Comparison between methods for the determination of the primary cosmic ray mass composition from the longitudinal profile of atmospheric cascades

The determination of the primary cosmic ray mass composition from the longitudinal development of atmospheric cascades is still a debated issue. In this work we discuss several data analysis methods and show that if the entire information contained in the longitudinal profile is exploited, reliable results may be obtained. Among the proposed methods FCC ('Fit of the Cascade Curve'), MTA ('Multiparametric Topological Analysis') and NNA ('Neural Net Analysis') with conjugate gradient optimization algorithm give the best accuracy.Comment: 22 pages, 11 figures, accepted by Astroparticle Physics, minor misprints and an extra figure remove

Measuring Competitiveness at NUTS3 Level and Territorial Partitioning of the Italian Provinces

In this paper we propose a dashboard of indicators of territorial attractiveness at NUTS3 level in the framework of the EU Regional Competitiveness Index (RCI). Then, the Fuzzy C-Medoids Clustering model with multivariate data and contiguity constraints is applied for partitioning the Italian provinces (NUTS3). The novelty is the territorial level analized, and the identification of the elementary indicators at the basis of the construction of the eleven composite competitiveness pillars. The positioning of the Italian provinces is deeply analyzed. The clusters obtained with and without contraints are compared. The obtained partition may play an important role in the design of policies at the NUTS3 level, a route already considered by the Italian government. The analysis developed and the related set of indicators at NUTS3 level constitute an information base that could be effectively used for the implementation of the National Recovery and Resilience Plan (NRRP)

UAV LOW-COST SYSTEM FOR EVALUATING AND MONITORING THE GROWTH PARAMETERS OF CROPS

New generation sensors (RGB, thermal, NIR and multispectral cameras) on unmanned aerial vehicles are continuously being developed for precision farming applications. In particular, this paper presents a study and an experimentation linked to the determination of viticulture growth indices by integrating the innovative techniques of digital photogrammetry from UAV platform, GPS satellite technique and traditional measures. Furthermore we demonstrate that the products from the processed raw-data represent good quality support to determine health state of the crop, and provide in addition a quantitative evaluation of the observed data. Through the use of such a technology it is possible to improve productivity between 15% and 17%, reducing the market price of the product and the costs of control and management. In particular, during the monitoring campaign lasting three years from 2015 to 2017, it was possible to observe that vine cultivation increased the growth index by about 12% following the corrections resulting from the critical interpretation of the results

Analisi microstrutturale di giunzioni Friction Stir Welding in alluminio AA6060-T6: correlazione tra parametri di processo e dimensione dei grani

Il presente lavoro illustra i risultati di una campagna sperimentale finalizzata allo studio della microstruttura digiunzioni ottenute mediante tecnologia FSW – Friction Stir Welding. La campagna sperimentale è stata eseguitasu piatti di alluminio AA6060-T6 di spessore 8 mm saldati di testa. Le saldature sono state ottenute variandoi parametri di processo, vale a dire la velocità di rotazione (S [giri/min]) e la velocità di avanzamento (f [mm/min]) dell’utensile. L’esame metallografico è stato effettuato con lo scopo di esaminare la microstrutturadella sezione trasversale dei giunti in funzione dei parametri di processo e di valutare la dimensione deigrani nelle varie regioni della zona di saldatura: Nugget, ZTA – Zona Termicamente Alterata, ZTMA - ZonaTermo-Meccanicamente Alterata. Il conteggio dei grani è stato effettuato secondo la norma ASTM E112-96(2004). Il rapporto f/S tra velocità di avanzamento e velocità di rotazione è risultato essere un parametroparticolarmente significativo per la variazione della microstruttura delle giunzioni esaminate. Il Nugget hamesso in luce una microstruttura a grani molto fini aventi una dimensione media pari a circa un terzo di quelladei grani del materiale base. La dimensione dei grani in questa zona decresce linearmente all’aumentare delrapporto f/S. La ZTMA è risultata costituita da grani fortemente allungati ed orientati diversamente rispetto aquelli delle zone circostanti. Anche in questo caso è stato possibile osservare una relazione pressoché linearetra dimensione dei grani e rapporto f/S. La ZTA ha invece evidenziato una dimensione dei grani che decresceall’aumentare del rapporto f/S. La qualità delle giunzioni, in termini di resistenza a trazione, è stata infinecorrelata con le caratteristiche metallurgiche rilevate nella zona di saldatura

