Avaliação sensorial de uvas de mesa produzidas no Vale do São Francisco e comercializadas em João Pessoa - PB

Tomando-se como base o nível crescente de exigência do consumidor por frutas de mesa, as características de qualidade das uvas 'Itália', 'Festival' ('Superior Seedless'), 'Benitaka' e 'Isabel', expostas à venda em três redes de supermercados, na cidade de João Pessoa - Paraíba - Brasil, foram avaliadas em dezembro de 2007. Inicialmente, foram selecionados e treinados julgadores que estabeleceram e definiram os seguintes atributos sensoriais de importância: tonalidade e uniformidade de cor, aroma, firmeza, presença de sementes, suculência, doçura, acidez, sabor e qualidade global. Os diâmetros, comprimentos e pesos das bagas estavam condizentes com os parâmetros comerciais ou varietais. Os conteúdos de sólidos solúveis (SS), com exceção da uva 'Benitaka', apresentaram-se em conformidade com os padrões comerciais. Apenas a cultivar Festival, com a menor acidez titulável (AT), apresentou relação SS/AT aceitável. Foram realizadas três sessões de análises descritivas quantitativas (ADQ), nas quais a uva 'Itália' foi a de melhor sabor e, em conjunto com a apirênica 'Festival', apresentou maiores doçuras e qualidade global. A cultivar Isabel apresentou a cor mais forte , enquanto a Festival foi a melhor no atributo semente. Aplicou-se o Teste de Preferência por Ordenação, no qual as uvas 'Itália' e 'Festival' foram as preferidas.

Podridão peduncular e qualidade de mangas 'Tommy atkins' procedentes do mercado atacadista de Campina Grande-PB

O Brasil destaca-se no cenário mundial como um dos maiores produtores de manga (Mangifera indica L.). No entanto, perdas significativas são observadas em todas as etapas da cadeia produtiva, sobretudo na comercialização varejista, sendo estas correlacionadas em quase sua totalidade à incidência de doenças fúngicas. Neste sentido, objetivou-se com este trabalho determinar a incidência natural de Lasiodiplodia theobromae, agente causal da podridão peduncular, e aspectos da qualidade pós-colheita de mangas 'Tommy Atkins', comercializadas no mercado atacadista da Empresa Paraibana de Abastecimento e Serviços Agrícolas (EMPASA) de Campina Grande-PB. Para a determinação da incidência natural da doença, coletaram-se 40 frutos no estádio de maturação 'de vez', de quatro diferentes estabelecimentos de comercialização, que foram encaminhados ao Laboratório de Fitopatologia (CCA/UFPB). Após sanificação, os frutos foram mantidos sob condições ambientes (28 ± 2 ºC e UR 75 ± 6%) por oito dias, determinando-se o aparecimento dos primeiros sintomas e sinais do patógeno. As características de qualidade foram determinadas através da coleta de 10 frutos de cada estabelecimento de comercialização da EMPASA. Os frutos foram transportados ao Laboratório de Biologia e Tecnologia Pós-Colheita (CCA/UFPB), onde foram avaliados quanto aos teores de Sólidos Solúveis (SS), Acidez Titulável (AT), Relação SS/AT e pH. Os dados foram submetidos à análise de variância, e as médias, comparadas pelo teste de Tukey, a 5% de probabilidade. A manga comercializada no mercado atacadista da EMPASA de Campina Grande apresentou baixo conteúdo de SS e elevada AT, caracterizando fruto no início da maturação. Os frutos apresentaram 88,9% de incidência natural de podridão peduncular no oitavo dia de armazenamento, o que compromete a qualidade do produto no varejo, constituindo-se em uma causa das elevadas perdas pós-colheita.

Mineralización estratiforme de Pb-Zn-Cu en el Paleozoico de Bassegoda (Pirineo Oriental)

Al Sur del pico de Bassegoda existe una mineralización estratiforme de galena, esfalerita y pirita con calcopirita y arsenopirita, en forma de diseminaciones y lentejones masivos, situadas dentro de un tramo de 10 metros de micaesquistos y dolomias negras. Estos niveles mineralizados se hallan en el contacto entre micaesquistos y dolomias masivas que contienen piroclastos cidos. Tanto el tipo de depósito como la litologia encajante, permiten correlacionar esta mineralización con un conjunto de concentraciones metalicas estratiformes y estratoligadas del Cambro-Ordovicico del NE de Cataluña.

