Search

We analyze in details the impact of the 10 ν τ events seen in the OPERA experiment [1] in constraining the Non Standard Interaction parameter ε μ τ affecting neutrino propagation in matter and the allowed parameter space of models with one sterile neutrino of the 3 + 1 type. [ABSTRACT FROM AUTHOR]

In the recent years experiments have established the existence of neutrino os- cillations and most of the oscillation parameters have been measured with a good accuracy. The search for New Physics in neutrino oscillation will be an experimental concrete possi- bility in the next future. In this paper we investigate the ability of the DUNE facility to search for Non Standard Interaction (NSI) in neutrino propagation in matter, emphasizing the role of different assumptions on the shape and absolute normalization errors of both ve and vμ signals. We also study in detail the effects of NSI and systematics in the extraction of standard oscillation parameters. [ABSTRACT FROM AUTHOR]

Al-SBA-15 samples with molar Si/Al ratios of 3, 22 and 73 were synthesized and tested for the acid-catalyzed transesterification of Jatropha curcas oil with methanol. Being non-edible, low-cost and acidic, Jatropha oil is an interesting feed for biodiesel production, as its use would not entrain competition between food and fuel markets. For fundamental reasons, soybean oil, a typical high quality feed, was also investigated, as its negligible free fatty acids content would not mask the extent of transesterification by the simultaneous occurrence esterification. All the catalysts were characterized as to their composition, structure and texture by ICP-AES, 27 Al MAS NMR, X-ray diffraction and nitrogen physisorption. Surface acidity was assessed by ammonia adsorption microcalorimetry. The nature of the organic material adsorbed/trapped on the catalyst during reaction was determined by GC–MS after solvent extraction. The possibility of recovering the activity of the catalayst after a reaction cycle was also checked. In the case of soybean oil, the best-performing catalyst was that with Si/Al = 3 (90 mol% fatty acids methyl esters yield at 180 °C, reaction time 24 h, methanol/oil ratio 12). In the case of Jatropha oil, the three catalysts showed a virtually identical performance (ca. 100 mol% methyl esters yield at 180 °C, reaction time 24 h, methanol/oil ratio 12), in spite of their remarkable differences in terms of both concentration and strength distribution of the acid sites. Esterification of the free fatty acids present in the feed occurred in parallel to triglycerides transesterification, both reactions being catalysed by the acid sites of the catalyst, as well as by the acids present in the feed. Several secondary reactions occurred during the transformation of both soybean oil and Jatropha oil. The corresponding reaction pathways were outlined. [ABSTRACT FROM AUTHOR]

Layered double hydroxides were prepared by pH-controlled co-precipitation method with a Mg/Al molar ratio between 1.5 and 4.0 and used as precursors for obtaining, through calcination, a series of MgAl mixed oxides, which were used as catalysts for soybean oil transesterification with methanol. The mixed oxide with the highest Mg/Al ratio was doped with potassium for obtaining highly basic catalysts. Three different potassium salts (KCO, KNO, CHCOOK) were used for loading potassium on the support (K loading ca. 3 mass%) by two different techniques, namely conventional incipient wetness impregnation and innovative mechanical milling. All the catalysts were characterized as to their chemical composition, structure and texture by inductively coupled plasma atomic emission spectroscopy, X-ray diffraction and N physisorption, respectively. Their basic and acid features were assessed by adsorption microcalorimetry, using CO and NH as probe molecules, respectively. Catalytic testing was carried out in a slurry batch reactor operated at 343 K and atmospheric pressure. The occurrence of potassium leaching into the liquid phase was checked for the K-doped catalysts. The initial activity of the heterogeneous catalysts was interpreted in terms of surface basicity, by taking into account a possible role of acidity in determining the mechanism. [ABSTRACT FROM AUTHOR]

We show that the relatively large best fit value of sin²2θ13=0.14(0.17) measured in the T2K experiment for fixed values of i) the Dirac CP violation phase δ=0, and ii) the atmospheric neutrino mixing parameters θ23=π/4, |Δm32²|=2.4 x 10-3 eV², can be reconciled with the Daya Bay result sin²2θ13=0.090±0.009 if the effects of non-standard neutrino interactions (NSI) in the relevant ...e→...e and νμ→νe oscillation probabilities are taken into account. [ABSTRACT FROM AUTHOR]

