68 research outputs found
DEVELOPMENT OF NEW HIGHLY CONJUGATED MOLECULES AND THEIR APPLICATION IN THE FIELD OF RENEWABLE ENERGY AND BIOMATERIALS
No full textNegli ultimi anni, i materiali funzionalizzati ibridi hanno iniziato ad essere largamente impiegati in applicazioni altamente tecnologiche, dai sensori bio/medicali alla produzione di energie rinnovabili. Per questa ragione sono diventati l’oggetto di diversi studi nell’ambito della scienza dei materiali. Allo
stesso tempo, le molecole organiche coniugate sono state intensivamente analizzate per via delle loro proprietà particolari riconducibili alla presenza di un lungo sistema di legami π, dalla possibilità di condurre elettricità al loro largo spettro di assorbimento della radiazione luminosa. Questo lavoro di
tesi si è concentrato sull’introduzione di questi sistemi all’interno di due tipi di materiali ibridi, dei dispositivi fotovoltaici per la produzione di elettricità (in particolare delle celle solari sensibilizzate a coloranti) e di carburanti alternativi (idrogeno), e degli idrogel biocompatibili sensibili agli stimoli (capaci
di condurre elettricità e di reagire a stimoli luminosi), ed inoltre sullo studio della loro influenza sulle caratteristiche del materiale finale.In recent years hybrid functional materials began to be employed in a series of technologically advanced applications spanning from bio/medical sensors, to renewable energy generation. For this reason, they became the focus of several studies in the field of materials science. At the same time, conjugated molecules have also been intensively investigated, due to the properties arising by the presence of long π-conjugated systems, from the possibility to conduct electricity to the ability to absorb light in a wide range of wavelengths. This PhD work focused on the introduction of such systems in two different kinds of hybrid materials, namely photovoltaic devices for the production of electricity (in particular Dye Sensitzed Solar Cells) and alternative fuels hydrogen), and biocompatible stimuli-responsive hydrogels (capable to conduct electricity and to react upon irradiation), and on the study of their influence on the characteristics of the final material.Ces dernières années, les matériaux fonctionnels hybrides ont commencé à être employés pour des applications de la haute technologie, allant des senseurs bio/médicaux, à la production d’énergie renouvelable. Pour cette raison, ils sont devenus le centre de plusieurs études dans le domaine des
sciences des matériaux. Simultanément, des molécules conjuguées ont été examinée intensément à cause de leurs propriétés venant de leurs longs systèmes π, allant de la possibilité de conduire l’électricité, à leur capacité d’absorber la lumière dans une grande fenêtre spectrale. Le travail de cette
thèse se concentre sur l’introduction de tels systèmes dans deux sortes de matériaux hybrides, les dispositifs photovoltaïques pour la production d’électricité (en particuliers les cellules solaires à pigment photosensible) et de carburants alternatifs (hydrogène), et pour les hydrogels biocompatibles
sensibles aux stimuli (capables de conduire l’électricité et de réagir sous irradiation), et sur l’étude de leur influence sur les caractéristiques du matériau final
Modelling the Archipelago: Corfu as a Case Study for a Digital Edition of Cristoforo Buondelmonti’s Liber Insularum
No full textThe Liber Insularum by Cristoforo Buondelmonti can be considered the first guide to the Greek islands, each of them described by a textual paragraph and illustrated by color maps, in a format which gave rise to the new literary genre of Isolaria.” Mapping the Aegean: Cristoforo Buondelmonti’s Liber Insularum” is a Marie Skłodowska-Curie project aimed at the study of this book. This paper illustrates the application of Cadmus, a structured content management tool, to the creation of a digital edition of the Liber and to do this, we focus on the text and map of Corfu as a case study. After a historical introduction on the author and his work and the presentation of the project, we explain why we chose to use this tool and its main characteristics, and we offer a concrete example of its application to the material pertaining to the description of Corfu by showing its frontend output
Towards Sustainable H2Production: Rational Design of Hydrophobic Triphenylamine-based Dyes for Sensitized Ethanol Photoreforming
