Levels of metals, arsenic and phosphorus in sediments from two sectors of a Brazilian Marine Protected Area (Tupinambas Ecological Station)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Soroprevalência da brucelose bovina em frigoríficos com diferentes níveis de serviço de inspeção no estado de São Paulo

Pós-graduação em Medicina Veterinária - FMVZ

Comparison among different pH values of Rhodamine B solution impregnated into mesoporous silica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do estado nutricional de mudas de Gonçalo Alves (Astronium Fraxinifolium)

The planting of seedlings, the establishment and maintenance of the natural regeneration process, or the combination thereof, are methods used in the recovery of degraded or disturbed environments, however, often require the addition of soil conditioners. This study aimed to evaluate the influence of conditioners, introduced in degraded soil on growth and nutritional status of Astronium fraxinifolium seedlings. To conduct the experimentation were used as degraded soil conditioner, ash from sugarcane bagasse (CZ) and macrophytes (MC), at the doses of 0, 15, 30 and 45 t ha-1 and 0, 16 and 32 t ha-1 respectively, which combined produced 12 treatments, with three replications, and for field installation, was used the experimental randomized block design. Astronium fraxinifolium (Gonçalo Alves) seedlings, native tree species in cerrado, were introduced in the experimental area and, after 12 months, were evaluated for leaf concentration of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese and zinc (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn, respectively). Seedlings and adult plants of A. fraxinifolium were collected in preserved cerrado reserve were also analyzed for nutrients foliar concentration to perform a comparative analysis. The leaves collection in the preserved cerrado and experimental area, was accompanied by soil sampling (0.0 - 0,20 m deep), which was analyzed for phosphorus, OM (organic matter), pH, K, Ca, Mg, Al+H (potential acidity), Al (aluminum), Cu, Fe, Mn and Zn. The results show that the applied residues contributed to raise the foliar concentration of Cu and Fe. The foliar concentration of nutrients was higher in A. fraxinifolium seedlings from preserved cerrado, except for B, which was similar between areas, besides Cu and Fe with higher levels in the seedlings from experimental area. The combined addition of residues (MC and CZ), led to increase the plants height and diameter. This...

Seasonal Distribution of Airborne Trace Elements and Water-Soluble Ions in Sao Paulo Megacity, Brazil

This study deals with the seasonal distribution of Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn and water soluble ions (Cl-, PO43-, NO3-, SO42-, HCOO-, CH3COO-, oxalate, succinate, Na+, NH4+, K+, Mg2+ and Ca2+) found in PM10 samples (particulate matter less than 10 mu m in diameter) Sao Paulo City, Brazil, (April 2003-May 2004). Higher atmospheric levels were found for SO42-, NO3-, Cl- and PO43- while the main organic anions were oxalate and formate. Atmospheric levels for elements were: Fe > Al > Ca > K > Na > Mg > Zn > Cu > Pb. Some sources were predominant for some species: (i) fuel burning and/or biomass burning (NO3-, HCOO-, C2O42-, K+, Mg2+, Ca2+, Fe, Pb, Zn, Al, Ca, K and Mg), (ii) gas-to-particle conversion (SO42- and NH4+) and (iii) sea salt spray (Cl-, Na+ and Na).

Effects of laser focusing and fluence on the analysis of pellets of plant materials by laser-induced breakdown spectroscopy

The effects of laser focusing and fluence on LIBS analysis of pellets of plant leaves was evaluated. A Q-switched Nd:YAG laser (5ns, 10Hz, 1064nm) was used and the emission signals were collected by lenses into an optical fiber coupled to a spectrometer with Echelle optics and ICCD. Data were acquired from the accumulation of 20 laser pulses at 2.0 mu s delay and 5.0 mu s integration time gate. The emission signal intensities increased with both laser fluence and spot size. Higher sensitivities for Ca, K, Mg, P, Al, B, Cu, Fe, Mn, and Zn determinations were observed for fluences in the range from 25 to 60Jcm(-2). Coefficients of variation of site-to-site measurements were generally lower than 10% (n=30 sites, 20 laser pulses/site) for a fluence of 50Jcm(-2) and 750 mu m spot size. For most elements, there is an indication that accuracy is improved with higher fluences. (C) 2012 Elsevier B.V. All rights reserved.

