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2013
Silva, F., J. Xavier, F. A. M. Pereira, J. Morais, N. Dourado, and M. F. S. F. de Moura. "Determination of cohesive laws in wood bonded joints under mode I loading using the DCB test." Holzforschung. 67 (2013): 835-959. AbstractWebsite
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Silva, Tiago A. N., and M. A. R. Loja Differential Evolution on the Minimization of Thermal Residual Stresses in Functionally Graded Structures. Eds. Ana Madureira, Cecilia Reis, and Viriato Marques. Vol. 61. Computational Intelligence and Decision Making Trends and Applications, From Intelligent Systems, Control and Automation: Science and Engineering Bookseries, 61. Dordrecht: Springer Netherlands, 2013. Abstract
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Arnold, Barry C., Carlos A. Coelho, and Filipe J. Marques. "The distribution of the product of powers of independent uniform random variables." Journal of Multivariate Analysis. 113 (2013): 19-36. Abstract
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Coelho, Carlos A., Barry C. Arnold, and Filipe J. Marques. "The distribution of the product of powers of independent uniform random variables." J. Mult. Anal. 113 (2013): 19-36. Abstract
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Raje, Vivek P., Patrícia I. Morgado, Maximiano P. Ribeiro, Ilídio J. Correia, Vasco D. B. Bonifácio, Paula S. Branco, and Ana Aguiar-Ricardo. "Dual on–off and off–on switchable oligoaziridine biosensor." Biosensors and Bioelectronics. 39 (2013): 64-69. AbstractWebsite
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Martins, R.M., Siqueira MacHado Freitas S. M. O. "The effect of homogenization method on the properties of carbamazepine microparticles prepared by spray congealing." Journal of Microencapsulation. 30 (2013): 692-700. AbstractWebsite

The aim of this study was to investigate the influence of ultrasound and high-shear mixing on the properties of microparticles obtained by spray congealing. Dispersions containing 10% carbamazepine and 90% carrier Gelucire® 50/13 (w/w) were prepared using magnetic stirring, high-shear mixing, or ultrasound. Each preparation was made using hot-melt mixing spray congealing to obtain the microparticles. All microparticles presented a spherical shape with high encapsulation efficiency (>99%). High-shear mixing and ultrasound promoted a decrease in the size of microparticles (D90) to 62.8 ± 4.1 μm and 64.9 ± 3.3 μm, respectively, while magnetic stirring produced microparticles with a size of 84.1 ± 1.4 μm. The use of ultrasound led to microparticles with increased moisture content as identified through sorption isotherm studies. In addition, rheograms showed distinct rheological behaviour among different dispersion preparations. Therefore, the technique used to prepare dispersions for spray congealing can affect specific characteristics of the microparticles and should be controlled during the preparation. © 2013 Informa UK Ltd. All rights reserved.

Wang, J.a, Elamurugu Li Jiao Zhao Martins Fortunato E. b H. a. "Effect of N and P codoping on ZnO properties." Advanced Materials Research. 645 (2013): 64-67. AbstractWebsite

Nitrogen and Phosphorus co-doped (N+P)- zinc oxide (ZnO) films were RF sputtered on corning glass substrates at 350 °C and comparatively studied with undoped, N-, and P- doped ZnO. X-ray diffraction spectra confirmed that the ZnO structure with a preferred orientation along <002> direction. Scanning electron microscope analysis showed different microstructure for the N+P co-doping, and thus probably confirming the co-existence of both the dopants. X-ray photoelectron spectroscopy spectra revealed that the chemical composition in N+P co-doped ZnO are different from that found in undoped, N-, and P- doped ZnO. The atomic ratio of N and P in N+P co-doped ZnO is higher than that in single N or P doped ZnO. One broad ZnO emission peak around 420 nm is observed in photoluminescence spectra. The relative intensity of the strongest peak obtained from co-doped ZnO films is about twice than the P- doped and thrice than the pure and N- doped films. © (2013) Trans Tech Publications, Switzerland.