No full textDonor–acceptor dyes are a well-established class of photosensitizers, used to enhance visible-light harvesting in solar cells and in direct photocatalytic reactions, such as H2 production by photoreforming of sacrificial electron donors (SEDs). Amines—typically triethanolamine (TEOA)—are commonly employed as SEDs in such reactions. Dye-sensitized photoreforming of more sustainable, biomass-derived alcohols, on the other hand, was only recently reported by using methanol as the electron donor. In this work, several rationally designed donor–acceptor dyes were used as sensitizers in H2 photocatalytic production, comparing the efficiency of TEOA and EtOH as SEDs. In particular, the effect of hydrophobic chains in the spacer and/or the donor unit of the dyes was systematically studied. The H2 production rates were higher when TEOA was used as SED, whereas the activity trends depended on the SED used. The best performance was obtained with TEOA by using a sensitizer with just one bulky hydrophobic moiety, propylenedioxythiophene, placed on the spacer unit. In the case of EtOH, the best-performing sensitizers were the ones featuring a thiazolo[5,4-d]thiazole internal unit, needed for enhancing light harvesting, and carrying alkyl chains on both the donor part and the spacer unit. The results are discussed in terms of reaction mechanism, interaction with the SED, and structural/electrochemical properties of the sensitizers
Acute Symptomatic Sinus Bradycardia in High-Dose Methylprednisolone Therapy in a Woman With Inflammatory Myelitis: A Case Report and Review of the Literature
No full textHigh dose corticosteroid therapy is widely used as attack therapy of inflammatory central nervous system disorders and can induce several adverse reactions. Bradycardia is an infrequent event after corticosteroids administration and is often asymptomatic. We report a case of a woman admitted to the neurological department of our hospital for paraesthesias of the lower limbs. She received adiagnosis of inflammatory myelitis and high dose corticosteroid therapy was prescribed. During the therapy she complained of chest tightness, dyspnoea, weakness and malaise. An electrocardiogram revealed sinus bradycardia. A significant increase in body weight, probably due to plasma volume expansion, was detected. Bradycardia and high blood pressure spontaneously resolved in few days. We provide a collection and a statistical analysis of literature data about steroid induced bradycardia. We found that higher total doses are associated with lower pulse rate and symptomatic bradycardia. Bradycardia is more frequent in older patients and those with underlying cardiac disease or with autonomic disturbance. However clinicians must be aware about the occurrence of symptomatic bradycardia in all patients who undergo high dose corticosteroid therapy, not only in those at risk, to early detect and treat this potentially dangerous condition
Validation and performance analysis of a parallel ported code for simulating the effects of lightning strokes on telecommunication buildings
No full textThe Artemis subproject, in the framework of the UE Capri project, deals with porting on parallel architectures of a Method of Moment (MoM) code for electromagnetic design and hardening of telecommunication centres against the effects of lightning strokes. After a preliminary stage of the work during which QR and LU algorithms for large complex matrix inversion were implemented both on Alenia's Quadrics (SIMD) and Cray T3D (MIMD) platforms, in order to choose the best suitable machine for such a kind of problem, the code has been ported on the last one. In this paper the parallel code validation and the performance improvement analysis with respect to the sequential one will be reported and discussed. © 1997 Springer-Verlag Berlin Heidelberg
Développement de nouvelles molécules hautement conjuguées et leurs applications dans le domaine des énergies renouvelables et des biomatériaux
No full textIn recent years hybrid functional materials began to be employed in a series of technologically advanced applications spanning from bio/medical sensors, to renewable energy generation. For this reason, they became the focus of several studies in the field of materials science. At the same time, conjugated molecules have also been intensively investigated, due to the properties arising by the presence of long π-conjugated systems, from the possibility to conduct electricity to the ability to absorb light in a wide range of wavelengths. This PhD work focused on the introduction of such systems in two different kinds of hybrid materials, namely photovoltaic devices for the production of