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Nanopartículas de MCM-41 fueron utilizadas como soporte para el complejo metalocénico (Me2Si(Ind)2ZrCl2) y su cocatalizador metilaluminoxano (MAO), en la síntesis de polipropileno, Primeramente se estudiaron dos metodologías de impregnación, observando los efectos en la actividad catalítica y masa molecular. Con estos resultados posteriormente una tercera metodología de impregnación, más optimizada, fue utilizada consiguiendo significativas mejoras en la actividad catalítica. Los polímeros obtenidos fueron caracterizados por GPC y TGA. La utilización de estas nanopartículas como soporte dio lugar a la formación de nanocompósitos de polipropileno de manera in situ. La última metodología de impregnación empleada resultó ser adecuada para este propósito, ya que permite modificar la cantidad de soporte que se desea incorporar y variar la concentración de catalizador que será impregnada.

A preservação do património cultural é vista, atualmente, como uma questão de cidadania, tendo-se assistido a uma tendência para a proteção dos sítios cujo património cultural abrange, também, a paisagem. Este artigo apresenta uma proposta de criação de uma Infraestrutura de Dados Espaciais (IDE) regional e temática, complementada por um Sistema de Informação Geográfica (SIG) para o Alto Douro Vinhateiro (ADV), território classificado pela UNESCO, em 14 de Dezembro de 2001, como Património Mundial na categoria de paisagem cultural. O desenvolvimento de uma IDE consistente e operativa, de modo a promover ações de catalogação e consequente intervenção eficiente e eficaz mas acima de tudo de partilha de dados, implica considerar a dimensão holística da natureza dos mesmos integrando as dimensões histórica, arqueológica, ambiental, arquitetónica, urbanística, económica, social e regulamentar. A utilização da tecnologia SIG pode ser uma prática eficiente para a gestão e preservação de Sítios Culturais Património Mundial da Humanidade, constituindo-se como uma plataforma de análise para a monitorização dos recursos culturais, bem como dos indicadores de desenvolvimento sustentável. A associação da inovação tecnológica à inovação organizacional proporciona os meios necessários para uma gestão racional dos fatores e processos que contribuem para a deterioração ou conservação do património.

Este trabalho pretendeu desenvolver uma aplicação WebSIG (SIAGF, Sistema de Informação e de Apoio à Gestão Florestal; GOMES, 2012) baseada em software Open Source, cujo objetivo passa por centralizar e organizar dados geográficos relevantes para a gestão florestal, promovendo a sua disponibilização e difusão via internet, utilizando uma interface comum. O SIAGF tem por base os Planos de Gestão Florestal e pretende dotar e facilitar o acesso, por parte dos gestores florestais e técnicos, a um conjunto de informação de cariz espacial, de forma rápida, simples e deslocalizada, bem como possibilitar uma maior interação entre estes últimos e o proprietário, que pode aceder de igual forma à informação sobre a sua propriedade. A aplicação está vocacionada para associações, empresas ou entidades públicas, que manipulam e gerem informação relativa a várias propriedades e a vários proprietários. A simplicidade das ferramentas disponíveis permite que o sistema possa ser usado por utilizadores menos familiarizados com os SIG mas que reconhecem a importância da análise espacial no processo de tomada de decisões. This work aims to develop a WebGIS application (SIAGF, System of Information and Support to Forest Management; GOMES, 2012) based on Open Source software, whose goal is to centralize and organize geographic data relevant to forest management, available through the internet, using a simple interface. Access to information is so relocated by an access point to the internet and a computer. The SIAGF is based on Forest Management Plans and aims to provide and facilitate access, by forest managers and technicians, to a set of space-oriented information, quickly, simply and ubiquitous, while we intend to enable greater interaction between managers, technicians and owners. The application is designed for associations, corporations or public entities who manipulate and manage information about properties and their owners. The simplicity of the available tools allows the system to be used even by those less familiar with GIS who recognize the importance of spatial analysis in decision-making.

The use of sulfate-reducing bacteria in bioremediation process for the treatment of afluents with high-content of sulfate and metal generates an excess of sulfide.

