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1.
J Chem Technol Biotechnol ; 89(9): 1317-1323, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25558121

RESUMO

BACKGROUND: Iron ochres are gelatinous sludges that can cause problems in terms of water management. In this work, the application of iron ochre obtained from a river has been applied to catalytically crack methane - another potential waste product - into two useful products, hydrogen and a magnetic carbon-containing composite. RESULTS: The powder X-ray diffraction (XRD) pattern of the iron ochre was found to be consistent with the expected 2-line ferrihydrite, and energy dispersive X-ray (EDX) analysis showed Fe to be a major component although some Si and Ca were present. The sample was observed to contain a fraction with a tubular morphology consistent with the presence of extra-cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transform into an active catalyst for hydrogen production yielding a magnetic carbon-containing composite material comprising filamentous carbon and encapsulating graphite. CONCLUSION: The application of two waste products - iron ochre and methane - to generate two useful products - hydrogen and a magnetic carbon-containing composite - has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra-cellular biogenic iron oxide which may be of interest in terms of other applications. © 2014 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

2.
Chem Commun (Camb) ; 48(13): 1877-9, 2012 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-22228444

RESUMO

Bulk quantities of graphene nanosheets and nanodots have been selectively fabricated by mechanical grinding exfoliation of natural graphite in a small quantity of ionic liquids. The resulting graphene sheets and dots are solvent free with low levels of naturally absorbed oxygen, inherited from the starting graphite. The sheets are only two to five layers thick. The graphene nanodots have diameters in the range of 9-29 nm and heights in the range of 1-16 nm, which can be controlled by changing the processing time.


Assuntos
Grafite/química , Química Verde/métodos , Líquidos Iônicos/química , Nanopartículas/química , Nanotecnologia/métodos
3.
Phys Chem Chem Phys ; 13(47): 20923-6, 2011 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-22030615

RESUMO

Tungsten oxide nanorods were prepared from commercial crystalline WO(3) particles treated with triethylamine under electron beam irradiation in an electron microscope operating at 200 kV. The amine acts as a molecular knife, cleaving the particles under beam irradiation.

4.
Chem Commun (Camb) ; (23): 2677-9, 2008 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-18535705

RESUMO

A facile one-pot approach gave isolated silver nanoparticles anchored on a mesostructured silica matrix in a self-assembled way; these gave 100% CO conversion in CO oxidation at room temperature, which is higher than or comparable to the conversion obtained using noble metal catalysts.

5.
Chem Commun (Camb) ; (32): 3411-3, 2006 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-16896478

RESUMO

Mesostructured silicates containing metal nanoparticles have been synthesised via templating around a pre-formed, metal-containing mesophase using a non-ionic surfactant.


Assuntos
Cristais Líquidos/química , Metais Pesados/química , Nanopartículas/química , Silicatos/síntese química , Tamanho da Partícula , Porosidade , Sensibilidade e Especificidade , Silicatos/química , Espectrofotometria , Raios X
6.
Chem Commun (Camb) ; (32): 3414-6, 2006 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-16896479

RESUMO

Using a one-pot approach employing true liquid crystal templating on neutral surfactants and simple metal salt precursors, mesostructured, mesoporous silicates have been prepared in which bimetallic nanoparticles are deposited; magnetic properties of PtCo systems so prepared are evaluated.


Assuntos
Magnetismo , Metais Pesados/química , Nanopartículas/química , Silicatos/síntese química , Dióxido de Silício/química , Cobalto/química , Tamanho da Partícula , Platina/química , Porosidade , Silicatos/química
7.
J Histochem Cytochem ; 50(3): 353-64, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11850438

RESUMO

Postnatal skeletal muscle fiber type is commonly defined by one of four major myosin heavy chain (MyHC) gene isoforms (slow/I, 2a, 2x, and 2b) that are expressed. We report on the novel use of combined TaqMan quantitative real-time RT-PCR and image analysis of serial porcine muscle sections, subjected to in situ hybridization (ISH) and immunocytochemistry (IHC), to quantify the mRNA expression of each MyHC isoform within its corresponding fiber type, termed relative fiber type-restricted expression. This versatile approach will allow quantitative temporospatial comparisons of each MyHC isoform among muscles from the same or different individuals. Using this approach on porcine skeletal muscles, we found that the relative fiber type-restricted expression of each postnatal MyHC gene showed wide spatial and temporal variation within a given muscle and between muscles. Marked differences were also observed among pig breeds. Notably, of the four postnatal MyHC isoforms, the 2a MyHC gene showed the highest relative fiber type-restricted expression in each muscle examined, regardless of age, breed, or muscle type. This suggests that although 2a fibers are a minor fiber type, they may be disproportionately more important as a determinant of overall muscle function than was previously believed.


Assuntos
Expressão Gênica , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/genética , Suínos/crescimento & desenvolvimento , Actinas/genética , Envelhecimento , Animais , Imuno-Histoquímica , Hibridização In Situ , Fibras Musculares Esqueléticas/química , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/química , Isoformas de Proteínas/genética , Sondas RNA , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Especificidade da Espécie , Suínos/metabolismo
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