CuNiAl and MgCuNiAl mixed oxides (Cu/Ni = 0.29 and 0.32 mol/mol) were obtained from layered double hydroxide precursors (M/Al = 2 mol/mol) synthesized by pH-controlled co-precipitation. After structural and textural characterization (by X-ray diffraction and N physisorption, respectively), the acid and basic features of the mixed oxides were investigated by adsorption microcalorimetry. NH and CO were used for probing the acid and basic features, respectively. By the use of temperature-programmed technique, the redox features of the oxides were investigated as well. The behaviour of the oxides as catalysts for the conversion of 4-methylpentan-2-ol at 448, 473, and 523 K under atmospheric pressure was studied in a fixed-bed reactor. The dehydration products distribution and the relative extents of the dehydration and dehydrogenation reactions are discussed in terms of the possible occurrence, depending on the lack or presence of Mg in the oxide and the reaction temperature, of either acid-base-governed E1 and E2 mechanisms or Cu-promoted reaction pathways. [ABSTRACT FROM AUTHOR]

Abstract: Following the bovine spongiform encephalopathy (BSE) epidemics across Europe in the early 1990s, the removal of designated BSE specified risk material (SRM) became mandatory to minimize the risk of consumer''s exposure to the infectious agent. Despite this preventive measure, cross-contamination of edible meat with SRM can occur during conventional slaughter, primarily by carcass splitting, captive bolt stunning, and head removal. BSE-affected subjects accumulate the pathological feature in the central nervous system (CNS). Currently, there are no markers that can identify the presence of SRM in meat as a whole. Nevertheless, some assays are able to detect traces of CNS, hence this parameter is officially taken as indicative of SRM contamination. In this two-stage study, we carried out a survey to estimate the prevalence of carcass contamination at two slaughterhouses, one large and the other medium-sized; we then compared three different methods (conventional vs. suction vs. water-jet) for spinal cord removal employed at the large slaughterhouse to assess their performance in preventing the spread of central nervous tissue (CNT) over the carcass. The prevalence of carcass contamination was 68.4%. Compared to the other two spinal cord removal techniques (conventional and suction), the water-jet system was associated with less CNS contamination (62 vs. 60 vs. 36%, respectively; P = 0.0047). [Copyright &y& Elsevier]

Abstract: In this paper we analyze the compatibility of two-zero neutrino Majorana textures with the recent experimental data. Differently from previous works, we use the experimental data to fix the values of the non-vanishing mass matrix entries and study in detail the correlations and degree of fine-tuning among them, which is also a measure of how naturally a given texture is able to describe all neutrino data. This information is then used to expand the textures in powers of the Cabibbo angle; extracting random coefficients, we show that only in few cases such textures reproduce the mixing parameters in their 3σ ranges. [Copyright &y& Elsevier]

Abstract: It has been shown that the Cabibbo angle can be predicted in terms of group theoretical quantities, if the dihedral group plays the role of a flavor symmetry. We extend a supersymmetric model to the lepton sector and show that and the deviation of from maximal mixing in the neutrino sector originate, similar to the Cabibbo angle in the quark sector, from a mismatch of different subgroups of and are of the size of the Cabibbo angle. The mixing angles in the charged lepton sector are small. Thus, the lepton mixing angle is naturally in its experimentally preferred range and within its 3σ range. The solar mixing angle is of order one and the charged lepton mass hierarchy is correctly reproduced. Leading order results are only slightly perturbed, if next-to-leading order corrections are taken into account. [Copyright &y& Elsevier]

Abstract: We present a three-flavor fit to the recent and T2K oscillation data with different models for the neutrino–nucleus cross section. We show that, even for a limited statistics, the allowed regions and best fit points in the and planes are affected if, instead of using the Fermi gas model to describe the quasielastic cross section, we employ a model including the multinucleon emission channel. [Copyright &y& Elsevier]

In the light of the recent Daya Bay result $\theta_{13}^{\mathrm{DB}}=8.8^{\circ}\pm0.8^{\circ}$, we reconsider the model presented in Meloni et al. (J. Phys. G 38:015003, ), showing that, when all neutrino oscillation parameters are taken at their best fit values of Schwetz et al. (New J. Phys. 10:113011, ) and where $\theta_{13}=\theta_{13}^{\mathrm{DB}}$, the predicted values of the CP phase are δ≈± π/4. [ABSTRACT FROM AUTHOR]

Abstract: A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude. [Copyright &y& Elsevier]

