7 research outputs found
Selection, Identification and Functional Performance of Ammonia-Degrading Microbial Communities from an Activated Sludge for Landfill Leachate Treatment
Get PDFThe increasing amounts of municipal solid waste and their management in landfills caused an increase in the production of leachate, a liquid formed by the percolation of rainwater through the waste. Leachate creates serious problems to municipal wastewater treatment plants; indeed, its high levels of ammonia are toxic for bacterial cells and drastically reduce the biological removal of nitrogen by activated sludge. In the present work, we studied, using a metagenomic approach based on next-generation sequencing (NGS), the microbial composition of sludge in the municipal wastewater treatment plant of Porto Sant’Elpidio (Italy). Through activated sludge enrichment experiments based on the Repetitive Re-Inoculum Assay, we were able to select and identify a minimal bacterial community capable of degrading high concentrations of ammonium (NH4+-N ≅ 350 mg/L) present in a leachate-based medium. The analysis of NGS data suggests that seven families of bacteria (Alcaligenaceae, Nitrosomonadaceae, Caulobacteraceae, Xanthomonadaceae, Rhodanobacteraceae, Comamonadaceae and Chitinophagaceae) are mainly responsible for ammonia oxidation. Furthermore, we isolated from the enriched sludge three genera (Klebsiella sp., Castellaniella sp. and Acinetobacter sp.) capable of heterotrophic nitrification coupled with aerobic denitrification. These bacteria released a trace amount of both nitrite and nitrate possibly transforming ammonia into gaseous nitrogen. Our findings represent the starting point to produce an optimized microorganisms’s mixture for the biological removal of ammonia contained in leachate
Entre « raisons » et expériences. Les mathématiques pratiques et leurs interprètes : livres d'abaque et abacistes au XVe siècle
No full textCette thèse se situe à l'intersection de différents domaines de recherche et de méthodologie historique : l'histoire de la culture et de l'école, abordée sous l'angle de la diffusion des connaissances mathématiques, véhiculées par les traités d'abaque et dans les institutions éducatives spécialisées, telles que les écoles d'abaque ; l'histoire sociale, avec une référence particulière à l'histoire professionnelle et familiale des abacistes (maîtres et non-maîtres), qui ont appris et pratiqué ces connaissances à travers la rédaction de livres d'abaque ; l'histoire monétaire et mathématique, explorée via l'analyse des techniques de calcul et des données monétaires, issues des textes mathématiques examinés. L'objectif de la recherche était l'étude et la reconstruction des caractéristiques, des mécanismes de production et de circulation des traités d'abaque (ou abaci), en particulier des manuscrits rédigés au XVe siècle, période à laquelle - comme le montrent le catalogue de Warren Van Egmond et les travaux plus récents de Raffaele Danna - la production des abaci a atteint son apogée en Italie, s'étendant à la France, l'Allemagne et l'Espagne. Grâce à la définition d'un échantillon de livres principalement toscans (la majorité des abaci du XVe siècle étant toscans, et en particulier florentins), un examen comparatif des contenus mathématiques a été effectué. Cet examen révèle ainsi des affinités et des divergences révélatrices des différentes approches et instances culturelles qui ont présidé à la compilation des abaci. À travers cette double perspective, nous avons exploré les techniques de calcul et les applications pratiques (commerciales, algébriques et géométriques) que l'on retrouve dans les manuscrits, en les replaçant dans le contexte plus large des écoles de calcul et des pratiques éducatives de l'époque, et en apportant un éclairage nouveau sur les processus d'alphabétisation et de professionnalisation qui ont accompagné l'expansion des connaissances mathématiques en Europe. La recherche s'est donc concentrée sur les responsables de la transmission des connaissances mathématiques à la fin du Moyen Âge : les abacistes, entendus au sens large : non seulement les maîtres d'abaque mais aussi les simples compilateurs et transcripteurs de manuels à usage personnel (et familial). Une attention particulière a été accordée à la reconstitution des vicissitudes de trois personnalités : le marchand florentin Matteo di Niccolò Cerretani (1444-1519), rédacteur du « Libro di ragioni » du manuscrit Palatino Baldovinetti 229 de la Bibliothèque Nationale de Florence ; le frère mineur et maître d'abaque à Prato Mariotto di ser Giovanni Guiducci (1427-post 1496), auteur du « Libro d'arismetricha » conservé dans le fonds des Conventi Soppressi, codex J X 36 de laBibliothèque Nationale de Florence ; l'apothicaire faentin Giovanni Battista di Michele daSant'Eufemia († 1487), rédacteur du « Libro sopra arismetricha » et du « Rasone de perticha » dans le manuscrit Plimpton 195 de l'université Columbia à New York.This PhD thesis stands at the crossroads of various areas of historical methodology: the history of culture and education, examined in relation to the dissemination of mathematical knowledge through abacus treatises (abaci) and specialized educational institutions such as abacus schools; social history, with a particular focus on the professional and familial trajectories of abacists (both teachers and practitioners) who learned and applied this knowledge through the creation of abacus manuscripts; and monetary and mathematical history, explored through the analysis of computational techniques and monetary data derived from the