1000 resultados para Bennich-Björkman, Bo
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Il versante sinistro delle Gole di Scascoli (BO) è caratterizzato da una marcata tendenza evolutiva per crollo e ribaltamento. Negli ultimi 25 anni si sono verificati eventi parossistici con volumi di roccia coinvolti rispettivamente di 7000 m3, 20000 m3 e 35000 m3. Il sito è di grande rilevanza a causa del forte fattore di rischio rappresentato per la strada di fondovalle ad esso adiacente. Il lavoro di tesi è stato finalizzato allo studio dei fenomeni di versante di una parete rocciosa inaccessibile nota in letteratura come “ex-Mammellone 1” mediante tecniche di telerilevamento quali TLS (Terrestrial Laser Scanning) e CRP (Close Range Photogrammetry) al fine affiancare il rilievo geomeccanico soggettivo dell’area svolto nel 2003 da ENSER Srl in seguito ai fenomeni di crollo del 2002. Lo sviluppo di tecnologie e metodi innovativi per l’analisi territoriale basata sull’impiego di UAV (Unmanned Aerial Vehicle, meglio noti come Droni), associata alle tecniche di fotogrammetria digitale costituisce un elemento di notevole ausilio nelle pratiche di rilevamento in campo di sicurezza e tempi di esecuzione. Il lavoro ha previsto una prima fase di rilevamento areo-fotogrammetrico mediante strumentazione professionale e amatoriale, a cui è seguita l’elaborazione dei rispettivi modelli. I diversi output sono stati confrontati dal punto di vista geomorfologico, geometrico, geomeccanico e di modellazione numerica di caduta massi. Dal lavoro è stato possibile indagare l’evoluzione morfologica del sito in esame negli ultimi 10 anni, confrontare diversi metodi di rilevamento e analisi dati, sperimentare la robustezza e ripetibilità geometrica del metodo fotogrammetrico per il rilievo di fronti rocciosi e mettere a punto un metodo semiautomatico di individuazione e analisi delle giaciture delle discontinuità.
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La tesi di laurea ha come oggetto il complesso della pieve di San Giorgio di Samoggia che è situata nel comune di Valsamoggia (BO). Il complesso, composto da chiesa, canonica, campanile, casa dell’enfiteuta e cella campanaria, sorge isolato dal paese, in una zona collinare caratterizzata dalla presenza di importanti formazioni calanchive e si trova attualmente in un cattivo stato di conservazione dovuto soprattutto all’assenza di interventi di manutenzione negli ultimi ottant’anni. Il lavoro si è sviluppato nelle seguenti fasi: - Ricostruzione delle vicende costruttive tramite ricerca sulle fonti indirette (bibliografiche e archivistiche) - Rilievo diretto del complesso realizzato tramite la tecnica delle trilaterazioni e conseguente restituzione grafica di planimetrie, sezioni e prospetti del complesso - Analisi dello stato di fatto e di degrado del manufatto, ponendo una particolare attenzione alle tecniche costruttive utilizzate - Progetto di una serie di interventi di consolidamento aventi ad oggetto i tetti e i solai di piano della chiesa e della canonica - Proposta di attualizzazione funzionale della porzione di complesso che in passato era l’abitazione dell’enfiteuta che coltivava il fondo annesso alla pieve.
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Bokrecension
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El 27 de febrero de 2010 la costa de Chile central fue afectada por terremoto Mw=8.8 el cual generó un tsunami de magnitud 4 que asoló principalmente bahías pequeñas en un tramo costero de 800 km. Unas 484 personas perdieron la vida. En la Región del Bio-Bío, murieron 199 personas ya que en este sector se localiza la segunda conurbación más importante del país. Con el propósito de analizar los efectos territoriales generados por este tsunami en la costa de la región, se iniciaron trabajos de terreno para determinar la altura y run-up de la ola, catastrar los efectos sobre la población y localizar sectores de mayor impacto. Estas actividades están posibilitando generar estudios de vulnerabilidad para diferentes localidades de la región, comparando escenarios pre y post tsunami para generar mapas de riesgo por tsunami para eventos de similares características, que sirvan posteriormente como instrumentos de gestión del riesgo. En esta contribución, se presentan los resultados de los trabajos de campo realizados en siete localidades afectadas por el tsunami (Tirúa, Lebu, Tubul-Raqui, LLico, Coliumo, Laraquete y Arauco). En estos sectores, las áreas inundadas fluctúan entre 59 y 458 has, con alturas de ola entre 3 y 30 m.