Environmental samples, raw materials and fermented sausages produced in sardinia (Italy) were analysed in order to investigate the prevalence and enumeration of L. monocytogenes. Isolates were identified by single PCR and characterised by multiplex PCR-based serogrouping. the contamination routes of L. monocytogenes in the plants were traced using PFGE. In addition, a quantitative assessment of the in vitro biofilm formation was carried out. Fermented sausages seem to be regularly contaminated with L. monocytogenes: results showed the ability of the pathogen to overcome the hurdles of the manufacturing process and adapt to the processing plant environments, forming biofilms. [ABSTRACT FROM AUTHOR]

In this study, MgNiAl mixed oxides derived from layered double hydroxide precursors were prepared by pH-controlled co-precipitation. Three samples were prepared with a (Mg + Ni)/Al ratio of 2 and a Ni/Mg with ratios of 0.22, 0.47, and 4.05. The structural, textural and redox features of the oxides were investigated by a variety of techniques, including X-ray diffraction, transmission electron microscopy, N physisorption, and temperature-programmed reduction. The acid and base properties were assessed by NH and CO adsorption microcalorimetry, respectively. The acid-base features were also investigated by testing the catalytic behaviors of the oxides for the conversion of 4-methylpentan-2-ol under both mild and stressed conditions. The reactant alcohol can undergo dehydration into 4-methylpent-1-ene, 4-methylpent-2-ene, and skeletal isomers of C-alkenes, as well as dehydrogenation to 4-methylpentan-2-one and higher ketones, the product selectivity being governed by the concentration and strength of the acid and base sites. Comparison between the calorimetric and test reaction results is discussed. [ABSTRACT FROM AUTHOR]

Abstract: We study a model based on the dihedral group in which the dark matter is stabilized by the interplay between a remnant symmetry, of the same spontaneously broken non-abelian group, and an auxiliary introduced to eliminate unwanted couplings in the scalar potential. In the lepton sector the model is compatible with normal hierarchy only and predicts a vanishing reactor mixing angle, . Since , we also have a simple prediction for the effective mass in terms of the solar angle: . There also exists a large portion of the model parameter space where the upper bounds on lepton flavor violating processes are not violated. We incorporate quarks in the same scheme finding that a description of the CKM mixing matrix is possible and that semileptonic K and D decays mediated by flavor changing neutral currents are under control. [Copyright &y& Elsevier]

Abstract: We present a model based on the non-Abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts for very small reactor angle and deviation from maximal atmospheric mixing for large . Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be . [Copyright &y& Elsevier]

Abstract: SBA-15 functionalization with the guanidine base 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used to prepare TBD-grafted catalysts for the soybean oil transesterification reaction. The structural and textural features of both the support and the catalysts were investigated by X-ray diffraction, transmission electron microscopy, and nitrogen physisorption. CHN analysis and FTIR characterization were also carried out on the catalysts before and after reaction. Potentiometric titration was also used to confirm CHN analysis data for the fresh catalysts. Mild conditions (atmospheric pressure and 343K) were chosen for catalytic testing in a batch reactor. The influence of the base content and the reaction time on the methyl esters yield was investigated. All the catalysts were found active for the soybean oil conversion. Comparison with the catalytic behaviour of a commercial TBD-grafted polymer showed a superior performance of the functionalized SBA-15 catalysts. The higher the functionalization extent, the higher the activity, just a few hours being required for a 100mol% methyl esters yield. Over such a short reaction time leaching was observed to occur only to an extremely low extent, which makes possible to reuse the catalysts after a regeneration step consisting in a simple NaOH treatment of the recovered samples. During such treatment the catalyst base sites – poisoned (through protonation) by the free fatty acids – are freed, and their activity is restored. [Copyright &y& Elsevier]

Abstract: Catalytic conversion of 4-methyl-pentan-2-ol (MPO) was investigated over oxidic materials obtained by the calcination of MgNiCuAl layered double hydroxide (LDH) precursors. Keeping constant the M2+/M3+ ratio equal to 2 (where M2+ =Mg2+, Cu2+, Ni2+ and M3+ =Al3+) various compositions of LDHs were prepared and characterised by X-ray diffraction (XRD), inductively coupled plasma (ICP), N2 adsorption/desorption and X-ray photoelectron spectra (XPS). The acid–base properties have been investigated by the means of physico-chemical methods such as microcalorimetry, by using ammonia (for acid sites) and carbon dioxide (for base sites) as probe molecules. The conversion of 4-methyl-pentan-2-ol (MPO) was chosen as test reaction to investigate the catalytic activity and selectivity of the oxidic materials obtained by the calcination of MgNiCuAl LDHs and to correlate them with the acid–base properties of the oxide surfaces. Copper was found to increase the alcohol dehydrogenation. [Copyright &y& Elsevier]

