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2013
Figueiredo, V., JV Pinto, J. Deuermeier, R. Barros, E. Alves, R. Martins, and E. Fortunato. "{p-Type Cu O Thin-Film Transistors Produced by Thermal Oxidation}." Journal of Display Technology. 9 (2013): 735-740. Abstract

Thin-films of copper oxide Cu O were produced by thermal oxidation of metallic copper (Cu) at different tempera- tures (150–450 C). The films produced at temperatures of 200, 250 and 300 C showed high Hall motilities of 2.2, 1.9 and 1.6 cm V s , respectively. Single Cu O phases were obtained at 200 Cand its conversion toCuO starts at 250 C. For lower thick- nesses 40 nm, the films oxidized at 250 Cshowed a complete conversion to CuO phase. Successful thin-film transistors (TFTs) were produce by thermal oxidation of a 20 nm Cu film, obtaining p-type Cu O (at 200 C) and CuO (at 250 C) with On/Off ratios of 6 10 and 1 10 , respectively.

Parthiban, Shanmugam, Elamurugu Elangovan, Pradipta K. Nayak, Alexandra Gonçalves, Daniela Nunes, Lu\'ıs Pereira, Pedro Barquinha, Tito Busani, Elvira Fortunato, and Rodrigo Martins. "{Performances of Microcrystalline Zinc Tin Oxide Thin-Film Transistors Processed by Spray Pyrolysis}." 9 (2013): 825-831. Abstract
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Branquinho, Rita, Joana V. Pinto, Tito Busani, Pedro Barquinha, Luis Pereira, Pedro Viana Baptista, Rodrigo Martins, and Elvira Fortunato. "{Plastic Compatible Sputtered Ta O Sensitive Layer for Oxide Semiconductor TFT Sensors}." 9 (2013): 723-728. Abstract
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Branquinho, Rita, Joana V. Pinto, Tito Busani, Pedro Barquinha, Luis Pereira, Pedro Viana Baptista, Rodrigo Martins, and Elvira Fortunato. "{Plastic Compatible Sputtered Ta O Sensitive Layer for Oxide Semiconductor TFT Sensors}." Journal of Display Technology. 9 (2013): 723-728. Abstract

The effect of post-deposition annealing temperature on the pH sensitivity of room temperature RF sputtered Ta O was investigated. Structural and morphological features of these films were analyzed before and after annealing at various tem- peratures. The deposited films are amorphous up to 600 Cand crystallize at 700 C in an orthorhombic phase. Electrolyte-insu- lator-semiconductor (EIS) field effect based sensors with an amor- phousTa O sensing layer showed pHsensitivity above 50 mV/pH. For sensors annealed above 200 C pH sensitivity decreased with increasing temperature. Stabilized sensor response andmaximum pHsensitivitywas achieved after low temperature annealing at 200 C, which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors

Branquinho, Rita, Joana V. Pinto, Tito Busani, Pedro Barquinha, Luis Pereira, Pedro Viana Baptista, Rodrigo Martins, and Elvira Fortunato. "{Plastic compatible sputtered Ta2O5 sensitive layer for oxide semiconductor tft sensors}." IEEE/OSA Journal of Display Technology. 9 (2013): 723-728. AbstractWebsite

The effect of post-deposition annealing temperature on the pH sensitivity of room temperature RF sputtered Ta2O5 was investigated. Structural and morphological features of these films were analyzed before and after annealing at various temperatures. The deposited films are amorphous up to 600 °C and crystallize at 700 °C in an orthorhombic phase. Electrolyte-insulator-semiconductor (EIS) field effect based sensors with an amorphous Ta2O5 sensing layer showed pH sensitivity above 50 mV/pH. For sensors annealed above 200 °C pH sensitivity decreased with increasing temperature. Stabilized sensor response and maximum pH sensitivity was achieved after low temperature annealing at 200 °C, which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors.

