3,411 research outputs found
Experimental determination of the frequency and field dependence of Specific Loss Power in Magnetic Fluid Hyperthermia
Magnetic nanoparticles are promising systems for biomedical applications and
in particular for Magnetic Fluid Hyperthermia, a promising therapy that
utilizes the heat released by such systems to damage tumor cells. We present an
experimental study of the physical properties that influences the capability of
heat release, i.e. the Specific Loss Power, SLP, of three biocompatible
ferrofluid samples having a magnetic core of maghemite with different core
diameter d= 10.2, 14.6 and 19.7 nm. The SLP was measured as a function of
frequency f and intensity of the applied alternating magnetic field H, and it
turned out to depend on the core diameter, as expected. The results allowed us
to highlight experimentally that the physical mechanism responsible for the
heating is size-dependent and to establish, at applied constant frequency, the
phenomenological functional relationship SLP=cH^x, with 2<x<3 for all samples.
The x-value depends on sample size and field frequency/ intensity, here chosen
in the typical range of operating magnetic hyperthermia devices. For the
smallest sample, the effective relaxation time Teff=19.5 ns obtained from SLP
data is in agreement with the value estimated from magnetization data, thus
confirming the validity of the Linear Response Theory model for this system at
properly chosen field intensity and frequency
Unexpected Variation of the Codeine/Morphine Ratio Following Fatal Heroin Overdose
Postmortem samples from 14 cases of suspected heroin overdose
were subjected to a preliminary systematic toxicological analysis in
order to highlight the presence of unknown exogenous compounds
(e.g., drugs of abuse, alcohol) that may have played a role in the
mechanism of death. This analysis unveiled histories of poly-drug
use in seven of the cases under investigation. Moreover, the concentrations
of morphine and codeine in the brain were also investigated,
and the results were compared with the data obtained from the blood
specimens. The concentration of morphine in blood ranged from 33 to
688 ng/mL, while the concentration of codeine ranged from 0 to
193 ng/mL. However, in the brain, the concentration of morphine
was found to be between 85 and 396 ng/g, while the levels of codeine
ranged from 11 to 160 ng/g. The codeine/morphine ratio in
the blood ranged from 0.043 to 0.619; however, in the brain, the
same ratio was found to be between 0.129 and 0.552. In most
cases, a significantly higher codeine/morphine ratio was found in
the brain, suggesting the accumulation of codeine in brain tissue
due its high lipophilicity as compared with morphine
A proposal for Video Signature Tool and Video Fingerprinting
In this document we present and evaluate a video signature system, proposed by Signals and Communications Laboratory – Department of Electronic for Automation, University of Brescia (Italy)
High Dynamic Range Image Watermarking Robust Against Tone-Mapping Operators
High dynamic range (HDR) images represent the future format for digital images since they allow accurate rendering of a wider range of luminance values. However, today special types of preprocessing, collectively known as tone-mapping (TM) operators, are needed to adapt HDR images to currently existing displays. Tone-mapped images, although of reduced dynamic range, have nonetheless high quality and hence retain some commercial value. In this paper, we propose a solution to the problem of HDR image watermarking, e.g., for copyright embedding, that should survive TM. Therefore, the requirements imposed on the watermark encompass imperceptibility, a certain degree of security, and robustness to TM operators. The proposed watermarking system belongs to the blind, detectable category; it is based on the quantization index modulation (QIM) paradigm and employs higher order statistics as a feature. Experimental analysis shows positive results and demonstrates the system effectiveness with current state-of-art TM algorithms
Identification versus CBCD: a comparison of different evaluation techniques
Fingerprint techniques have a significant advantage in respect of watermarking: a fingerprint can be extracted in each moment of the lifetime of a multimedia content. This aspect is fundamental to solve the problem of copy detection mainly because many copies can be available in huge amount of data in circulation and because each copy can be attacked in several ways (compression, re-encoding, text-overlay, etc.). In this paper the problem of copy detection is studied and tested from two different point of views: content based and identification approaches. The results show that the proposed system is quite robust to some copy modifications and most of all show that the overall results depend on the evaluation method used for testing
Cyclic response of masonry piers retrofitted with timber frames and boards
The quasi-static in-plane cyclic response of two single-leaf calcium silicate unreinforced masonry piers was investigated to show the effectiveness of an innovative timber retrofit solution. The aim of the intervention is to increase the pier in-plane and out-of-plane strength and displacement capacity, thus reducing the seismic vulnerability of this typology of unreinforced masonry construction with a light, cost-effective, sustainable and reversible approach. The retrofit technique consists of a timber frame mechanically connected by means of steel fasteners to the masonry pier and building floors. Oriented strand timber boards are then nailed to the frame. In-plane quasi-static shear-compression cyclic tests were performed on two single-leaf calcium silicate brick piers with identical geometry and masonry mechanical properties: one was tested unstrengthened while the other was tested in the retrofitted configuration. The experimental results showed evident improvements in the lateral force-displacement response of the retrofitted specimen. More specifically, compared with the bare masonry pier, the retrofitted pier exhibited slightly higher stiffness, larger strength and significantly greater displacement capacity
Slicings of parallelogram polyominoes: Catalan, schröder, baxter, and other sequences
We provide a new succession rule (i.e. generating tree) associated with Schröder numbers, that interpolates between the known succession rules for Catalan and Baxter numbers. We define Schröder and Baxter generalizations of parallelogram polyominoes, called slicings, which grow according to these succession rules. In passing, we also exhibit Schröder subclasses of Baxter classes, namely a Schröder subset of triples of non-intersecting lattice paths, a new Schröder subset of Baxter permutations, and a new Schröder subset of mosaic floorplans. Finally, we define two families of subclasses of Baxter slicings: the m-skinny slicings and the m-rowrestricted slicings, for m ∈ N. Using functional equations and the kernel method, their generating functions are computed in some special cases, and we conjecture that they are algebraic for any m
Evaluation of Core Experiment for MPEG-7 Video Signature Tool
The present document evaluates and discusses the experiment conditions proposed in the VCE-7 CE on Video Signature, discussed in the previous MPEG meetings [MPEG-VS-09-01] [MPEG-VS-09-02]. In particular we present some simulation results that show the weaknesses of the evaluation procedure, proposed in the VCE-7 CE on Video Signature, and that highlight some aspects that could impair the performance evaluation of the here considered technology in a realistic environment. Therefore, we propose a new Core Experiment which will consider this issues
A proposal for Video Signature Tool and Video Fingerprinting
In this document we present and evaluate a video signature system, proposed by Signals and Communications Laboratory – Department of Electronic for Automation, University of Brescia (Italy). The proposed Video Signature is MPEG-7 compliant. The technology is based on the use of many different features (color, motion, etc.). The preliminary studies show that these features have relevant characteristics in their development in time. The testing results prove that the features act differently with respect of the type and modification the query suffered
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