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Ageing mechanism and mechanical degradation behaviour of polychloroprene rubber in a marine environment: Comparison of accelerated ageing and long term exposure ArchiMer
Le Gac, Pierre-yves; Le Saux, V.; Paris, M; Marco, Y..
Polymers are widely used in marine environments due to their excellent properties and good weathering resistance. Despite this extensive use, their long term behaviour in such an aggressive environment is still not well known. To assess the polymer durability within reasonable durations, it is essential to perform accelerated ageing tests to accelerate the degradation kinetics but without any modification of the degradation process. This study therefore proposes and validates accelerated ageing tests to study marine ageing of a silica-filled chloroprene rubber (CR) used for offshore applications. Several accelerated ageing protocols are investigated for temperatures ranging from 20 to 80 degrees C in renewed natural seawater. The ageing consequences are...
Tipo: Text Palavras-chave: Chloroprene rubber; Degradation; Sea water; Silica; Accelerated ageing; Natural ageing.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00073/18429/20232.pdf
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Anatomical characterization of Passiflora cincinnata Mast. fruit subjected to refrigeration Rev. Bras. Frutic.
Carvalho,Carolina Rodrigues Victor de; Mapeli,Ana Maria; Oliveira,Andreia Barroncas de.
Abstract Passiflora cincinnata is a species of wild passion fruit whose fruit has potential for use by the food industry. In this context, an anatomical study of the pericarp may help in understanding the changes which occur during the postharvest period. The objective of this work was to anatomically characterize the P. cincinnata pericarp, focusing on the structural changes which occur during refrigerated storage. The selected fruits were kept in net-like packaging at 5°C and evaluated every 15 days for a period of 90 days. Pericarp samples were hand cut on these dates for structural description and to detect starch, phenolic compounds, alkaloids, polysaccharides, proteins, lipids and lignin through histochemical tests. Other samples were analyzed by...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Calcium oxalate crystals; Wild passion fruit; Postharvest; Histochemical tests; Silica.
Ano: 2021 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452021000200202
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Evaluation of Some Biological Aspects of the Presence of Abrasive Silica and Thickening Silica  in Basic Formulations of Dentifrices International Journal of Morphology
Pedrazzi,Vinícius; Del Ciampo,José Orestes; do Nascimento,Cássio; Issa,João Paulo Mardegan.
The aim of this study was to evaluate some biological characteristics and toxicity of basic formulations of dentifrices containing such substances, and to compare them with two existing products in market which also contains silic in their formulations. In this way, it was evaluated some biological parameters: weight of the animals, oral toxicity, hematological parameters, urinary analysis, and histological evaluation. The thrombocytes were also statistically at normal levels. The glutamate-pyruvate transaminase (TGP) showed normal aspect in 5 of the tested groups, as in control. Meanwhile, the oxalacetic transaminase (AST) in one group had a small increase in the control group. Regarding urine, in exception the rats of one group, the rats of the 4 other...
Tipo: Journal article Palavras-chave: Silica; Dentifrices; Histology; Wistar rats.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022009000100028
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Evaluation of the Toxicity of Silver/Silica and Titanium Dioxide Particles in Mammalian Cells BABT
Pittol,Michele; Tomacheski,Daiane; Simões,Douglas Naue; Ribeiro,Vanda Ferreira; Santana,Ruth Marlene Campomanes.
ABSTRACT The increasing concern over the spread of diseases has lead to a high consumption of antimicrobial additives in the medical and industrial fields. Since these particles can lixiviate from loaded materials, the contact between this additive and mammalian cells can occur during manufacture, use and disposal of the products. Silver on fumed silica (AgNP_SiO2) and titanium dioxide (TiO2) can be used as antimicrobial additives that are applied in polymeric formulation. While these additives can inhibit bacteria, fungus and virus proliferation; they may also be harmful to humans. Standard toxicological studies were undertaken using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide), CBPI (cytokinesis-block proliferation index) and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Titanium dioxide; Silver; Silica; Toxicology; Mammalian cell.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100318
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Geochemistry and mineralogy of a silica chimney from an inactive seafloor hydrothermal field (East Pacific Rise, 18°S) ArchiMer
Dekov, V. M.; Lalonde, Stefan; Kamenov, G. D.; Bayon, Germain; Shanks, W. C., Iii; Fortin, D.; Fouquet, Yves; Moscati, R. J..