Fernandes-Silva, S., J. Moreira-Silva, T. H. Silva, R. I. Perez-Martin, C. G. Sotelo, J. F. Mano, A. R. C. Duarte, and R. L. Reis. "{Porous hydrogels from shark skin collagen crosslinked under dense carbon dioxide atmosphere}." Macromolecular Bioscience. 13 (2013). Abstract

The possibility to fabricate marine collagen porous structures crosslinked with genipin under high pressure carbon dioxide is investigated. Collagen from shark skin is used to prepare pre-scaffolds by freeze-drying. The poor stability of the structures and low mechanical properties require crosslinking of the structures. Under dense CO 2 atmosphere, crosslinking of collagen pre-scaffolds is allowed for 16 h. Additionally, the hydrogels are foamed and the scaffolds obtained present a highly porous structure. In vitro cell culture tests performed with a chondrocyte-like cell line show good cell adherence and proliferation, which is a strong indication of the potential of these scaffolds to be used in tissue cartilage tissue engineering. The development of an optimized processing technique for the preparation of stable structures from marine origin collagen is described. The samples are processed under a dense carbon dioxide atmosphere that promotes crosslinking and enhances the morphology of the 3D architectures obtained. © 2013 WILEY-VCH Verlag GmbH {&} Co. KGaA, Weinheim.

a.M. Ramos, S. Pereira, M. T. Cidade, G. Pereira, R. Branquinho, L. Pereira, R. Martins, and E. Fortunato. "{Preparation and characterization of cellulose nanocomposite hydrogels as functional electrolytes}." Solid State Ionics. 242 (2013): 26-32. AbstractWebsite
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Ramos, A. M., S. Pereira, M. T. Cidade, G. Pereira, R. Branquinho, L. Pereira, R. Martins, and E. Fortunato. "{Preparation and characterization of cellulose nanocomposite hydrogels as functional electrolytes}." Solid State Ionics. 242 (2013): 26-32. AbstractWebsite

In this work Laponite was combined with a modified abundant natural polymer, (caboxymethyl cellulose), acrylic sodium salt polymer and lithium perchlorate aiming to produce inexpensive and sustainable nanocomposite electrolytes for functional electrochemical devices. Optical, electrochemical, structural, morphological and rheological characterization was performed in order to evaluate their properties and potential advantages as electrolyte. It was verified that the addition of Laponite led to an ionic conductivity at room temperature (25 C) in the range of 6 to 9 ?? 10- 5 Scm - 1 this value being then determined by the composition of the nanocomposite. These electrolytes were applied to electrochromic devices using evaporated nickel oxide thin film as the electrochromic layer. The devices exhibited a significant transmittance modulation that exceeds 45 {%} at 600 nm. ?? 2013 Elsevier B.V.

Engineering, Tissue, Cell Based, Campus D. E. Gualtar, Maria Manuela, Estima Gomes, A. N. A. Rita, Cruz Duarte, Sentido D. E. Fornecer, U. M. A. Estrutura, Porosa E. Interconectada, and Suporte D. E. A. O. Crescimento. "{PT 106220}." 106220 (2013). Abstract
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Engineering, Tissue, Cell Based, Campus D. E. Gualtar, Maria Manuela, Estima Gomes, A. N. A. Rita, Cruz Duarte, Sentido D. E. Fornecer, U. M. A. Estrutura, Porosa E. Interconectada, and Suporte D. E. A. O. Crescimento. "{PT 106220}." 106220 (2013). Abstract
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Morawiec, Seweryn, Manuel J. Mendes, Salvatore Mirabella, Francesca Simone, Francesco Priolo, and Isodiana Crupi. "{Self-assembled silver nanoparticles for plasmon-enhanced solar cell back reflectors: correlation between structural and optical properties}." Nanotechnology. 24 (2013): 265601. AbstractWebsite

The spectra of localized surface plasmon resonances (LSPRs) in self-assembled silver nanoparticles (NPs), prepared by solid-state dewetting of thin films, are discussed in terms of their structural properties. We summarize the dependences of size and shape of NPs on the fabrication conditions with a proposed structural-phase diagram. It was found that the surface coverage distribution and the mean surface coverage (SC) size were the most appropriate statistical parameters to describe the correlation between the morphology and the optical properties of the nanostructures. The results are interpreted with theoretical predictions based on Mie theory. The broadband scattering efficiency of LSPRs in the nanostructures is discussed towards application as plasmon-enhanced back reflectors in thin-film solar cells.

