1,938 research outputs found

    Metodologie innovative per il supporto alla progettazione e all’analisi delle prestazioni di impianti ad energia solare a concentrazione ed eolici off-shore utilizzando immagini satellitari ottiche e SAR

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    In questo lavoro presentiamo delle nuove metodologie, sviluppate nell’ambito del progetto SATENERG (Servizi sATellitari per le ENergie Rinnovabili di nuova Generazione) finanziato dall’Agenzia Spaziale Italiana, sia per il supporto alla progettazione/pianificazione che per il monitoraggio quasi in tempo reale e l’analisi delle prestazioni degli impianti ad energia rinnovabile di nuova generazione (CSP, CPV ed eolici off-shore) utilizzando immagini satellitari. In particolare per quanto riguarda gli impianti solari a concentrazione (CSP e CPV), abbiamo sviluppato un metodo per ricavare l’irradianza solare incidente al suolo (in particolare la sua componente diretta normale rispetto ai raggi solari, fondamentale per questo tipo di impianti) da immagini ottiche satellitari. Ciò, unito ad un modello di funzionamento di tali impianti e degli inverter, ci ha resi in grado di poter sviluppare un servizio di supporto nella progettazione e pianificazione di nuove costruzioni di impianti CSP e CPV (analizzando serie storiche di dati satellitari) ed anche un servizio di monitoraggio e analisi delle prestazioni per quelli già esistenti (usando invece immagini satellitari quasi in tempo reale). In maniera simile, usando immagini SAR (Synthetic Aperture Radar), abbiamo sviluppato un metodo per ricavare l’intensità e la direzione del vento in aree marine da remoto che ci ha permesso, utilizzando anche un modello di impianto eolico off-shore (turbina e inverter), di sviluppare sia un servizio di supporto alla progettazione/pianificazione che un servizio di monitoraggio quasi in tempo reale della produzione di un impianto eolico off-shore. Le prime applicazioni di queste nuove metodologie hanno già portato ad avere ottimi risultati in vari casi di prova sia per quanto concerne il monitoraggio dell’irradianza diretta su piano normale, in cui l’irradianza misurata e quella ricavata da dato satellitare non si sono discostate più del 10%, sia per quanto riguarda il calcolo dell’intensità e direzione del vento da immagini SAR, in cui l’errore rispetto al dato misurato è rimasto al di sotto del 15%, fornendo quindi una buona base per il monitoraggio della energia AC prodotta dagli impianti.In this work we present new methodologies aimed to support both planning and near-real-time monitoring of new generation solar and wind energy plants (CSP, CPV and wind off-shore) using satellite imagery. Such methodologies are currently being developed in the scope of SATENERG, a project funded by ASI (Italian Space Agency). In particular, for what concerns the concentrating solar energy plants (CSP and CPV) we developed a method to calculate solar irradiance at ground (and its direct normal component, that has primary importance in this type of plants) starting from satellite optical images. Then, using also detailed opto-electronic models of the plants and inverters, we are able to calculate the producible energy, which can be used to support either the design of potential plants (using historical series of satellite images) or the monitoring and performance analysis of existing plants (using near-real- time satellite imagery). Producible energy and other interesting parameters, like production efficiency, return on investment etc., are delivered through dedicated web services. In a similar way, we developed also a method to calculate the intensity and the direction of off-shore wind from satellite SAR (Synthetic Aperture Radar) images that permitted us, together with detailed models of wind turbine and inverters, to develop a new service in support to both planning and near-real-time monitoring activities of off-shore wind plants. The first applications of these methods gave successful results in several test cases: we obtained a maximum error of 10% for satellite retrieved direct normal solar irradiance and a maximum error of 15% for wind direction and intensity calculated from SAR images (with respect to in-situ measured data)

    A method for characterizing the stability of light sources

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    We describe a method for measuring small fluctuations in the intensity of a laser source with a resolution of 10⁻⁴. The current signal generated by a PIN diode is passed to a front-end electronics that discriminates the AC from the DC components, which are physically separated and propagated along circuit paths with different gains. The gain long the AC signal path is set one order of magnitude larger than that along the DC signal path in such a way to optimize the measurement dynamic range. We then derive the relative fluctuation signal by normalizing the input-referred AC signal component to its input-referred DC counterpart. In this way the fluctuation of the optical signal waveform relative to the mean power of the laser is obtained. A "Noise-Scattering-Pattern method" and a "Signal-Power-Spectrum method" are then used to analyze the intensity fluctuations from three different solid-state lasers. This is a powerful tool for the characterization of the intensity stability of lasers. Applications are discussed

    Agronomic and Environmental Benefits of Cover Crops in Northern Italy

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    Cover crops have a number of benefits (reduction of nitrate leaching and of soil erosion, control of weed seed bank, increase of soil organic matter and increase of cash crop yield), but these were seldom quantified in cropping systems of Northern Italy. This experiment aimed to quantify some of these effects, by comparing cover crop species and their management techniques

    Far-field spectral characterization of conical emission and filamentation in Kerr media

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    By use of an imaging spectrometer we map the far-field (θ−λ\theta-\lambda) spectra of 200 fs optical pulses that have undergone beam collapse and filamentation in a Kerr medium. By studying the evolution of the spectra with increasing input power and using a model based on stationary linear asymptotic wave modes, we are able to trace a consistent model of optical beam collapse high-lighting the interplay between conical emission, multiple pulse splitting and other effects such as spatial chirp.Comment: 8 pages, 9 figure