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La tesi propone un esempio di riqualificazione energetica di un edificio residenziale sito a Castel Maggiore (Bologna) con l’applicazione della pratica di detrazione fiscale Bonus 110% introdotta nell’anno 2020 con il Decreto Rilancio. Il lavoro segue l’iter burocratico e progettuale alla base di questa pratica, a partire dalle fasi preliminari di studio dello stato di fatto dell’edificio fino alla realizzazione degli interventi proposti. La tesi si sviluppa come segue. I primi due capitoli definiscono alcuni concetti base della termotecnica e le regole per l’applicazione del Bonus 110. I due capitoli successivi forniscono la situazione dell’edificio allo stato di fatto sia per quanto riguarda la struttura e l’impianto termico sia per quanto riguarda le dispersioni termiche e il fabbisogno energetico. Allo stato di fatto il condominio presenta strutture non coibentate, infissi e impianto termico datati. Il quinto capitolo riporta gli interventi previsti: quelli trainanti sono il rifacimento dell’impianto termico e la coibentazione delle pareti esterne e della copertura; quelli trainati sono la sostituzione degli infissi e l’installazione dell’impianto fotovoltaico. Il sesto capitolo presenta il dimensionamento del generatore di calore e dell’impianto fotovoltaico, nonché i risultati ottenuti con l’analisi energetica dell’edificio in seguito all’esecuzione degli interventi proposti. Il settimo capitolo riporta i dimensionamenti dei vari componenti dell’impianto, mentre nell’ottavo capitolo si esegue l’analisi economica complessiva. Gli interventi effettuati comportano un calo drastico delle dispersioni termiche e dell’indice di prestazione energetica, un maggior comfort all’interno dei locali e un notevole aumento nell’uso di energia primaria rinnovabile. L’edificio passa dalla classe energetica F alla classe energetica A4, realizzando così pienamente gli obiettivi di efficientamento energetico e rientrando ampiamente nei requisiti imposti dalla pratica Bonus 110%.
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Introdução: A mortalidade infantil e fetal são consideradas como indicadores clássicos e consagrados das condições de vida e saúde de uma população. O óbito infantil e fetal é potencialmente evitável, e, portanto, identificar fatores determinantes desses óbitos é imprescindível. Objetivo: Identificação das causas evitáveis que levaram a mortalidade fetal e de crianças menores de um ano a partir da investigação de óbitos no município de Angelândia - MG no ano de 2013. Metodologia: Foram analisadas fichas de investigação de óbitos fetais e de menores de um ano ocorridos no município. Optou-se pela revisão narrativa da literatura. Foram usados os seguintes descritores: Mortalidade Infantil, Mortalidade Neonatal, Assistência Pré-natal e para inclusão dos textos no estudo adotou-se os critérios: trabalhos que abordam o tema de forma integral; disponíveis gratuitamente on-line; publicados em português e trabalhos elaborados no período de janeiro de 2000 a janeiro 2014 além de investigação de óbitos fetais e de crianças menores de um ano. Resultados: Foram analisadas sete fichas de Investigação de óbitos, entre elas ocorreram, cinco óbitos fetais, um óbito neonatal e um óbito infantil. Plano de Ação: Mobilização das autoridades responsáveis pela saúde pública do município através da apresentação do resultado deste estudo para que providências sejam tomadas em relação à mortalidade infantil. Conclusão: Conclui-se que foi possível identificar as principais causas de óbitos e o importante papel das causas reduzíveis por adequada atenção ao recém-nascido e à mulher durante a gestação e parto.