Mendes, Manuel J., Estela Hernández, Esther López, Pablo García-Linares, Iñigo Ramiro, Irene Artacho, Elisa Antolín, Ignacio Tobías, Antonio Martí, and Antonio Luque. "{Self-organized colloidal quantum dots and metal nanoparticles for plasmon-enhanced intermediate-band solar cells}." Nanotechnology. 24 (2013): 345402. AbstractWebsite

A colloidal deposition technique is presented to construct long-range ordered hybrid arrays of self-assembled quantum dots and metal nanoparticles. Quantum dots are promising for novel opto-electronic devices but, in most cases, their optical transitions of interest lack sufficient light absorption to provide a significant impact in their implementation. A potential solution is to couple the dots with localized plasmons in metal nanoparticles. The extreme confinement of light in the near-field produced by the nanoparticles can potentially boost the absorption in the quantum dots by up to two orders of magnitude. In this work, light extinction measurements are employed to probe the plasmon resonance of spherical gold nanoparticles in lead sulfide colloidal quantum dots and amorphous silicon thin-films. Mie theory computations are used to analyze the experimental results and determine the absorption enhancement that can be generated by the highly intense near-field produced in the vicinity of the gold nanoparticles at their surface plasmon resonance. The results presented here are of interest for the development of plasmon-enhanced colloidal nanostructured photovoltaic materials, such as colloidal quantum dot intermediate-band solar cells.

Guerreiro, Bruno J. {Sensor-based Control and Localization of Autonomous Systems in Unknown Enviornments}. Instituto Superior Técnico, University of Lisbon, 2013. Abstract
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Guerreiro, Bruno J. {Sensor-based Control and Localization of Autonomous Systems in Unknown Enviornments}. Instituto Superior Técnico, University of Lisbon, 2013. Abstract
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Machado, J., A. Blanco, P. Fonte, D. Galaviz, L. Lopes, Ferreira R. Marques, and P. Teubig. "{Simulations of a new detection concept for high-energy neutrons based on timing RPCs}." Journal of Instrumentation. 8 (2013): P07020. AbstractWebsite
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Martí, Antonio, Elisa Antolín, Pablo {García Linares}, Iñigo Ramiro, Irene Artacho, Esther López, Estela Hernández, Manuel J. Mendes, Alex Mellor, Ignacio Tobías, David {Fuertes Marrón}, Cesar Tablero, Ana B. Cristóbal, Christopher G. Bailey, Maria Gonzalez, Michael Yakes, Mathew P. Lumb, Robert Walters, and Antonio Luque. "{Six not-so-easy pieces in intermediate band solar cell research}." Journal of Photonics for Energy. 3 (2013): 31299. AbstractWebsite

Abstract.  The concept of intermediate band solar cell (IBSC) is, apparently, simple to grasp. However, since the idea was proposed, our understanding has improved and some concepts can now be explained more clearly than when the concept was initially introduced. Clarifying these concepts is important, even if they are well known for the advanced researcher, so that research efforts can be driven in the right direction from the start. The six pieces of this work are: Does a miniband need to be formed when the IBSC is implemented with quantum dots? What are the problems for each of the main practical approaches that exist today? What are the simplest experimental techniques to demonstrate whether an IBSC is working as such or not? What is the issue with the absorption coefficient overlap and the Mott's transition? What would the best system be, if any?

