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1.
J Microsc ; 282(1): 45-59, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33216353

RESUMO

A new high-temperature detector dedicated to the collection of backscattered electrons is used in combination with heating stages up to 1050°C, in high-vacuum and low-vacuum modes in order to evaluate its possibilities through signal-to-noise ration measurements and different applications. Four examples of material transformations occurring at high temperature are herein reported: grain growth during annealing of a rolled platinum foil, recrystallisation of a multiphased alloy, oxidation of a Ni-based alloy and complex phase transformations occurring during the annealing of an Al-Si coated boron steel. The detector could be potentially adapted to any type of SEM and it offers good opportunities to perform high-temperature experiments in various atmospheres.

2.
Arq. bras. med. vet. zootec. (Online) ; 71(5): 1591-1594, set.-out. 2019. ilus
Artigo em Português | VETINDEX, LILACS | ID: biblio-1038658

RESUMO

O presente artigo é um relato sobre uma fêmea de D. novemcinctus que foi capturada de forma imprevista, durante um projeto de avaliação sanitária de animais silvestres sinantrópicos do município de Toledo/PR (autorização Sisbio/Ibama n. 55109-1). Durante a avaliação física, amostras de fezes foram coletadas após defecação espontânea e encaminhadas para análise. O material foi submetido aos métodos de flutuação simples em solução hipersaturada de cloreto de sódio e centrífugo-flutuação em sacarose. Na leitura das lâminas obtidas pelo método de centrífugo-flutuação em sacarose, foram observadas estruturas com comprimento de aproximadamente 10µm, forma bicônica e um tampão em cada extremidade, compatíveis com esporocistos de Monocystis sp. Protozoários do filo Apicomplexa, os Monocystis sp., são geralmente parasitas de anelídeos, como as minhocas. Esse organismo é comumente correlato a pseudoparasitismo em vários animais, porém não foram encontrados relatos de pseudoparasitismo desse agente em tatus-galinhas, logo essa é a primeira descrição de Monocystis sp. em espécime de D. novemcinctus.(AU)


The present article is an account of a female of D. novemcinctus which was captured during a sanitary evaluation project of synanthropic wild animals of the municipality of Toledo/PR (license SISBIO/ICMBIO n°. 55109-1). During a physical evaluation, samples of feces were collected, after spontaneous defecation, and sent for analysis. The material was subjected to simple flotation methods in hypersaturated sodium chloride solution and centrifugal-flotation solutions in sucrose. In a test reading by the centrifugal-flotation method in sucrose, structures with approximately 10µm, biconical shape and one plate at each end were observed, compatible with sporocysts of Monocystis sp. Protozoa of the phylum Apicomplexa, like Monocystis sp., it is common parasitic annelids, such as worms. This organism is a correlate of pseudoparasitism in several animals but was not found to describe this product as an agent in nine banded armadillos, so this is a first description of Monocystis sp. in specimen of D. novemcinctus.(AU)


Assuntos
Animais , Feminino , Tatus/parasitologia , Apicomplexa/parasitologia , Animais Selvagens/parasitologia
3.
Micron ; 85: 15-25, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27031057

RESUMO

This paper focusses on the study of the underdrawings of 16th century easel paintings attributed to the workshop of the Portuguese-Flemish Master Frei Carlos. This investigation encompasses multidisciplinary research that relates the results of surface exams (infrared reflectography, standard light photography and infrared photography) with analytical investigations. The surface analysis of Frei Carlos' underdrawings by infrared reflectography has shown heterogeneous work, revealing two different situations: (1) an abundant and expressive underdrawing, revealing a Flemish influence and (2) a simple and outlined underdrawing. This preliminary research raised an important question related to this Portuguese-Flemish workshop and to the analytical approach: Is the underdrawing's heterogeneity, as observed in the reflectograms, related to different artists or is this rather an effect that is produced due to the use of different materials in the underdrawing's execution? Consequently, if different materials were used, how can we have access to the hidden underdrawings? In order to understand the reasons for this dissemblance, chemical analysis of micro-samples collected in underdrawing areas and representing both situations were carried out by optical microscopy, micro Fourier transform infrared spectroscopy (µ-FTIR), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDX) and micro-Raman spectroscopy (µ-Raman). Taking into account the different possibilities and practical and theoretical limitations of surface and punctual examinations in the study of easel painting underdrawings, the methodology of research was adjusted, sometimes resulting in a re-analysis of experimental results. This research shows the importance of combining multispectral surface exams and chemical analysis in the understanding of the artistic creative processes of 16th century easel paintings.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 157: 146-152, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26761414

RESUMO

In archaeometry, the advantages of a combined use of Raman spectroscopy and X-ray fluorescence spectroscopy are extensively discussed for applications such as the analysis of paintings, manuscripts, pottery, etc. Here, we demonstrate for the first time the advantage of using both techniques for analysing glyptics. These engraved gemstones or glass materials were originally used as stamps, to identify the owner, for instance on letters, but also on wine vessels. For this research, a set of 64 glyptics (42 Roman glass specimens and 22 modern ones), belonging to the collection of the museum 'Quinta das Cruzes' in Funchal (Madeira, Portugal), was analysed with portable Raman spectroscopy and handheld X-ray fluorescence (hXRF). These techniques were also used to confirm the gemological identification of these precious objects and can give extra information about the glass composition. Raman spectroscopy identifies the molecular composition as well as on the crystalline phases present. On the other hand, hXRF results show that the antique Roman glass samples are characterised with low Pb and Sn levels and that the modern specimens can be discriminated in two groups: lead-based and non-lead-based ones.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 153: 379-85, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26344483