Lima, M. M. R. A., L. F. C. Braz, R. C. C. Monteiro, JP Veiga, AMP Pinto, and AS Pouzada. "Effect of Phosphogypsum on the Clinkerization Temperature of Portland Cement Clincker." Advanced Materials Forum Vi, Pts 1 and 2. 730-732 (2013): 94-99. Abstract
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Lima, M. M. R. A., L. F. C. Braz, R. C. C. Monteiro, and JP Veiga. "Effect of phosphogypsum on the clinkerization temperature of portland cement clincker." Materials Science Forum. 730-732 (2013): 94-99. AbstractWebsite

Phosphogypsum (PG) is a pollutant residue resulting from the production of phosphoric acid in the phosphated fertilizers industry. About 180 millions of tons of PG are generated worldwide per year, which originates storage problems because of the environmental restrictions and the high costs of storage spaces. Taking into account the mineralizer properties of PG it has been studied a way to valorize this residue as an alternative material in the production of Portland cement clinker. The PG and the raw-materials (limestone, marl, sand and iron oxide) were chemical, mineralogical and thermally characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and differential thermal analysis and termogravimetric analysis (DTA/TGA). After milling, the phosphogypsum was mixed with the raw-materials in different amounts up to 10% weight. The raw mixtures were submitted to two types of firing schedules, heating up to 1500°C without any holding time or heating up to 1350°C and holding for 20 minutes. After firing, the clinkers were analyzed by optical microscopy, milled and characterized in terms of chemical and mineralogical compositions. The clinkers were used to produce cement mortar according to NP EN 196-1 standard. The resultant test specimens were mechanically tested at 2 and 28 days according to the same standard. The obtained results show a reduction of about 140°C in the clinkerization temperature, when a raw mixture with 5% phosphogypsum was used. Standard clinkers, without phosphogypsum addition, which were fired at 1500°C, originated test specimens with a compressive strength of 48.1MPa at 28 days. Test specimens produced with clinker containing 5% phosphogypsum present higher compressive strength values at 28 days, being 55.1MPa for clinkers produced at 1500°C, and 49.4 MPa for clinkers produced at 1350°C. © (2013) Trans Tech Publications, Switzerland.

Lima, Maria Margarida Rolim Augusto, L. F. C. Braz, Regina Monteiro, and JP Veiga. "Effect of Phosphogypsum on the Clinkerization Temperature of Portland Cement Clincker." Materials Science Forum. Vol. 730. Trans Tech Publ, 2013. 94-99. Abstract
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Golshahi, S.a, Rozati Botelho Do Rego Wang Elangovan Martins Fortunato S. M. b A. "Effect of substrate temperature on the properties of pyrolytically deposited nitrogen-doped zinc oxide thin films." Materials Science and Engineering B: Solid-State Materials for Advanced Technology. 178 (2013): 103-108. AbstractWebsite

The effect of substrate temperature (Ts) on the properties of pyrolytically deposited nitrogen (N) doped zinc oxide (ZnO) thin films was investigated. The Ts was varied from 300 °C to 500 °C, with a step of 50 °C. The positive sign of Hall coefficient confirmed the p-type conductivity in the films deposited at 450 °C and 500 °C. X-ray diffraction studies confirmed the ZnO structure with a dominant peak from (1 0 0) crystal plane, irrespective of the variation in Ts. The presence of N in the ZnO structure was evidenced through X-ray photoelectron spectroscopy (XPS) analysis. The obtained high N concentration reveals that the 450 °C is the optimal Ts. Atomic force microscope (AFM) analysis showed that the surface roughness was increased with the increasing Ts until 400 °C but then decreased. It is found that the transmittance of the deposited films is increased with the increasing Ts. The optical band gap calculated from the absorption edge showed that the films deposited with T s of 300 °C and 350 °C possess higher values than those deposited at higher Ts. © 2012 Elsevier B.V.