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Interactions between flowers and their visitors span the spectrum from mutualism to antagonism. The literature is rich in studies focusing on mutualism, but nectar robbery has mostly been investigated using phytocentric approaches focused on only a few plant species. To fill this gap, we studied the interactions between a nectar-robbing hermit hummingbird, Phaethornis ruber, and the array of flowers it visits. First, based on a literature review of the interactions involving P. ruber, we characterized the association of floral larceny to floral phenotype. We then experimentally examined the effects of nectar robbing on nectar standing crop and number of visits of the pollinators to the flowers of Canna paniculata. Finally, we asked whether the incorporation of illegitimate interactions into the analysis affects plant-hummingbird network structure. We identified 97 plant species visited by P. ruber and found that P. ruber engaged in floral larceny in almost 30 % of these species. Nectar robbery was especially common in flowers with longer corolla. In terms of the effect on C. paniculata, the depletion of nectar due to robbery by P. ruber was associated with decreased visitation rates of legitimate pollinators. At the community level, the inclusion of the illegitimate visits of P. ruber resulted in modifications of how modules within the network were organized, notably giving rise to a new module consisting of P. ruber and mostly robbed flowers. However, although illegitimate visits constituted approximately 9 % of all interactions in the network, changes in nestedness, modularity, and network-level specialization were minor. Our results indicate that although a flower robber may have a strong effect on the pollination of a particular plant species, the inclusion of its illegitimate interactions has limited capacity to change overall network structure.
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This study describes the sperm morphology of the mayfly Hexagenia (Pseudeatonica) albivitta (Ephemeroptera). Its spermatozoon measures approximately 30 μm of which 9 μm corresponds to the head. The head is composed of an approximately round acrosomal vesicle and a cylindrical nucleus. The nucleus has two concavities, one in the anterior tip, where the acrosomal vesicle is inserted and a deeper one at its base, where the flagellum components are inserted. The flagellum is composed of an axoneme, a mitochondrion and a dense rod adjacent to the mitochondrion. A centriolar adjunct is also observed surrounding the axoneme in the initial portion of the flagellum and extends along the flagellum for at least 2 μm, surrounding the axoneme in a half-moon shape. The axoneme is the longest component of the flagellum, and it follows the 9+9+0 pattern, with no central pair of microtubules. At the posterior region of the flagellum, the mitochondrion has a dumb-bell shape in cross sections that, together with the rectangular mitochondrial-associated rod, is responsible for the flattened shape of the flagellum. An internal membrane is observed surrounding both mitochondrion and its associated structure.
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The interplay between the biocolloidal characteristics (especially size and charge), pH, salt concentration and the thermal energy results in a unique collection of mesoscopic forces of importance to the molecular organization and function in biological systems. By means of Monte Carlo simulations and semi-quantitative analysis in terms of perturbation theory, we describe a general electrostatic mechanism that gives attraction at low electrolyte concentrations. This charge regulation mechanism due to titrating amino acid residues is discussed in a purely electrostatic framework. The complexation data reported here for interaction between a polyelectrolyte chain and the proteins albumin, goat and bovine alpha-lactalbumin, beta-lactoglobulin, insulin, k-casein, lysozyme and pectin methylesterase illustrate the importance of the charge regulation mechanism. Special attention is given to pH congruent to pI where ion-dipole and charge regulation interactions could overcome the repulsive ion-ion interaction. By means of protein mutations, we confirm the importance of the charge regulation mechanism, and quantify when the complexation is dominated either by charge regulation or by the ion-dipole term.