electricity (in particular Dye Sensitzed Solar Cells) and alternative fuels (hydrogen), and biocompatible stimuli-responsive hydrogels (capable to conduct electricity and to react upon irradiation), and on the study of their influence on the characteristics of the final material.Ces dernières années, les matériaux fonctionnels hybrides ont commencé à être employés pour des applications de la haute technologie, allant des senseurs bio/médicaux, à la production d’énergie renouvelable. Pour cette raison, ils sont devenus le centre de plusieurs études dans le domaine des sciences des matériaux. Simultanément, des molécules conjuguées ont été examinée intensément à cause de leurs propriétés venant de leurs longs systèmes π, allant de la possibilité de conduire l’électricité, à leur capacité d’absorber la lumière dans une grande fenêtre spectrale. Le travail de cette thèse se concentre sur l’introduction de tels systèmes dans deux sortes de matériaux hybrides, les dispositifs photovoltaïques pour la production d’électricité (en particuliers les cellules solaires à pigment photosensible) et de carburants alternatifs (hydrogène), et pour les hydrogels biocompatibles sensibles aux stimuli (capables de conduire l’électricité et de réagir sous irradiation), et sur l’étude de leur influence sur les caractéristiques du matériau final
Progetto di un Palazzetto dello Sport nel Comune di Carrara
No full textDurante il lavoro di tes si sono studiate le piante della struttura la disposizione interna degli spazi e soprattutto la copertura della struttura con i relativi particolari costruttivi
Synthesis of Silatrane-Containing Organic Sensitizers as Precursors for Silyloxyl Anchoring Group in Dye Sensitized Solar Cells
No full textA series of organic D-π-A dyes, endowed with different silicon-based anchoring groups, has been prepared to assess the stability of such anchoring moieties on nanocrystalline TiO 2 in dye-sensitized solar cells. Due to the difficulties encountered in finding a reliable and robust preparation protocol to obtain pure trialkoxysilanes, replacement with a silatrane moiety was evaluated. It was found that the silatrane group could be easily introduced on three different molecular scaffolds by using a simple amide coupling reaction mediated by EDC-Cl. Furthermore, the spectroscopic properties and anchoring mode on nanocrystalline TiO 2 of the silatrane dyes were found to be nearly identical to those of the trialkoxysilane compounds, and both gave a much more stable attachment to the semiconductor compared with their cyanoacrylic acid counterpart, as shown by desorption experiments
Photoinduced excitation and charge transfer processes of organic dyes with siloxane anchoring groups: a combined spectroscopic and computational study
No full textDye-sensitized solar cells (DSSCs) have attracted significant interest in the last few years as effective low-cost devices for solar energy conversion. We have analyzed the excited state dynamics of several organic dyes bearing both cyanoacrylic acid and siloxane anchoring groups. The spectroscopic properties of the dyes were studied both in solution and when adsorbed on a TiO2 film using stationary and time-resolved techniques, probing the sub-picosecond to nanosecond time interval. The comparison between the spectra registered in solution and on the solid substrate evidences different pathways for the energy and electron relaxation. The transient spectra of the TiO2-adsorbed dyes show the appearance of a long wavelength excited state absorption band, attributed to the cationic dye species, which is absent in the spectra measured in solution. Furthermore, the kinetic traces of the samples adsorbed on TiO2 film show a long decay component not present in solution which constitutes an indirect evidence of electron transfer between the dye and the semiconductor. The interpretation of the experimental results has been supported by theoretical DFT calculations of the excited state energies and by the analysis of molecular orbitals of the analyzed dye molecules
Cardiac Tumors: Diagnosis, Prognosis, and Treatment
No full textCardiac masses frequently present significant diagnostic and therapeutic clinical challenges and encompass a broad set of lesions that can be either neoplastic or non-neoplastic. We sought to provide an overview of cardiac tumors using a cardiac chamber prevalence approach and providing epidemiology, imaging, histopathology, diagnostic workup, treatment, and prognoses of cardiac tumors
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