Nico, C. a, M. P. F. a Graça, M. b Elisa, B. A. b Sava, R. C. C. c Monteiro, L. a Rino, and T. a Monteiro. "Effects of ultraviolet excitation on the spectroscopic properties of Sm3+ and Tb3+ doped aluminophosphate glasses." Optical Materials. 35 (2013): 2382-2388. AbstractWebsite

Li2O-BaO-Al2O3-La2O 3-P2O5 glasses optically activated with rare earth ions with the 4f5, and 4f8 electronic configuration (Sm3+ and Tb3+, respectively) were analyzed by Raman spectroscopy, absorption, excitation photoluminescence, decay curves and temperature dependent photoluminescence. The spectroscopic characteristics of the as-prepared and heat treated samples at temperatures below and above T g were studied as well as their room temperature photometric properties under ultraviolet excitation. All the doped glasses exhibit typical signatures of the lanthanides in their trivalent charge state. For the samarium doped glass heat treated at 250 C (<Tg) the Sm2+ luminescence was also observed. The analysis of the luminescence efficiency was performed in the interval range of 14 K to room temperature, where the integrated intensity of the luminescence was found to decrease for the Sm 3+ and Tb3+ ions in the studied temperature range. Luminescence decay curves were found to be non-exponential for the 4G5/2 → 6H7/2 and 5D3 → 7F4 transitions of the Sm3+ and Tb3+ ions, respectively. The results strongly suggest the occurrence of energy transfer processes through cross relaxation phenomena, mediated by dipole-dipole interaction in all the studied samples. The decay of the 5D4 → 7F5 emission of the Tb3+ ions was found to be single exponential with a time constant of ∼3.1 ms. Based on the spectroscopic characteristics, models for recombination processes are proposed. The room temperature luminance photometric properties with ultraviolet excitation show that the samarium doped glasses have much lower luminance intensity (around 0.3 Cd/m2) when compared with the 6-7 Cd/m2 observed for the terbium doped ones. © 2013 Elsevier B.V. All rights reserved.

Mendes, Ana, Daniel Aelenei, L. Aguiar, C. Pereira, M. Neves, Silva P, Azevedo Susana, D. Mendes, L. Guimar, and J. Teixeira. "The Effects on Health of Indoor Air Quality and Thermal Comfort In Elderly Care Centers." 2nd International Conference on Occupational & Environmental Toxicology. 2013. Abstract
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Neagu, B., E. R. Neagu, R. Igreja, and C. Dias. "Electric Field Distribution Around the Deep Brain Stimulation Electrode Inferred from Dielectric Measurements." Advanced Materials Forum Vi, Pts 1 and 2. Eds. AMP Pinto, and AS Pouzada. Vol. 730-732. Materials Science Forum, 730-732. 2013. 26-31. Abstract
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Neagu, B., E. R. Neagu, R. Igreja, C. Dias, AMP Pinto, and AS Pouzada. "Electric Field Distribution Around the Deep Brain Stimulation Electrode Inferred from Dielectric Measurements." Advanced Materials Forum Vi, Pts 1 and 2. 730-732 (2013): 26-31. Abstract
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AS, Pedrosa, Borges JPMR, Neagu E, Marat-Mendes JN, and Lança MCH Electrical characterization of biphasic ceramics used in hard tissue replacement. Coimbra Portugal, 2013. Abstract