An inactive vent field comprised of dead chimneys was discovered on the ultrafast East Pacific Rise (EPR) at 18°S during the research campaign NAUDUR with the R/V Le Nadir in December 1993. One of these chimneys was sampled, studied and found to be largely composed of silica-mineralized bacterial-like filaments. The filaments are inferred to be the result of microbial activity leading to silica (± Fe-oxyhydroxide) precipitation. The chimney grew from the most external layer (precipitated 226 ± 4 yr. B.P.) towards the central chimney conduit. Hydrothermal activity ceased 154 ± 13 yr. B.P. and the chimney conduit was completely sealed. Mixing between an end-member hydrothermal fluid and seawater explains the Sr–Nd isotopic composition of the chimney....
Tipo: Text Palavras-chave: Chimney; C-O-Si-Sr-Nd-Pb-Th-U isotopes; Hydrothermal; Seafloor; Silica.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00280/39143/37698.pdf
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High-latitude forcing of diatom productivity in the southern Agulhas Plateau during the past 350 kyr ArchiMer
Romero, O. E.; Kim, J. -h.; Barcena, M. A.; Hall, I. R.; Zahn, R.; Schneider, R..
The hydrography of the Indian-Atlantic Ocean gateway has been connected to high-latitude climate dynamics by oceanic and atmospheric teleconnections on orbital and suborbital timescales. A wealth of sedimentary records aiming at reconstructing the late Pleistocene paleoceanography around the southern African continent has been devoted to understanding these linkages. Most of the records are, however, clustered close to the southern South African tip, with comparatively less attention devoted to areas under the direct influence of frontal zones of the Southern Ocean/South Atlantic. Here we present data of the composition and concentration of the diatom assemblage together with bulk biogenic content and the alkenone-based sea surface temperature (SST)...
Tipo: Text Palavras-chave: Agulhas; SST; Diatoms; Fronts; Silica; Southern Ocean.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00294/40555/39440.pdf
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Immobilization of cyclodextrin glucanotransferase on aminopropyl-functionalized silica-coated superparamagnetic nanoparticles Electron. J. Biotechnol.
Ibrahim,Abdelnasser S.S.; Al-Salamah,Ali A; El-Toni,Ahmed Mohamed; El-Tayeb,Mohamed A; Elbadawi,Yahya B.
Background: Cyclodextrin glycosyltransferase (CGTase) from Amphibacillus sp. NPST-10 was successfully covalently immobilized on aminopropyl-functionalized silica coated superparamagnetic nanoparticles; and the properties of immobilized enzyme were investigated. The synthesis process included preparing of core magnetic magnetite (Fe3O4) nanoparticles using solvothermal synthesis; followed by coating of Fe3O4 nanoparticles with dense amino-functionalized silica (NH2-SiO2) layer using in situ functionalization method. The structure of synthesized Fe3O4@NH2-SiO2 nanoparticles was characterized using TEM, XRD, and FT-IR analysis. Fe3O4@NH2-SiO2 nanoparticles were further activated by gluteraaldehyde as bifunctional cross linker, and the activated nanoparticles...
Tipo: Journal article Palavras-chave: Amphibacillus sp. NPST-10; Cyclodextrin glucanotransferase; Immobilization; Magnetic nanoparticle; Silica.
Ano: 2013 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000600010
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Interferência da fração mineral na estimativa do grau de humificação da matéria orgânica em agregados organominerais por ressonância paramagnética eletrônica Rev. Bras. Ciênc. Solo
Bayer,C.; Martin-Neto,L.; Saab,S. C.; Mielniczuk,J..
