3,497 research outputs found
Highly conductive, ionic liquid-based polymer electrolytes
In this manuscript is reported a thermal and impedance spectroscopy investigation carried out on quaternary polymer electrolytes, to be addressed as separators for lithium solid polymer batteries, containing large amount of the N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide ionic liquid. The target is the development of Li+ conducting membranes with enhanced ion transport even below room temperature. Polyethylene oxide and polymethyl methacrylate were selected as the polymeric hosts. A fully dry, solvent-free procedure was followed for the preparation of the polymer electrolytes, which were seen to be self-consistent and handled even upon prolonged storage periods (more than 1 year). Appealing ionic conductivities were observed especially for the PEO electrolytes, i.e., 1.6 × 10-3and 1.5 × 10-4 S cm-1 were reached at 20 and -20°C, respectively, which are ones the best, if not the best ion conduction, never detected for polymer electrolytes
Three-way ordinal non symmetrical correspondence analysis for the evaluation of the patient satisfaction
In some recent articles, emphasis has been given to the partition of the Goodman-Kruskal’s tau index using orthogonal polynomials for the study of the non symmetrical relations in three-way contingency tables. New graphical techniques that consider such a partition and allow for the analysis of asymmetric relationships have been proposed, including three-way ordinal non symmetrical correspondence analysis (Simonetti, 2003). Such a procedure takes into account the presence of an ordinal predictor and response variables. In this paper we demonstrate the applicability of such a technique for the patient satisfaction evaluation
Guided Microwave Detection of Corrosion Product in Insulated Pipelines
Corrosion under insulation (CUI) is a common cause of pipeline failure in the oil and gas industry. Its detection with conventional inspection techniques is challenging due to the presence of the insulation layer and a protective metallic cladding that prevent direct access to the pipe surface. Guided microwave testing has been proposed as a cost-effective approach to screen an extended length of a pipeline for the presence of water, which is a necessary precursor for CUI. The pipe and metallic cladding naturally form a large coaxial transmission line in which the insulation acts as a dielectric and supports the propagation of microwave signals. The inspection is performed by launching the signal from an array of antennas permanently installed at one location along the pipeline. Wet insulation is then detected according to the radar principle since water results in the partial reflection of the incident microwave owing to the permittivity contrast between dry and wet insulation. This paper reviews the underpinning principles of longrange guided microwave testing and presents a new study aimed at enhancing the selectivity of the technique by detecting corrosion product inside the insulation which is more reliable indicator of CUI progression
Clusterization of multi-channel electromyograms into muscle-specific activations to drive a subject-specific musculoskeletal model:towards fast and accurate clinical decision-making
Guided Wave Tomography of Pipe Bends
Detection and monitoring of corrosion and erosion damage in pipe bends are open challenges due to the curvature of the elbow, the complex morphology of these defects, and their unpredictable location. Combining model based inversion with guided ultrasonic waves propagating along the elbow and inside its walls, offers the possibility of mapping wall-thickness losses over the entire bend and from a few permanently installed transducers under the realm of guided wave tomography (GWT). This paper provides the first experimental demonstration of GWT of pipe bends based on a novel curved ray tomography algorithm and an optimal transducer configuration consisting of two ring arrays mounted at the ends of the elbow and a line of transducers fixed to the elbow extrados. Using realistic, localized corrosion defects it is shown that detection of both the presence and progression of damage can be achieved with 100% sensitivity regardless of damage position around the bend. Importantly, this is possible for defects as shallow as 0.50% of wall thickness (WT) and for maximum depth increments of just 0.25% of WT. However, due to the highly irregular profile of corrosion defects, GWT generally underestimates maximum depth relative to the values obtained from 3-D laser scans of the same defects, leading in many cases to errors between 4 and 8% of WT
Evaluation of immunization practices in Naples, Italy.
This paper reports the results of a survey on vaccination coverage among children born in January 1995 and residing at the beginning of the study (March 1998) in the city of Naples, Italy. The percentages vaccinated, at various times from birth, with oral polio vaccine (OPV), have been compared with those found in a similar survey conducted at the end of 1985 regarding the cohort of children born in June 1983. By the fourth month of life 67% of the 1995 cohort were vaccinated with the first doses of OPV, an increase of about 26% on that found in the 1983 cohort. Similar results were found with the second doses. Among the 1995 cohort 49% were vaccinated with the third dose of OPV within the thirteenth month of life; the corresponding value for the 1983 cohort was 33%. Within the twenty-fourth month of life, in the 1995 cohort, 86% completed the primary cycle of vaccination with OPV; the corresponding figure for the 1983 cohort was 65%. At the end of the third year of life 80% of the 1995 cohort received the fourth dose of OPV. A significant association has been found between socioeconomic status and coverage level
Correlation Functions Along a Massless Flow
A non-perturbative method based on the Form Factor bootstrap approach is
proposed for the analysis of correlation functions of 2-D massless integrable
theories and applied to the massless flow between the Tricritical and the
Critical Ising Models.Comment: 11 pages (two figures not included in the text), Latex file,
ISAS/EP/94/15
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