Particle identification with the opal jet chamber in the region of the relativistic rise

An important goal of the OPAL jet chamber is particle identification at high momenta by exploiting the relativistic rise of the energy loss. Extensive tests have been performed with the full scale prototype of the OPAL jet chamber to measure the energy loss in an argon-methane-isobutane mixture as function of momentum and particle species. The measurements were done under various operating conditions in order to optimise the operating point, to investigate sources of systematic errors, to monitor the stability of the energy loss measurement and to develop calibration procedures. The particle separation capability in the region of the relativistic rise has been studied at gas pressures of 3 and 4 bar. The adopted operating point represents a reasonable compromise between the requirements for particle identification and tracking accuracy.     

Mapping Apennines river paths along different hydrological conditions from satellite images: A description of the method and potential applications

Climate change is producing large impacts on rivers, amplifying hydrological extremes. Prolonged drought periods result in dramatic stress for river biota and associated processes due to low discharge, reducing the interactions between rivers and their lateral environments or leading to hydrological intermittency. New quantitative methods are needed, to correlate discharge with the available riverine habitats. In this work we have mapped the wet surface and paths of two stretches of the Taro and Trebbia Apennine rivers, analyzing satellite images from periods with contrasting discharge. The considered stretches are critical due to different human pressures (large water withdrawals for agriculture and industrial use) and are particularly vulnerable to further, climate-driven discharge reductions. The produced images offer multiple possibilities to extract qualitative and quantitative information at the whole stretch scales, including habitat reduction along with decreasing discharge, threshold discharge limiting lateral interactions, or the evaluation of longitudinal river continuity. We discuss the limitation and the potentialities of the method and the maps produced in terms of possible application in the field of river geomorphology, ecology, the definition of ecological river flow, risk assessment, and river management.     

Coherent lower and upper conditional previsions defined by Hausdorff inner and outer measures to represent the role of conscious and unconscious thought in human decision making

Annals of Mathematics and Artificial Intelligence - The model of coherent lower and upper conditional previsions, based on Hausdorff inner and outer measures, is proposed to represent the...     

Ligandless Copper‐Catalyzed Coupling of Heteroaryl Bromides with Gaseous Ammonia

A range of different N‐ and S‐containing heterocyclic bromides can be efficiently coupled with gaseous ammonia in the presence of copper(II) acetylacetonate [Cu(acac)₂] as catalyst and in the absence of additional ligands. Unstable aminothiophenes and aminobenzothiophenes can be further reacted in situ to afford functionalized derivatives.     

Development of nano-sized hydroxyapatite reinforced composites for tissue engineering scaffolds

Nano-sized hydroxyapatite (nanoHA) reinforced composites, mimicking natural bone, were produced. Examination by transmission electron microscopy revealed that the nanoHA particles had a rod-like morphology, 20–30 nm in width and 50–80 nm in length. The phase composition of hydroxyapatite was confirmed by X-ray diffraction. The nanoHA particles were incorporated into poly-2-hydroxyethylmethacrylate (PHEMA)/polycaprolactone (PCL) matrix to make new nanocomposites: nanoHA-PHEMA/PCL. Porous nanocomposite scaffolds were then produced using a porogen leaching method. The interconnectivity of the porous structure of the scaffolds was revealed by non-destructive X-ray microtomography. Porosity of 84% was achieved and pore sizes were approximately around 300–400 μm. An in vitro study found that the nanocomposites were bioactive as indicated by the formation of a bone-like apatite layer after immersion in simulated body fluid. Furthermore, the nanocomposites were able to support the growth and proliferation of primary human osteoblast (HOB) cells. HOB cells developed a well organized actin cytoskeletal protein on the nanocomposite surface. The results demonstrate the potential of the nanocomposite scaffolds for tissue engineering applications for bone repair.     

Transcranial direct current stimulation: estimation of the electric field and of the current density in an anatomical human head model

This paper investigates the spatial distribution of the electric field and of the current density in the brain tissues induced by transcranial direct current stimulation of the primary motor cortex. A numerical method was applied on a realistic human head model to calculate these field distributions in different brain structures, such as the cortex, the white matter, the cerebellum, the hippocampus, the medulla oblongata, the pons, the midbrain, and the thalamus. The influence of varying the anode area, the cathode area, and the injected current was also investigated. An electrode area as the one typically used in clinical practice (i.e., both electrodes equal to 35 cm(2)) resulted into complex and diffuse amplitude distributions over all the examined brain structures, with the region of maximum induced field being below or close to the anode. Variations in either the anode or cathode area corresponded to changes in the field amplitude distribution in all the brain tissues, with the former variation producing more diffuse effects. Variations in the injected current resulted, as could be expected, in linearly correlated changes in the field amplitudes.     

Yeast dynamics during the fermentation of brined green olives treated in the field with kaolin and Bordeaux mixture to control the olive fruit fly

The yeast microbiota associated with naturally fermented and inoculated green table olives, differently treated in the field with non-conventional repellent and antiovipositional products in the control of Bactrocera oleae, was analysed using a combination of culture-dependent and -independent molecular fingerprinting. The routine yeast isolation gave rise to 118 strains, whose identification was performed by PCR-RFLP of the internal transcribed spacer (ITS) regions. Total DNA was extracted directly from the brine throughout fermentation by means of an experimental protocol that included the removal of Taq polymerase inhibitors. Denaturing Gradient Gel Electrophoresis (DGGE) of 26S rRNA gene PCR amplicons highlighted the yeast community. Comparison of both culture-dependent and independent methods indicated that the yeast species Saccharomyces cerevisiae, Wickerhamomyces anomalus, Candida diddensiae and Issatchenkia orientalis were dominant during fermentation despite the addition of the Lactobacillus plantarum starter used in brining. The resultant isolated species were unaffected by treatments in field, except for C. diddensiae whose growth was delayed by kaolin.     

A general 3D approach for the analysis of multi-axial fracture behavior of reinforced concrete elements

The behavior of cracked reinforced concrete structural components is here analyzed through a three-dimensional model, which includes all the interface phenomena generated along cracks, such as aggregate bridging and interlock, tension stiffening and dowel action, as well as the non-linear response of concrete in compression and in tension. The model is able to effectively describe the progressive development of multi-axial cracking, by considering the crack re-orientation and the change of the crack spacing as loading increases. The proposed formulation, which is expressed in terms of secant stiffness matrix, is obtained by taking into account the flexibility contributions of cracks and of the concrete between adjacent cracks, in both the singly and the multi-cracked stage. Finally, this model is implemented into a finite element code and is validated through comparisons with significant experimental data available in the literature.     

Multi-directional modeling of crack pattern in 2D R/C members

A macro-scale approach to R/C modeling is proposed in this paper by formulating a comprehensive model, that describes R/C behavior in the uncracked stage (solid concrete) and in the cracked stage, the latter with either unidirectional cracking (primary cracks) or with bidirectional cracking (primary and secondary cracks) or even multi-directional cracking. The secant stiffness matrix is formulated by means of a direct procedure, based on the assumption that the solid concrete and the reinforcement work in parallel, while the solid concrete between the cracks and the cracks themselves work in series. The resistant mechanisms active at the crack interface are introduced by means of their highly nonlinear laws, that are taken from the literature and are based on well-documented tests. The reliability and accuracy of the proposed model are checked against a few well-documented tests on 2D R/C members failing past the formation of secondary cracks.