A concentração de radicais livres semiquinona (CRLS), determinada por ressonância paramagnética eletrônica (EPR), é considerada um índice do grau de humificação, sendo uma importante determinação em estudos qualitativos da matéria orgânica do solo. Neste trabalho, avaliou-se a interferência da fração mineral na quantificação da CRLS em agregados organominerais 20-53, 2-20 e < 2 ∝m de Podzólico Vermelho-Amarelo, Podzólico Vermelho-Escuro e Latossolo Roxo. A CRLS foi determinada pela área do sinal, estimada pela aproximação intensidade do sinal (I, em cm), multiplicada pela sua largura de linha ao quadrado (∆H², em Gauss). Os parâmetros espectrais I e ∆H foram obtidos em espectros de EPR com e sem interferência da fração mineral. No Podzólico...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Radical livre semiquinona; Ferro; Silica.
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832000000100002
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Isolation of high quality DNA: a protocol combining &#8220;rennet&#8221; and glass milk Electron. J. Biotechnol.
Valter de Oliveira,Luiz Felipe; Wallau,Gabriel da Luz; Silva Loreto,Elgion Lucio.
High quality DNA is essential for many molecular biology techniques. However, the reagents used for that purpose usually are expensive and/or cause a high environmental impact. Here, we describe two alternative protocols that use inexpensive reagents and are not hazardous to the environment. The first protocol utilizes the enzyme chymosin, normally used as &#8220;rennet&#8221; in cheese production and which is easily obtained on the commercial market. The second protocol uses &#8220;rennet DNA extraction protocol&#8221; combined with the DNA binding capacity of glass powder (glass milk), which can easily be &#8220;home made&#8221;. The first protocol is used when a high yield of DNA is needed, whereas the second protocol is used for...
Tipo: Journal article Palavras-chave: Chymosin; DNA extraction; Glass milk; Rennet; Rennin; Silica.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000200011
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Ni isotope fractionation during coprecipitation of Fe(III)(oxyhydr)oxides in Si solutions ArchiMer
Neubeck, Anna; Hemmingsson, Christoffer; Boosman, Arjen; Rouxel, Olivier; Bohlin, Madeleine.
The dramatic decline in aqueous Ni concentrations in the Archean oceans during the Great Oxygenation Event is evident in declining solid phase Ni concentrations in Banded Iron Formations (BIFs) at the time. Several experiments have been performed to identify the main removal mechanisms of Ni from seawater into BIFs, whereby adsorption of Ni onto ferrihydrites has shown to be an efficient process. Ni isotopic measurements have shown limited isotopic fraction during this process, however, most experiments have been conducted in simple solutions containing varying proportions of dissolved Fe and Ni as NO3 salts, as opposed to Cl salts which are dominant in seawater. Further, Archean oceans were, before the advent of siliceous eukaryotes, likely saturated with...
Tipo: Text Palavras-chave: Stable Ni isotopes; Ferrihydrite precipitation; Co-precipitation experiment; Banded; Iron Formation; Silica.
Ano: 2021 URL: https://archimer.ifremer.fr/doc/00661/77275/78710.pdf
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Novos sorventes baseados em Poli(Metiloctilsiloxano) sobre sílica para uso em extração em fase sólida. Repositório Alice
QUEIROZ, S. C. do N. de; MELO, L. F. C.; JARDIM, I. C. S. F..
This paper presents an easy and practical procedure to obtain silica-based C-8 type sorbents for use in solid-phase extraction. The materials are prepared by depositing poly(methyloctylsiloxane), PMOS, on the silica support. Two different treatments for immobilization were used: thermal treatment or gamma irradiation. Suitable recoveries were obtained after pre-concentration of dilute solutions, at the ng/L level, of a mixture of pesticides, indicating the good performance of the materials.
Tipo: Artigo de periódico Palavras-chave: Extração em fase sólida; Técnica; Polímero; Sorvente; Irradiação gama; Procedimentos.; Silica; Pesticida; Tratamento Térmico..
