127 research outputs found
Magnetoelectric composite bilayer film by electrophoretic deposition
In the recent years the interest of the research community towards multiferroic composite materials was growing fast [1,2]. A number of papers relates to bulk materials while less attention is focused on films. Electrophoretic deposition (EPD) was applied to prepare magnetoelectric (ME) composite bilayer thick films based on perovskite phase and spinel cobalt ferrite as some of the best piezoelectric and magnetostrictive oxides belong these crystal groups. The co-deposition of titanium oxide (TO) and cobalt ferrite (CFO) nanoparticles and the deposition of niobium-doped lead titanate zirconate (PZTN) were made from colloidal suspensions in ethanol keeping constant voltage and recording the current. Good adhesion and compaction of the green film were achieved by optimization of deposition voltage and time while high density of the film and minimized interphase reactions occurred after sintering. The deposited volume, the mixing of dielectric and magnetic phases and the density and ordering of the films have been verified by electron scanning microscopy after heat treatment. No reactions between the different phases was found. The piezoelectric properties were measured on the sintered films.
[1] N.A. Spaldin, M. Fiebig, Science 309 (2005) 391. [2] R. Ramesh, N.A. Spaldin, Nat. Mater. 6 (2007) 21
Structure analysis of cobalt ferrite/titania-silica composite
Magnetodielectric bulk composite of a magnetic phase in dielectric matrix have been studied. Silica coated titania powder was produced by elctrocoagulation and used as dielectric matrix; while the cobalt ferrite powder was selected as magnetic filler. This study aims at tailoring the magnetic and dielectric phases and their interfaces in order to obtain new electromagnetic properties. The microstructure of sintered titaniasilica/cobalt ferrite composites has been related to compositional modifications in terms of silica/titania weight ratio and titania-silica/cobalt ferrite volume ratio. The crystalline structure was studied by XRD analysis supported also by EDS investigationand image analysis performed on the electron micrographs. The image analysis supported the XRD and EDS interpretations, and contributed to evaluate the effective volume contentof the phases after heat treatment
Magnetoelectric composite bilayer films by electrophoretic deposition
In the recent years the interest of the research community towards multiferroic composite materials was growing fast [1,2]. A number of papers relates to bulk materials while less attention is focused on films.
Electrophoretic deposition (EPD) was applied to prepare magnetoelectric (ME) composite bilayer thick films based on piezoelectric phases and cobalt ferrite. The deposition/co-depositionwere made from colloidal suspensions in ethanolkeeping constant voltage and recording the current. Good adhesion and compaction of the green film were achieved by optimization of deposition voltage and time while high density of the film and minimized interphase reactions occurred after sintering. The chemical activity between the two layers was controlled through the batches composition and it could lead to the synthesis of complex engineered structures.The deposited volume, the mixing of dielectric and magnetic phases and the density and ordering of the films have been verified by electron scanning microscopy after heat treatment. The piezoelectric properties were measured on the sintered films.
[1] N.A. Spaldin, M. Fiebig, Science 309 (2005) 391.
