Export 4149 results:
Sort by: Author Title Type [ Year  (Desc)]
2014
Moura, I., C. Carreira, S. Pauleta, R. F. Nunes, J. J. Moura, S. Ramos, S. Dell'acqua, and O. Einsle. "INSIGHTS INTO THE CATALYTICCYCLE OF Pseudomonas nautica NITROUS OXIDE REDUCTASE." Journal of Biological Inorganic Chemistry. Vol. 19. J Biol Inorg Chem, 19. 2014. S104. Abstract
n/a
Gaspar, D., S. N. Fernandes, G. dea Oliveira, J. G. Fernandes, P. Grey, R. V. Pontes, L. Pereira, R. Martins, M. H. Godinho, and E. Fortunato. "{Nanocrystalline cellulose applied simultaneously as the gate dielectric and the substrate in flexible field effect transistors.}." Nanotechnology. 25 (2014): 094008. AbstractWebsite

Cotton-based nanocrystalline cellulose (NCC), also known as nanopaper, one of the major sources of renewable materials, is a promising substrate and component for producing low cost fully recyclable flexible paper electronic devices and systems due to its properties (lightweight, stiffness, non-toxicity, transparency, low thermal expansion, gas impermeability and improved mechanical properties).Here, we have demonstrated for the first time a thin transparent nanopaper-based field effect transistor (FET) where NCC is simultaneously used as the substrate and as the gate dielectric layer in an 'interstrate' structure, since the device is built on both sides of the NCC films; while the active channel layer is based on oxide amorphous semiconductors, the gate electrode is based on a transparent conductive oxide.Such hybrid FETs present excellent operating characteristics such as high channel saturation mobility (>7 cm(2) V (-1) s(-1)), drain-source current on/off modulation ratio higher than 10(5), enhancement n-type operation and subthreshold gate voltage swing of 2.11 V/decade. The NCC film FET characteristics have been measured in air ambient conditions and present good stability, after two weeks of being processed, without any type of encapsulation or passivation layer. The results obtained are comparable to ones produced for conventional cellulose paper, marking this out as a promising approach for attaining high-performance disposable electronics such as paper displays, smart labels, smart packaging, RFID (radio-frequency identification) and point-of-care systems for self-analysis in bioscience applications, among others.

Miguel, Catarina, Joana V. Pinto, Mark Clarke, and Maria J. Melo. "{The alchemy of red mercury sulphide: The production of vermilion for medieval art}." Dyes and Pigments. 102 (2014): 210-217. AbstractWebsite

abstract Vermilion red, mercury sulphide (a-HgS), was one of the most important reds in art and its use as a pigment dates back to Antiquity. In medieval Europe, it could be mined as cinnabar, or produced as vermilion by heating mercury with sulphur. This work aims to study the production of synthetic vermilion as a medieval pigment and to confirm which was the source (mineral or artificial) of the reds used in Portuguese medieval illuminations. The production of synthetic vermilion was based on the process described in the Judaeo-Portuguese medieval treatise “The book on how to make colours”, using materials and technologies as close as possible to the medieval ones. The reaction mechanism was studied by following the heating process by X-ray diffraction, and it was possible to conclude that the transformation from black cubic b-HgS into red hexagonal a-HgS is a solid-state phase transition, occurring at 235 ?C. This result is contrary to what published in technical art literature, in which this process is described as a sublimation. Moreover, Scanning Electron Microscopy evidenced a sinterization effect on the artificial vermilion, not found in medieval original samples nor in paints prepared with mineral cinnabar from Almadén (Spain). Red mercury sulphide, natural and synthetic,was then prepared as a parchment-glue paint and compared to proteinaceous red paints from 12the13th century minia- tures produced in important medieval monasteries, previously fully characterized by a multi-analytical approach (m-Energy dispersive X-ray fluorescence, m-Fourier Transform Infrared Spectroscopy, Raman microscopy). A comparative Electron probe microanalysis of the red paints point to amineral provenance for medieval vermilion found in Portuguese illuminations

