4,559 research outputs found
Operators in Rigged Hilbert spaces: some spectral properties
A notion of resolvent set for an operator acting in a rigged Hilbert space
\D \subset \H\subset \D^\times is proposed. This set depends on a family of
intermediate locally convex spaces living between \D and \D^\times, called
interspaces. Some properties of the resolvent set and of the corresponding
multivalued resolvent function are derived and some examples are discussed.Comment: 29 page
Kant’s reevaluation of monadology : a historical - philosophical puzzle
In the Critique of pure reason (1781), as is well known, Kant offers a schematic presentation of Leibniz\u2019s philosophy, interpreted as a paradigmatic case of conceptual \u201camphiboly\u201d, where the fundamental distinction between the conditions of sense knowledge and intellectual knowledge is missed: accordingly, Leibniz\u2019s mistake would consist in handling phenomena, i.e. the objects of sense, as if they were \u2018things in themselves\u2019, modeled on pure intellectual cognition. Among other theses, the monadological view would directly arise from this mistake: more precisely, from the idea that simple beings would be prior to composite ones, and their intrinsic properties would be basic with respect to their external, i.e. spatial, relations (KrV A 260/B 316)
Influence of the Height of Municipal Solid Waste Landfill on the Formation of Perched Leachate Zones
Waste settlement as well as consolidation phenomena, which occur inside a landfill for municipal solid waste (MSW), can cause a decrease in waste permeability. This can lead to a reduction in conveyance of the leachate drainage system. It is therefore possible that a so-called perched leachate zone will form. Such a zone is constituted by an area in the body of the landfill where the leachate is temporarily trapped and is unable to infiltrate downward. This phenomenon is influenced by many factors, which include rain infiltration rate, waste moisture and composition, landfill height, and so on. The main aim of the paper is to elucidate the role played by landfill height in the formation of perched leachate zones using a one-dimensional (1D) mathematical model. The model allows for the simulation of the perco- lation fluxes throughout an MSW landfill based on mass-balance equations. The results showed a different response in terms of flow rates throughout the landfill, highlighting the important role of landfill height in the formation of perched leachate zones. Landfill height influences not only the formation of perched leachate zones but also their extension throughout the body of the landfill
static and dynamic response of titanium alloy produced by electron beam melting
Abstract The suitability of Titanium alloys for many specialized applications requiring excellent performances at both static and dynamic strain rates, benefits of modern manufacturing technologies like the additive manufacturing, oriented toward the obtainment of complicated component shapes. The EBM methodology for the production of Ti6Al4V components is based on the localized melting of alloy powders by way of guided electron beams scanning the powder volume by successive planar trajectories; for this reason, the whole production process may confer a certain degree of anisotropy to the components. The material behavior of the EBM alloy may be orientation-dependent in terms of stress-strain elastoplastic response as well as in terms of damage sensitivity and ductile fracture under given triaxiality histories. The static and dynamic behavior of a sintered Ti6Al4V alloy is investigated here by way of quasistatic tension-torsion tests and dynamic tensile Hopkinson bar (SHTB) tests. The outcome of the latter experiments, compared to similar tests results from the literature concerning Ti alloy obtained by classical metallurgical techniques, gives some indications about how the technological process may affect the final performance of the material and the component
Exosomes from metastatic cancer cells transfer amoeboid phenotype to non-metastatic cells and increase endothelial permeability: their emerging role in tumor heterogeneity