Accessory phases as a tool to investigate magmatic underplating in polymetamorphic metasediments : an example from a fossil lower crust : Ivrea Verbano zne, NW Italy

The Ivrea and the Strona-Ceneri zones, NW italy and S Switzerland, offer the possibility to study the continental crust of the Southern Alps. Because of its high metamorphic degree and the abundant Permo- Carboniferous mafic intrusions, the Ivrea Zone is classically interpreted an exposed section trough the Permian lower crust. The present work is focused here on metasedimentary slices (septa) intercalated within Permian gabbro (mafic complex). In particular I studied the evolution of accessory phases such as rutile and zircon and the chemistry of the metasediments. The septa build an irregular and discontinuous band that cut obliquely the mafic complex from its deepest part (N) to its roof (S). The chemistry of the metasediments evolves along the band and the chemical evolution can be compared with that observed in the country-rock surrounding the mafic intrusion to the NE and overprinted by a main regional metamorphic event. This suggests that the degree of chemical depletion of the septa was mainly established during the same regional metamorphic event. Moreover it suggests that incorporation of the septa within the gabbro did not modify their original stratigraphie distribution within the crust. It implies that the mafic complex has been emplaced following a dynamic substantially different from the classic model of « gabbro glacier » (Quick et al., 1992; Quick et al., 1994). It is more likely that it has been emplaced by repeated injections of sills at different depths during a protracted period of time. Zircon trace elements and U-Pb ages suggest that regional metamorphism occurred 330-320Ma, the first sills in the deepest part of the Mafic Complex are injected at ~300Ma, the mafic magmas reached higher levels in the crust at 285Ma and the magmatic activity continued locally until 275Ma. The ages of detrital cores in zircons fix the maximal sedimentation age at ~370Ma, this age corresponds therefore with the maximal age of the incorporation of the Ivrea zone within the lower crust. I propose that the Ivrea zone has been accreted to the lower crust during the Hercynian orogeny sensu lato. The analysis of detrital ages suggests that the source terrains for the Ivrea zone and those for the Strona-Ceneri zone have a completely different Palaeozoic history. The systematic analysis of rutile in partially molten metasediments of the Ivrea zone reveals the occurrence of two generations. The two generations are characterized by a different chemistry and textural distribution. A first generation is formed during pro-grade metamorphism in the restitic counterpart. The second generation is formed in the melts during cooling at the same time that part of the first generation re-equilibrate. Re-equilibration of the first generation seems to be spatially controlled by the presence of fluids. Locally the second generation forms overgrowths on the first generation. Considered the different diffusivity of U and Pb in rutile, U heterogeneities have important implication for U-Pb dating of rutile. ID-TIMS and LA-ICPMS dating coupled with a careful textural investigation (SEM) suggest that rutile grains are characterized by multiple path along which Pb diffusion can occur: volume diffusion is an important process, but intragrain and subgrain boundaries provide additional high diffusivity pathways for Pb escape and reduce drastically the effective diffusion length. -- La zone d'Ivrea et la zone de Strona-Ceneri, en Italie nord-occidentale et Suisse méridionale, offrent la possibilité d'étudier la croûte continentale des Alpes du Sud. En raison du haut degré métamorphique et l'abondance d'intrusions mafiques d'âge Permo-Carbonifère [complexe mafique), la zone d'Ivrea est interprétée classiquement comme de la croûte inférieure permienne. Ce travail ce concentre sur des bandes metasédimentaires (septa) incorporées dans les magmas mafiques lors de l'intrusion. Les septa forment une bande irrégulière qui coupe obliquement le complexe mafique du bas (N) vers le haut (S). La chimie des septa évolue du bas vers le haut et l'évolution chimique se rapproche de l'évolution observé dans la roche encaissante l'intrusion affecté par un événement métamorphique régionale. Cette relation suggère que le degré d'appauvrissement chimique des septa a été établit principalement lors de l'événement métamorphique régional. De plus l'incorporation dans les gabbros n'a pas perturbée la distribution stratigraphique originelle des septa. Ces deux observations impliquent que le métamorphisme dans la roche encaissante précède la mise en place du gabbro et que cette dernière ne se fait pas selon le modèle classique (« gabbro glacier » de Quick et al., 1992, 1994), mais se fait plutôt par injections répétées de sills a différentes profondeurs. Les âges U-Pb et les éléments traces des zircons suggèrent que le métamorphisme régionale a eu lieu 330-320Ma, alors que les premiers sills dans la partie profonde du Mafic Complex s'injectent à ~300Ma, le magmatisme mafique atteigne des niveaux supérieurs à 285Ma et continue localement jusqu'à 270Ma. Les âges des coeurs détritiques des zircons permettent de fixer l'âge maximale de sédimentation à ~370Ma ce qui correspond donc à l'âge maximale de l'incorporation de la zone d'Ivrea dans la croûte inférieur. L'analyse systématique des rutiles, nous a permit de montrer l'existence de plusieurs générations qui ont une répartition texturale et une chimie différente. Une génération se forme lors de l'événement UHT dans les restites, une autre génération se forme dans les liquides lors du refroidissement, au même temps qu'une partie de la première génération se rééquilibre au niveau du Zr. Localement la deuxième génération peut former des surcroissances autour de la première génération. Dans ces cas, des fortes différences en uranium entre les deux générations ont des importantes implications pour la datation U-Pb sur rutile. Classiquement les ratios Pb/U dans le rutile sont interprétés comme indiquant l'âges du refroidissement du minéral sous une température à la quelle la diffusion du Pb dans le minéral n'est plus détectable et la diffusion à plus hautes températures est assumée se faire par «volume diffusion» dans le grain (Mezger et al., 1989). Par des datations ID-TIMS (sur grain entier) et LA-ICPMS (in-situ) et une analyse texturale (MEB) approfondie nous montrons que cette supposition est trop simpliste et que le rutile est repartie en sous-domaines. Chacun de ces domaines a ça propre longueur ou chemin de diffusion spécifique. Nous proposons donc une nouvelle approche plus cohérente pour l'interprétation des âges U-Pb sur rutile.