This work describes the synthesis of ZnS powders in high yield and via a straightforward process, under ambient conditions (temperature and pressure), by adding to aqueous zinc (II) a nutrient solution containing biologically generated sulfide from sulfate-reducing bacteria (SRB). The powders obtained as above were composed mainly of ZnS (sphalerite) nanoparticles (NP's) exhibiting a spheroidal morphology (20–30 nm). The NP's morphological properties and crystalline phase were not markedly altered by the SRB growth media composition neither by the presence of bacterial cells. The relevance of this method to obtain ZnS supported solid substrates has been demonstrated by performing the synthesis in the presence of TiO2 and SiO2 submicron particles.

During the metabolism of organic matter (CH2O), sulfate-reducing bacteria (SRB) use sulfate as the terminal electron acceptor, resulting in the production of H2S. This biologically generated sulfide, in the presence of metal ions, can be used for metal precipitation (Bhagat et al., 2004). The use of SRB in bioremediation processes, namely, in the reduction of highcontent sulfate and metal effluents, is well documented (Costa and Duarte, 2005; Garcia et al., 2001). Nevertheless, the process generates an excess of sulfide and the elimination of the sulfide in excess and disposal of the metal sulfides produced are also problems that need to be carefully addressed. Copper monosulfide (CuS) has gained considerable attention in material science due to its excellent potential in catalysis (Mallick et al., 2007), optical functionality (Liz-Marzan, 2006) and electronic functionalities (Kamat, 2002).

This paper reviews progress in organometallic -olefin polymerisation catalysts supported on zeolites or mesoporous silicas, discussing the role of these nanostructured materials in establishing new catalytic behaviours and polymer properties. Zeolites and other nanostructured materials show unique structural and surface features that have been used with advantage in the immobilisation of a large variety of catalysts, including -olefin polymerisation catalysts such as metallocene complexes. The characteristics of these materials, such as the ordered porous system, the large surface area and a tuneable acidity have a great impact on the immobilisation of the catalyst, with implication on the formation and nature of active species and polymerisation activity. Methods of preparation, diffusion limitations and confinement effects are rationalised and their role on the catalytic system and final polymer properties is discussed. This review is mainly focused on metallocene catalysts but examples of post-metallocene catalysts and olefin polymerisation behaviour of nonorganometallic complexes, covering Ziegler-Natta Ti/V catalysts and Phillips Cr catalysts, as well as metal-modified mesoporous carriers are described and discussed. Additionally, the effects of the nanostructured supports on the morphologies and physical properties of the polyolefins are also covered, and an account is made on how mesoporous materials can be used in the preparation of novel polyolefin nanoblends and nanocomposites.

In recent years, the development of mechanically reinforced nanocomposites based on biodegradable polyester matrices has gained a strong incentive due to their potential use as biomaterials and to growing worldwide environmental concerns.

Mesoporous silicas exhibit stable three-dimensional structures, made of ordered channels with well-defined geometries and dimensions at nanometer scale, able to host intercalation reactions.

Os autores apresentam dois casos clínicos de tuberculose costal. Em ambos, os doentes eram do sexo masculino, sendo que, no decorrer da investigação, o primeiro dos doentes revelou elevado grau de imunodepressão. Apesar da clínica característica, com um quadro insidioso de febre associada a abcessos frios da parede costal, flutuantes, com tendência a fistulização e tendo ambos os doentes recebido ciclos de antibioterapia sem aparente resposta à mesma, o diagnóstico revelou-se difícil. No primeiro caso, só o elevado grau de suspeição e a decisão de iniciar terapêutica quádrupla antibacilar, com resolução total das queixas, conduziu ao diagnóstico. No segundo caso, apenas o exame realizado em meio de Löwenstein, com material obtido por punção, confirmou o diagnóstico. A tuberculose costal é uma patologia infecciosa rara e de difícil diagnóstico. O mesmo baseia-se no elevado grau de suspeição, na endemicidade da tuberculose e na existência de possíveis comorbilidades imunodepressoras.

