Thyreophoran dinosaurs have spike- and club-shaped osteoderms probably used for defensive weapons. The structural and histological variations have been little known. Here, we provide the comparisons of the internal structures in defensive weapons of ankylosaurs and stegosaurs, using spikes of a polacanthid (Gastonia) and a nodosaurid (Edmontonia), clubs of ankylosaurids (Saichania and Ankylosauridae indet. from Canada), and spikes of stegosaurids (Stegosaurus and Dacentrurus), which sheds light on understandings of evolutionary history and functional implications of defensive weapons in thyreophorans. In ankylosaurs, the structural and histological features of spikes and clubs are similar with those of small osteoderms in having thin compact bones, thick cancellous bones with large vascular canals, and abundant collagen fibers. A previous study demonstrated that each of three groups of ankylosaurs (polacanthid, nodosaurid, and ankylosaurid) has distinct characteristic arrangements of collagen fibers in small osteoderms. This study shows that spikes and clubs of ankylosaurs maintain the same characteristic features for each group despite of the differences in shapes and sizes. Conversely, the spike-shaped osteoderms in primitive (Dacentrurus) and derived (Stegosaurus) stegosaurids have similar structure to each other and are significantly different from the other types of stegosaur osteoderms (throat bony ossicles and plates) in having thick compact bones with a medullary cavity. These lack abundant collagen fibers unlike ankylosaur osteoderms. The spikes of ankylosaurs and stegosaurs are similar in shape, but their structural and histological features are different in having unique structures of collagen fibers for ankylosaurs and thick compact bones for stegosaurs, providing enough strength to have large spikes and to use them as defensive weapons. Although the shapes of ankylosaur clubs are different from spikes, the internal structures are similar, suggesting that ankylosaurs maintain similar structures despite of different shapes in osteoderms. These results indicate that ankylosaurs and stegosaurs used different strategies independently to evolve defensive weapons.

An European directive established that all EU countries must have, until the end of 2006, a recovery network for the electric and electronic equipment waste (WEEE). In Portugal, a group of producers formed a non-profit organization to design and manage this waste now. In this work, a model developed previously by the authors to design and plan a generic WEEE network is presented and applied to the Portuguese case. The results obtained are discussed and compared with the network that is currently operating.

As questões associadas aos processos de localização empresarial têm vindo a adquirir uma dimensão cada vez mais política do que apenas económica ou técnica. O desenvolvimento tecnológico tem vindo a facilitar uma maior amplitude de escolhas e de orientações relativas à localização das actividades empresariais. Mas o mesmo se passa com a deslocalização das mesmas. As consequências sociais podem ser igualmente importantes pois podem gerar processos de desagregação social, forte mobilidade territorial e, frequentemente, incremento de processos de desigualdade social.

This paper presents the mobile technology utilization in improving the remote access to the data acquisition processes of several automated monitoring system for air quality, water quality, and crop canopy microclimate. The system facilitates mobile environmental management and decision making by using in-situ measurements, GSM/GPRS informational fluxes, Pocket PCs, dGPS and mobile GIS resources. Data is retrieved via GSM/GPRS data modem to remote computer using digital (GSM) phone network. The main outcomes of this study were as follows: 1. designing the hardware, communication and software infrastructure of the system using telemetry features, 2. establishing the wireless connections and remote access from PDAs to the measurement servers, 3. programming and testing specific control virtual instruments (Vis) in NI LabVIEWTM, 4. obtaining a portable solution of statistical analysis and survey with PDA Vi (Virtual Instruments) interfaces for Pocket PC to gather, store, customize and report data combined with statistical processing functions, and 5. identifying mobile GIS applications for the environmental protection. The remote-accessing of the GIS server features, provided in-situ electronically reviews, mark up, and precise measurements of the site pollution plans. One possible solution to overcome the PDA hardware and software restraints is enabling the remote access and control of the DAQ and GIS software resources of the measurement server via internet.

