Carbon storage in the soil under different land uses in the south of Portugal

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POLISphone: Creating and Performing With a Flexible Soundmap

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TV white spaces maps computation through interference analysis

“Copyright © [2011] IEEE. Reprinted from ICT Future Network & Mobile Summit 2011. ISBN: 978-1-4577-0928-9. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”For the characterization of TV White Spaces (TVWS), an extensive simulation of the impact of interfering signals was undertaken in a generalized scenario. The simulation for these investigations was derived from a Monte Carlo methodology using SEAMCAT, and the results include the computation of TVWS maps as it can be done with the access to a geo-location database, or based on autonomous sensing only. Geo-location database approach is shown to utilize TVWS spectrum more efficiently. The impact of Professional Wireless Microphone Systems (PWMS) devices on the availability of TVWS is also analyzed and imposes additional limitations of the maximum power emitted by secondary spectrum users

Interference study between wireless microphone systems and TV white space devices

“Copyright © [2012] IEEE. Reprinted from IEEE International Conference on Communications – ICC’2012. ISBN: 978-1-4577-2052-9 This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”This work focus on a coexistence study between wireless microphone systems and secondary users of the TV White Spaces, using a Monte-Carlo methodology. Exclusion areas around wireless microphone receivers, for co-channel and adjacent channel interference, are computed, considering indoor and outdoor scenarios. Using this methodology, impact and tendencies of several parameters over the probability of interference are analyzed, like spectral channel spacing, separation distance and propagation scenario. As an example, for outdoor scenarios, the spectral spacing between primary system and secondary users, ranging from 0 MHz (co-channel operation) to 16 MHz (2 DVB-T channels) results in a protection distance of 13.9 km and 2.2 km, respectively

Morphological and geometrical characterization of historical churches of Yucatan, Mexico

This paper deals with the architectonic, constructive, and geometrical characterization of Yucatan stone masonry churches in Mexico. The work aims at finding statistical correlations between geometric parameters that characterise the main cross section of the churches. For this, a detailed historical and architectonic review was performed and a description of the structural elements and connections among them were provided combining existing data and visual survey of churches under ruins. In addition, a database of 44 Yucatan churches was built with the geometric features of the cross section and linear correlations were studied between the geometric parameters. Additional churches from different regions of Mexico were also considered for a systematic comparison. Besides, simple geometric relations between geometric key parameters as a function of the span of the churches with semi-circular canon vaults were derived and further compared with empirical relations provided in historical treatises from the 16th to 18th centuries was carried. Based on the results obtained, it was seen that the key geometric parameters defining the thickness of canon vaults and thickness and height of the stone masonry walls are reasonably close to some proposals provided in historical treatises.The authors wish to express their gratitude to the National Institute of Anthropology and History of Mexico (INAH), the Commission of Ecclesiastical Properties and Sacred Art of the Archdiocese of Yucatan, the Yucatan State Government Restoration Department, the Faculty of Architecture of the Autonomous University of Yucatan, and the Teacher Professional Development Program (PRODEP) for all collaborationand suppor

Combination of a geolocation database access with infrastructure sensing in TV bands

This paper describes the implementation and the technical specifications of a geolocation database assisted by a spectrum-monitoring outdoor network. The geolocation database is populated according to Electronic Communications Committee (ECC) report 186 methodology. The application programming interface (API) between the sensor network and the geolocation database implements an effective and secure connection to successfully gather sensing data and sends it to the geolocation database for post-processing. On the other hand, the testbed allows authorized TV white space devices to gain access to the services of the geolocation database, according to a draft implementation of Internet Engineering Task Force (IETF) Protocol to Access White Space (PAWS) Two experimental methodologies are available with the testbed: one focused on coexistence studies with commercial wireless microphones, when the testbed is used for sensing only, and another for demonstration purposes, when the testbed is also used to emulate wireless microphone signals. Overall, this hybrid approach is a promising solution for the effective use of TV white spaces and for the coexistence with digital TV broadcast signals, or dynamic incumbent systems, such as unregistered wireless microphones

