444 research outputs found
Analysis and design of a Current-Fed Dual Half-Bridge Converter
openIn this thesis the Current-Fed Dual-Half Bridge (CFDHB) converter has
been presented and studied under three degrees of freedom. This is an
isolated bidirectional converter useful in a lot of applications
characterized by sources and/or loads that benefit from a smooth
input/output current. A design methodology has been proposed which
reduces the RMS current in all devices and guarantees the soft
commutations of all switches in a wide range of operating points.
Finally, simulation and experimental verification complete the work.In this thesis the Current-Fed Dual-Half Bridge (CFDHB) converter has
been presented and studied under three degrees of freedom. This is an
isolated bidirectional converter useful in a lot of applications
characterized by sources and/or loads that benefit from a smooth
input/output current. A design methodology has been proposed which
reduces the RMS current in all devices and guarantees the soft
commutations of all switches in a wide range of operating points.
Finally, simulation and experimental verification complete the work
Redefining gender in the Jazz Age: the women of "The Great Gatsby".
openNe "Il Grande Gatsby" (1925) di Francis Scott Fitzgerald, i tre principali personaggi femminili incarnano diverse versioni della cosiddetta Nuova Donna, un'icona femminile sovversiva nata durante il dopoguerra, come risultato della rivoluzione morale degli anni '20. La Nuova Donna contribuĂŹ ad offuscare i confini tra i generi maschile e femminile mostrando una figura androgina e vivendo uno stile di vita spensierato e materialistico, che rifletteva perfettamente la cultura di massa consumistica dell'EtĂ del Jazz degli anni '20. Nonostante le donne cominciassero a rivendicare la loro indipendenza e ottenere un certo grado di potere nel campo dominato dagli uomini, erano ancora relegate in una sfera subordinata, vittime di una mentalitĂ patriarcale. Oltre ai conflitti di genere, all'interno del romanzo l'autore rispecchia la rigida scala socio-economica su cui si basava la societĂ americana, una gerarchia inflessibile che non risparmiava nessuno. Di fatto, nonostante la modernizzazione della societĂ , la nazione rimase profondamente disomogenea dal momento che il genere femminile, trattato come "altro", le minoranze razziali e le classi inferiori lavoratrici subivano ancora ingiustizie e disparitĂ .In Francis Scott Fitzgeraldâs The Great Gatsby (1925), the three main female characters embody different versions of the so-called New Woman, a subversive female icon who was born during the post-war era, as a result of the 1920s revolution in manners and morals. The New Woman contributed to blurring the boundaries between the male and female genders by displaying an androgynous figure and living a carefree, materialistic lifestyle, which perfectly reflected the consumeristic mass culture of the 1920s Jazz Age. Despite the fact that women started to claim their independence and gain a certain degree of power in the male-dominated field, they were still relegated to a subordinate sphere, victims of a patriarchal mindset. In addition to the gender conflicts, within the novel the author mirrors the socio-economic rigid scale the American society was based on, an inflexible hierarchy that spared no one. As a matter of fact, in spite of the modernization of society, the nation remained deeply unequal since the female gender, treated as âotherâ, racial minorities and the working lower classes still suffered injustices and disparities
Burning, dumping, and site use during the Middle and Upper Palaeolithic at Hohle Fels Cave, SW Germany