mathematical texts under examination.The aim of the research was the study and reconstruction of the characteristics, production mechanisms and circulation of abacus treatises, with particular regard to the manuscript codices written during the 15th century; a period in which - as can be seen from Warren Van Egmond's catalogue and the more recent work of Raffaele Danna - the production of abaci reached its peak in Italy, spreading also to France, Germany and Spain. By defining a sample of manuscripts (19), predominantly Tuscan, a comparative analysis of their mathematical content revealed affinities and divergences. These variations reflect the diverse approaches and cultural influences that shaped the compilation of the abaci. The research therefore focused on the directors of the transmission of mathematical and computational knowledge at the end of the Middle Ages: the abacists, understood in the broadest sense: not only abacus masters but also simple compilers and transcribers of manuals for personal (and family) use. Through this dual perspective, we have explored the calculation techniques and practical applications (commercial, algebraic and geometric) found in the manuscripts, relating them to the broader context of abacus schools and educational practices of the period and shedding new light on the processes of literacy and professionalisation that accompanied the expansion of mathematical knowledge in Europe.Particular attention has been paid to the reconstruction of three figures: the Florentine merchant Matteo di Niccolò Cerretani (1444-1519), author of the "Libro di ragioni" preserved in codex Palatino Baldovinetti 229 at the Biblioteca Nazionale Centrale in Florence; the franciscan friar and abacus master, Mariotto di ser Giovanni Guiducci (1427-post 1496), author of the "Libro d'arismetricha" contained in codex Conventi Soppressi J X 36 at the same library; and the Faentine apothecary Giovanni Battista di Michele da Sant'Eufemia (†1487), author of the "Libro sopra arismetricha" and the "Rasone de perticha", preserved in codex Plimpton 195 at Columbia University in New York
FRA RAGIONI ED ESPERIENZE. LA MATEMATICA "PRATICA" E I SUOI INTERPRETI: LIBRI D'ABACO E ABACISTI NEL XV SECOLO.
No full textLa presente tesi dottorale si pone all’incrocio di diversi ambiti della ricerca e della metodologia storica: la storia della cultura e della scuola, approcciate in relazione alla diffusione di saperi matematici veicolati dalla trattatistica d’abaco e da agenzie educative specializzate come le scuole d’abaco; la storia sociale, con particolare riferimento alle vicende professionali e familiari di abacisti (maestri e non) che quei saperi hanno appreso e praticato attraverso la redazione di libri d’abaco; la storia monetaria e matematica, percorse mediante l’analisi di tecniche di calcolo e dati monetali desunti dai testi matematici presi in esame. Obiettivo della ricerca è stato lo studio e la ricostruzione delle caratteristiche, dei meccanismi di produzione e di circolazione della trattatistica d’abaco, con particolare riguardo ai codici manoscritti redatti nel corso del XV secolo; periodo in cui la produzione di abaci raggiunse il suo culmine in Italia, propagandosi anche in Francia, Germania e Spagna. Attraverso la definizione di un campione di libri (19) perlopiù toscani (essendo toscana, e particolarmente fiorentina, la maggior parte degli abaci quattrocenteschi), si è proceduto all’esame comparato dei contenuti matematici, rilevando così affinità e divergenze indicative delle diverse impostazioni e delle varie istanze culturali che presiedevano alla compilazione degli abaci. La ricerca si è quindi appuntata sui registi della trasmissione delle conoscenze matematiche e computistiche alla fine del medioevo: gli abacisti, intesi latamente: non soltanto maestri d’abaco ma anche “semplici” compilatori e trascrittori di manuali ad uso personale (e familiare). Tramite questa duplice prospettiva, abbiamo esplorato le tecniche di calcolo e le applicazioni pratiche (commerciali, algebriche e geometriche) presenti nei manoscritti, correlandole al più ampio contesto delle scuole d’abaco e delle pratiche educative del periodo e gettando nuova luce sui processi di alfabetizzazione e professionalizzazione che hanno accompagnato l’espansione della conoscenza matematica in Europa. Particolare attenzione è stata dedicata alla ricostruzione delle vicende di tre personalità: il mercante fiorentino Matteo di Niccolò Cerretani (1444-1519), autore del "Libro di ragioni" del codice Palatino Baldovinetti 229 della Biblioteca Nazionale Centrale di Firenze; il frate minore nonché maestro d’abaco a Prato Mariotto di ser Giovanni Guiducci (1427-post 1496), autore del "Libro d’arismetricha" del codice Conventi Soppressi J X 36 della Nazionale di Firenze; lo speziale faentino Giovanni Battista di Michele da Sant’Eufemia († 1487), estensore del "Libro sopra arismetricha" e della "Rasone de perticha" del codice Plimpton 195 della Columbia University di New York.The PhD thesis stands at the crossroads of various areas of historical methodology: the history of culture and education, examined in relation to the dissemination of mathematical knowledge through abacus treatises (abaci) and specialized educational institutions such as abacus schools; social history, with a particular focus on the professional and familial trajectories of abacists (both teachers and practitioners) who learned and applied this knowledge through the creation of abacus manuscripts; and monetary and mathematical history, explored through the analysis of computational