Martins, Rui M. S., F. Beckmann, R. Castanhinha, R. Araújo, O. Mateus, and P. K. Pranzas Tomographic techniques for the study of exceptionally preserved dinosaur and crocodile fossils from the mesozoic of Portugal. VII Encontro Nacional de Biologia Evolutiva, Coimbra, 21 Dezembro 2011., 2011.
AbstractPortugal is ranked within the ten countries with more dinosaur taxa and the Lourinhã Formation is known
by the Late Jurassic findings of dinosaurs and other fossils. Often, studies of the external morphological
characteristics of the fossils are not sufficient and, observations of internal structures, using non-
destructive techniques, are required. The fossils here presented belong to the Museum da Lourinhã
(Portugal) and comprise a lower jaw of a basal crocodilian (possibly a Tomistomidae), eggshells and
several vertebrae from the exceptionally well preserved in ovo remains of Late Jurassic theropod dinosaur
Lourinhanosaurus. Neutron Tomography (NT) experiments with this material has been carried out at the
Geesthacht Neutron Facility in Germany. Additionally, eggshell fragments and several vertebrae have
been studied by Synchrotron-Radiation based Micro-Computed Tomography (SRμCT) at the HARWI II and
BW2 beamlines, respectively. These beamlines are operated by the Helmholtz-Zentrum Geesthacht at the
storage ring DORIS III at the Deutsches Elektronen–Synchrotron DESY in Hamburg, Germany. In both cases
(NT and SRμCT) complete 3D recordings have been obtained using a non-destructive procedure. The high-
quality tomographic datasets can be effectively studied through interactive digital visualization. Hence,
these visualization methods provide precious information about the 3D internal micro morphology of
fossils, like the network of the eggshell pores, often invisible in more traditional techniques, and provide a
direct window into the evolutionary history of organisms.
Cunha, Jácome, Joost Visser, Tiago Alves, and João Saraiva. "
Type-Safe Evolution of Spreadsheets."
Proceedings of the 14th International Conference Fundamental Approaches to Software Engineering (FASE '11): Part of the Joint European Conferences on Theory and Practice of Software (ETAPS '11). Eds. Dimitra Giannakopoulou, and Fernando Orejas. Vol. 6603. Lecture Notes in Computer Science, 6603. Springer, 2011. 186-201.
AbstractSpreadsheets are notoriously error-prone. To help avoid the introduction of errors when changing spreadsheets, models that capture the structure and interdependencies of spreadsheets at a conceptual level have been proposed. Thus, spreadsheet evolution can be made safe within the confines of a model. As in any other model/instance setting, evolution may not only require changes at the instance level but also at the model level. When model changes are required, the safety of instance evolution can not be guarded by the model alone. We have designed an appropriate representation of spreadsheet models, including the fundamental notions of formulæand references. For these models and their instances, we have designed coupled transformation rules that cover specific spreadsheet evolution steps, such as the insertion of columns in all occurrences of a repeated block of cells. Each model-level transformation rule is coupled with instance level migration rules from the source to the target model and vice versa. These coupled rules can be composed to create compound transformations at the model level inducing compound transformations at the instance level. This approach guarantees safe evolution of spreadsheets even when models change.
Afonso, Marcos, Pedro Pereira, and João Martins. "
Weather Monitoring System for Renewable Energy Power Production Correlation."
Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2011. Ed. Luis Camarinha-Matos. Vol. 349. IFIP Advances in Information and Communication Technology, 349. Costa de Caparica - Portugal: Springer Boston, 2011. 481-490.
AbstractThis work describes the development of a system designed for renewable power generation integration. It continuously acquires wind, solar and temperature data, which is automatically correlated with energy parameters, obtained from renewable energy systems. The developed system was installed in an urban building equipped with photovoltaic cells and wind renewable generation. To validate the developed application, it was analyzed data of a wind generator and a set of photovoltaic panels, installed near to the weather station. The developed application allows, in addition to the acquisition of weather and energy data, their continuous monitoring and correlation through a graphical user interface, providing a friendly interactivity with the user.
Folgosa, Filipe, Cristina M. Cordas, Joana A. Santos, Alice S. Pereira, Jose J. G. Moura, Pedro António Brito Tavares, and Isabel Moura. "
{New spectroscopic and electrochemical insights on a class I superoxide reductase: Evidence for an intramolecular electron transfer pathway.}."
Biochemical Journal (2011).