Dumped deposits are a valuable source of information for inferring past behaviour. They provide insights into site maintenance, social organization and settlement dynamics. Hohle Fels Cave in SW Germany offers a unique opportunity to investigate the importance of dumping and site maintenance during the Middle and Upper Palaeolithic of the Swabian Jura. In this paper, we analyse anthropogenic deposits at Hohle Fels employing micromorphology and fabric analysis in order to reconstruct their formation and understand the human behaviours behind their accumulation. Our study indicates that dumping residues from combustion features in the interior of Hohle Fels Cave has a long history extending back to Neanderthal occupation at the site during the Middle Palaeolithic. Despite some reworking via down-slope movement, most of the features demonstrate that the siteâs inhabitants dumped burnt material, which was previously the fuel for domestic hearths, in specific locations within the cave. The intentionality of the action and the characteristics of the features provide important information for reconstructing the mode and spatial organization of occupations at the site. The combustion features from the Middle Palaeolithic allow us to reassess the hypothesis that Neanderthalsâ use of the site was less intense and documented a lesser degree of spatial patterning than subsequent Upper Palaeolithic occupations. This research also provides insight for examining the regional variability of pyrotechnology and site maintenance during the Middle and Upper Palaeolithic.publishedVersio
PROPERTIES OF COMPOUND NUCLEUS FROM EXPERIMENTAL MEASUREMENT OF THE Si28 (n,α) Mg25 REACTION. EUR 416.e
Studio e progettazione di un intervento di rinnovo tecnologico di sottostazione elettrica (SSE) ferroviaria di conversione
L'elaborato fornisce lo studio di una ignota sottostazione elettrica ferroviaria di conversione per la trazione elettrica alla tensione di 3 kVcc, sottoposta ad un intervento di rinnovo tecnologico con finalitĂ di risolvere i problemi emersi durante il suo esercizio attraverso un'analisi e una progettazione secondo le normative vigenti.ope
Fire and Beyond: a Geoarchaeological Analysis of the Anthropogenic Features from Fumane Cave (NE Italy) and Hohle Fels (SW Germany)
Anthropogenic features provide direct evidence of human activities that took place during
the occupation of a site and as such are valuable sources of information for inferring past
behaviour. Their identification and interpretation is essential for archaeological research,
and geoarchaeology has the potential to unravel their nature and place them into context.
One of the main goals in the analysis of archaeological features is to investigate the
relationship between humans and fire. A major issue in the investigation of human
evolution and pyrotechnology is that fire and the ability to produce it are seen by some as
one of the primary characteristics that distinguish modern humans from Neanderthals.
Around this main debate, other threads open up. In fact, features like hearths can also
provide insights into site maintenance, social organization, and settlement dynamics.
Here I investigate the anthropogenic features from two important Palaeolithic caves in
Europe, Fumane Cave (IT) and Hohle Fels (DE). Both sites cover the transition from the
Middle to Upper Palaeolithic, providing the unique opportunity to explore Neanderthal and
modern human settlements. First, I analysed the thin sections using micromorphology to
understand the nature of the features and their link to human activities. Second, I obtained
complete information by applying complementary analyses to selected samples. Third, I
executed experimental work on burning bones in a controlled environment to understand
better changes in bones heated at low temperatures.
The results show a diverse set of anthropogenic features such as hearths, hearth bases,
dumps, occupational horizons and laminated/trampled surfaces. Their presence reflects
different activities, including combustion and site maintenance/use, carried out by humans
within the site. Further, I infer fuel choice, occupation of sites and the mobility of the groups
that inhabited them. Fumane Cave and Hohle Fels appear as a complex system of human
behaviour based on a close relationship with the surrounding landscape. Finally,
experimentation on charred bones reveals the potential of organic petrology in
investigating fat-derived char and determining a range of combustion temperatures.
