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2013
Silva, Ricardo, Duarte Viúla M. Faria, Pinho A. Ramos, and Micael Inácio. "A physical approach for considering how anchorage head size influences the punching capacity of slabs strengthened with vertical steel bolts." Structural Concrete. 14 (2013): 389-400. AbstractWebsite

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Figueiredo, V., JV Pinto, J. Deuermeier, R. Barros, E. Alves, R. Martins, and E. Fortunato. "p-Type CuxO Thin-Film Transistors Produced by Thermal Oxidation." Journal of Display Technology. 9.9 (2013): 6. AbstractWebsite
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Baltazar, LG, F. M. A. Henriques, F. Jorne, and M. T. Cidade. "Performance improvement of hydraulic lime based grouts for masonry consolidation: an experimental study." 131 (2013): 417-430. Abstract
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Branquinho, R., JV Pinto, T. Busani, P. Barquinha, L. Pereira, P. Viana Baptista, R. Martins, and E. Fortunato. "Plastic Compatible Sputtered Ta2O5 Sensitive Layer for Oxide Semiconductor TFT Sensors." Display Technology, Journal of. 9.9 (2013): 723-728. Abstract

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.

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." 242 (2013): 26-32. Abstract
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Baltazar, LG, F. M. A. Henriques, F. Jorne, and M. T. Cidade. "Performance improvement of hydraulic lime based grouts for masonry consolidation: An experimental study." Structural Studies, Repairs and Maintenance of Heritage Architecture XIII, WIT Transactions on the Built Environment. Southampton: WIT Press, 2013. 417-430.
Amado, M. P., and F. Poggi Planning for solar smart cities. CISBAT 13. Lausanne, CH: the Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne ISBN: 978-2-8399-1280-8, 2013.
Ramos, Tania Rodrigues Pereira, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa. "Planning Waste Cooking Oil Collection Systems." Waste Management. 33.8 (2013): 1691-1703. AbstractWebsite

This research has been motivated by a real-life problem of a waste cooking oil collection system characterized by the existence of multiple depots with an outsourced vehicle fleet, where the collection routes have to be plan. The routing problem addressed allows open routes between depots, i.e., all routes start at one depot but can end at the same or at a different one, depending on what minimizes the objective function considered. Such problem is referred as a Multi-Depot Vehicle Routing Problem with Mixed Closed and Open Inter-Depot Routes and is, in this paper, modeled through a Mixed Integer Linear Programming (MILP) formulation where capacity and duration constraints are taken into account. The model developed is applied to the real case study providing, as final results, the vehicle routes planning where a decrease of 13% on mileage and 11% on fleet hiring cost are achieved, when comparing with the current company solution.

Salminen, J., J. Dinis, and O. Mateus Preliminary magnetostratigraphy for Jurassic/Cretaceous transition in Porto da Calada, Portugal. In: Veikkolainen, T., Suhonen, K., Näränen, J., Kauristie, K., and Kaasalainen, S. (eds.). XXVI Geofysiikan päivät,. May 21-22 2013 in Helsinki, 2013.salminen.johanna_gfp2013_portugal_preliminary_magnetostratigraphy_for_jurassic_cretaceous_transition_in.pdf
Figueiredo, Angelo Miguel, João Sardinha, Geoffrey R. Moore, and Eurico J. Cabrita. "Protein destabilisation in ionic liquids: the role of preferential interactions in denaturation." Phys. Chem. Chem. Phys..15 (2013): 19632-19643. AbstractWebsite

The preferential binding of anions and cations in aqueous solutions of the ionic liquids (ILs) 1-butyl- 3-methylimidazolium ([C4mim]+) and 1-ethyl-3-methylimidazolium ([C2mim]+) chloride and dicyanamide (dca-) with the small alpha-helical protein Im7 was investigated using a combination of differential scanning calorimetry, NMR spectroscopy and molecular dynamics (MD) simulations. Our results show that direct ion interactions are crucial to understand the effects of ILs on the stability of proteins and that an anion effect is dominant. We show that the binding of weakly hydrated anions to positively charged or polar residues leads to the partial dehydration of the backbone groups, and is critical to control stability, explaining why dca- is more denaturing than Cl-. Direct cation–protein interactions also mediate stability; cation size and hydrophobicity are relevant to account for destabilisation as shown by the effect of [C4mim]+ compared to [C2mim]+. The specificity in the interaction of IL ions with protein residues established by weak favourable interactions is confirmed by NMR chemical shift perturbation, amide hydrogen exchange data and MD simulations. Differences in specificity are due to the balance of interaction established between ion pairs and ion-solvent that determine the type of residues affected. When the interaction of both cation and anion with the protein is strong the net result is similar to a non-specific interaction, leading ultimately to unfolding. Since the nature of the ions is a determinant of the level of interaction with the protein towards denaturation or stabilisation, ILs offer a unique possibility to modulate protein stabilisation or even folding events.

Karlovich, Alexei Yu., and Ilya M. Spitkovsky. "Pseudodifferential operators on variable Lebesgue spaces." Operator Theory, Pseudo-Differential Equations, and Mathematical Physics. Operator Theory: Advances and Applications, 228. Eds. Yuri I. Karlovich, Luigi Rodino, Bernd Silbermann, and Ilya M. Spitkovsky. Basel: Birkhäuser, 2013. 173-183. Abstract

Let \(\mathcal{M}(\mathbb{R}^n)\) be the class of bounded away from one and infinity functions \(p:\mathbb{R}^n\to[1,\infty]\) such that the Hardy-Littlewood maximal operator is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R}^n)\). We show that if \(a\) belongs to the Hörmander class \(S_{\rho,\delta}^{n(\rho-1)}\) with \(0<\rho\le 1\), \(0\le\delta<1\), then the pseudodifferential operator \(\operatorname{Op}(a)\) is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R}^n)\) provided that \(p\in\mathcal{M}(\mathbb{R}^n)\). Let \(\mathcal{M}^*(\mathbb{R}^n)\) be the class of variable exponents \(p\in\mathcal{M}(\mathbb{R}^n)\) represented as \(1/p(x)=\theta/p_0+(1-\theta)/p_1(x)\) where \(p_0\in(1,\infty)\), \(\theta\in(0,1)\), and \(p_1\in\mathcal{M}(\mathbb{R}^n)\). We prove that if \(a\in S_{1,0}^0\) slowly oscillates at infinity in the first variable, then the condition \[ \lim_{R\to\infty}\inf_{|x|+|\xi|\ge R}|a(x,\xi)|>0 \] is sufficient for the Fredholmness of \(\operatorname{Op}(a)\) on \(L^{p(\cdot)}(\mathbb{R}^n)\) whenever \(p\in\mathcal{M}^*(\mathbb{R}^n)\). Both theorems generalize pioneering results by Rabinovich and Samko [RS08] obtained for globally log-Hölder continuous exponents \(p\), constituting a proper subset of \(\mathcal{M}^*(\mathbb{R}^n)\).

Micael Inácio, António Ramos, Válter Lúcio, and Duarte Faria. "Punching of High Strength Concrete Flat Slabs - Experimental Investigation." fib symposium Tel Aviv 2013. Tel Aviv: fib, 2013. 377-380. Abstract

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Gouveia, Nuno, Nelson Fernandes, Duarte Faria, António Ramos, and Válter Lúcio. "Punching of Steel Fibre Reinforced Concrete Flat Slabs." fib symposium Tel Aviv 2013. Ed. Fib. Tel Aviv: IACIE, 2013. 1-4. Abstract

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Ramos, A., Lúcio Faria Almeida Fernandes Inácio Mamede Dinarte Silva V. D. A. "Punçoamento em Estruturas de Betão Armado." 2º Congresso Internacional da Habitação no Espaço Lusofono. Ed. FFCT. Lisbon 2013. 2013. Abstract

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Gouveia, N. D., D. M. V. Faria, and A. M. P. Ramos. "Punçoamento em lajes de betão com fibras de aço." Revista Internacional TECH ITT by Construlink. 11 (2013). Abstract

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b b b b b Figueiredo, V.a b, Pinto Deuermeier Barros Alves Martins Fortunato J. V. a J. "P-Type CuxO thin-film transistors produced by thermal oxidation." IEEE/OSA Journal of Display Technology. 9 (2013): 735-740. AbstractWebsite

Thin-films of copper oxide Cu O were produced by thermal oxidation of metallic copper (Cu) at different temperatures (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 C and its conversion to CuO starts at 250 C. For lower thicknesses 40 nm, the films oxidized at 250 C showed 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. © 2005-2012 IEEE.

Martins, R.a, Pereira Fortunato L. b E. c. "Paper electronics: A challenge for the future." Digest of Technical Papers - SID International Symposium. Vol. 44. 2013. 365-367. Abstract

In this paper we report results concerning the use of paper as substrate and as an electronic component for the next generation of sustainable low cost electronic systems, where different examples of applications are given. © 2013 Society for Information Display.