AbstractSuperoxide reductases are enzymes involved in bacterial resistance to reactive oxygen species, catalyzing the reduction of superoxide anions to hydrogen peroxide. So far three structural classes have been identified. Class I enzymes have two iron-center containing domains. Most studies have been focused on the catalytic iron site (center II), but the role of center I is yet poorly understood. The possible roles of this iron site were approached by an integrated study using both classical and fast kinetics measurements as well as direct electrochemistry. A new heterometallic form of the protein with a zinc-substituted center I, maintaining the iron active site center II was obtained, resulting in a stable derivative useful for comparison with the native all-iron from. Second order rate constants for the electron transfer between reduced rubredoxin and the different SOR forms were determined to be 2.8x107 (M-1s-1) and 1.3x106 (M-1s-1) for SORFe(IIII)-Fe(II) and for SORFe(IIII)-Fe(III) forms respectively, and 3.2x106 (M-1s-1) for the SORZn(II)-Fe(III) form. The results obtained seem to indicate that center I transfers electrons from the putative physiologic donor, rubredoxin, to the catalytic active iron site (intramolecular process). In addition, electrochemical results show that conformational changes are associated to the redox state of center I, which may enable a faster catalytic response towards superoxide anion. The apparent rate constants calculated for the SOR-mediated electron transfer also support this observation.
Martins, R., B. Brás, I. Ferreira, L. Pereira, P. Barquinha, N. Correia, R. Costa, T. Busani, A. Gonçalves, and A. Pimentel Away from silicon era: the paper electronics. SPIE OPTO. International Society for Optics and Photonics, 2011.
Abstractn/a
Martins, R., B. Bras, I. Ferreira, L. Pereira, P. Barquinha, N. Correia, R. Costa, T. Busani, A. Goncalves, A. Pimentel, and E. Fortunato. "
Away from silicon era: the paper electronics."
Oxide-Based Materials and Devices Ii. Eds. F. H. Teherani, D. C. Look, and D. J. Rogers. Vol. 7940. Proceedings of SPIE, 7940. 2011.
Abstractn/a
Martins, Rodrigo, Arokia Nathan, Raquel Barros, LuÍs Pereira, Pedro Barquinha, Nuno Correia, Ricardo Costa, Arman Ahnood, Isabel Ferreira, and Elvira Fortunato. "
Complementary metal oxide semiconductor technology with and on paper."
Advanced Materials. 23.39 (2011): 4491-4496.
Abstractn/a
Carvalho, Carlos, Guilherme Lavareda, and Nuno Paulino. "
A DC-DC Step-Up mu-Power Converter for Energy Harvesting Applications, Using Maximum Power Point Tracking, Based on Fractional Open Circuit Voltage."
TECHNOLOGICAL INNOVATION FOR SUSTAINABILITY. Ed. LM CamarinhaMatos. Vol. 349. IFIP Advances in Information and Communication Technology, 349. Soc Collaborat Networks; IFIP WG 5.5 COVE CoOperation Infrastructure Virtual Enterprises & Elect Business; IEEE Ind Elect Soc; U2; Uninova, 2011. 510-517.
AbstractA DC-DC step-up micro power converter for solar energy harvesting applications is presented. The circuit is based on a switched-capacitor voltage tripler architecture with MOSFET capacitors, which results in an, area approximately eight times smaller than using MiM capacitors for the 0.131 mu m CMOS technology. In order to compensate for the loss of efficiency, due to the larger parasitic capacitances, a charge reutilization scheme is employed. The circuit is self-clocked, using a phase controller designed specifically to work with an amorphous silicon solar cell, in order to obtain the maximum available power from the cell. This will be done by tracking its maximum power point (MPPT) using the fractional open circuit voltage method. Electrical simulations of the circuit, together with an equivalent electrical model of an amorphous silicon solar cell, show that the circuit can deliver a power of 1132 mu W to the load, corresponding to a maximum efficiency of 66.81%.
R., Neagu E., C. Dias, Lança M. Carmo, Igreja R., Inacio P., and Marat-Mendes J. N. "
Discrimination between Space Charge and Dipolar Contributions in Ferroelectric Polymers."
14th International Symposium on Electrets. International Symposium on Electrets. 2011.
AbstractThe final thermally stimulated discharge current method allows a better selection of the experimental conditions for sample polarization. By decreasing the ratio between the charging time and the discharging time, the apparent peak is of the same order of magnitude as the genuine peaks and there is only a partial overlap between then. Two peaks have been identified for polyamide 11, one associated with the glass transition around 60 °C and the second associated with the Curie transition around 96 °C.