This dissertation shows the importance of a micro-contextual approach within
archaeological research, the potential of the investigation of anthropogenic features to reconstruct past human activities, and the need to consider them part of the cultural
material. An anthropogenic feature is comparable to many other artefacts and must be
treated as such to gain information on both natural processes and human behaviour
DEVELOPMENT OF MOUSE MODELS OF ORAL SQUAMOUS CELL CARCINOMA (OSCC) METASTASIS FOR THE EVALUATION OF EMERGING ANTI-METASTATIC NANOMEDICINE DRUGS
Oral Squamous Cell Carcinoma (OSCC) is included in the Head and Neck Squamous Cell Carcinoma (HNSCC) group, which is the sixth most common cancer diagnosed worldwide. While the locoregional control has been increased thanks to the combination therapy, the incidence of distant metastasis is increasing. Nanomedicine therapies have been clinically approved for the treatment of several types of cancers and were used in few clinical trials on HNSCC patients. However, the efficacy of nanomedicine therapies was limited, especially for the treatment of metastatic OSCC. In the preclinical setting, more advanced nanomedicine platforms have been developed against metastatic cancers. One of this platform, iNPG-pDox, obtained promising results against lung metastasis in a preclinical model of breast cancer. The lungs are the most common site of distant metastasis reported in OSCC and there is an unmet need for novel therapies targeting distant metastasis. The aim of the present work was to establish two preclinical models of OSCC lung metastasis by orthotopic and tail vein injection of OSCC cells and to perform preliminary in vitro evaluations of pDox nanoparticles in two cell lines of metastatic OSCC (HSC-3 and HSC-3 M1, isolated from HSC- 3 lung metastases). In vitro, pDox nanoparticles were able to effectively kill both HSC-3 and HSC-3 M1 cells, without any significant difference between the two cell lines. In vivo, lung metastases of OSCC were observed in both preclinical models. In particular, the orthotopic model also developed regional lymph node metastases, characteristic of metastatic growth observed in OSCC patients. The other model obtained by tail vein injection presented only lung metastases. Therefore, orthotopic models should be preferred to non-orthotopic models for the preclinical evaluation of anti-metastatic nanomedicine therapies such as iNPG-pDox in OSCC. Moreover, such preclinical model of OSCC lung metastasis may be used to investigate the molecular mechanisms of OSCC regional and distant metastasis, which are still poorly understood
Physicochemical properties of some honeys produced from different plants in Morocco
Abstract Seventy-three Moroccan honey samples were collected between 2005 and 2008. In this study, water content, pH, acidity (free, lactone and total acidity), electrical conductivity (EC), colour, diastase, hydroxymethylfurfural (HMF) and sugar content were all determined in different types of bee honey which include multifloral, honeydew and nine types of unifloral honeys ( Euphorbia resinifera , Euphorbia echinus , Citrus , eucalyptus, carob, thyme, lavender, Ziziphus and rosemary). The moisture shows values of 14.3% and 20.2%, pH between 3.52 and 5.13, the total acidity ranges between 11.94 and 58.03 meq kg â1 , hydroxymethylfurfural (HMF) content shows values between 0.09 and 53.38 mg kg â1 ; diastase values were between 4.3° and 24.6° Gothe; electrical conductivity between 119.9 and 1741 ÎŒs cm â1 and fructose, glucose and sucrose values range between 35.07â46.26%, 23.7â39.3% and 0.42â2.98%. A statistical analysis was carried out to classify 10 types of honeys, and identified the most significant parameters, using analysis of variance, principal component analysis (PCA) and stepwise discriminant analysis (SDA). PCA showed that the cumulative variance was 74.97% and about 88.9% of samples was correctly classified. The principal aim of this study was to contribute more to the knowledge of the Moroccan honeys by means of the analysis of chemical composition and of physical parameters. Seventy-three Moroccan unifloral, multifloral and honeydew honey samples, including types that have never been studied before, produced in different regions in Morocco ( Table 1 , Table 2 ), were analysed to define its main features. As a consequence, we present data on water content, electrical conductivity, pH, free acidity, lactone acidity, total acidity, diastase, 5-(hydroxymethyl)-2-furaldehyde (HMF) amounts, fructose, glucose and sucrose
PIXE and ToF-SIMS analysis of streaker samplers filters
This paper presents methodological innovations introduced in the characterisation of urban aerosol collected in Italy in a recent campaign. Two complementary ion beam analysis (IBA) techniques were used to analyse Nuclepore filters used in continuous streaker samplers to collect airborne particles in four Italian towns. Na to Pb elemental concentrations were obtained by particle induced X-ray emission (PIXE), while time of flight secondary ion mass spectrometry (ToF-SIMS) produced, on the same samples, time trends for several elements and molecular fragments. In addition, light attenuation measurements were used as a tracer for black carbon. The data produced by these three techniques was merged into a unique data set to address the characterisation of particulate matter sources. Correlations between elemental concentration trends (PIXE) and relative trends for molecular fragments (ToF-SIMS) and black carbon (light attenuation) have been studied by cluster and principal component analysis
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