Abstract: Saharan dust (SD) episodes occurring at the Mediterranean island of Lampedusa (35.52° N, 12.63° E) from May 1999 to December 2005 have been shown to occur in the 26% of the cloud-free days [Meloni, D., di Sarra, A., Biavati, G., DeLuisi, J.J., Monteleone, F., Pace, G., Piacentino, S., Sferlazzo, D.M., 2007. Seasonal behavior of Saharan dust events at the Mediterranean island of Lampedusa in the period 1999–2005, Atmos. Environ. 41, 3041–3056]. In this paper we focus on intense SD events detected until September 2006, characterized by large values of the Saharan Dust Event Index (SDEI), the sum of the daily average aerosol optical depth at 500 nm, τ, over the duration of the dust episode. The SDEI index provides an indication about the intensity of SD events, due either to a long duration and/or to high dust optical depth. A total of 24 episodes characterized by large values of SDEI are examined. The NCEP-based maps of geopotential height and temperature at 700 mbar are used to identify the main circulation patterns driving SD to the Central Mediterranean and Lampedusa. Dust transport episodes in summer last for several days, and the corresponding SDEI values are the highest of the year. These episodes are mainly governed by two circulation patterns: the trough extending near the Atlantic coast of Europe and the high pressure system present in North Africa, generally above 25° N. This configuration causes strong south-westerly flows from the Sahara towards Southern Italy. The time evolution of τ for these long SD events shows that the largest values (>0.3) are usually observed when the two patterns are present simultaneously, while low (<0.3) τ values are measured when the Atlantic trough influence is weak. Moreover, the most probable loading region typically shows a warm kernel in North-Western Sahara, with a tongue extending north-eastward towards Sicily. In spring, moderate to high τ are measured, and SD episodes last as long as 13 days. Two synoptic configurations can be distinguished. Days with large τ are associated with the 700 mbar geopotential height features typical of summer. Days with moderate τ are found to be characterized by the Saharan high, but with the close low replaced by the Atlantic trough descending West of Africa or above the Iberian peninsula. In winter the typical meteorological conditions are determined by the presence of westerly cyclones. Depressions centered over Portugal, Central/Northern Europe, and Western Mediterranean have been shown to drive dust transport to Lampedusa. [Copyright &y& Elsevier]

Multi-filter rotating shadowband radiometer (MFRSR) measurements have been carried out at Lampedusa (35. 52°N, 12. 63°E) in 1999, and continuously since 2001. This study describes the Saharan dust (SD) events at Lampedusa on the basis of daily average optical depth at 500nm, τ, and Ångström exponent, α, derived from these observations. Back-trajectories ending at Lampedusa at 2000 and 4000m altitude were calculated by means of the HYSPLIT model. SD events are identified as those for which the trajectories interact with the mixed layer in places where the surface wind exceeds 7ms−1, or spend a large fraction of time over the Sahara. The SD days display values of α+Δα⩽1, with Δα equal to the standard deviation of the daily α. Out of 911 days with cloud-free intervals, 233 (26%) are classified as SD, and correspond to 111 episodes of various duration, from 1 to 13 consecutive days. The occurrence of SD events is maximum in summer (33%), when also the largest seasonal average of τ (0. 40) is measured, and minimum in winter (7%), when the smallest seasonal average of α (0. 08) is found. SD days have been identified from the back-trajectories also in days lacking of observations, due to either cloudiness or measurement interruptions. The frequency of occurrence of SD days shows little change with respect to the cloud-free periods (24%). The seasonal distribution shows a peak in May (38%), followed by July (37%). Regions of SD production were derived from the HYSPLIT trajectories and NCEP-reanalysis surface winds. Finally, the MFRSR measurements at the solar zenith angle of 60° have been used to derive the single scattering albedo (SSA) for cases clearly dominated by dust (τ⩾0. 40 and α+Δα⩽0. 5). The average SSA for the whole period is 0. 77±0. 04 at 415. 6nm and 0. 94±0. 04 at 868. 7nm. [Copyright &y& Elsevier]