[2] R. Ramesh, N.A. Spaldin, Nat. Mater. 6 (2007) 21
Diabetic patient with three-vessel disease and left main involvement. Surgery yes, but not always
AbstractCoronary artery disease (CAD) is known to be the main cause of morbidity and mortality in patients with diabetes mellitus. Although they do not often show typical recognized symptoms, diabetic patients suffer from more extensive CAD and hence higher incidence of multi-vessel CAD than in non-diabetic subjects. Literature has given the strength of evidence in favor of surgical revascularization in diabetic patients with multi-vessel disease. We report the case of a 61-year old active smoker and diabetic man with atypical symptoms and positive treadmill test. The coronary angiography revealed a severe three-vessel disease and distal left main involvement (SYNTAX score=49). As the patient refused to follow heart team indication to undergo coronary bypass grafting, a percutaneous coronary intervention was successfully performed with intra-aortic balloon counterpulsation support and intravascular ultrasound optimization. The mid-term outcome was good
Impact of safety factor and magnetic shear profiles on edge turbulence in circular limited geometry
International audienceThe impact of magnetic configuration on edge turbulence properties in circular limiter geometry is investigated using TOKAM3X, a three-dimensional (3D), first-principle, fluid code for edge plasma. The theoretical spatial tilting of magnetic shear on turbulence fluctuations is recovered. Magnetic shear is found to generate or enhance poloidal high/low field sides (HFS/LFS) and up/down asymmetries. A simulation mimicking the impact of an X-point on circular limiter geometry leads to the formation of two transport barriers that are stable in time, thus leading to the improvement of core particle confinement and to reduction of radial turbulent transport. The magnetic shear, which also strongly enhances the E × B shear, is responsible for the barrier formation
Environmental assessment of individual and collective manure management systems
In intensive livestock area with large nutrient surplus collective management systems can be a suitable solution. However, the collective system should carefully evaluated for environmental sustainability to avoid cross effects. The aim of this study was to evaluate the environmental effects of the introduction of a collective treatment plant for energy production and nitrogen removal. For this purpose an assessment methodology, for individual farms and collective treatments plants, has been defined to estimate the emissions of the main pollutants to the air (CO2, CH4, N2O, NH3) and to the soil (N). The method devised has been assessed in a case study (a treatment plant collecting manure from 12 farms). The main effect of the introduction of the collective management system from the environmental point of view is a reduction of greenhouse gases emissions of 61% due to methane emission reduction and renewable energy production. Furthermore, it reduces the amount of nitrogen to be applied to land from 430 kg ha-1 to about 220 kg ha-1, decreases the emission of ammonia in the air by about 17% due to lower amount of nitrogen that is managed by farms in the storage and spreading operations
Gout in Duke Federico of Montefeltro (1422-1482): a new pearl of the Italian Renaissance
The article examines the truthfulness of historical accounts claiming that Renaissance Duke Federico of Montefeltro (1422-1482) suffered from gout. By direct paleopathological assessment of the skeletal remains and by the philological investigation of historical and documental sources, primarily a 1461 handwritten letter by the Duke himself to his personal physician, a description of the symptoms and Renaissance therapy is offered and a final diagnosis of gout is formulated. The Duke's handwritten letter offers a rare testimony of ancient clinical self-diagnostics and Renaissance living-experience of gout. Moreover, the article also shows how an alliance between historical, documental and paleopathological methods can greatly increase the precision of retrospective diagnoses, thus helping to shed clearer light onto the antiquity and evolution of diseases
X-point and divertor filament dynamics from Gas Puff Imaging on TCV
A new Gas Puff Imaging (GPI) diagnostic has been installed on the TCV
tokamak, providing two-dimensional insights into Scrape-Off-Layer (SOL)
turbulence dynamics above, at and below the magnetic X-point. A detailed study
in L-mode, attached, lower single-null discharges shows that statistical
properties have little poloidal variations, while vast differences are present
in the 2D behaviour of intermittent filaments. Strongly elongated filaments,
just above the X-point and in the divertor far-SOL, show a good consistency in
shape and dynamics with field-line tracing from filaments at the outboard
midplane, highlighting their connection. In the near-SOL of the outer divertor
leg, shortlived, high frequency and more circular (diameter 15 sound
Larmour radii) filaments are observed. These divertor-localised filaments
appear born radially at the position of maximum density and display a radially
outward motion with velocity 400\,m/s that is comparable to radial
velocities of upstream-connected filaments. Conversely, in these discharges
( pointing away from the divertor), these divertor filaments'
poloidal velocities differ strongly from those of upstream-connected filaments.
The importance of divertor-localised filaments upon radial transport and
profile broadening is explored using filament statistics and in-situ kinetic
profile measurements along the divertor leg. This provides evidence that these
filaments contribute significantly to electron density profile broadening in
the divertor.Comment: This is the version of the article before peer review or editing, as
submitted by an author to IOPScience Nuclear Fusion. IOP Publishing Ltd is
not responsible for any errors or omissions in this version of the manuscript
or any version derived from it. 15 pages, 15 figure
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