1,721,188 research outputs found
Development of an electromagnetic model to characterize the field diffracted by a human body for AAL applications
No full textIl lavoro di ricerca presentato in questa tesi riguarda lo sviluppo e
l’implementazione di un modello analitico, per la caratterizzazione dei campi
diffratti da un corpo umano, per applicazioni nell’ambito del Ambient Assisted
Living (AAL).
Negli ultimi anni c’è stata una crescente domanda di sensori senza contatto
destinati al monitoraggio da remoto dei parametri vitali, al fine di migliorare
la qualità di vita dei pazienti.
Questo tipo di sistemi prevede l’utilizzo di una tecnologia basata sulla
propagazione di onde elettromagnetiche, e la loro corretta progettazione prevede
l’analisi dell’interazione tra corpo umano e onda EM. Programmi di simulazione
elettromagnetica sono in grado di caratterizzare tale interazione, ma richiedono
un consumo di memoria enorme e una grande quantità di tempo di calcolo.
Invece, un modello analitico riduce l’onere computazionale, e si dimostra affidabile
e sufficientemente accurato.
A tale scopo, un modello EM basato su un approccio di tipo ottica-fisica è
presentato in questa tesi, in cui il corpo umano è stato riprodotto mediante
forme canoniche omogenee. Misure e simulazioni effettuate con il modello
EM, implementato in MATLAB, sono stati eseguite e confrontate, per analizzare
l’accuratezza e la fattibilità del modello analitico, considerando una sfera
metallica, oggetti omogenei senza perdite (sfera e cilindro), e strutture complesse
dielettriche (manichino e target reale). Inoltre, tecniche di radar Doppler
sono state studiate e implementate nel modello, al fine di analizzare e discriminare
attività generali di un target in movimento. Il modello EM permette di
ottimizzare la progettazione di sensori senza contatto, per il monitoraggio da
remoto dei parametri vitali, per il rilevamento di cadute e della spesa energetica
relativa ad attività fisiche di persone anziane in ambienti chiusi
Organic & Hybrid Photonic Crystals for Controlling Light-Matter Interaction Processes
No full textOrganic & Hybrid Photonic Crystals for Controlling Light-Matter Interaction Processe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Cellulose ternary photonic crystal created by solution processing
No full textFor the first time, a multiplanar photonic crystal structure has been obtained using cellulose as a structural material. This all-polymer system, made of cellulose, polyvinyl alcohol and poly(N-vinylcarbazole) is a ternary planar photonic crystal composed by 7 repeated trilayers produced by spin coating. Trimethylsilyl cellulose is used as a precursor to be converted to cellulose. Transverse Transmission Electron Microscopy analysis of our systems confirms the multilayered structure whose optical response can be theoretically accounted for. Preliminary results on the response of the photonic crystal to water vapors envisage the use of this system for humidity optical sensing
Clinical experiences with intranasal esketamine for major depressive disorder resistant to treatment and with a psychiatric emergency. case presentations
No full textRecently, esketamine became availableas an intranasal formulation, proposed for treatment-resistant depression (TRD). Three cases of TRD are presented, two with features of a psychiatric emergency. The first case is a 35-year-old man with MDD onset at the age of 27 years, with five previous failed therapies. The second patient is a middle-aged man with a 21-year MDD onset and six previous antidepressant treatments discontinued for poor therapeutic effects and tolerability. He also presented suicidal ideation with intent and a history of a failed suicide attempt by self-cutting his forearms. The third case is a 28-year-old female with a first MDD episode in 2020, treated first with amitriptyline and then with intravenous clomipramine. She had a history of a previous suicide attempt by self-cutting and, by her admission, showed active suicidal ideation with intent. In all three cases, a rapid reduction of depressive symptoms was observed with a subsequent complete resolution of suicidal ideation and intent in the two patients with such risk. Intranasal esketamine treatment was carried out with concomitant oral antidepressant therapy. The third patient reported the only recorded side effect: dissociation 20 min after every esketamine administration. Our preliminary experience proved esketamine's effectiveness on TRD symptoms and successful outcomes in psychiatric emergencies such as suicide risk
Correction to “Photoelectrochemistry and Drift–Diffusion Simulations in a Polythiophene Film Interfaced with an Electrolyte”
Get PDF: Although the efficiency of organic polymer-based retinal devices has been proved, the interpretation of the working mechanisms that grant photostimulation at the polymer/neuron interface is still a matter of debate. To contribute solving this issue, we focus here on the characterization of the interface between poly(3-hexyltiophene) films and water by the combined use of electrochemistry and mathematical modeling. Simulations well reproduce the buildup of photovoltage (zero current condition) upon illumination of the working electrode made by a polymer film deposited onto an indium tin oxide (ITO) substrate. Due to the essential unipolar transport in the photoexcited film, diffusion leads to a space charge separation that is responsible for the initial photovoltage. Later, electron transfer reactions toward oxygen in the electrolyte extract negative charge from the polymer. In spite of the simple model studied, all of these considerations shed light on the possible coupling mechanisms between the polymeric device and the living cell, supporting the hypothesis of pseudocapacitive coupling
Sintesi di materiale ibrido a base di PVAL e ossido di titanio idrato per applicazioni fotoniche
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