Rahangdale, H. V., M. Guerra, P. K. Das, S. De, J. P. Santos, D. Mitra, and S. Saha. "Determination of subshell-resolved <span class="aps-inline-formula"><math><mi>L</mi></math></span>-shell-ionization cross sections of gold induced by 15–40-keV electrons." Physical Review A. 89 (2014): 052708. AbstractWebsite
n/a
Carepo, M. S., S. R. Pauleta, A. G. Wedd, J. J. Moura, and I. Moura. "Mo-Cu metal cluster formation and binding in an orange protein isolated from Desulfovibrio gigas." J Biol Inorg Chem. 19 (2014): 605-14. AbstractWebsite

The orange protein (ORP) isolated from the sulfate-reducing bacterium Desulfovibrio gigas (11.8 kDa) contains a mixed-metal sulfide cluster of the type [S2MoS2CuS2MoS2](3-) noncovalently bound to the polypeptide chain. The D. gigas ORP was heterologously produced in Escherichia coli in the apo form. Different strategies were used to reconstitute the metal cluster into apo-ORP and obtain insights into the metal cluster synthesis: (1) incorporation of a synthesized inorganic analogue of the native metal cluster and (2) the in situ synthesis of the metal cluster on the addition to apo-ORP of copper chloride and tetrathiomolybdate or tetrathiotungstate. This latter procedure was successful, and the visible spectrum of the Mo-Cu reconstituted ORP is identical to the one reported for the native protein with absorption maxima at 340 and 480 nm. The (1)H-(15)N heteronuclear single quantum coherence spectra of the reconstituted ORP obtained by strategy 2, in contrast to strategy 1, exhibited large changes, which required sequential assignment in order to identify, by chemical shift differences, the residues affected by the incorporation of the cluster, which is stabilized inside the protein by both electrostatic and hydrophobic interactions.

Altstadt, S. G., et al. "{$^{13,14}$B(n, $\gamma$) via Coulomb Dissociation for Nucleosynthesis towards the r-Process}." Nuclear Data Sheets. 120 (2014): 197-200. AbstractWebsite
n/a
Cunha, Jácome, João Paulo Fernandes, Jorge Mendes, Rui Pereira, and João Saraiva. "Design and Implementation of Queries for Model-Driven Spreadsheets." Central European Functional Programming School - 5th Summer School, CEFP 2013, Revised Selected Papers. Eds. Viktória Zsók, and et al. Lecture Notes in Computer Science. Heidelberg: Springer, 2014. Abstractdsl13_query.pdf

This paper presents a domain-specific querying language for model-driven spreadsheets. We briefly show the design of the language and present in detail its implementation, from the denormalization of data and translation of our user-friendly query language to a more efficient query, to the execution of the query using Google. To validate our work, we executed an empirical study, comparing QuerySheet with an alternative spreadsheet querying tool, which produced positive results.

Maiti, B. K., T. Aviles, I. Moura, S. R. Pauleta, and JJG Moura. "Synthesis and characterization of [S2MoS2Cu(n-SPhF)](2-) (n = o, m, P) clusters: Potential F-19-NMR structural probes for Orange Protein." Inorg Chem Commun. 45 (2014): 97-100. AbstractWebsite

Three fluorinated Mo-Cu-thiolate isomers,[Ph4Ph[S2MoS2Cu(n-SPhF)], [n-SPhF = 2-fluorothiophenol (la)], 3-fluorothiophenol (lb), and 4-fluorothiophenol (1c)] were synthesized and spectroscopically characterized. The F-19-NMR signal of the fluorine atom in the.benzene has different chemical shift for each isomer, which is highly influenced by the local environment that can be manipulated by different solvents and solutes. The fluorine-19 chemical shift is an advantageous NMR structural probe in alternative to H-1-NMR [B.K. Maiti, T. Aviles, M. Matzapetakis, I. Moura, S.R. Pauleta, JJ.G. Moura, Eur. J. Inorg. Chem. (2012) 4159.], that can be used to provide local information on the pocket of the metal cluster in the Orange Protein (ORP). (C) 2014 Elsevier B.V. All rights reserved.