Submitted by João Lourenço (jlouren@ualg.pt) on 2012-03-12T17:45:39Z No. of bitstreams: 1 ARKIVOC, 2010.pdf: 305410 bytes, checksum: c47aecc72bfb083ef10030e5089cf4cc (MD5) Approved for entry into archive by Emília Pacheco(epacheco@ualg.pt) on 2012-03-13T23:23:41Z (GMT) No. of bitstreams: 2 ARKIVOC, 2010.pdf: 305410 bytes, checksum: c47aecc72bfb083ef10030e5089cf4cc (MD5) 7220475146155845.zip: 228357 bytes, checksum: 62ae4ebb70b09718364c8f631f0e0d0b (MD5) Made available in DSpace on 2012-03-13T23:23:41Z (GMT). No. of bitstreams: 2 ARKIVOC, 2010.pdf: 305410 bytes, checksum: c47aecc72bfb083ef10030e5089cf4cc (MD5) 7220475146155845.zip: 228357 bytes, checksum: 62ae4ebb70b09718364c8f631f0e0d0b (MD5) Previous issue date: 2010

The synthesis of self-reinforced polyethylene-based materials prepared by in-situ polymerisation is described. The methodology developed uses MCM-41 mesoporous material in a triple role: as catalyst carrier for ethylene polymerisation within its pores and channels in a first stage, as nanofiller of the formed polyethylene matrixdur ing its useful lifetime and, finally, as promoter for long-term waste disposal. As evidenced by FTIR analysis, when the polymer is formed under these confined conditions different interactions between the MCM-41 material and the polyethylene matrix occur, when compared to simple blends. The influence of the filler content on the rigidity of the resulting nanocomposites is analysed by microhardness measurements and corroborated by the storage modulus values: a significant increase in rigidity is observed as the filler contents rises. In addition, thermogravimetric studies show interesting features concerning the degradability of these materials. The catalytic action of MCM-41 during degradation involves a reduction of the energetic requirements for their cracking and, therefore, a positive environmental impact.

Mesoporous MCM-41 exhibits a stable framework structure, well-defined nanopores and a large surface area. When combined with metallocene polymerisation catalyst, these mesoporous materials, provide a unique route for preparing polyolefin-based nanocomposites by in situ polymerisation.

Submitted by Americo Lemos (alemos@ualg.pt) on 2012-04-13T12:32:43Z No. of bitstreams: 1 Tet. Lett. 2009.pdf: 189740 bytes, checksum: cd13d2d1c5b0329a6b45d8cf48265370 (MD5) Approved for entry into archive by Merja Muzavor(mmuzavor@ualg.pt) on 2012-04-18T15:28:58Z (GMT) No. of bitstreams: 2 7748028731142730.zip: 119893 bytes, checksum: 2ca4f697fe0109cac117c57b9c6bd1e1 (MD5) Tet. Lett. 2009.pdf: 189740 bytes, checksum: cd13d2d1c5b0329a6b45d8cf48265370 (MD5) Made available in DSpace on 2012-04-18T15:28:58Z (GMT). No. of bitstreams: 2 7748028731142730.zip: 119893 bytes, checksum: 2ca4f697fe0109cac117c57b9c6bd1e1 (MD5) Tet. Lett. 2009.pdf: 189740 bytes, checksum: cd13d2d1c5b0329a6b45d8cf48265370 (MD5) Previous issue date: 2009

Submitted by João Lourenço (jlouren@ualg.pt) on 2013-01-03T10:31:58Z No. of bitstreams: 1 Cat. com. (2008).pdf: 203438 bytes, checksum: f25fdc3391df5627e186e6d8940f540a (MD5) Approved for entry into archive by Merja Muzavor (mmuzavor@ualg.pt) on 2013-01-07T14:26:23Z (GMT) No. of bitstreams: 2 7220475146155845.zip: 150049 bytes, checksum: cdbbb1d01c80caf00eadccff01427482 (MD5) Cat. com. (2008).pdf: 203438 bytes, checksum: f25fdc3391df5627e186e6d8940f540a (MD5) Made available in DSpace on 2013-01-07T14:26:23Z (GMT). No. of bitstreams: 2 7220475146155845.zip: 150049 bytes, checksum: cdbbb1d01c80caf00eadccff01427482 (MD5) Cat. com. (2008).pdf: 203438 bytes, checksum: f25fdc3391df5627e186e6d8940f540a (MD5) Previous issue date: 2008