Seasonal distribution of airborne trace elements and water-soluble ions in São Paulo Megacity, Brazil

This study deals with the seasonal distribution of Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn and water soluble ions (Cl-, PO4(3-), NO3-, SO4(2-), HCOO-, CH3COO-, oxalate, succinate, Na+, NH4+, K+, Mg2+ and Ca2+) found in PM10 samples (particulate matter less than 10 mm in diameter) São Paulo City, Brazil, (April 2003-May 2004). Higher atmospheric levels were found for SO4(2-), NO3-, Cl- and PO4(3-) while the main organic anions were oxalate and formate. Atmospheric levels for elements were: Fe > Al > Ca > K > Na > Mg > Zn > Cu > Pb. Some sources were predominant for some species: (i) fuel burning and/or biomass burning (NO3-, HCOO-, C2O4(2-), K+, Mg2+, Ca2+, Fe, Pb, Zn, Al, Ca, K and Mg), (ii) gas-to-particle conversion (SO4(2-) and NH4+) and (iii) sea salt spray (Cl-, Na+ and Na).

Produzione di compositi a matrice di alluminio con rinforzo particellare nanometrico

Le leghe di alluminio da fonderia rivestono un ruolo fondamentale in ambito industriale e in particolare il settore dei trasporti ha notevolmente incrementato il loro impiego per la realizzazione di componenti strutturali. Al fine di aumentare ulteriormente la resistenza specifica, tali leghe possono essere impiegate come matrici per lo sviluppo di compositi (Metal Matrix Composites, MMCs), le cui fasi di rinforzo possono avere diversa composizione, forma e dimensione. In particolare, nel caso di rinforzo particellare, più le particelle sono piccole e finemente disperse nella matrice, più elevato può essere l’incremento delle prestazioni meccaniche. In quest’ottica, la ricerca ha portato allo sviluppo dapprima di compositi caratterizzati da un rinforzo micrometrico e, in anni recenti, si sta concentrando sul rinforzo nanometrico (Metal Matrix Nano Composites, MMNCs). I nano-compositi possono essere ottenuti attraverso metodologie differenti: tecniche in situ, in cui il rinforzo viene generato all’interno della matrice attraverso opportune reazioni chimiche, e tecniche ex situ, in cui i dispersoidi vengono inseriti nella matrice fusa, una volta già formati. Sebbene l’incremento prestazionale ottenibile da tali materiali sia stato dimostrato, è necessario far fronte ad alcune problematiche connesse a ciascuna tecnologia produttiva quali, ad esempio, il controllo dei parametri di processo, per quanto riguarda le tecniche in situ, e l’ottenimento di una efficace dispersione delle nano-particelle all’interno della matrice, nel caso delle metodologie ex-situ. Lo scopo della presente attività di tesi è lo studio di fattibilità, basato anche su un’ampia indagine bibliografica, e l’implementazione di metodologie produttive, su scala di laboratorio, volte allo sviluppo di MMNCs a matrice in lega di alluminio (A356, Al-Si-Mg). L’interesse è stato posto in primo luogo sul processo in situ di gas bubbling, mirato all’ottenimento di rinforzo d’allumina, indotto dalla reazione tra matrice metallica e gas ossidante (in questo caso aria secca industriale). In secondo luogo, dal punto di vista delle tecniche ex situ, è stato approfondito l’aspetto della dispersione delle particelle di rinforzo nel fuso, prestando particolare attenzione alla tecnica di trattamento ultrasonico del metallo.