Saponaro, A. C., M. Matzapetakis, B. Santoro, S. R. Pauleta, and A. Moroni. "The Auxiliary Subunit TRIP8B Inhibits the Binding of CAMP to HCN2 Channels Through an Allosteric Mechanism." Biophysical Journal. Vol. 106. Biophys J, 106. 2014. 758a. Abstract
n/a
Johnston, E. M., S. Dell'acqua, S. Ramos, S. R. Pauleta, I. Moura, and E. I. Solomon. "Determination of the active form of the tetranuclear copper sulfur cluster in nitrous oxide reductase." J Am Chem Soc. 136 (2014): 614-7. AbstractWebsite

N2OR has been found to have two structural forms of its tetranuclear copper active site, the 4CuS Cu(Z)* form and the 4Cu2S Cu(Z) form. EPR, resonance Raman, and MCD spectroscopies have been used to determine the redox states of these sites under different reductant conditions, showing that the Cu(Z)* site accesses the 1-hole and fully reduced redox states, while the Cu(Z) site accesses the 2-hole and 1-hole redox states. Single-turnover reactions of N2OR for Cu(Z) and Cu(Z)* poised in these redox states and steady-state turnover assays with different proportions of Cu(Z) and Cu(Z)* show that only fully reduced Cu(Z)* is catalytically competent in rapid turnover with N2O.

Espadinha-Cruz, Pedro, António Gonçalves-Coelho, António Mourão, and António Grilo. "Business Interoperability: Dyadic supply chain process decomposition using Axiomatic Design." 2014. 93-100. Abstract
n/a
JP, Borges, Canejo JP, Fernandes SN, Brogueira P, and GODINHO MH. "Cellulose‐Based Liquid Crystalline Composite Systems." Nanocellulose Polymer Nanocomposites: Fundamentals and Applications. Ed. Vijay Kumar Thakur. Scrivener Publishing - Wiley. Scrivener Publishing - Wiley, 2014. 215-235. Abstract
n/a
F., Caeiro, Gomes M.I., and Vandewalle B. "Semi-Parametric Probability-Weighted Moments Estimation Revisited." (2014). Abstract

n/a

Savita, Singh, Kale Sandip, Gawande Manoj, Velhinho Alexandre, and Jayarama Radha. "A synthesis of copper based metal-organic framework for O-acetylation of alcohols." 44 (2014): 24-28. Abstract
n/a
Pereira, Sónia, Alexandra Gonçalves, Nuno Correia, Joana Pinto, Lu\'ıs Pereira, Rodrigo Martins, and Elvira Fortunato. "{Electrochromic behavior of NiO thin films deposited by e-beam evaporation at room temperature}." Solar Energy Materials and Solar Cells. 120 (2014): 109-115. AbstractWebsite
n/a
Maiti, B. K., L. B. Maia, K. Pal, B. Pakhira, T. Aviles, I. Moura, S. R. Pauleta, J. L. Nunez, A. C. Rizzi, CD Brondino, S. Sarkar, and J. J. Moura. "One electron reduced square planar bis(benzene-1,2-dithiolato) copper dianionic complex and redox switch by O2/HO(-)." Inorg Chem. 53 (2014): 12799-808. AbstractWebsite