The influence of the pH on the infrared spectrum of L-alanine has been analyzed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The amino acid was precipitated from aqueous solutions and dried at 36.5 °C, in order to stabilize cationic L-alanine or alaninium [CH3CH(NH3 +)COOH] at pH 1, the zwitterionic form [CH3CH(NH3 +)COO-] at pH 6, and anionic L-alanine or alaninate [CH3CH(NH2)COO-] at pH 13. New insight on the specific inter and intramolecular interactions in the different forms of L-alanine was reached by a novel methodological approach: an infrared technique not used before to analyze solid amino acid samples (DRIFTS), in combination with a detailed analysis based on spectral deconvolution. The frequency ranges of interest include the carbonyl/carboxyl stretching and amine deformation modes and the OH/NH stretching modes. It was shown that intermolecular hydrogen bonds between the NH3 + and COO- groups are predominant in the zwitterionic form, whereas in cationic L-alanine, H bonds between the COOH groups are responsible for the formation of dimers. In anionic L-alanine, only strong electrostatic interactions between the COOgroups and Na+ ions are proposed, evidencing the relevant role of the counterion.

The spread of systems that provide parallelism either "in-the- large" (grid infrastr-uctures, clusters) or "in-the-small" (multi -core chips), creates new opportunities for exploiting parallelism in a wider spectrum of application domains. However, the increasing complexity of parallel and distributed platforms renders the programming, the use, and the management of these systems a costly endeavor that requires advanced expertise and skills. Therefore, there is an increasing need for powerful support tools and environments that will help end-users, application programmers, software engineers and system administrators to manage the increasing complexity of parallel and distributed platforms. © 2008 Springer-Verlag Berlin Heidelberg. 5168 LNCS 1 2 Conference code: 73640

SAPO-34 and SAPO-11 with an increased number of acid sites were synthesized by adding methylamine (MA) as co-template to tetraethylammonium hydroxide (TEAOH) or dipropylamine (DPA) respectively used as true templates.

International audience; The electronic state spectroscopy of perfluorocyclobutane (c-C4F8) has been investigated using high resolution vacuum ultraviolet (vuv) photoabsorption spectroscopy in the energy range 6.0 11eV . The electron energy loss spectrum (EELS) was also recorded in the nonelectric dipolar interaction mode ( 100eV incident energy, 10° scattering angle) over the 8 14eV energy-loss range and the excited states in the 11 14eV spectral region have been observed. An HeI photoelectron spectrum recorded between 11.0 and 19.8eV is compared with earlier lower resolution results. This has allowed us to derive a more precise value of 12.291±0.002eV for the ground neutral state vertical ionization energy. All spectra presented in this paper represent the highest resolution data yet reported for perfluorocyclobutane, to the best of our knowledge. Ab initio calculations have been performed for helping in the assignment of the spectral bands for both neutral excited states and ionic states.

A novel copper-substituted aluminophosphate (CuIST-2) has been synthesized using methylamine as a templating agent. X-Ray diffraction studies provide evidence for an AEN topology similar to the parent Cu-free IST-2.

Heterogeneous olefin polymerisation catalysts were prepared by combining zirconocene with a series of purely siliceous and Al-containingMCM- 41 supports with different Si/Al ratios, using simplified and improved versions of the well-known direct impregnation and “MAO pre-treatment” methods. The catalysts were tested in ethylene polymerisation. Analysis of polymerisation activities and kinetic profiles led to a rationalisation on the effect of support Si/Al ratios and methods used for catalyst preparation over the catalytic behaviour for ethylene polymerisations. Polymers were characterised by scanning electron microscopy and differential scanning calorimetry. A mechanism is proposed to associate the formation or absence of fibrous morphology with polymerisation activities.