Ano: 2006 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/15350
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OBSERVAÇÃO MICROSCÓPICA DE INCLUSÕES MINERAIS NO XILEMA DE ESPÉCIES TROPICAIS DA AMAZÔNIA Acta Amazonica
VASCONCELLOS,Francisco José de; FREITAS,Jorge Alves de; SILVA,Ademir Castro e.
Foi investigada a distribuição de inclusões minerais (cristais e grãos de sílica) no xilema secundário de 53 famílias, representando 250 espécies de madeiras amazônicas. Grãos de silica ocorrem em cerca de 36% das espécies estudadas, frequentemente nas células dos raios. Cristais nas células dos raios são geralmente solitários, enquanto que nas fibras e células do parênquima axial são algumas vezes em cadeias cristalíferas. Os cristais são frequentemente do tipo prismático e somente em uma espécie (Scleronema micranthum)foi encontrado cristal do tipo drusa.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Madeiras da Amazônia; Inclusões minerais; Silica; Cristais.
Ano: 1995 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59671995000200055
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Survival of groundnut seeds under different storage conditions Open Agri
Sastry, D.V.S.S.R..
Palavras-chave: Seed viability; Seed longevity; Seed testing; Seed storage; Groundnuts; Sampling; Silica; Storage; Germplasm; Temperature.
Ano: 2007 URL: http://agropedia.iitk.ac.in/openaccess/?q=node/3356
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Weathering Resistance of Waterborne Polyurethane Coatings Reinforced with Silica from Rice Husk Ash Anais da ABC (AABC)
MONTEIRO,WESLEY F.; MIRANDA,GABRIELA M.; SOARES,RAFAEL R.; SANTOS,CLÁUDIA A.B. DOS; HOFFMANN,MAURÍCIO S.; CARONE,CARLOS L.P.; LIMA,VIVIANE DE; SOUZA,MILTON F. DE; CAMPANI,ADRIANO D.; EINLOFT,SANDRA M.O.; LIMA,JEANE E. DE; LIGABUE,ROSANE A..
Abstract: Waterborne polyurethanes (WPUs) are interesting materials for coatings when compared to solvent-based polyurethanes, once that reducing the concentration of volatile organic compounds that are harmful for human health and the environment. However, the WPU has low weathering resistance. In order to improve this behavior among others properties, inorganic fillers has been added in these systems. SiO2 particles from various sources, mainly, from agro-industrial waste, as rice husk has attracted the scientific and technological interest. In this study, the accelerated weathering essay was performed in waterborne polyurethane (WPU)/ silica (from rice husk ash) composites in order to evaluate the thermal and physical changes in these materials. These...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Waterborne polyurethane; Rice husk ash; Silica; Accelerated weathering resistance.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000700403
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دراسة مواد البناء البديلة فى منطقة البحر الأحمر: المواد البوزولانية OceanDocs
Edris, Abass Edris Alsaid.
Pozzolana is a materials that content Reactive Silica with Alumina which defines as Siliceous materials, also include ferroginous materials. In generally, this study aimed to estimate Alternative building materials ( pozzolanic materials ) and create new cementic materials such as Lime-Pozzolana Cement and Ordinary Portland-Pozzolana Cement . The results shows that there is no good and sufficient pozzolanic materials as Obsidian , Scoria, Diatomaceous Earth and Volcanic Ash , but some types of burnt clays and Rhyolite in addition to bricks Reject and miskeet Ash was shown . This study is subjected in Arbaat Delta clay , salloum Delta clay , Rhyolite Rocks , bricks Reject and miskeet Ask as Natural and artificial pozzolanic materials. The identification of...
Tipo: Theses and Dissertations Palavras-chave: Silica.
Ano: 2012 URL: http://hdl.handle.net/1834/5073
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ใช้ซิลิก้าควบคุมแมลงศัตรูข้าว Thai Agricultural
Patchanee Chaiyawat.
Tipo: Collection Palavras-chave: Rice; Insect pest Control; Silica; ข้าว; แมลงศัตรูข้าว; การป้องกันกำจัด; ซิลิก้า.
Ano: 2005 URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5294
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