1,720,970 research outputs found
Transmission line model for meander antennas
No full textNowadays valuable and efficient numerical methods allow an empirical approach in the design of antennas for high-frequency wireless communication systems. Generally these numerical techniques apply either time- or frequency-domain algorithms demanding high computational efforts and long-time processing. Moreover, the initially assumed geometrical configuration can strongly affect the numerical convergence efficiency. With reference to a meander antenna, this paper highlights the computational improvement achievable by applying a transmission line model to the definition of an initial geometry, to be numerically optimized, the sizes of which are nearly to the final ones
An Analytical 3D Model of Metal Foams for EM Shielding Applications
No full textIn this paper a preliminary electromagnetic shielding behaviour of metal foams, is developed and discussed. Metal foams represent a novel class of materials which promise new interesting properties employable for various purposes. More specifically, the realization of electromagnetic shields has been considered and experimental Shielding Effectiveness (SE) measurements have been performed, demonstrating very good performance. In order to allow the design of metal foam EM shields, double 3D wire-mesh screens, obtained as a development of a previously 2D laminated shield, has been presented, comparing the relative results with experimental measure. The good agreement among the preliminary data paves the way to obtain an efficient analytical model of the complex electromagnetic behavior of metal foams
E-field distribution improvement by new hyperthermia applicators
No full textIt is well known that the hyperthermia (HT)
treatment method in cancer therapy makes use of the controlled
electromagnetic heating in the patient’s body. With regard to the
deep body hyperthermia therapy, we have reviewed in this paper
the most recent technology and technique of electromagnetic
deep heating (Sigma-Eye applicator) based on annular phased
arrays (APA) antennas. In order to improve the performance of
the Sigma-Eye applicator, a new profile of the antenna was
designed using a substrate material with high permittivity. The
good results of the simulations compared with the classical
Sigma-Eye applicator in terms of SAR deposition and focus
capability lead us to further improvements of both the heat
generation devices and the treatment planning methods
Measurements in the hyperpolarized helium-3 for medical applications
No full textHyperpolarized helium-3 (3He) gas, is a new contrast agent for lung imaging diagnostic in functional Magnetic Resonance Imaging (fMRI) becoming an important technique to diagnose diseases and abnormalities in the respiratory tract. In this paper is described a new modular production method of 3He gas, hyperpolarized using the Metastability Exchange Optical Pumping Technique (MEOP). A standard set of measurements has been collected considering a prototype developed by ITEL Telecomunicazioni srl, able to produce one litre of 3He polarized gas at the pressure of 1000 mbar. A 27% of polarization at a pressure of 1 mbar is obtained in the optical pumping cell in a single run, while a time of about 20 minutes is needed to pump the gas at a final pressure of 1000 mbar in the storage cell
Novel biological and molecular characterization in radiopharmaceutical preclinical design
No full text
Impact of 68Ga-DOTATOC PET/CT in comparison to 111In-Octreotide SPECT/CT in management of neuro-endocrine tumors: A case report
Full text linkRationale:In the diagnostics of neuroendocrine tumors (NETs), scintigraphy and Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) with 111Indium-Octreotide occupy a prominent place.The introduction in clinical practice of 68Gallium-labelled somatostatin analogues (DOTA-TOC, DOTA-TATE, DOTA-NOC) for Positron Emission Tomography/Computed Tomography (PET/CT), significantly improved NETs diagnostics due to greater sensitivity and improved lesion detection in addition to better patient convenience and decreased radiation dose.Patient concerns:We report a case of a patient who was diagnosed with a neuroendocrine tumor of the ileocecal valve.Diagnoses:Diagnosis was made by ultrasonography, CT, and colonoscopy. Hystology after surgery was G2 NET of ileo-cecal valve. Restaging was carried out by 111In-Octreotide SPECT/CT and, 1 month later, by 68Ga-DOTATOC PET/CT. 18F-FDG PET/C was also carried out.Interventions:68Ga-DOTATOC PET/CT showed larger disease that modified disease management from surgery to medical treatment.Outcomes:After an initial improvement in the patient clinical condition, the tumor caused a worsening with the appearance of ascites.Lessons:68Ga-DOTA-conjugate PET/CT is appropriate in low and intermediate NET (Ki67 index respectively ≤3% and 3%-20%) characterized by better survival and better response after Peptide Receptor Radionuclide Therapy.18F-FDG is mostly useful in high grade (G3) of disease, so that 68Ga-DOTA-conjugate SUV and 18F-FDG SUV have an opposite trend in relation to the tumor grade. 68Ga-DOTATOC PET/CT changes, as in our case, therapeutic management in about 40% of cases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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