Software transactional memory is a promising programming model that adapts many concepts borrowed from the databases world to control concurrent accesses to main memory (RAM). This paper discusses how to support revertible operations, such as memory allocation and release, within software libraries that will be used in software memory transactional contexts. The proposal is based in the extension of the transaction life cycle state diagram with new states associated to the execution of user-defined handlers. The proposed approach is evaluated in terms of functionality and performance by way of a use case study and performance tests. Results demonstrate that the proposal and its current implementation are flexible, generic and efficient

Software transactional memory (STM) is a promising programming model that adapts many concepts borrowed from the databases world to control concurrent accesses to main memory (RAM) locations. This paper aims at discussing how to support apparently irreversible operations within a memory transaction.

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Dinosaurs and other fossils have been artificially enhanced, or totally forged, to increase their commercial value. The most problematic forgeries to detect are based on original fossils that are artificially assembled. Several techniques are suggested for detecting hoaxes: detailed visual examination, chemical analysis, Xray or CT-scan, and ultraviolet light. It is recommended that museums and paleontological researchers do not purchase and/or trade fossils lacking clear provenience information. Exceptions to that general rule should be closely examined using techniques described herein.

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There is a sustained interest both from theoretical and from practical points of view to understand the isothermal charging and the isothermal discharging currents in dielectrics. The measured currents are analyzed either in terms of polarization mechanisms or in terms of charge injection/extraction at the metal-dielectric interface and the conduction current through the dielectric material. As long as we do not know the nature of the origin of the current, it is not clear what information we can get by analyzing the experimental data. We propose to measure the open-circuit isothermal charging and discharging currents just to overpass the difficulties related to the analysis of the conduction mechanisms in dielectric materials. We demonstrate that besides a polarization current, there is a current related with charge injection or extraction at the metal-dielectric contact and a reverse current related to the charge trapped into the superficial trap states of the dielectric and that can jump at the interface in a reverse way. An analytical expression for the current is proposed. By fitting the experimental data to this analytical equation, two important parameters can be determined: (i) the highest value of the relaxation time for the polarization mechanisms still involved into the transient current and (ii) the height of the potential barrier W-0 at the metal-dielectric interface at the initial time when the step voltage is applied. The value obtained for Al-polyethylene terephthalate interface is (0.43 +/- 0.02) eV. For a charging voltage of 220 V there are 6x10(14) trapped electrons/m(2). (c) 2008 American Institute of Physics.

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Software transactional memory is a promising programming model that adapts many concepts borrowed from the databases world to control concurrent accesses to main memory (RAM). This paper discusses how to support revertible operations, such as memory allocation and release, within software libraries that will be used in software memory transactional contexts. The proposal is based in the extension of the transaction life cycle state diagram with new states associated to the execution of user-defined handlers. The proposed approach is evaluated in terms of functionality and performance by way of a use case study and performance tests. Results demonstrate that the proposal and its current implementation are flexible, generic and efficient

Software transactional memory (STM) is a promising programming model that adapts many concepts borrowed from the databases world to control concurrent accesses to main memory (RAM) locations. This paper aims at discussing how to support apparently irreversible operations within a memory transaction.

The possibility of using fly ash and shale as alternative raw materials for the production of structural ceramics was investigated. Fly ash is a by-product from coal-burning power plants, and shale is a sedimentary rock that if ground finely enough can exhibit a clay-like plasticity. Ceramic samples containing 10-50 wt% fly ash were formed from mechanical mixing of both kinds of powders that were packed and sintered in the temperature range 950-1200°C It was verified that powders with larger fly ash content exhibited lower packing density resulting in compacts with a lower sintered density. Although an increase in fly ash content was associated to a larger presence of porosity in the sintered samples, as confirmed by microstructural analysis, all studied compositions when sintered at the highest temperatures exhibited satisfactory values for water absorption (< 10%), for flexural strength (20-64 MPa) and for hardness (20-30 GPa) indicating that they have potential to be applied in the production of structural ceramics.

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