Diffuse reflectance and chromatography techniques were used to study three Ti-MCM-41 solid powders, containing 1%, 2.5% and 8% of Ti, and to investigate the photochemistry of benzophenone adsorbed on their surfaces. The observed ground state absorption, luminescence and transient absorption spectra depend on the Ti content of the solid support. The luminescence intensity of the pure powders and of the solids with adsorbed benzophenone decreases with the Ti content. The benzophenone triplet emission was detected in all solids but its half-lives decrease with the Ti content of the support. Hydrogen-bonded excited benzophenone luminescence is also quenched but was detected only on supports with low Ti percentage. Transient absorption reveals the formation of trapped electrons and the presence of ligand-to-metal charge transfer in the pure solids, under 266 nm excitation. Ti aggregates are present in all used solid supports. Triplet–triplet absorption of benzophenone was observed in all solids under argon atmosphere. Transient absorption due to the OH–benzophenone radical was detected in all conditions and increases with the Ti content of the powder. 2-Hydroxybenzophenone and benzoic acid are the major photodegradation products in air-equilibrated conditions.

O objetivo deste trabalho foi avaliar o efeito da taxa de alimentação de 5%, 7,5% e 10% do peso vivo dia, sobre o desempenho e parâmetros metabólicos de tambaqui. Made available in DSpace on 2012-08-24T01:02:59Z (GMT). No. of bitstreams: 1 PAB4081.pdf: 284901 bytes, checksum: 326521a49b397e8324bb7c3c5a4bd5ea (MD5) Previous issue date: 2006-10-04

Estudos conducentes à avaliação das possibilidades de enrelvamento em vinhas estão a decorrer na Região dos Vinhos Verdes (sub-região de Monção) e na Estremadura (Alenquer). No ensaio de Monção, com a casta ‘Alvarinho’ e no ensaio em Alenquer, com a casta ‘Cabernet Sauvignon’, comparam-se 4 sistemas de gestão do solo. Em qualquer dos ensaios a densidade e a biomassa total da flora foi influenciada significativamente pelas técnicas de gestão do solo tendo-se também verificado uma selecção de espécies por modalidade, com incremento de gramíneas e leguminosas no enrelvamento. No ensaio de Monção, em três anos consecutivos, e comparativamente às modalidades herbicida foliar a toda a área e mobilização do solo, o enrelvamento a toda a área por espécies residentes induziu uma redução significativa da produção e vigor da videira em resultado de um menor peso unitário do cacho e do sarmento, sem afectar a qualidade do mosto à vindima. Nos dois primeiros anos do ensaio de Alenquer (2002-03) os 4 sistemas de gestão do solo - mobilização da entrelinha, cobertura orgânica morta (casca de pinheiro) alternada com enrelvamento natural permanente, enrelvamento natural permanente e enrelvamento semeado permanente - não influenciaram de forma significativa quer a produção quer o vigor das videiras. Quanto à qualidade das uvas, apenas em 2003 se registaram diferenças significativas na acidez total, tendo-se obtido valores inferiores nas modalidades com enrelvamento. Em 2002, devida à elevada precipitação ocorrida no final da maturação, na modalidade mobilizada verificou-se uma maior dificuldade de circulação da máquina de vindimar comparativamente às modalidades com cobertura do solo. Os resultados evidenciam a possibilidade de utilização dos relvados como técnicas passíveis de manipulação do vigor da videira e de melhoria da circulação das máquinas info:eu-repo/semantics/publishedVersion

Apresenta-se o diagnóstico, análise e reforço de um edifício dos anos 30, realizado essencialmente em betão armado, mas com paredes de contorno em cantaria de granito. Devido a uma alteração de uso, de seminário para arquivo, realizaram-se diferentes análises estruturais (lineares e não-lineares) para definir as condições de segurança do edifício. Dada a necessidade de reforço, discutem-se diferentes alternativas e detalha-se o projecto de execução.