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We present the genome sequences of a new clinical isolate of the important human pathogen, Aspergillus fumigatus, A1163, and two closely related but rarely pathogenic species, Neosartorya fischeri NRRL181 and Aspergillus clavatus NRRL1. Comparative genomic analysis of A1163 with the recently sequenced A. fumigatus isolate Af293 has identified core, variable and up to 2% unique genes in each genome. While the core genes are 99.8% identical at the nucleotide level, identity for variable genes can be as low 40%. The most divergent loci appear to contain heterokaryon incompatibility ( het) genes associated with fungal programmed cell death such as developmental regulator rosA. Cross-species comparison has revealed that 8.5%, 13.5% and 12.6%, respectively, of A. fumigatus, N. fischeri and A. clavatus genes are species-specific. These genes are significantly smaller in size than core genes, contain fewer exons and exhibit a subtelomeric bias. Most of them cluster together in 13 chromosomal islands, which are enriched for pseudogenes, transposons and other repetitive elements. At least 20% of A. fumigatus-specific genes appear to be functional and involved in carbohydrate and chitin catabolism, transport, detoxification, secondary metabolism and other functions that may facilitate the adaptation to heterogeneous environments such as soil or a mammalian host. Contrary to what was suggested previously, their origin cannot be attributed to horizontal gene transfer ( HGT), but instead is likely to involve duplication, diversification and differential gene loss (DDL). The role of duplication in the origin of lineage-specific genes is further underlined by the discovery of genomic islands that seem to function as designated ""gene dumps'' and, perhaps, simultaneously, as "" gene factories''.
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Context. The formation of ultra-compact dwarf galaxies (UCDs) is believed to be driven by interaction, and UCDs are abundant in the cores of galaxy clusters, environments that mark the end-point of galaxy evolution. Nothing is known about the properties of UCDs in compact groups of galaxies, environments where most of galaxy evolution and interaction is believed to occur and where UCDs in an intermediate stage in their evolution may be expected. Aims. The main goal of this study is to detect and characterize, for the first time, the UCD population of compact groups of galaxies. For that, two nearby groups in different evolutionary stages, HCG22 and HCG90, were targeted. Methods. We selected about 40 UCD candidates from pre-existing photometry of both groups, and obtained spectra of these candidates using the VLT FORS2 instrument in MXU mode. Archival HST/ACS imaging was used to measure their structural parameters. Results. We detect 16 and 5 objects belonging to HCG22 and HCG90, respectively, covering the magnitude range -10.0 > M(R) > -11.5 mag. Their integrated colours are consistent with old ages covering a broad range in metallicities (metallicities confirmed by the spectroscopic measurements). Photometric mass estimates put 4 objects in HCG90 and 9 in HCG22 in the mass range of UCDs (> 2 x 10(6) M(circle dot)) for an assumed age of 12Gyr. These UCDs are on average 2-3 times larger than the typical size of Galactic GCs, covering a range of 2 less than or similar to r(h) less than or similar to 21 pc. The UCDs in HCG22 are more concentrated around the central galaxy than in HCG90, at the 99% confidence level. They cover a broad range in [alpha/Fe] abundances from sub-to super-solar. The spectra of 3 UCDs (2 in HCG22, 1 in HCG90) show tentative evidence of intermediate age stellar populations. The clearest example is the largest and most massive UCD (similar to 10(7) M(circle dot)) in our sample, which is detected in HCG22. Its properties are most consistent with a stripped dwarf galaxy nucleus. We calculate the specific frequency (S(N)) of UCDs for both groups, finding that HCG22 has about three times higher S(N) than HCG90. Conclusions. The ensemble properties of the detected UCDs supports two co-existing formation channels: a star cluster origin (low-luminosity, compact sizes, old ages, super-solar alpha/Fe), and an origin as tidally stripped dwarf nuclei (more extended and younger stellar populations). Our results imply that the UCDs detected in both groups do not, in their majority, originate from relatively recent galaxy interactions. Most of the detected UCDs have likely been brought into the group along with their host galaxies.