Influence of the single-particle structure on the nuclear surface and the neutron skin

We analyze the influence of the single-particle structure on the neutron density distribution and the neutron skin in Ca, Ni, Zr, Sn, and Pb isotopes. The nucleon density distributions are calculated in the Hartree-Fock+BCS approach with the SLy4 Skyrme force. A close correlation is found between the quantum numbers of the valence neutrons and the changes in the position and the diffuseness of the nuclear surface, which in turn affect the neutron skin thickness. Neutrons in the valence orbitals with low principal quantum number and high angular momentum mainly displace the position of the neutron surface outwards, while neutrons with high principal quantum number and low angular momentum basically increase the diffuseness of the neutron surface. The impact of the valence shell neutrons on the tail of the neutron density distribution is discussed.

PB 123

Postprint (published version)

Comportamento da atomização eletrotérmica de ouro, prata, bismuto, cádmio, chumbo e estanho em soluções aquosas e em etanol, a partir de diferentes superfícies atomizadoras

The atomization behavior of Au, Ag, Bi, Cd, Pb, and Sn from pyrolitic graphite coating (L'vov platform) with the use Pd and Mg solutions, and zirconium coated platform with the analytes in nitric acid 0.2% v/v and in ethanol was investigated. In ethanol medium, the sensitivity gain was three-fold for Bi and Cd using Zr as modifier. Without modifier, the ethanol medium is appropriate only for Au and Cd. In nitric acid medium, the Zr coated platform elevates sensitivity at least two-fold for Bi and Cd. The method was applied to the determination of Ag, Au and Bi of certified steel samples, after on-line preconcentration, sorption on a minicolumn filled with C-18 bonded to silica gel and elution with ethanol. The concentrations obtained agreed with the recommended values.