Ethylene was copolymerized with the non-conjugated diene 5,7-dimethylocta-1,6-diene by metallocene catalysts, homogenous and supported on MCM-41 mesoporous material activated by methylaluminoxane at room temperature. The employed metallocenes were (BzCp)2ZrCl2 (1), (C18H37Cp)2ZrCl2 (2), (CH3)2Si(Ind)2ZrCl2 (3) and /2C(Cp,Flu)ZrCl2 (4). Diene incorporation and thermal characteristic of the polymers were determined by 13CNMR and DSC. For the homogeneous systems, only the unbridged metallocene (1) showed a decrease in the activity as the diene content was increased. The ability for diene incorporation in the polymer chain followed the catalyst order (1) < (3) < (2) < (4). Regarding the supported systems, it was observed that all of them showed lower activity than the corresponding homogeneous catalysts. A sharp loss of activity in relation to the homogeneous counterpart was noticed by employing the ansa-metallocenes on MCM-41, especially the complex (4) supported catalyst. The effect of the mesoporous material as support on the behavior of the studied metallocene homogeneous systems in ethylene–diene copolymerization was an increase of polymer molecular weight, maintaining the same level of diene incorporation, except for catalyst (2), when a decrease of the diene incorporation was observed.

Cyclic voltammetric experiments of framework Co(II) ions in three different CoAPO structures have provided evidence for a screening effect created by solvent or template molecules which results in a facile oxidation (and a difficult reduction) of the Co(II) ions incorporated into the most open (the less strained) structures. An apparent contradiction of these findings with respect to theoretical expectations is discussed.

Num ensaio instalado na Região dos Vinhos Verdes, sub-região de Monção, com a casta ‘Alvarinho’, compararam-se, durante 3 anos consecutivos, 4 sistemas de manutenção do solo: enrelvamento permanente natural, herbicida foliar a toda a área, mobilização do solo e enrelvamento permanente natural alternado com mobilização do solo. A densidade da flora natural foi influenciada significativamente pelas técnicas de manutenção do solo tendo-se também verificado uma selecção de espécies por modalidade, com incremento de espécies de gramíneas e leguminosas no enrelvamento. Comparativamente às modalidades herbicida foliar a toda a área e mobilização do solo, o enrelvamento a toda a área por espécies residentes induziu uma redução significativa da produção e vigor da videira em resultado de um menor peso unitário do cacho e do sarmento, sem afectar a qualidade do mosto à vindima. A modalidade de enrelvamento permanente natural alternado com mobilização apresentou valores intermédios que não diferiram significativamente das restantes modalidades. Os resultados evidenciam a possibilidade de utilização dos relvados como técnicas passíveis de manipulação do vigor da videira. Todavia, a redução de vigor observada nas modalidades relvadas, caso persista nos próximos anos, poderá comprometer a perenidade da videira, pelo que será de considerar a possibilidade de utilização de modalidades menos competitivas. Dans un essai installé dans la région des “Vinhos Verdes”, avec le cépage blanc ‘Alvarinho’, on a comparé, pendant 3 ans, 4 techniques d’entretien du sol: enherbement permanent naturel, nonculture par désherbage chimique, travail du sol et enherbement permanent naturel alterné (un interligne sur deux) avec travail du sol. La densité de la flore spontanée a été influencé par les techniques d’entretien du sol. On a vérifié aussi une sélection des espèces par traitement, avec une augmentation des graminées et fabacées dans le traitement enherbé. En comparaison avec les traitements non-culture par désherbage chimique et travail du sol, l’enherbement permanent naturel a induit une réduction significative du rendement et de la vigueur de la vigne, sans affecter la qualité du moût à la vendange. L’enherbement permanent naturel alterné avec travail du sol n´a pas présenté des différences significatives dans le rendement et vigueur par rapport aux autres traitements. Les résultats montrent la possibilité d’utiliser l’enherbement permanent pour la maîtrise de la vigueur de la vigne. Toutefois, si la réduction de la vigueur observée sur les traitements enherbés continue dans les prochaines années, la pérennité de la vigne peut être affectée. Dans cette situation il faut utiliser des techniques d’entretien du sol moins compétitives. In a vineyard of the variety ‘Alvarinho’ at northern Portugal, the effect of different soil management systems on flora evolution and richness, vine yield, vigour, and berry composition, was investigated. Four soil management strategies were applied: natural plant cover (RNA), chemical weed control to entire vineyard floor with foliage herbicides (HERB); soil mobilization (MOB) and natural plant cover alternated with soil mobilization (RMOB). The treatments had a significant effect on the flora species number per m². A selection of species was also observed, with an increase of the grass and legume species in the cover cropping treatment. The natural plant cover (RNA) induced a significant yield and vigour reduction due to a lower cluster and shoot weight without affecting berry composition. The RMOB treatment showed intermediate values not significantly different from other treatments. The results show the possibility of the use of the resident vegetation to control vine vigour. Nevertheless if the vigour reduction continues in the next years it can negatively affect vine longevity. In that case the use of low competition management techniques like for example the permanent natural plant cover alternated with soil mobilization seems to be a better choice.