We present in this paper the analysis of the measurement of the unknown PMNS parameters θ13 and δ at future LBL facilities performing complete three parameters fits, each time fully including in the fit one of the atmospheric and solar oscillation parameters within its present (future) error. We show that, due to the presence of degeneracies, present uncertainties on θ23 and $\Delta m^2_{23}$ worsen significantly the precision on (θ13,δ) at future LBL experiments. Only if a precision on the atmospheric parameters at least similar to what expected at T2K-I is reached, then the sensitivities to θ13 and δ that have been presented in the literature for many facilities (where θ23 and $\Delta m^2_{23}$ are generally considered as fixed external inputs) can indeed be almost recovered. On the other hand, the impact on this measurement of the uncertainties on the solar parameters, θ12 and $\Delta m^2_{12}$ is already negligible. Our analysis has been performed using three reference setups: the SPL Super-Beam and the standard low-γ β-Beam, both aiming toward a Mton Water Čerenkov detector located at L = 130 km; the 50 GeV Neutrino Factory with a 40 kton Magnetized Iron Detector to look for the "golden channel" ν e → νμ with baseline L = 3000 km and a 4 kton Emulsion Cloud Chamber to look for the "silver channel" ν e → ντ with baseline L = 732 km. [ABSTRACT FROM AUTHOR]

We compare the physical reach of a Neutrino Factory in the 2+2 and 3+1 four-family models, with similar results in the two schemes; in both cases huge CP-violating effects can be observed with a near detector in the νμ→ντ channel. We also study the capability of long baseline experiments (optimized for the study of the three-family mixing parameter space) in distinguishing a three (active) neutrino model from a four-family scenario. [Copyright &y& Elsevier]

Isomorphously substituted Fe-MFI zeolite catalysts with various Si/Al and/or Si/Fe ratios were synthesized and characterized by many different techniques, such as ICP, XRD, SEM, TPR, microcalorimetry, FTIR, and EPR. Under standard reaction conditions the best catalyst gave 20% benzene conversion and over 90% selectivity to phenol. For Fe-ZSM5 catalysts, addition of steam to the feed improved catalyst activity, selectivity, and durability. Phenol formed onto Fe-based sites only. Active sites could very likely be composed of oxygen-bridged, extraframework binuclear Fe redox species, charge-compensating the framework Fe3+ or Al3+ ions. Surface acidity was not responsible for activity in the main reaction, but it was heavily involved in catalyst deactivation by coking. Catalyst deactivation derived mainly from the decomposition-condensation of phenol onto acid sites; the stronger the latter, the quicker was the coking rate. [Copyright &y& Elsevier]

We notice that looking for νe→ντ at the same time as νe→νμ oscillations could significantly help to reduce the errors in the leptonic CP-violating phase δ measurement. We show how the νe→νμ (“golden”) and νe→ντ (“silver”) transitions observed at an OPERA-like 2 kton lead-emulsion detector at L=732 km, in combination with the νe→νμ transitions observed at a 40 kton magnetized iron detector with a baseline of L=3000 km, strongly reduce the so-called (θ13,δ) ambiguity. We also show how a moderate increase in the OPERA-like detector mass (4 kton instead of 2 kton) completely eliminates the clone regions even for small values of θ13. [Copyright &y& Elsevier]

Assuming the existence of a new real scalar singlet s0 coupled to the Standard Model via a scalar quartic portal interaction, we compute the radiative corrections to the decay rates of the heavy scalar mass eigenstate to a couple of gauge bosons ZZ and W+W-(γ), showing that they can give a contribution as large as O(5%) and O(7%), respectively. We also explicitly analyze in detail their dependence on the heavy mass mS and on the scalar mixing angle α, finding that, especially in the large-mass region, these depend on the sign and the assumed value of sinα. [ABSTRACT FROM AUTHOR]

We consider the νμ→ ντ appearance channel in the future Deep Underground Neutrino Experiment (DUNE) which offers a good statistics of the ντ sample. In order to measure its impact on constraining the oscillation parameters, we consider several assumptions on the efficiency for ντ charged-current signal events (with subsequent τ → e decay) and the related backgrounds and study the effects of various systematic uncertainties. Two different neutrino fluxes have been considered, namely a CP-violation optimized flux and a ντ optimized flux. Our results show that the addition of the νμ→ ντ appearance channel does not reduce the current uncertainties on the standard 3-ν oscillation parameters while it can improve in a significant way the sensitivity to the Non-Standard Interaction parameter |∈μτ| and to the new mixing angle θ34 of a sterile neutrino model of the 3 + 1 type. [ABSTRACT FROM AUTHOR]