RESUMO

This case study illustrates the analytical characterization of 12 academic nude paintings by Veloso Salgado, made between 1883 and 1893. The study was done with in situ methods (infrared reflectography and EDXRF) and benchtop equipment (Raman and FTIR microscopes and SEM-EDS). Infrared reflectography revealed underdrawings, painting style, execution method and retouched/restored areas. Analytical techniques allowed the identification of gypsum, lead white, barium white, zinc white, yellow ochre, chrome yellow, zinc yellow, vermilion, synthetic ultramarine blue, cerulean blue, Prussian blue, viridian, green earth, Paris green, red ochre, raw umber and lamp black. These results provide valuable information on Salgado's palette and his artistic production technique and allow the distinction between palettes used in Lisbon and Paris and consequently, technical interchanges between both Academies. Finally, this study intends to start a systematic analytical study of the Faculty of Fine Arts' collection, allowing the characterization of many other authors and their influences for the development of painting methodology in this Academy.

7.
Anal Bioanal Chem ; 406(3): 887-95, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24327076

RESUMO

The knowledge about the microbial communities present in mural paintings is of utmost importance to develop effective conservation and mitigation strategies. The present paper describes a methodological approach for the detailed characterisation of microorganisms thriving in mural paintings by combining culture-dependent methods that allow the identification of microorganisms capable of growing in the laboratory conditions and to obtain high cell densities for further studies, and culture independent methods, such as denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. The coupled use of culture-dependent methods and DGGE does not give enough information to investigate the diversity and abundance of microorganisms present in wall paintings. Pyrosequencing, a novel molecular technique, used here for the first time in this area of research, allowed the identification of a large number of microorganisms, confirming some already identified by the cultivation-dependent methods such as fungi of the genera Penicillium and Cladosporium, but also providing a great contribution in the identification of several genera and species, not previously identified in these artworks, giving also a detailed overview of contaminants which was not possible with the other approaches. The results obtained on several mural painting samples show a strong relationship between the most deteriorated areas of the paintings and higher microbial contamination.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Contaminação por DNA , Difosfatos/química , Pinturas , Análise de Sequência de DNA/métodos , Contagem de Colônia Microbiana , Microscopia Eletrônica de Varredura
9.
Microsc Microanal ; 17(5): 702-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21888755

RESUMO

In this work, we present the results of an analytical method developed for detailed pigment identification, stratigraphy, and degradation of the paint layers of mural paintings applied in the study of the 17th century frescoes from the Misericordia Church of Odemira (Southwest Portugal). In situ X-ray fluorescence spectrometry analyses were performed on three panels of the mural paintings and complemented by colorimetric measurements. The different color areas were also sampled as microfragments (approx. 1 mm2) that were studied as taken or mounted in epoxy resin to expose the different paint layers. The microfragments of paint layers and their cross sections were characterized by optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Furthermore, elemental analysis was obtained with spatially resolved confocal synchrotron radiation µ-X-ray fluorescence spectrometry performed at ANKA synchrotron FLUO beamline. Occasionally, phase analysis by µ-X-ray diffraction was also performed. Results from the different techniques allowed pigment identification and, in some cases, the evaluation of color changes due to degradation processes and, considering the Southern Portugal geology, the identification of their possible provenance. The pigments used were essentially yellow, brown and red ochres, smalt blue, copper green, and black earths, probably from local sources.

10.
Sci Total Environ ; 380(1-3): 237-46, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17379272

RESUMO

The efficiency of constructed wetlands systems in the removal of pollutants can be significantly enhanced by using a support matrix with a greater capacity to retain contaminants by sorption phenomena, ionic exchange or other physico-chemical processes. The aim of this work was to evaluate the efficiencies of 3 different materials, Light Expanded Clay Aggregates [LECA] (in two different particle sizes), Expanded Perlite and Sand, for the removal from water of one pharmaceutical compound (clofibric acid) and one pesticide (MCPA). Both belong to the class of phenoxyacetic compounds. In addition, relationships were established between the compounds' removal efficiencies and the physico-chemical properties of each material. LECA exhibited a high sorption capacity for MCPA, while the capacity for clofibric acid was more modest, but still significant. In contrast, perlite had a very limited sorption capacity while sand did not exhibit any sorption capacity for any of the compounds. LECA with smaller particle sizes showed higher efficiencies than larger grade LECA and can achieve efficiencies near 100% for the lower concentrations in the order of 1 mg l(-1). However, the use of these smaller particle media at larger scales may present problems with hydraulic conductivities. The results show that expanded clay presents important advantages in laboratory studies and could be used as a filter medium or a support matrix in constructed wetlands systems.


Assuntos
Fenoxiacetatos/metabolismo , Eliminação de Resíduos Líquidos/instrumentação , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Áreas Alagadas , Ácido 2-Metil-4-clorofenoxiacético/análise , Ácido 2-Metil-4-clorofenoxiacético/química , Ácido 2-Metil-4-clorofenoxiacético/metabolismo , Adsorção , Óxido de Alumínio/química , Silicatos de Alumínio/química , Argila , Ácido Clofíbrico/análise , Ácido Clofíbrico/química , Ácido Clofíbrico/metabolismo , Filtração , Tamanho da Partícula , Fenoxiacetatos/análise , Fenoxiacetatos/química , Dióxido de Silício/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
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