Le nuove procedure di analisi di sicurezza in ambito urbano ed extra urbano

Nel 2011 si sono registrati in Italia 205.638 incidenti stradali con lesioni a persone. Il numero dei morti (entro il 30° giorno) è stato di 3.860, quello dei feriti ammonta a 292.019.Rispetto all’obiettivo fissato dall’Unione Europea nel Libro Bianco del 2001, che prevedeva la riduzione della mortalità del 50% entro il 2010, benché sia vicina a questo traguardo, l’Italia non ha ancora raggiunto tale livello (Figura I.1). Sulle strade urbane si sono verificati 157.023 incidenti, con 213.001 feriti e 1.744 morti. Sulle Autostrade gli incidenti sono stati 11.007, con 18.515 feriti e 338 decessi. Sulle altre strade extraurbane, ad esclusione delle Autostrade, si sono verificati 37.608 incidenti, con 65.503 feriti e 1.778 morti. L’indice di mortalità mostra che gli incidenti più gravi avvengono sulle strade extraurbane (escluse le autostrade), dove si registrano 4,7 decessi ogni 100 incidenti. Gli incidenti sulle strade urbane sono meno gravi, con 1,1 morti ogni 100 incidenti. Sulle Autostrade tale indice è pari a 3,1. L’indice di mortalità si mantiene superiore alla media giornaliera (1,9 decessi ogni 100 incidenti) per tutto l’arco di tempo che va dalle 21 alle 7 del mattino, raggiungendo il valore massimo intorno alle 5 del mattino (6,0 decessi ogni 100 incidenti). La domenica è il giorno nel quale si registra il livello più elevato dell’indice di mortalità (2,8 morti per 100 incidenti). In 7 casi su 10 (69,7%) le vittime sono i conducenti di veicoli, nel 15,3% i passeggeri trasportati e nel 15,1% i pedoni. La categoria di veicolo più coinvolta in incidente stradale è quella delle autovetture(66,1%), seguono motocicli (14,0%), i ciclomotori (5,4%) e le biciclette (4,5%).

Molecular variability of Meningococcal antigens in carriage and disease strains and in other Neisseria species

This PhD thesis is focused on the study of the molecular variability of some specific proteins, part of the outer membrane of the pathogen Neisseria meningitidis, and described as protective antigens and important virulence factors. These antigens have been employed as components of the vaccine developed by Novartis Vaccines against N. meningitidis of serogroup B, and their variability in the meningococcal population is a key aspect when the effect of the vaccine is evaluated. The PhD project has led to complete three major studies described in three different manuscritps, of which two have been published and the third is in preparation. The thesis is structured in three main chapters, each of them dedicated to the three studies. The first, described in Chapter 1, is specifically dedicated to the analysis of the molecular conservation of meningococcal antigens in the genomes of all species classified in the genus Neisseria (Conservation of Meningococcal Antigens in the Genus Neisseria. A. Muzzi et al.. 2013. mBio 4 (3)). The second study, described in Chapter 2, focuses on the analysis of the presence and conservation of the antigens in a panel of bacterial isolates obtained from cases of the disease and from healthy individuals, and collected in the same year and in the same geographical area (Conservation of fHbp, NadA, and NHBA in carrier and pathogenic isolates of Neisseria meningitidis collected in the Czech Republic in 1993. A. Muzzi et al.. Manuscript in preparation). Finally, Chapter 3 describes the molecular features of the antigens in a panel of bacterial isolates collected over a period of 50 years, and representatives of the epidemiological history of meningococcal disease in the Netherlands (An Analysis of the Sequence Variability of Meningococcal fHbp, NadA and NHBA over a 50-Year Period in the Netherlands. S. Bambini et al.. 2013. PloS one e65043).

Produzione e funzionamento di un dispositivo spin valve

Il fenomeno della magnetoresistenza gigante (GMR) consiste nella marcata variazione della resistenza elettrica di una struttura in forma di film sottile, composta da un’alternanza di strati metallici ferromagnetici (FM) e non magnetici (NM), per effetto di un campo magnetico esterno. Esso è alla base di un gran numero di sensori e dispositivi magnetoelettronici (come ad esempio magnetiche ad accesso casuale, MRAM, ad alta densità) ed ulteriori innovazioni tecnologiche sono in via di elaborazione. Particolarmente rilevanti sono diventate le Spin Valve, dispositivi composti da due strati FM separati da uno spaziatore NM, metallico. Uno dei due film FM (free layer) è magneticamente più soffice rispetto all’altro (reference layer), la cui magnetizzazione è fissata mediante accoppiamento di scambio all’interfaccia con uno strato antiferromagnetico (AFM) adiacente. Tale accoppiamento causa l’insorgenza di una anisotropia magnetica unidirezionale (anisotropia di scambio) per lo strato FM, che si manifesta in uno shift orizzontale del ciclo di isteresi ad esso associato (effetto di exchange bias), solitamente accompagnato anche da un aumento del campo coercitivo. Questo lavoro di tesi riporta la deposizione e la caratterizzazione magnetica e magnetoresistiva di due valvole spin, una a struttura top (SVT) composta da strati di Si/Cu[5 nm]/Py[5 nm]/Cu[5 nm]/Py[5 nm]/IrMn[10 nm], ed una a struttura bottom (SVB), di composizione Si/Cu[5 nm]/IrMn[10 nm]/Py[5 nm]/Cu[5 nm]/Py[5 nm], allo scopo di verificare il comportamento magnetoresistivo gigante del dispositivo per questa particolare scelta dei materiali. I campioni sono stati depositati mediante DC Magnetron sputtering, e caratterizzati magneticamente mediante magnetometro SQUID; la caratterizzazione resistiva è stata eseguita tramite metodo di van der Pawn. Vengono infine presentati i risultati sperimentali, in cui si osserva una variazione di magnetoresistenza nei campioni nell’ordine del punto percentuale.