Hydroxyapatite [Hap; Ca10(PO4)6(OH)2) and b-tricalcium phosphate [b-TCP; Ca3(PO4)2] are biocompatible calcium phosphates used in skeletal surgery. The natural HAp is one of the main components of bone and, as a synthetic material, has been widely used for bone replacement presenting good bioactivity. Nevertheless synthetic HAp presents a slow in vivo degradation rate which is disadvantageous for bone’s reparative process. b-TCP has also good osteogenic characteristics presenting the ability to form strong bonds with the bone however, its degradation rate is too fast [1]. Therefore, a composite combining these two ceramics is valuable as it exhibits a suitable degradation rate. Because of the piezoelectric properties of bone it is known that electrical polarization of calcium phosphates can enhance the bioactivity and biointegration of implants [2]. Previous studies have already showed that HAp/b-TCP ceramics can be electrically polarized and that electrical polarization enhances osteogenesis in the early stage of the implantation process. However further studies are required to understand, optimize and improve the polarization technique [1]. In this work a commercial biphasic ceramic powders were pressed in a mold at 200 MPa to produce disc shaped samples. Afterwards, the samples were sintered at temperatures from 950ºC to 1150ºC and the influence of the heat treatment in the electrical polarization and subsequent bioactivity was investigated. The samples were polarized under a high DC electric field at relatively lower temperature (200oC) compared to previous studies and the stability of polarization was tested using TSDC (thermally depolarization currents) measurements. It was studied the influence of the water, initially present in the material, in the total charge deposited during polarization, its stability and its relation with heat treatment after pressing. The influence of the addition of b-TCP on sample’s stored charge was also evaluated. Finally bioactivity tests in a simulated body fluid solution were made taking into account the signal of the charge in each surface of the disc samples so that the results could be compared to previous ones.

Baptista, AC, I. Ferreira, and J. P. Borges. "Electrospun Fibers in Composite Materials for Medical Applications." Journal of Composites and Biodegradable Polymers. 1 (2013): 56-65. Abstract
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Dantas, Francisco, Alessandro Garcia, Jon Whittle, and João Araújo. "Enhancing design models with composition properties: a software maintenance study." AOSD. 2013. 49-60. Abstract
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Igreja, R., H. Domingos, J. P. Borges, and C. J. Dias. "Enhancing the response of chemocapacitors with electrospun nanofiber films." Materials Science Forum. 730-732 (2013): 197-202. AbstractWebsite
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Igreja, R., H. Domingos, J. P. Borges, C. J. Dias, AMP Pinto, and AS Pouzada. "Enhancing the Response of Chemocapacitors with Electrospun Nanofiber Films." Advanced Materials Forum Vi, Pts 1 and 2. 730-732 (2013): 197-202. Abstract
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Aelenei, Daniel, Susana Azevedo, João Viegas, Ana Mendes, Ana Luisa Papoila, Manuela Cano, Pedro Martins, and Nuno Neuparth. "Environment and Health in Children Day Care Centres in Portugal - results from phase II on the ventilation characteristics of 16 schools." CLIMA 2013. 978-80-260-4001-9. 2013. Abstract
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Coelho, Carlos A., Filipe J. Marques, and Sandra Oliveira. "The exact distribution of the likelihood ratio test statistic used to test simultaneously the equality of means and circularity of the covariance matrix." AIP Conference Proceedings. Vol. 1558. AIP, 2013. 789-792. Abstract
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Pinto, J.V.a, Branquinho Barquinha Alves Martins Fortunato R. a P. a. "Extended-gate ISFETs based on sputtered amorphous oxides." IEEE/OSA Journal of Display Technology. 9 (2013): 729-734. AbstractWebsite

We present the results obtained with an extended-gate ISFET totally based on amorphous oxides (GIZO as the semiconductor, +{\hbox{Ta}}-{2}{\hbox{O}}-{5}{\ hbox{:SiO}}-inf2-inf as the dielectric and +{\hbox{Ta}}-{2}{\hbox{O}}-inf5-inf as the sensitive layer). A full characterization of the device was performed with constant ionic strength pH buffer solutions, revealing a sensitivity of 40 mV/pH with small hysteresis, and good linearity in the pH 4-pH 10 range buffer solutions. These results clearly show that it is possible to produce room-temperature disposable and low cost bio-sensors. © 2005-2012 IEEE.

Batista, Sofia Andreia, Neuza Pedro, and João Freitas. "Fatores determinantes no sucesso da adoção e uso continuado do Moodle no ensino superior." III Colóquio Luso-Brasileiro de Educação a Distância e Elearning. http://lead.uab.pt/OCS/index.php/CLB/club/paper/view/169, 2013. Abstract
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