techniques and monetary data derived from the mathematical texts under examination. The aim of the research was the study and reconstruction of the characteristics, production mechanisms and circulation of abacus treatises, with particular regard to the manuscripts written during the 15th century; a period in which the production of abaci reached its peak in Italy, spreading also to France, Germany and Spain. By defining a sample of manuscripts (19), predominantly Tuscan, a comparative analysis of their mathematical content revealed affinities and divergences. The research therefore focused on the actors of the transmission of mathematical and computational knowledge at the end of the Middle Ages: the abacists, understood in a broadest sense. Through this dual perspective, we have explored the calculation techniques and practical applications (commercial, algebraic and geometric) found in the manuscripts, relating them to the broader context of abacus schools and educational practices of the period and shedding new light on the processes of literacy and professionalisation that accompanied the expansion of mathematical knowledge in Europe. Particular attention has been paid to the reconstruction of three figures: the Florentine merchant Matteo di Niccolò Cerretani (1444-1519), author of the "Libro di ragioni" preserved in codex Palatino Baldovinetti 229 at the Biblioteca Nazionale Centrale in Florence; the franciscan friar and abacus master, Mariotto di ser Giovanni Guiducci (1427-post 1496), author of the "Libro d’arismetricha" contained in codex Conventi Soppressi J X 36 at the same library; and the Faentine apothecary Giovanni Battista di Michele da Sant’Eufemia (†1487), author of the "Libro sopra arismetricha" and the "Rasone de perticha", preserved in codex Plimpton 195 at Columbia University in New York.Cette thèse se situe à l'intersection de différents domaines de recherche et de méthodologie historique : l'histoire de la culture et de l'école, abordée sous l'angle de la diffusion des connaissances mathématiques, véhiculées par les traités d'abaque et dans les institutions éducatives spécialisées, telles que les écoles d'abaque ; l'histoire sociale, avec une référence particulière à l'histoire professionnelle et familiale des abacistes (maîtres et non-maîtres), qui ont appris et pratiqué ces connaissances à travers la rédaction de livres d'abaque ; l'histoire monétaire et mathématique, explorée via l'analyse des techniques de calcul et des données monétaires, issues des textes mathématiques examinés. L'objectif de la recherche était l'étude et la reconstruction des caractéristiques, des mécanismes de production et de circulation des traités d'abaque (ou abaci), en particulier des manuscrits rédigés au XVe siècle, période à laquelle la production des abaci a atteint son apogée en Italie, s'étendant à la France, l'Allemagne et l'Espagne. Grâce à la définition d'un échantillon de livres principalement toscans, un examen comparatif des contenus mathématiques a été effectué. La recherche s’est donc concentrée sur les responsables de la transmission des connaissances mathématiques à la fin du Moyen Âge : les abacistes, entendus au sens large. À travers cette double perspective, nous avons exploré les techniques de calcul et les applications pratiques (commerciales, algébriques et géométriques) que l'on retrouve dans les manuscrits, en les replaçant dans le contexte plus large des écoles de calcul et des pratiques éducatives de l'époque, et en apportant un éclairage nouveau sur les processus d'alphabétisation et de professionnalisation qui ont accompagné l'expansion des connaissances mathématiques en Europe. Une attention particulière a été accordée à la reconstitution des vicissitudes de trois personnalités : le marchand florentin Matteo di Niccolò Cerretani (1444-1519), rédacteur du Libro di ragioni du manuscrit Palatino Baldovinetti 229 de la Bibliothèque nationale de Florence ; le frère mineur et maître d'abaque à Prato Mariotto di ser Giovanni Guiducci (1427-post 1496), auteur du "Libro d'arismetricha" conservé dans le fonds des Conventi Soppressi, codex J X 36 de la Bibliothèque nationale de Florence ; l'apothicaire faentin Giovanni Battista di Michele da Sant'Eufemia († 1487), rédacteur du "Libro sopra arismetricha" et de "Rasone de perticha" dans le manuscrit Plimpton 195 de l'université Columbia à New York
Dell'Ospitalità. L'essere per l'inizio di Nunzio Incardona
No full textThe author explores the work of Nunzio Incardona using the Derridean category of hospitality. The hermeneutic gain is an unprecedented reading of the beginning of philosophy that Incardona takes from Hegel
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
No full textInternational audienceSpinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far
First low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO data
No full textInternational audienceWe report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7 [1/Hz]. At the frequency of best strain sensitivity, near 100 Hz, we set 90% confidence upper limits of 1.8×10-25. At the low end of our frequency range, 20 Hz, we achieve upper limits of 3.9×10-24. At 55 Hz we can exclude sources with ellipticities greater than 10-5 within 100 pc of Earth with fiducial value of the principal moment of inertia of 1038 kg m2
Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO
No full textInternational audienceDuring their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100 M⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93 Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits