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We propose a model for D(+)->pi(+)pi(-)pi(+) decays following experimental results which indicate that the two-pion interaction in the S wave is dominated by the scalar resonances f(0)(600)/sigma and f(0)(980). The weak decay amplitude for D(+)-> R pi(+), where R is a resonance that subsequently decays into pi(+)pi(-), is constructed in a factorization approach. In the S wave, we implement the strong decay R ->pi(+)pi(-) by means of a scalar form factor. This provides a unitary description of the pion-pion interaction in the entire kinematically allowed mass range m(pi pi)(2) from threshold to about 3 GeV(2). In order to reproduce the experimental Dalitz plot for D(+)->pi(+)pi(-)pi(+), we include contributions beyond the S wave. For the P wave, dominated by the rho(770)(0), we use a Breit-Wigner description. Higher waves are accounted for by using the usual isobar prescription for the f(2)(1270) and rho(1450)(0). The major achievement is a good reproduction of the experimental m(pi pi)(2) distribution, and of the partial as well as the total D(+)->pi(+)pi(-)pi(+) branching ratios. Our values are generally smaller than the experimental ones. We discuss this shortcoming and, as a by-product, we predict a value for the poorly known D ->sigma transition form factor at q(2)=m pi(2).
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Structural and optical properties of stable glasses in the Y(2)O(3)-CaO-B(2)O(3) system, containing the same Y/Ca ratio as the YCa(4)O(BO(3))(3) (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy. Changes in optical functions with composition are associated with an increase in the number of non-bridging oxygen and to calcium/yttrium oxides content. Refractive indexes values (from 1.597 to 1.627 at lambda=2 mu m) are in good agreement with those of the YCOB crystal, an indication that these glasses are potential candidates for optical applications due to their ease of shaping as large bulk samples or fibers.
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The structure of laser glasses in the system (Y(2)O(3))(0.2){(Al(2)O(3))(x))(B(2)O(3))(0.8-x)} (0.15 <= x <= 0.40) has been investigated by means of (11)B, (27)Al, and (89)Y solid state NMR as well as electron spin echo envelope modulation (ESEEM) of Yb-doped samples. The latter technique has been applied for the first time to an aluminoborate glass system. (11)B magic-angle spinning (MAS)-NMR spectra reveal that, while the majority of the boron atoms are three-coordinated over the entire composition region, the fraction of three-coordinated boron atoms increases significantly with increasing x. Charge balance considerations as well as (11)B NMR lineshape analyses suggest that the dominant borate species are predominantly singly charged metaborate (BO(2/2)O(-)), doubly charged pyroborate (BO(1/2)(O(-))(2)), and (at x = 0.40) triply charged orthoborate groups. As x increases along this series, the average anionic charge per trigonal borate group increases from 1.38 to 2.91. (27)Al MAS-NMR spectra show that the alumina species are present in the coordination states four, five and six, and the fraction of four-coordinated Al increases markedly with increasing x. All of the Al coordination states are in intimate contact with both the three-and the four-coordinate boron species and vice versa, as indicated by (11)B/(27)Al rotational echo double resonance (REDOR) data. These results are consistent with the formation of a homogeneous, non-segregated glass structure. (89)Y solid state NMR spectra show a significant chemical shift trend, reflecting that the second coordination sphere becomes increasingly ""aluminate-like'' with increasing x. This conclusion is supported by electron spin echo envelope modulation (ESEEM) data of Yb-doped glasses, which indicate that both borate and aluminate species participate in the medium range structure of the rare-earth ions, consistent with a random spatial distribution of the glass components.
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In this work we performed a thorough spectroscopic and thermo-optical investigation of yttrium aluminoborate glasses doped with neodymium ions. A set of samples, prepared by the conventional melt-quenching technique and with Nd(2)O(3) concentrations varying from 0.1 to 0.75 mol %, were characterized by ground state absorption, photoluminescence, excited state lifetime measurements, and thermal lens technique. For the neodymium emission at 1064 nm ((4)F(3/2) -> (4)I(11/2) transition), no significant luminescence concentration quenching was observed and the experimental lifetime values ranged around 70 mu s. The obtained values of thermal conductivity and diffusivity of approximately 10.3 x 10(-3) W / cm K and 4.0 x 10(-3) cm(2) / s, respectively, are comparable to those of commercial laser glasses. Moreover, the fluorescence quantum efficiency of the glasses, calculated using the Judd-Ofelt formalism and luminescence decay, lies in the range from 0.28 to 0.32, larger than the typical values obtained for Nd(3+) doped YAl(3)(BO(3))(4) crystals. (c) 2009 American Institute of Physics. [DOI: 10.1063/1.3176503]