The goal of this study was to understand if exosomes derived from high-metastatic cells may influence the behavior of less aggressive cancer cells and the properties of the endothelium. We found that metastatic colon cancer cells are able to transfer their amoeboid phenotype to isogenic primary cancer cells through exosomes, and that this morphological transition is associated with the acquisition of a more aggressive behavior. Moreover, exosomes from the metastatic line (SW620Exos) exhibited higher ability to cause endothelial hyperpermeability than exosomes from the non metastatic line (SW480Exos). SWATH-based quantitative proteomic analysis highlighted that SW620Exos are significantly enriched in cytoskeletal-associated proteins including proteins activating the RhoA/ROCK pathway, known to induce amoeboid properties and destabilization of endothelial junctions. In particular, thrombin was identified as a key mediator of the effects induced by SW620Exos in target cells, in which we also found a significant increase of RhoA activity. Overall, our results demonstrate that in a heterogeneous context exosomes released by aggressive sub-clones can contribute to accelerate tumor progression by spreading malignant properties that affect both the tumor cell plasticity and the endothelial cell behavior
Langmuir-Schäfer Films of an Amphiphilic Ruthenium Complex Bearing an “Almost-Naked” Multi-Charged Head-Group
In this paper the preparation and characterization of Langmuir-Scha¨fer (LS) films of a novel amphiphilic dipolar
complex, [RuII(NH3)5(N-dodecyl-4,4¢-bpy)](PF6)3 (1), are reported. Preparation of these films, otherwise precluded
utilizing standard Langmuir procedures, is achieved by using a subphase at relatively high ionic strength, by addition
of NH4PF6. The morphology and the spectroscopic features of the floating films are investigated by Brewster angle
microscopy and UV-vis reflection spectroscopy at the water-air interface, respectively, whereas LS films are
characterized by absorption spectroscopy and atomic force microscopy. The overall results indicate the existence
of aggregates of 1 and formation of homogeneous, densely packed layers. The presented approach could represent
a general method to achieve Langmuir-Blodgett films of amphiphilic metal complexes having an “almost naked”
multicharged headgroup
Risultati di un test RFLP su ceppi vaccinali di Canine Distemper Virus in Italia
Canine Distemper (CD) is a highly contagious and multisystemic viral disease of domestic and wild carnivores. A published Restriction Fragment Length Polymorphism (RFLP) test, based on the presence of a PsiI cleavage site on hemagglutinin (H) gene, allows a rapid differentiation of all currently used vaccine strains by virulent field strains. The present study describes the results of this test carried out on different CD vaccines available in Italy in 2010. RFLP has also revealed that the CD strain present in the Vanguard (Pfizer Animal Health) vaccine reacts as a wild-type strain. Moreover, genetic analysis of H gene sequence has showed that Vanguard vaccine strain does not cluster in the group of vaccine strains (America-1), as expected based on the product description provided by the manufacturer, but it is more closely related to wild-type strains of the America-2 group. However, this protocol shows significant advantages to identify CD wild-type strains
Canine Mesenchymal Stem Cells from visceral and subcutaneuous adipose tissue for cell-based therapy
This study compared some characteristics of canine Adipose tissue-Derived Mesenchymal Stem Cells (cAD-MSCs) from subcutaneous and visceral fat. These findings were directed to obtain high quantity and quality cAD-MSCs for clinical cell-based therapy
Exploiting Slow Dynamics Effects for Damage Detection in Concrete
Nonlinear ultrasonic techniques have been developed over the last decades to detect the presence of damage in materials of interest in the field of civil engineering, such as concrete or mortar. The dependence on the strain amplitude of measurable quantities, such as wave velocity, damping factor, resonance frequency, etc. is normally considered a qualitative indicator of the presence of defects at the microstructural level. The experimental approaches proposed have the advantage of being sensitive to small variations in the sample microstructure and are therefore more adapted to detect the presence of small cracks or damaged areas with respect to traditional linear ultrasonic techniques. However, nonlinear methods are difficult to implement, since they usually require a calibrated experimental set-up which also behaves linearly at high amplitudes of excitation. The slow dynamics features, typical of the hysteresis generated by damage, have been given much less attention as a tool for damage detection even though their quantification is often less demanding in terms of an experimental set-up. Here, we provide the first evidence of how recovery, which is part of the slow dynamics process, is sensitive to the presence of damage in concrete samples and thus could be considered as an easy-to-measure nonlinear indicator for Structural Health Monitoring purposes
- …