During the last decades, the constant evolution of the construction systems has led to the possibility of carrying out increasingly complex architectural project. Among the wide range of construction systems, thin concrete shells with corrugated-edge stand out for their relevance. In this paper, the mechanical behaviour of thin concrete corrugated-edge shell inspired by Nervi's Flaminio dome has been analysed in detail, considering different load configurations (self-weight, uniform normal pressure and antisymmetric vertical load) and constraints (pure membrane vs. displacements restrained boundary conditions). Non-linear static analysis has been performed to assess the vertical load-bearing capacity of the corrugated-edge shell considering a Concrete Damaged Plasticity (CDP) constitutive model and linear and non-linear buckling analyses have been carried out to evaluate the effects of the corrugation on buckling behaviour. The results obtained from linear and non-linear analyses have been compared with those obtained for a concrete thin smooth-edge shell having the same geometric global characteristics. The comparison highlighted improvements provided by corrugated-edge in terms of structural behaviour. • Corrugation to increase structure stiffness, inspired by Flaminio Dome of Nervi. • Exact analytical geometry of corrugated-edge spherical shells. • Static analyses to highlight the structural enhancement due to corrugated shape. • Nonlinear analyses taking into account plasticity and buckling behaviour. [ABSTRACT FROM AUTHOR]

NiO-CeO 2 mixed oxides were prepared by the soft-template method with nominal Ni/Ce molar ratios between 0.3 and 4.0. NiO and CeO 2 pure oxides were also prepared through the same procedure. A second series of NiO-CeO 2 mixed oxides (nominal Ni/Ce values = 0.3–1.5 mol mol −1 ) was synthesized by using the soft-templated ceria as the support and depositing Ni through incipient wetness impregnation. All samples were characterized by different techniques as to their chemical composition, structure, morphology, texture, and redox features. NiO nanocrystals of about 4 nm in size were obtained in the case of the soft‐templated samples, regardless of the Ni loading. Larger NiO nanocrystals (up to 20 nm in size) were formed by depositing Ni through the impregnation procedure. The catalytic performance was investigated in the CO 2 methanation reaction after mild reduction pretreatment (H 2 at 400 °C for 1 h). Catalytic testing was performed under atmospheric pressure, 300 °C, 72,000 cm 3 h −1 g cat −1 , and stoichiometric H 2 /CO 2 molar ratio. Pure NiO as well as the two NiO-CeO 2 mixed oxides series showed high CO 2 conversions (up to 87 mol%) together with CH 4 selectivity values close to 100 mol%. Despite the significantly different size (6–8 and 15–35 nm, respectively) of the Ni 0 nanocrystals originated by NiO reduction, comparable CO 2 conversion values were observed for the soft-templated and impregnated catalysts. The catalyst stability as well as the effect of reaction temperature, space velocity, and H 2 /CO 2 molar ratio were investigated on selected samples. The catalytic results were explained by taking into account that CO 2 and H 2 are activated on different phases. [ABSTRACT FROM AUTHOR]

Mesostructured NiO CeO 2 mixed oxides, with Ni loadings in the range 5–35 wt% (g Ni /g CeO 2 ), were synthesized by the hard template procedure using SBA-15 as the template. A hard-templated CeO 2 was also prepared and used as the support for depositing Ni (5–35 wt%) by impregnation. Two NiO Al 2 O 3 catalysts were synthesized for comparison, by impregnating nickel on a commercial γ-alumina. All the samples were characterized by different techniques as to their chemical composition, structure, morphology, texture, and redox features. The catalytic performance was investigated in the CO 2 methanation reaction after mild reduction pretreatment (H 2 at 400 °C for 1 h). Catalytic testing was performed under atmospheric pressure, 300 °C, 72,000 cm 3 h −1 g cat −1 , and stoichiometric H 2 /CO 2 molar ratio. High catalytic activity, with CH 4 selectivity values ≥ 93 mol%, was obtained with the NiO CeO 2 mixed oxides (CO 2 conversions up to 76 mol%). When γ-Al 2 O 3 was used as the support, catalysts with low activity (CO 2 conversion ≤ 20 mol%) were obtained. On selected samples, additional catalytic runs were also performed for reaction times up to 30 h or with a higher space velocity value. The catalytic results were explained by taking into account the role of the nickel-ceria interactions both during the reduction of NiO and in the reactants activation. [ABSTRACT FROM AUTHOR]