Cross-platform demonstrator combining spectrum sensing and a geo-location database

“Copyright © [2012] IEEE. Reprinted from ICT Future Network & Mobile Summit 2012. ISBN: 978-1-4673-0320-0. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”After the digital switchover, a secondary access of the so-called TV White Spaces should not interfere with primary users, such as DVB-T systems and local wireless microphone devices. One consensual method for secondary spectrum users to avoid interference is to combine geo-location database with spectrum sensing. This paper describes an experimental platform that combines wireless microphone sensors with a web-based geo-location database access. Software defined radios and Internet technologies are the enabling tools in use. From test trials in a real scenario, the platform was capable to update a list of vacant channel from the geo-location database, using reliable information from blind sensing algorithms

Influence of Hydroxyapatite on Extruded 3D Scaffolds

AbstractIdeal scaffolds for tissue engineering must mimic the complex characteristics of natural tissues and their mechanical performance. In this work, Polycaprolactone (PCL) and composite Polycaprolactone/Hydroxyapatite (PCL/HA) (75/25) scaffolds were produced by using an extrusion-based process called BioExtruder. The structures were characterized regarding the chemical, thermal, morphological and mechanical properties, in order to investigate the effect of HA addition in the polymeric scaffolds. Results show that the incorporation of HA in the 3D structures improve both the thermal and mechanical properties

Invasive alien species in Macaronesia

"[…]. As a consequence of all the geographic conditions and of historical events, the Canaries show the richest biodiversity. As an example, regarding endemic taxa, the Canaries have 524 vascular plants and 2768 arthropods (Martín Esquivel et al. 2005) while the Azores have 72 and 267, respectively (Borges et al. 2005) and the archipelagos of Madeira and Selvagens altogether have 154 and 979 (Borges et al. 2008a) respectively. It is well known that there are several plant genera in the Canaries with high numbers of species (Aeonium, Echium, Argyranthemum, Sonchus, etc.), which probably resulted from adaptive radiation, while in the Azores endemic plant species are found at a rate of one, and more rarely two or three species per genus. An intermediate situation is found in Madeira where genera Argyranthemum (Asteraceae) and Sinapidendron (Brassicaceae) show six endemic taxa (Jardim & Sequeira 2008). There are also other significant differences among the archipelagos. For instance, regarding vertebrate taxa, in the Azores there are no native species of reptiles and there are only two native mammal species, two bats, one of which endemic (Nyctalus azoreum), while there are several species in those groups both in the Canaries and in Madeira, namely the small lizard from Madeira (Teira dugesii, with four subspecies) or the giant lizards from La Gomera (Gallotia bravoana), El Hierro (G. simonyi), Tenerife (G. intermedia) and Gran Canaria (G. stehlini), among others. Thus, although there are similarities among the different regions, important geographic differences dictated that the native flora and fauna would show striking differences among the archipelagos. This is of considerable importance in order to understand what happened in each region, regarding the introduction of alien species. For instance, it is usually accepted that several species of Mediterranean distribution are considered as native in Madeira or in the Canaries, while the same species are considered as alien in the Azores.

Da peste gay ao barebacking sex: AIDS, biopolitica e risco em sáude

Neste trabalho buscaremos problematizar questões pertinentes a epidemia da AIDS, perpassando por discussões sobre a peste gay como metáfora, o sexo seguro e o preservativo como um dispositivo biopolítico, a deshomossexulização da epidemia, risco em saúde, finalizando com o barebacking sex. Essas discussões se tornam pertinentes, principalmente num momento em que a questões como riscos, controle e medicalização da saúde se constituem como temas importantes da atualidade e o histórico da epidemia da AIDS podem contribuir significativamente para o fomento de tais reflexões. Acreditamos que apesar de existirem “estilos de vida escolhidos, eleições e condutas individuais pertencente ao âmbito do privado” que constituem dado