Alves, R. D., L. C. Rodrigues, J. R. Andrade, A. Pawlicka, L. Pereira, R. Martins, E. Fortunato, and M. M. Silva. "{Study and Characterization of a Novel Polymer Electrolyte Based on Agar Doped with Magnesium Triflate}." Molecular Crystals and Liquid Crystals. 570 (2013): 1-11. AbstractWebsite
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a. a. Ghumman, C., M. C. a. Moutinho, A. Santos, A. Tolstogouzov, and O. M. N. D. Teodoro. "{TOF-SIMS VG Ionex IX23LS: upgrade and application for the urinary stones analysis}." Surface and Interface Analysis. 45 (2013): 532-536. AbstractWebsite

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Duarte, Ana Rita C., Vitor E. Santo, Anabela Alves, Simone S. Silva, Joana Moreira-Silva, Tiago H. Silva, Alexandra P. Marques, Rui A. Sousa, Manuela E. Gomes, João F. Mano, and Rui L. Reis. "{Unleashing the potential of supercritical fluids for polymer processing in tissue engineering and regenerative medicine}." Journal of Supercritical Fluids. 79 (2013): 177-185. AbstractWebsite

One of the major scientific challenges that tissue engineering and regenerative medicine (TERM) faces to move from benchtop to bedside regards biomaterials development, despite the latest advances in polymer processing technologies. A variety of scaffolds processing techniques have been developed and include solvent casting and particles leaching, compression molding and particle leaching, thermally induced phase separation, rapid prototyping, among others. Supercritical fluids appear as an interesting alternative to the conventional methods for processing biopolymers as they do not require the use of large amounts of organic solvents and the processes can be conducted at mild temperatures. However, this processing technique has only recently started to receive more attention from researchers. Different processing methods based on the use of supercritical carbon dioxide have been proposed for the creation of novel architectures based on natural and synthetic polymers and these will be unleashed in this paper. © 2013 Elsevier B.V. All rights reserved.

Duarte, Ana Rita C., Vitor E. Santo, Anabela Alves, Simone S. Silva, Joana Moreira-Silva, Tiago H. Silva, Alexandra P. Marques, Rui A. Sousa, Manuela E. Gomes, João F. Mano, and Rui L. Reis. "{Unleashing the potential of supercritical fluids for polymer processing in tissue engineering and regenerative medicine}." Journal of Supercritical Fluids. 79 (2013): 177-185. AbstractWebsite

One of the major scientific challenges that tissue engineering and regenerative medicine (TERM) faces to move from benchtop to bedside regards biomaterials development, despite the latest advances in polymer processing technologies. A variety of scaffolds processing techniques have been developed and include solvent casting and particles leaching, compression molding and particle leaching, thermally induced phase separation, rapid prototyping, among others. Supercritical fluids appear as an interesting alternative to the conventional methods for processing biopolymers as they do not require the use of large amounts of organic solvents and the processes can be conducted at mild temperatures. However, this processing technique has only recently started to receive more attention from researchers. Different processing methods based on the use of supercritical carbon dioxide have been proposed for the creation of novel architectures based on natural and synthetic polymers and these will be unleashed in this paper. © 2013 Elsevier B.V. All rights reserved.

2012
Maiti, Biplab K., Teresa Aviles, Manolis Matzapetakis, Isabel Moura, Sofia R. Pauleta, and Jose J. G. Moura. "{Synthesis of {[}MoS4](2-)-M (M=Cu and Cd) Clusters: Potential NMR Spectroscopic Structural Probes for the Orange Protein}." {EUROPEAN JOURNAL OF INORGANIC CHEMISTRY} (2012): {4159-4166}. Abstract