    Características clínicas e epidemiológicas do câncer da boca em hospital-escola de 1994 a 2002: aumento da incidência em mulheres, predomínio de doença local avançada e baixa incidência de metástases regionais

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    PURPOSE: Description of clinical and epidemiological characteristics of patients who underwent surgery for oral cancer in a Medical School Teaching Hospital, and determination of differences with respect to other institutions and/or periods of time. METHOD: The charts of patients undergoing surgery for oral cancer from 1994 to 2002 were reviewed. Data were collected in a spreadsheet in order to analyze clinical and epidemiological features.. RESULTS: A total of 374 patients having undergone 406 operations was identified. Their ages varied from 14 to 94 years (mean = 57.4 years), with 255 men (68.2%), and 295 out 366 Caucasian (80.6%). A majority had tumors of the tongue and/or floor of mouth (55.6%), while 20.3% had lip cancer. Squamous cell carcinoma was found in 90.3%, and glandular carcinoma in 4%. T4 tumors in 39.6%, Tis or T1 lesions in 15.2% of all patients. Nearly 62% had no regional metastases, and the relative incidence in young patients (40 years or younger) reached 8.6%. CONCLUSION: In spite of the predominance of locally advanced tumors, a majority of patients had no neck metastases. The 31.8% incidence in females indicates an increasing incidence of oral cavity cancer among women when compared to previous periods at the same institution.OBJETIVO: Caracterizar epidemiológica e clinicamente a população atendida por câncer de boca em hospital-escola de atenção terciária e quaternária e verificar variações em relação a outras casuísticas e períodos. MÉTODO: Procedeu-se à revisão dos prontuários dos operados por câncer oral de 1994 a 2002. As características clínicas e epidemiológicas foram colocadas em planilhas e analisadas. RESULTADOS: Foram identificados 374 portadores de câncer da boca que foram submetidos a 406 operações. A idade dos doentes variou de 14 a 94 anos (média = 57,4 anos). Duzentos e cinqüenta e cinco eram do gênero masculino (68,2%). Duzentos e noventa e cinco entre 366 doentes eram caucasianos (80,6%). A maioria era portadora de tumores da língua e/ou do soalho da boca (194 entre 349 doentes; 55,6%), e 71 (20,3%) tinham tumores dos lábios. O carcinoma epidermóide foi encontrado em 90,3% e carcinomas glandulares em 4%. Os tumores T4 estavam presentes em 39,6% dos doentes; 15,2% tinham lesões Tis ou T1. Quase 62% dos pacientes não tinham metástases cervicais. A incidência relativa em jovens (com até 40 anos de idade) atingiu 8,6%. CONCLUSÃO: Apesar dos achados freqüentemente referidos na literatura terem se confirmado (como o predomínio de lesões avançadas localmente), a maioria dos doentes não apresentava metástases cervicais. Acima do observado em outras casuísticas, os 31,8% de mulheres na presente casuística indica a preocupante e crescente incidência no gênero feminino

    Genetic PTX3 deficiency and aspergillosis in stem-cell transplantation

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    BACKGROUND: The soluble pattern-recognition receptor known as long pentraxin 3 (PTX3) has a nonredundant role in antifungal immunity. The contribution of single-nucleotide polymorphisms (SNPs) in PTX3 to the development of invasive aspergillosis is unknown. METHODS: We screened an initial cohort of 268 patients undergoing hematopoietic stem-cell transplantation (HSCT) and their donors for PTX3 SNPs modifying the risk of invasive aspergillosis. The analysis was also performed in a multicenter study involving 107 patients with invasive aspergillosis and 223 matched controls. The functional consequences of PTX3 SNPs were investigated in vitro and in lung specimens from transplant recipients. RESULTS: Receipt of a transplant from a donor with a homozygous haplotype (h2/h2) in PTX3 was associated with an increased risk of infection, in both the discovery study (cumulative incidence, 37% vs. 15%; adjusted hazard ratio, 3.08; P=0.003) and the confirmation study (adjusted odds ratio, 2.78; P=0.03), as well as with defective expression of PTX3. Functionally, PTX3 deficiency in h2/h2 neutrophils, presumably due to messenger RNA instability, led to impaired phagocytosis and clearance of the fungus. CONCLUSIONS: Genetic deficiency of PTX3 affects the antifungal capacity of neutrophils and may contribute to the risk of invasive aspergillosis in patients treated (Funded by the European Society of Clinical Microbiology and Infectious Diseases and others) .with HSCT.Supported by grants from the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) (to Dr. Carvalho); the German Ministry for Education and Science (03Z2JN21, to Dr. Kurzai); the European Commission (FP7-HEALTH-2009-260338, to Dr. Romani; FP7-HEALTH-2011-280873, to Dr. Mantovani), the European Research Council (ERC-2008-AdG-233417, to Dr. Mantovani; ERC-2011-AdG-293714, to Dr. Romani), Associazione Italiana per la Ricerca sul Cancro (99629, to Dr. Mantovani); and Fundacao para a Ciencia e Tecnologia, Portugal (SFRH/BPD/46292/2008, to Dr. Carvalho; SFRH/BD/65962/2009, to Dr. Cunha; and SFRH/BPD/70783/2010, to Dr. Almeida)
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