A combination of advanced powder diffraction and NMR techniques have allowed the structure of the novel microporous aluminophosphate IST-1 (|(CH3NH2)4(CH3NHþ 3 )4(OH )4|½Al12P12O48 ) to be elucidated. The framework structure was determined in the non-centrosymmetric space group Pca21 (a ¼ 9:61523ð1Þ AA, b ¼ 8:67024ð1Þ AA, c ¼ 16:21957ð2Þ AA) from high-resolution synchrotron powder diffraction data using the program FOCUS. Extra framework species were then located on difference electron density maps. A hydroxyl group was found to bridge between two of the framework Al atoms, and one methylamine species, presumably protonated, could be located in the channels where it H-bonds to three framework oxygens. The most unusual feature of the structure is the second methylamine molecule, which bonds directly to a framework Al atom. The structure is entirely consistent with 31P and 27Al MAS NMR studies, which showed there to be three P (all 4-coordinate) and three Al (one 4-, one 5- and one 6-coordinate) sites, and with 13C MAS NMR, which showed there to be two different types of methylamine species in equal amounts. Assignment of the 31P, 27Al and 13C MAS NMR signals could be deduced from the crystallographic data,31P-27Al HETCOR spectra and ab initio calculations.

Two different aluminophosphate structures were synthesised in aqueous media using as main template methylamine (MA), directly added, or generated in situ from methylformamide (MF). Both involve novel AlPO4-n topologies that undergo structural transformations upon template removal, yielding above 350°C microporous thermostable materials with interesting properties. Tetraalkylammonium (TEA) cations were used optionally as co-templates along with MA. Only non protonated MA was found incorporated into the pore volume of both structures, in relatively strong interaction with the framework oxygens. TEA appeared to stabilise one of the phases at defined stages of nucleation and/or growth processes, without playing any specific structure-directing role.

A well-crystallized sample of CoAPO-37 was prepared. The incorporation of cobalt in the FAU structure framework was indirectly shown by FTIR spectroscopy, which shows peaks assigned to Bronstëd acid sites.

Submitted by Margarida Galamba (galamba@isa.utl.pt) on 2018-10-11T12:45:43Z No. of bitstreams: 1 REP-ANAIS-103-20083202065.pdf: 163067 bytes, checksum: 9eb5c59507975c68e85d6df48dc1a1e1 (MD5) Made available in DSpace on 2018-10-11T12:45:43Z (GMT). No. of bitstreams: 1 REP-ANAIS-103-20083202065.pdf: 163067 bytes, checksum: 9eb5c59507975c68e85d6df48dc1a1e1 (MD5) Previous issue date: 1999 info:eu-repo/semantics/publishedVersion

SAPO-40 exhibits five main OH species, describable as high-frequency ones (HF, at 3737, 3730, and 3724 cm-1) and low-frequency ones (LF1 and LF2, at 3559 and 3528 cm-1, respectively), the former probably sitting in 12-member-ring channels and the latter either in side pockets or eight-member-ring channels of the AFR structure. The low-temperature interaction of such OH species with CO shows that HF species have strictly similar acidity (comparable to that of HY zeolites), in contrast with previous results concerning H-transfer to NH3. The ease of interaction and the spectral features are in accord with the location in large cavities. The vibration of H-bonded hydroxyl has a noticeable structure with subbands. The interaction of CO with LF1 and LF2 species occurs with difficulty and yields nonlinear complexes because of the steric hindrance brought about by small cavities. Adsorption of N2 follows similar patterns.