{Two synthetic strategies of tetrathiomolybdate-metal clusters with the potential to be used as NMR structural probes for the location of the metal cofactor in the orange protein (ORP) are described. The first strategy is based on the substitution reaction in which small organic ligands bind directly to the metal centre in a molybdenumcopper hetero-dinuclear cluster. Interaction between {[}PPh4]2{[}MoS4CuCl] and either aliphatic {[}beta-mercaptoethanol (b-me)] or aromatic {[}o-aminobenzenethiol (abt)] thiols in the presence of a strong base resulted in the formation of {[}Ph4P]2{[}S2MoS2Cu(b-me)] (1a) and {[}Et4N]2{[}S2MoS2Cu(abt)]center dot H2O center dot 0.25DMF (1b), which can be used to obtain intermolecular NOEs. The compound 1a readily hydrolyzed to {[}Ph4P]2{[}OSMoS2Cu(b-me)] (1ahydro) in contact with a protic solvent. The second strategy consisted of the incorporation of cadmium into tetrathiomolybdate ({[}MoS4]2), which gives rise to the trinuclear cluster compound {[}PPh4]2{[}(MoS4)2Cd] (2). All clusters were characterized spectroscopically and their structure determined by X-ray diffraction. The NMR spectroscopic data are consistent with the formation of a complex with a 1:1 ratio of \{MoS4Cu\} and thiol. The 113Cd NMR chemical shift of compound 2 is consistent with the cadmium having a tetrahedral geometry and coordinated by four sulfur ligands. The tetraphenylphosphonium cation in compound 1a was replaced by a tetramethylammonium countercation originating in the water-soluble compound {[}Me4N-1a]. Solubility in aqueous buffers is a requirement for incorporating this cluster into apo-ORP. These compounds will be used to identify the exact location of the ORP heterometallic cluster using NMR methodologies.}

Gomes, Gabriela M. M., Ricardo Aguas, Joao S. Lopes, Marta C. Nunes, Carlota Rebelo, Paula Rodrigues, and Claudio J. Struchiner. "How host heterogeneity governs tuberculosis reinfection?" PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES. 279 (2012): 2473-2478. Abstract

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Bruno Pedras, Vitor Rosa, Richard Welter, Carlos Lodeiro, and Teresa Aviles. "{New quinoline alpha-diimine ligands as fluorescent probes for metal ions: Ultrasound-assisted and conventional synthetic methods}." {INORGANICA CHIMICA ACTA}. {381} (2012): {143-149}. Abstract

{Three new emissive 8-aminoquinoline derived probes (1)-(3) and one dinuclear Zn(II) complex (4) were synthesized and fully characterized. Their absorption spectra show maxima at 310-336 nm, and fluorescence emission between 456 and 498 nm. Compound (1) was characterized by single crystal X-ray diffraction. The effect upon Zn(II) and Cu(II) coordination to compounds (1)-(3) was studied by monitoring the changes in absorption and fluorescence spectra, and complemented by calculation of metal-ligand stability constants. The results indicate that compound (3) is the one that presents the most favorable geometry for coordinating two metal cations, fact that is confirmed by the synthesis of the dinuclear complex (4), with similar molecular geometry. (C) 2011 Elsevier B.V. All rights reserved.}

Vitor Rosa, Sara Realista, Ana Mourato, Luisa Maria Abrantes, Joao Henriques, Maria Jose Calhorda, Teresa Aviles, Michael G. B. Drew, and Vitor Felix. "{1,1 `-Bis(diphenylphosphino)ferrocene bridging two mono(cyclopentadienyl) cobalt moieties: Synthesis, structure, electrochemistry and DFT studies}." {JOURNAL OF ORGANOMETALLIC CHEMISTRY}. {712} (2012): {52-56}. Abstract

{Reaction of {[}Co(eta(5)-C5H5)(CO)(2)], 1, with 1,1'-bis(diphenylphosphino)ferrocene (dppf) yields the new trinuclear complex {[}Co(eta(5)-C5H5)(CO)](2)(mu-dppf), 2, which was structurally characterised by single crystal X-ray diffraction and showed two Co(eta(5)-C5H5)(CO) moieties covalently linked by a dppf bridge. Electrochemical studies in dichloromethane revealed that both Co(I) and Fe(II) in the precursors were oxidized to Co(II)/Co(III) and Fe(III), respectively. On the other hand, in 2 the two first oxidation waves were assigned to Co, the Fe(II) centre requiring a higher potential than in free dppf. DFT calculations showed that the HOMOs of 2 were localised in the Co fragments, owing to the destabilisation of the Co(eta(5)-C5H5)(CO) orbitals after binding dppf. (C) 2012 Elsevier B.V. All rights reserved.}