Radiative transfer simulations in the shortwave (SW) and longwave (LW) spectral regions have been carried out to investigate the time evolution of the atmospheric heating/cooling rates and their influence on the temperature profiles under different vertical distributions of the aerosol absorption. The case study is based on measurements made at Rome, Italy, on 20 June 2007, when a dust layer was present above the urban boundary layer (BL) and the column aerosol optical depth at 550 nm was about 0.37. Column-integrated aerosol optical depth and single scattering albedo, as well as vertical profiles of aerosol extinction and meteorological variables have been derived from observations and used in the simulations. Different profiles of the aerosol absorption are considered by varying the absorption of the BL aerosols and of the desert dust, without changing the overall columnar properties. Three scenarios have been considered, with absorbing (ABL) or scattering (SBL) particles in the BL, and with a vertically homogeneous case (HL), which is taken as the reference. Calculations show that, for the selected case, about 25% of the SW heating is offset by the LW cooling within the dust layer. Different longwave/all-wave contributions are observed in the BL, depending on the BL aerosol absorption. Changes of atmospheric temperature induced by aerosol-radiation interactions only, have been investigated, while interactions with the surface through changes of the latent and sensible heat flux have been neglected. The evolution of temperature is similar for the three scenarios within the dust layer, with a daytime increase and a smaller nighttime decrease. After 24 h, the increase of the atmospheric temperature due to the aerosol radiative processes is about 1 K. In the BL, the increase of temperature is strongly dependent on the aerosol absorption capability. The oscillatory behaviour of the temperature with time in the dust layer, and the different evolution in the BL are expected to affect the temperature vertical gradient and may influence related processes. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to quantify the sensitivity of shortwave radiative fluxes to changes in the vertical distribution of aerosol absorption, taken into account through the aerosol Single Scattering Albedo (SSA). The case study represents a real atmospheric situation with a desert dust layer (DDL) in the mid troposphere over an urban Boundary Layer (BL) observed at Rome on 20 June 2007. A moderately high aerosol optical depth (AOD), 0.292 at 550 nm, and low Ångström exponent of 0.30 were measured. The observed case was reconstructed with a radiative transfer model, in which the SSA of the boundary layer aerosols was varied from that of a highly absorbing aerosol type (urban) to a highly scattering one (clear marine). The SSA of the DDL is determined keeping fixed the measured SSA of the whole atmospheric column. The simulations show notable changes in the surface and top of the atmosphere (TOA) diffuse fluxes depending on the boundary layer aerosol properties. The aerosol radiative forcing (ARF) at the surface changes by 6–19 W m−2, depending on the solar zenith angle, when urban or clean marine particles are included in the boundary layer. The ARF differences observed at TOA are between 1 and 5 W m−2 when urban and clean marine aerosol types in the BL are respectively used, showing a smaller dependency on the solar zenith angle than at the surface. [Copyright &y& Elsevier]

Abstract: We study the measurement of the atmospheric neutrino oscillation parameters, and , at the disappearance channel at three conventional beam facilities, the SPL, T2K-phase I and NOνA. These two parameters have been shown to be of crucial importance in the measurement of two of the unknowns of the PMNS mixing matrix, and the leptonic CP-violating phase δ. In our analysis, the effect of the two discrete ambiguities, and , is explicitly taken into account. We analyse also the disappearance channel at the neutrino factory, and combine it with the “golden” and “silver” appearance channels to study its impact on the measurement of and δ. Eventually, we present the sensitivity of the four facilities to different observables: , δ, maximal , the sign of the atmospheric mass difference, , and the -octant, . [Copyright &y& Elsevier]

We upgrade the study of the physical reach of a neutrino factory considering the possibility to distinguish a three (active) neutrino oscillation scenario from the scenario in which a light sterile neutrino is also present. The distinction is easily performed in the so-called 2+2 scheme, but also in the more problematic 3+1 scheme it can be attained in some regions of the parameter space. We also discuss the CP violating phase determination, showing that the effects of a large phase in the three-neutrino theory cannot be reproduced in a four-neutrino, CP conserving, model. [Copyright &y& Elsevier]