Eddy covariance and sap flow measurement of energy and mass exchanges of woody crops in a Mediterranean environment

Evapotranspiration estimation by micrometeorological techniques through the assessment of mass and energy exchanges in the soil-plant-atmosphere continuum (SPAC) is a very active research area, involving both well-known and novel measurement techniques. A crucial aspect in validating experimental results is the integration of independent measurements of mass and energy exchanges in the SPAC. To this aim, the development and validation of an integrated approach in major tree crop species, involving different independent techniques, are presented. Eddy covariance estimates of ET fluxes were compared to up-scaled sap flow measurements in olive, orange and grapevine, three important Mediterranean tree crop species with contrasting ecophysiological characteristics and responses to water deficits. These differences can affect directly the degree of coupling of the tree to the environment and, consequently, the degree of correspondence between instantaneous transpirational flux at tree level and the micrometeorological measurement of ET at orchard level. Data were analyzed to verify to what extent, in the three species, transpirational flow at orchard level is regulated by tree conductance, capacitance effects related to tree size or by environmental demand. Hourly observations were helpful in detecting physiological processes of the three species only when data were analyzed taking into consideration their diurnal changes

Observations on midgut of Apis mellifera workers (Hymenoptera: Apoidea) under controlled acute exposures to a Bacillus thuringiensis-based biopesticide

International audienceAbstractMorphostructural investigations have been carried out on Apis mellifera workers treated with single controlled acute exposures to a biopesticide containing Bacillus thuringiensis (Bt), to detect midgut changes until 96 h. Our findings show concentration-dependence of these changes, reflecting in different degrees on both mortality and behaviour. In particular, some midgut changes are also found 96 h after treatment. Our results show that the tested product does not affect survival at presumable environmental concentrations, so confirming the lesser toxicity of Bt-based biopesticides compared to other pesticides. However, in the light of the discovered long-term changes, we discuss the opportunity of taking into account possible chronic exposures to Bt-based products on A. mellifera

Microstructural evaluation of solid state welds obtained by means of flat rolling process

In extrusion operations based on the use of porthole dies, for the fabrication of tubes and hollow profiles ingeneral, material solid state welding takes place thanks to the very high pressure and temperature at whichthe material undergoes. Nevertheless, the most important aspect in this process still remains the quality of thewelds, also because the testing of extruded tubes is still today an un-regulated matter. A technique based onthe flat rolling process is applied in this paper, in combination with micrographic and macrographic analyses, toassess the quality of solid-state welds obtained using different process conditions. Flat rolling experimental testsexecuted on sandwiches made of two rectangular specimens in AA6060 and AA6082 aluminium alloys wereperformed. The specimens were characterized by different heights in order to consider different compressionratios that mean different interface pressure and effective stress distributions. All the tests were repeatedat different temperature. By verifying if, the material bonding took place or not, it was possible to identify thewelding limits conditions in terms of pressure and temperature. Particular attention was paid to the study of boththe macrostructure and microstructure of the rolled specimens in order to identify the influence of the processparameters on both the material weldability and the metallurgical weld quality.Keywords: Extrusion - Flat rolling - Solid state bonding - Aluminum alloys - Metallurgical analysi

Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models.

Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB) and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS), near infrared (NIR) and thermal (TIR) observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alternating bare soil and canopy, we focused the attention on the main conceptual differences between one-source and two-sources energy balance models. Two different models have been tested: the widely used one-source SEBAL model, where soil and vegetation are considered as the sole source (mostly appropriate in the case of uniform vegetation coverage) and the two sources TSEB model, where soil and vegetation components of the surface energy balance are treated separately. Actual evapotranspiration estimates by means of the two surface energy balance models have been compared vs. the outputs of the agro-hydrological SWAP model, which was applied in a spatially distributed way to simulate one-dimensional water flow in the soil-plant-atmosphere continuum. Remote sensing data in the VIS and NIR spectral ranges have been used to infer spatially distributed vegetation parameters needed to set up the upper boundary condition of SWAP. Actual evapotranspiration values obtained from the application of the soil water balance model SWAP have been considered as the reference to be used for energy balance models accuracy assessment. Airborne hyperspectral data acquired during a NERC (Natural Environment Research Council, UK) campaign in 2005 have been used. The results of this investigation seem to prove a slightly better agreement between SWAP and TSEB for some fields of the study area. Further investigations are programmed in order to confirm these indications

Hidroquímica de la cuenca del río Calera, provincia de Tucumán, República Argentina

The Calera river basin is located at the north of Tucumán Province, northwest of Argentina. In this region, there is a population dedicated almost exclusively to cattle and agricultural exploitations. The aim of the present work is to carry out the hydrochemical study of the Calera river basin evaluating their physical-chemical parameters, in order to determine water quality for human supply and its aptitude for irrigation. The obtained results were plotted in hydrochemical diagrams and maps to classify the type of water and to know its evolutionary state. Different types of waters were detected. Sulphated calcic waters prevail over sodium sulphated and bicarbonated ones in all superficial waters, phreatic and semi-confined aquifers. The chemical parameters obtained in the water samples are inside the potability range established by the World Health Organization.La cuenca del río Calera se ubica al norte de la provincia de Tucumán, en el noroeste de Argentina. En esta región existe un asentamiento poblacional dedicado casi exclusivamente a la explotación agrícola- ganadera. El objetivo del presente trabajo es realizar el estudio hidroquímico de la cuenca del río Calera, mediante la evaluación de sus parámetros físico-químicos, con el fin de determinar la calidad del agua para el abastecimiento humano y su aptitud para riego. Los resultados obtenidos fueron volcados en diagramas y mapas hidroquímicos para clasificar el tipo de agua y conocer su estado evolutivo. De esta manera, se detectaron diferentes tipos de aguas, donde las sulfatadas-cálcicas predominan sobre las sulfatadas-sódicas y bicarbonatadas, tanto en las aguas superficiales, como en los acuíferos libres y semiconfinados. Los valores de los parámetros químicos obtenidos se encuentran dentro del rango de potabilidad establecido por la Organización Mundial de la Salud

Flight-Test Evaluation of Kinematic Precise Point Positioning of Small UAVs

An experimental analysis of Global Positioning System (GPS) flight data collected onboard a Small Unmanned Aerial Vehicle (SUAV) is conducted in order to demonstrate that postprocessed kinematic Precise Point Positioning (PPP) solutions with precisions approximately 6 cm 3D Residual Sum of Squares (RSOS) can be obtained on SUAVs that have short duration flights with limited observational periods (i.e., only ~≤5 minutes of data). This is a significant result for the UAV flight testing community because an important and relevant benefit of the PPP technique over traditional Differential GPS (DGPS) techniques, such as Real-Time Kinematic (RTK), is that there is no requirement for maintaining a short baseline separation to a differential GNSS reference station. Because SUAVs are an attractive platform for applications such as aerial surveying, precision agriculture, and remote sensing, this paper offers an experimental evaluation of kinematic PPP estimation strategies using SUAV platform data. In particular, an analysis is presented in which the position solutions that are obtained from postprocessing recorded UAV flight data with various PPP software and strategies are compared to solutions that were obtained using traditional double-differenced ambiguity fixed carrier-phase Differential GPS (CP-DGPS). This offers valuable insight to assist designers of SUAV navigation systems whose applications require precise positioning