Parthiban, S., Elangovan Nayak Gonçalves Nunes Pereira Barquinha Busani Fortunato Martins E. P. K. "Performances of microcrystalline zinc tin oxide thin-film transistors processed by spray pyrolysis." IEEE/OSA Journal of Display Technology. 9 (2013): 825-831. AbstractWebsite

In this work, we report results concerning the performances of thin-film transistors (TFTs) where the channel layer is based on microcrystalline zinc tin oxide (ZTO) processed by spray pyrolysis technique. TFTs made with 30 nm thick ZTO channel layer deposited at a substrate temperature of 400 C and 300 Cexhibited, respectively, a saturation mobility of 2.9 cm V s and 1.45 cm V s ; voltage of 0.15 V, and 0.2 V; a sub-threshold swing of 400 mV/dec and 500 mV/dec; ON/OFF ratio at the onset of hard saturation current of 3.5 10 and 6 10 , for a drain to source voltage of 10 V (close to or below the gate to source voltage). This indicates that the substrate temperature is relevant in determining the devices' electronic performances. © 2013 IEEE.

Valtchev, Stanimir. "Perspectives of Tunnel FET (TFET) in the Ultra-Low-Power Analog-Circuit design." Proceedings 28th Conference DCIS. 2013. Abstract
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Branquinho, R., Pinto Busani Barquinha Pereira Baptista Martins Fortunato J. V. T. "Plastic compatible sputtered ta-inf o 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 +{\hbox{Ta}}-{2}{\hbox{O}}5 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 +^{\circ}{\hbox{C}}+ and crystallize at 700 +^{\circ}{\hbox{C}}+ in an orthorhombic phase. Electrolyte-insulator- semiconductor (EIS) field effect based sensors with an amorphous +{\hbox{Ta}}-{2}{\hbox{O}}5 sensing layer showed pH sensitivity above 50 mV/pH. For sensors annealed above 200 +^{\circ}{\hbox{C}}+ pH sensitivity decreased with increasing temperature. Stabilized sensor response and maximum pH sensitivity was achieved after low temperature annealing at 200 +^{\circ}{\hbox{C}}+ , which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors. © 2005-2012 IEEE.

Ruivo, C.R.a b, Ferreira Vaz P. M. c D. "Prediction of thermal load temperature difference values for the external envelope of rooms with setback and setup thermostats." Applied Thermal Engineering. 51 (2013): 980-987. AbstractWebsite

The Cooling Load Temperature Difference (CLTD) values available in the literature for using the simplified CLTD method only apply to rooms under constant indoor air temperature. Due to this limitation, the present paper extends the application of this simplified approach to cooling and heating loads estimation of rooms with daily and weekend setback and setup thermostats, and introduces the term thermal load temperature difference (TLTD). To generate the values of TLTD, a transient heat transfer model, and the corresponding numerical tool, has been developed to predict the thermal behaviour of multilayered walls and flat roofs. The sol-air temperature concept is used. The internal thermal capacity of the room is assumed negligible. The TLTD evolutions have been generated for a wall and a roof, of high mass construction, with setback and setup thermostats in winter and summer scenarios. The periods in which the room is unoccupied have been taken in due account. The TLTD evolutions allowed the estimation of: the energy transferred at the inner surface and the maximum thermal load. Among the cases studied, the relative difference found in the energy transferred through the sunlit envelope, roof or wall under summer conditions, is about 20% when the temperature control strategy is changed from A to B. © 2012 Elsevier Ltd. All rights reserved.

b b b b Ramos, A.M.a b, Pereira Cidade Pereira Branquinho Pereira Martins Fortunato S. a M. T. "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.

Sava, B. A. a, M. a Elisa, L. b Boroica, and R. C. C. c Monteiro. "Preparation method and thermal properties of samarium and europium-doped alumino-phosphate glasses." Materials Science and Engineering B: Solid-State Materials for Advanced Technology. 178 (2013): 1429-1435. AbstractWebsite

The present work investigates alumino-phosphate glasses from Li 2O-BaO-Al2O3-La2O3-P 2O5 system containing Sm3+ and Eu3+ ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10-7 K-1 when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of Tg (vitreous transition temperature) and Tsr (high annealing temperature) but slowly increase in the case of Tir (low annealing temperature-strain point) and very slowly increase, being practically constant in the case of TD (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R 2) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric analysis did not show notable mass change for any of doped samples. DSC curves for both rare-earth-doped phosphate glasses, as bulk and powdered samples, showed Tg values in the range 435-450 C. Bulk samples exhibited a very weak exothermic peak at about 685 C, while powdered samples showed two weak exothermic peaks at about 555 C and 685 C due to devitrification of the glasses. Using designed melting and annealing programs, the doped glasses were improved regarding bubbles and cords content and strain elimination. © 2013 Elsevier B.V. All rights reserved.