingness to Pay, Emission Reductions, E85, Consumer/Household Economics, Environmental Economics and Policy, Q41, Q51,

Groundwater seepage landscapes from distant and local sources in experiments and on Mars

© 2014 Author(s). Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological implications of a groundwater or surface water origin are important for our understanding of the evolution of surface features on Mars, and a quantification of valley morphologies at the landscape scale may provide diagnostic insights on the formative hydrological conditions. However, flow patterns and the resulting landscapes produced by different sources of groundwater are poorly understood. We aim to improve the understanding of the formation of entire valley landscapes through seepage processes from different groundwater sources that will provide a framework of landscape metrics for the interpretation of such systems. We study groundwater seepage from a distant source of groundwater and from infiltration of local precipitation in a series of sandbox experiments and combine our results with previous experiments and observations of the Martian surface. Key results are that groundwater flow piracy acts on valleys fed by a distant groundwater source and results in a sparsely dissected landscape of many small and a few large valleys. In contrast, valleys fed by a local groundwater source, i.e., nearby infiltration, result in a densely dissected landscape. In addition, valleys fed by a distant groundwater source grow towards that source, while valleys with a local source grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flatter surfaces. We consider these results with respect to two Martian cases: Louros Valles shows properties of seepage by a local source of groundwater and Nirgal Vallis shows evidence of a distant source, which we interpret as groundwater flow from Tharsis

Did the ACA's "guaranteed issue" provision cause adverse selection into nongroup insurance? Analysis using a copula-based hurdle model

Prior to the Affordable Care Act (ACA), insurance companies could charge higher premiums, or outright deny coverage, to people with preexisting health problems. But the ACA's “guaranteed issue” provision forbids such price discrimination and denials of coverage. This paper seeks to determine whether, after implementation of the ACA, nongroup private insurance plans have experienced adverse selection. Our empirical approach employs a copula-based hurdle regression model, with dependence modeled as a function of dimensions along which adverse selection might occur. Our main finding is that, after implementation of the ACA, nongroup insurance enrollees with preexisting health problems do not appear to exhibit adverse selection. This finding suggests that the ACA's mandate that everyone acquire coverage might have attracted enough healthy enrollees to offset any adverse selection

Mid-Pleistocene Pozzolanic Volcanic Ash in Ancient Roman Concretes

The hydrated lime-volcanic ash mortars of imperial age concrete construction in Rome owe their extraordinary durability to a specific alteration facies of scoriaceous ash from the Pozzolane Rosse ignimbrite, erupted at 456±3 ka from Alban Hills volcano. Stratigraphic, petrographic, and chemical investigations demonstrate that during the warm, humid period preceding marine isotope stage 11, hydrolytic pedogenesis produced an argillic horizon in Pozzolane Rosse, with thick illuvial clay that had little reactivity with hydrated lime, as shown by mortars from the Forum of Julius Caesar (46 to 44 BC). In the underlying soil horizon, however, translocated halloysite overlies opal and poorly crystalline clay surface coatings. Imperial age mortars, as from the Forum and Markets of Trajan (AD 96 to 115), show strong reactivity of these components, altered scoria groundmass, and zeolites with hydrated lime. Romans deliberately selected this alkali-rich ash for optimal performance of pozzolanic concretes