Alchilazione in fase gassosa del fenolo con reagenti "green" in catalisi basica eterogenea

L’alchilazione del fenolo (PhOH) è un processo di grande rilevanza. I prodotti, alchilfenoli (dall’alchilazione del carbonio d’anello) ed eteri fenilici (dall’alchilazione dell’ossigeno fenolico), sono usati nella produzione di resine fenoliche ed in sintesi organica. I carbonati organici sono atossici, biodegradabili, ottenibili da fonti rinnovabili ed hanno un ottimo potere solvente per i composti organici e aromatici. Con un opportuno catalizzatore sono reattivi per l’alchilazione del PhOH, e potrebbero sostituire gli alchilanti usati industrialmente: quelli per la O- alchilazione, alchilioduro e dialchilsolfato, sono estremamente tossici, mentre gli alcoli, impiegati per la C-alchilazione, decompongono estesamente sui catalizzatori industriali. In questo lavoro di tesi, le prestazioni del dietilcarbonato (DEC) come agente etilante del PhOH sono state indagate a fondo al variare dei parametri operativi, e sono state poi confrontate con quelle dell’etanolo, dimostrando che il carbonato è molto più reattivo: sui catalizzatori basici il DEC mostra una chemoselettività prettamente orientata alla O-alchilazione e la conversione del PhOH può essere massimizzata agendo sui parametri operativi senza grandi variazioni nella selettività del prodotto di interesse; sui sistemi acido/base (ossido misto di Mg e Al) si è invece dimostrato possibile orientare l’alchilazione alternativamente all’ossigeno (fenetoli) o al carbonio (etilfenoli) aumentando la temperatura.

The new insight into dynamic crossover in glass forming liquids from the apparent enthalpy analysis

One of the most intriguing phenomena in glass forming systems is the dynamic crossover (T(B)), occurring well above the glass temperature (T(g)). So far, it was estimated mainly from the linearized derivative analysis of the primary relaxation time τ(T) or viscosity η(T) experimental data, originally proposed by Stickel et al. [J. Chem. Phys. 104, 2043 (1996); J. Chem. Phys. 107, 1086 (1997)]. However, this formal procedure is based on the general validity of the Vogel-Fulcher-Tammann equation, which has been strongly questioned recently [T. Hecksher et al. Nature Phys. 4, 737 (2008); P. Lunkenheimer et al. Phys. Rev. E 81, 051504 (2010); J. C. Martinez-Garcia et al. J. Chem. Phys. 134, 024512 (2011)]. We present a qualitatively new way to identify the dynamic crossover based on the apparent enthalpy space (H(a)(') = dlnτ/d(1/T)) analysis via a new plot lnH(a)(') vs. 1∕T supported by the Savitzky-Golay filtering procedure for getting an insight into the noise-distorted high order derivatives. It is shown that depending on the ratio between the "virtual" fragility in the high temperature dynamic domain (m(high)) and the "real" fragility at T(g) (the low temperature dynamic domain, m = m(low)) glass formers can be splitted into two groups related to f < 1 and f > 1, (f = m(high)∕m(low)). The link of this phenomenon to the ratio between the apparent enthalpy and activation energy as well as the behavior of the configurational entropy is indicated.