This study examines the relationships linking methanesulfonic acid (MSA, arising from the atmospheric oxidation of the biogenic dimethylsulfide, DMS) in atmospheric aerosol, satellite-derived chlorophyll a (Chl- a ), and oceanic primary production (PP), also as a function of sea ice melting (SIM) and extension of the ice free area in the marginal ice zone (IF-MIZ) in the Arctic. MSA was determined in PM 10 samples collected over the period 2010–2012 at two Arctic sites, Ny Ålesund (78.9°N, 11.9°E), Svalbard islands, and Thule Air Base (76.5°N, 68.8°W), Greenland. PP is calculated by means of a bio-optical, physiologically based, semi-analytical model in the potential source areas located in the surrounding oceanic regions (Barents and Greenland Seas for Ny Ålesund, and Baffin Bay for Thule). Chl- a peaks in May in the Barents sea and in the Baffin Bay, and has maxima in June in the Greenland sea; PP follows the same seasonal pattern of Chl- a , although the differences in absolute values of PP in the three seas during the blooms are less marked than for Chl- a . MSA shows a better correlation with PP than with Chl- a , besides, the source intensity (expressed by PP) is able to explain more than 30% of the MSA variability at the two sites; the other factors explaining the MSA variability are taxonomic differences in the phytoplanktonic assemblages, and transport processes from the DMS source areas to the sampling sites. The taxonomic differences are also evident from the slopes of the correlation plots between MSA and PP: similar slopes (in the range 34.2–36.2 ng m −3 of MSA/(gC m −2 d −1 )) are found for the correlation between MSA at Ny Ålesund and PP in Barents Sea, and between MSA at Thule and PP in the Baffin Bay; conversely, the slope of the correlation between MSA at Ny Ålesund and PP in the Greenland Sea in summer is smaller (16.7 ng m −3 of MSA/(gC m −2 d −1 )). This is due to the fact that DMS emission from the Barents Sea and Baffin Bay is mainly related to the MIZ diatoms, which are prolific DMS producers, whereas in the Greenland Sea the DMS peak is related to an offshore pelagic bloom where low-DMS producer species are present. The sea ice dynamic plays a key role in determining MSA concentration in the Arctic, and a good correlation between MSA and SIM (slope = 39 ng m −3 of MSA/10 6 km 2 SIM) and between MSA and IF-MIZ (slope = 56 ng m −3 of MSA/10 6 km 2 IF-MIZ) is found for the cases attributable to bloomings of diatoms in the MIZ. Such relationships are calculated by combining the data sets from the two sites and suggest that PP is related to sea ice melting and to the extension of marginal sea ice areas, and that these factors are the main drivers for MSA concentrations at the considered Arctic sites. [ABSTRACT FROM AUTHOR]

Measurements of spectral global and diffuse ultraviolet (UV) irradiance, and of spectral actinic flux were made jointly with determinations of cloud properties during a two- month experimental campaign that took place in southern Italy in May-June 2010. The cloud modification factor (CMF) which is the ratio between the incoming radiation under cloudy and in cloud-free conditions, was obtained for the global (direct plus diffuse) and diffuse components of the irradiance, and for the actinic flux in the UV spectral range for overcast conditions. Measurements of the diffuse irradiance and actinic flux CMFs are very scarce, and are particularly important to characterize the radiation field and verify the behaviour of radiative transfer models in cloudy conditions. In addition to measurements, one-dimensional radiative transfer simulations are used to investigate the cloud influence on the spectral solar UV radiation. The analysis shows that the wavelength dependence of CMF for the global irradiance is mainly due to the normalization for cloud-free conditions. The CMF for the diffuse irradiance and for the actinic flux displays a strong dependence on the solar zenith angle. This dependence appears to be mainly driven by the large role played by the zenith radiation in overcast conditions. Radiative transfer model determinations of CMF satisfactorily reproduce observations. [ABSTRACT FROM AUTHOR]

Mycobacterium spp. and Photobacterium damselae subsp. piscicida are recognized as the most frequent causative agents of granulomatous lesions in fish. Although frequent episodes of mycobacterial infections have been reported in wild fish worldwide, only sporadic cases have been documented to date in Italy. To investigate for the presence of lesions referable to mycobacteriosis and to identify the mycobacterial species involved, a total of 159 wild mullets were fished from the eastern coast of the Ligurian Sea, killed and necropsied. Liver and spleen samples were collected from all fish for histopathological and microbiological analyses. Molecular investigations for identification of Photobacterium damselae subsp. piscicida were performed. Gross examination revealed granulomatous lesions in one animal; microscopically, 42.14% of fish displayed granulomas with various histological features, 19.50% resulted positive at Ziehl-Neelsen staining, and were confirmed as mycobacterial lesions by culture. The identified colonies were characterized as M. fortuitum, M. abscessus, M. flavescens, M. chelonae, M. septicum and M. nonchromogenicum. In all, 35% of animals resulted positive for Photobacterium damselae subsp. piscicida. These data suggest widespread mycobacterial infection also by Photobacterium damselae subsp. piscicida infections in wild fish. Moreover, the pathogenicity of some mycobacterial species, previously considered as saprophytic, was demonstrated. [ABSTRACT FROM AUTHOR]