The complex [Ph4P]2[Cu(bdt)2] (1(red)) was synthesized by the reaction of [Ph4P]2[S2MoS2CuCl] with H2bdt (bdt = benzene-1,2-dithiolate) in basic medium. 1(red) is highly susceptible toward dioxygen, affording the one electron oxidized diamagnetic compound [Ph4P][Cu(bdt)2] (1(ox)). The interconversion between these two oxidation states can be switched by addition of O2 or base (Et4NOH = tetraethylammonium hydroxide), as demonstrated by cyclic voltammetry and UV-visible and EPR spectroscopies. Thiomolybdates, in free or complex forms with copper ions, play an important role in the stability of 1(red) during its synthesis, since in its absence, 1(ox) is isolated. Both 1(red) and 1(ox) were structurally characterized by X-ray crystallography. EPR experiments showed that 1(red) is a Cu(II)-sulfur complex and revealed strong covalency on the copper-sulfur bonds. DFT calculations confirmed the spin density delocalization over the four sulfur atoms (76%) and copper (24%) atom, suggesting that 1(red) has a "thiyl radical character". Time dependent DFT calculations identified such ligand to ligand charge transfer transitions. Accordingly, 1(red) is better described by the two isoelectronic structures [Cu(I)(bdt2, 4S(3-,)*)](2-) <--> [Cu(II)(bdt2, 4S(4-))](2-). On thermodynamic grounds, oxidation of 1(red) (doublet state) leads to 1(ox) singlet state, [Cu(III)(bdt2, 4S(4-))](1-).

Nunes, D., A. Pimentel, P. Barquinha, P. A. Carvalho, E. Fortunato, and R. Martins. "Cu2O polyhedral nanowires produced by microwave irradiation." Journal of Materials Chemistry C. 2 (2014): 6097-6103. AbstractWebsite
n/a
Santos, Lidia, Joana P. Neto, Ana Crespo, Daniela Nunes, Nuno Costa, Isabel M. Fonseca, Pedro Barquinha, Luis Pereira, Jorge Silva, Rodrigo Martins, and Elvira Fortunato. "WO3 Nanoparticle-Based Conformable pH Sensor." Acs Applied Materials & Interfaces. 6 (2014): 12226-12234. AbstractWebsite
n/a
Johnston, E. M., S. Dell'acqua, S. Gorelsky, S. R. Pauleta, I. Moura, and E. I. Solomon. "Electronic structure and reactivities of resting and intermediate forms of the tetranuclear copper cluster in nitrous oxide reductase." Abstracts of Papers of the American Chemical Society. Vol. 248. Abstr Pap Am Chem S, 248. 2014. Abstract
n/a
Moura, JJG, B. K. Maiti, C. Carreira, L. B. Maia, S. P. Carepo, S. R. Pauleta, and I. Moura. "Metal substituted rubredoxins: a sulfur rich coordination site as models for metalloenzymes." Journal of Biological Inorganic Chemistry. Vol. 19. J Biol Inorg Chem, 19. 2014. S731. Abstract
n/a
Kasthurirangan, S., J. K. Saha, A. N. Agnihotri, A. Banerjee, A. Kumar, D. Misra, J. P. Santos, A. M. Costa, P. Indelicato, T. K. Mukherjee, and L. C. Tribedi. "High-resolution x-ray spectra from highly charged Si, S and Cl ions showing evidence of fluorescence active resonant states." Journal of Physics: Conference Series. 488 (2014): 132027-2. AbstractWebsite

We have measured the x-ray spectra from highly charged Si, S and Cl ions in collisions with thin foils using a high-resolution x-ray spectrometer. The observed lines have been assigned to various transitions in H-, He- and Li-like ions. For proper identification of line positions, the theoretical calculations have been carried out using a state-of-the-art MCDF code including QED effects, with which the experimental data is in excellent agreement. We have also observed, for the first time, x-rays arising out of the decay of long-lived resonant states in the He-like ions of each species. Details will be presented.

N., Pereira, Goes J., Rodrigues M., and Faria P. "A New Mismatch-Insensitive 1.5-Bit MDAC with Unity Feedback-Factor and Enhanced Performance." 21st IEEE International Conference on Electronics Circuits and Systems. Marseille, France: IEEE, 2014.
Pinho, Fernando F. S., Válter J. G. Lúcio, Luís Moura, Nuno Travassos, and Inês Almeida. "Evaluation of cover deviation and resistance of steel anchorages in masonry walls." IMC2014 - 9th International Masonry Conference 2014. Universidade do Minho, Guimarães 2014.
Mana, Ana, and Fernando F. S. Pinho. "Influence of non-compliant fly ashes in air-lime mortars." IMC2014 - 9th International Masonry Conference 2014. Universidade do Minho, Guimarães 2014.