Adsorção de As, Cu, Pb e Cr na avaliação da capacidade de fixação de metais por resíduo de mineradoras de ferro

Two samples of residues from iron mining plants have been investigated for their retention capacity of As, Cu, Cr, and Pb. The sample with the higher content of iron oxides showed the highest capacity to retain metals. The adsorption affinity series changes from Pb>Cu>Cr~As to As>Pb>Cu>Cr or As>Cu>Cr>Pb, depending on the material and the concentration of the initial solution. In the competitive environment, the Pb adsorption decreases and the As, Cu and Cr adsorption increases. Sequential extraction procedures, carried out after adsorption batch experiments, showed that the most important adsorption process occurs in the oxide fraction and that the major part of the absorbed metal is remobilized from exchangeable and oxide fractions.

Preparação de amostra de fígado bovino e estudo de micro homogeneidade para a determinação de Cd E Pb por espectrometria de absorção atômica com atomização eletrotérmica e amostragem direta de sólido

This work describes a systematic study for bovine liver sample preparation for Cd and Pb determination by solid sampling electrothermal atomic absorption spectrometry. Samples were prepared using different procedures: (1) drying in a household microwave oven followed by drying in a stove at 60 ºC until constant mass, and (2) freeze-drying. Ball and cryogenic mills were used for grinding. Particle size, sample size and micro sample homogeneity were investigated. All prepared samples showed good homogeneity (He < 10) even for low sample mass, but samples dried in a microwave oven/stove and ground in a ball mill presented the best homogeneity.

Aplicação de Zr/Ti-PILC no processo de adsorção de Cu(II), Co(II) e Ni(II) utilizando modelos físico-químicos de adsorção e termodinâmica do processo

The aim of this investigation is to study how Zr/Ti-PILC adsorbs metals. The physico-chemical proprieties of Zr/Ti-PILC have been optimized with pillarization processes and Cu(II), Ni(II) and Co(II) adsorption from aqueous solution has been carried out, with maximum adsorption values of 8.85, 8.30 and 7.78 x10-1 mmol g-1, respectively. The Langmuir, Freundlich and Temkin adsorption isotherm models have been applied to fit the experimental data with a linear regression process. The energetic effect caused by metal interaction was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.

Determinação simultânea de As, Cd e Pb em amostras de água purificada para hemodiálise por espectrometria de absorção atômica com forno de grafite, após otimização multivariada baseada no uso de planejamento experimental

This paper reports the development of a methodology for simultaneously determining As, Cd and Pb, employing GF AAS with polarized Zeeman-effect background correction. In order to make the procedure applicable, the influence of pyrolysis and atomization temperatures and the amount of chemical modifiers were studied. Factorial and central composite designs were used to optimize these variables. Precision and accuracy of the method were investigated using Natural Water Reference material, Nist SRM 1640. Results are in agreement with certified values at the 95% confidence limit when the Student t-test is used. This methodology was used for quality control of purified water for hemodialysis.

Determination of Cd and Pb in fuel ethanol by filter furnace electrothermal atomic absorption spectrometry

A method was developed for quantification of Cd and Pb in ethanol fuel by filter furnace atomic absorption spectrometry. Filter furnace was used to eliminate the need for chemical modification, to stabilize volatile analytes and to allow the application of short pyrolysis step. The determinations in samples were carried out against calibration solutions prepared in ethanol. Recovery tests were made in seven commercial ethanol fuel samples with values between 90 and 120%. Limits of detection were 0.1 µg L-1 for Cd and 0.3 µg L-1 for Pb. Certified water samples (APS 1071, APS 1033, NIST 1643d, NIST 1640) were also used to evaluate accuracy and recoveries from 86.8% to115% were obtained.

Analytical procedures for determining Pb and Sr isotopic compositions in water samples by ID-TIMS

Few articles deal with lead and strontium isotopic analysis of water samples. The aim of this study was to define the chemical procedures for Pb and Sr isotopic analyses of groundwater samples from an urban sedimentary aquifer. Thirty lead and fourteen strontium isotopic analyses were performed to test different analytical procedures. Pb and Sr isotopic ratios as well as Sr concentration did not vary using different chemical procedures. However, the Pb concentrations were very dependent on the different procedures. Therefore, the choice of the best analytical procedure was based on the Pb results, which indicated a higher reproducibility from samples that had been filtered and acidified before the evaporation, had their residues totally dissolved, and were purified by ion chromatography using the Biorad® column. Our results showed no changes in Pb ratios with the storage time.