Recommended Nomenclature for the Sapphirine and Surinamite Groups (Sapphirine Supergroup)

Minerals isostructural with sapphirine-1A, sapphirine-2M, and surinamite are closely related chain silicates that pose nomenclature problems because of the large number of sites and potential constituents, including several (Be, B, As, Sb) that are rare or absent in other chain silicates. Our recommended nomenclature for the sapphirine group (formerly-aenigmatite group) makes extensive use of precedent, but applies the rules to all known natural compositions, with flexibility to allow for yet undiscovered compositions such as those reported in synthetic materials. These minerals are part of a polysomatic series composed of pyroxene or pyroxene-like and spinel modules, and thus we recommend that the sapphirine supergroup should encompass the polysomatic series. The first level in the classification is based on polysome, i.e. each group within the supergroup Corresponds to a single polysome. At the second level, the sapphirine group is divided into subgroups according to the occupancy of the two largest M sites, namely, sapphirine (Mg), aenigmatite (Na), and rhonite (Ca). Classification at the third level is based on the occupancy of the smallest M site with most shared edges, M7, at which the dominant cation is most often Ti (aenigmatite, rhonite, makarochkinite), Fe(3+) (wilkinsonite, dorrite, hogtuvaite) or Al (sapphirine, khmaralite); much less common is Cr (krinovite) and Sb (welshite). At the fourth level, the two most polymerized T sites are considered together, e.g. ordering of Be at these sites distinguishes hogtuvaite, makarochkinite and khmaralite. Classification at the fifth level is based on X(Mg) = Mg/(Mg + Fe(2+)) at the M sites (excluding the two largest and M7). In principle, this criterion could be expanded to include other divalent cations at these sites, e.g. Mn. To date, most minerals have been found to be either Mg-dominant (X(mg) > 0.5), or Fe(2+)-dominant (X(Mg) < 0.5), at these M sites. However, X(mg) ranges from 1.00 to 0.03 in material described as rhonite, i.e. there are two species present, one Mg-dominant, the other Fe(2+)-dominant. Three other potentially new species are a Mg-dominant analogue of wilkinsonite, rhonite in the Allende meteorite, which is distinguished front rhonite and dorrite in that Mg rather than Ti or FC(3+) is dominant at M7, and an Al-dominant analogue of sapphirine, in which Al > Si at the two most polymerized T sites vs. Al < Si in sapphirine. Further splitting of the supergroup based on occupancies other than those specified above is not recommended.

Springtime Nutrient and Phytoplankton Dynamics on Georges Bank

The dynamics of phytoplankton and nutrients before, during and after the winter-spring bloom on Georges Bank were studied on 6 monthly survey cruises from January to June 1999. We measured hydrography, phytoplankton cell densities, chlorophyll a, dissolved inorganic nutrients (NO3 + NO2, NH4, Si(OH)(4), PO4), dissolved organic nitrogen (DON) and phosphorus (DOP), particulate organic carbon (POC) and nitrogen (PON) and total particulate phosphorus (TPP). We present evidence that phytoplankton production may be significant year-round, and that the winter-spring bloom may have started in January. From January to April the phytoplankton was comprised almost exclusively of diatoms, reaching cell densities in March and April of ca. 450 cells ml(-1); chlorophyll a concentrations exceeded 10 mug l(-1) in April. Diatoms decreased to relatively low levels in May (< 50 x 10(3) cells l(-1)) and increased again in June (>300 x 10(3) cells l(-1)). Densities of dinoflagellates and nanoflagellates were low (< 10 x 10(3) cells l(-1)) from January to April, and increased in May and June to nearly 300 x 10(3) cells l(-1). Nitrate + nitrite concentrations in January were <3 muM in the shallow, central portion of the bank and decreased steadily each month. Silicate was also <3 muM over an even larger area of the central bank in January and declined to <1.5 muM over most of the Bank in April. The data suggest that silicate depletion, not DIN, contributed to the cessation of the diatom bloom. Regeneration of silicate occurred in May and June, presumably as a result of rising water temperatures in late spring which increased the dissolution rate of diatom frustules from the earlier diatom bloom. Dissolved organic nitrogen may have been utilized at the start of the winter-spring bloom; concentrations were ca, 14 muM in January, dropping to < 6 mug l(-1) in February, after which DON concentrations steadily rose to > 15 mug l(-1) in June. Overall micro-and nanoplankton biomass, measured as POC, PON and TPP, increased over the 6 mo period, as did nutritional quality of that biomass as indicated by declining C:N ratios. Our results suggest there may have been an increase in the heterotrophic component of the plankton in May and June which coincided with a second burst in diatom abundance. We discuss general features of planktonic production and nutrient dynamics with respect to year-round production on the Bank.