684 research outputs found
Occurrence of Gastroliths in _Baurusuchus_ (Baurusuchidae, Mesoeucrocodylia) from Adamantina Formation, Bauru Basin
The fossil record of Baurusuchidae Mesoeucrocodylia in the General Salgado county and its surroundings is one of the best regarding preservation, completeness and articulation of skull and skeleton remains, including specimens that shown even the most delicate bone structures and cartilaginous tissues. 

One of them, UFRJ DG 288-R, has preserved its skull and about 80% of its skeleton. During the removal of the rock matrix, on what should be the specimen’s abdominal region, together with fragments of gastralia were observed some small well-polished weathered angulous to subrounded clasts, presumed to be gastroliths. 

These xenoliths occur in a restrict cluster, where at least four peeble-sized stones are visible in the surface of the specimen. The texture and fabrics of these rock fragments differs from the surrounding matrix, presenting darker purplish tones. In thin section, one of the fragments revealed isotropic texture, with opaque minerals in abundance, of euhedric to subhedric habits. The mineralogical composition presents mainly clay minerals as weathering products; biotite and chlorite are common, being the last the result of hidratation of the first. Although highly altered, the low quartz content, small-sized and well-formed crystals suggests maphic composition in volcanic context, possibly representing a basalt fragment. 

In extant Crocodyliformes, the occurrence of gastroliths is commonly associated with food processing in the stomach, diving ballast, hunger stress and/or supplementary mineral ingestion. 

As baurusuchids are characterized as medium to large size fully terrestrial predator/scavengers, based on skeletal data, the ballast function of gasthroliths is excluded in this case. As mentioned above, extant crocodyliforms such as _Caiman_ and _Crocodylus_ ingest stones when under stressful conditions of lack of food, water or when in high population density. Osteoderms are one of the primary sources for calcium and a reservoir for the homeostasis. The hunger stress can be observed in the osteoderms histological cuts as an abnormal concentration of osteoclasts at its inner region overwhelming the presence of osteoblasts and consuming the osteocytes. The preservation of osteoderms associated with gasthroliths may reveal if the stone ingestion in baurusuchids is a normal or driven by hunger behavior. 

The paleoenvironmental conditions dominating the Adamantina Formation during the Late Cretaceous are considered mainly arid, marked with strong seasonality, alternating long droughts and short rainy periods, associated with flashflood events. The stressful condition created during the dry season would cause famine and mass mortality, thus forcing animals to endure or escape. The baurusuchids underwent the dry seasons through behavorial responses of self burial and probably stone ingestion, although natural bahavior cannot be eliminated as a cause. 

Financial support provided by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant no 305780/2006–9), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Instituto Virtual de Paleontologia/ Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (IVP/FAPERJ, grant no E–26/152.541/2006).

Kriging models for aero-elastic simulations and reliability analysis of offshore wind turbine support structures
This PhD research is funded by Lloyd’s Register Group Services Ltd., Aberdeen. Sriramula’s work within the Lloyd’s Register Foundation Centre for Safety and Reliability Engineering at the University of Aberdeen. The Foundation helps to protect life and property by supporting engineering-related education, public engagement and the application of research.Peer reviewedPostprin
Multi-monitorização de estufa agrícola
A agricultura tem recorrido, tradicionalmente, a métodos empíricos que não rentabilizavam a produção e estava fortemente dependente das condições meteorológicas.
Para melhorar a produção agrícola, surgiram as estufas agrícolas que permitem culturas de elevado valor acrescentado. Estas permitem também a elaboração de estudos de conceitos de causa-efeito, que possibilitam a construção de modelos e sistemas para melhorar a produção e a qualidade de determinada colheita.
Com base nesta realidade, este artigo apresenta e descreve um trabalho que se encontra em fase de desenvolvimento por investigadores de duas escolas do Instituto Politécnico de Castelo Branco (IPCB) e que visa o desenvolvimento de um sistema para monitorização de uma estufa agrícola situada na Escola Superior Agrária (ESA) daquele Instituto
Greenhouse watching system using multi-technologies
Traditional agriculture uses empiric methods and is very exposed to meteorological conditions. To increase the agriculture production, greenhouses had appeared to allow crops with higher quality. Greenhouses also permit the study of cause-effect concepts that by them allow building models that improve the crop’s production and quality.
Based on this reality, this paper presents a system developed by researchers of two schools of the Instituto Politécnico of Castelo Branco(IPCB) to monitor a greenhouse located in the campus of Escola Superior Agrária (ESA). This proposed system uses several different technologies
Time-Sensitive Networking to Improve the Performance of Distributed Functional Safety Systems Implemented over Wi-Fi
Industry 4.0 has significantly improved the industrial manufacturing scenario in recent years. The Industrial Internet of Things (IIoT) enables the creation of globally interconnected smart factories, where constituent elements seamlessly exchange information. Industry 5.0 has further complemented these achievements, as it focuses on a human-centric approach where humans become part of this network of things, leading to a robust human–machine interaction. In this distributed, dynamic, and highly interconnected environment, functional safety is essential for adequately protecting people and machinery. The increasing availability of wireless networks makes it possible to implement distributed and flexible functional safety systems. However, such networks are known for introducing unwanted delays that can lead to safety performance degradation due to their inherent uncertainty. In this context, the Time-Sensitive Networking (TSN) standards present an attractive prospect for enhancing and ensuring acceptable behaviors. The research presented in this paper deals with the introduction of TSN to implement functional safety protocols for wireless networks. Among the available solutions, we selected Wi-Fi since it is a widespread network, often considered and deployed for industrial applications. The introduction of a reference functional safety protocol is detailed, along with an analysis of how TSN can enhance its behavior by evaluating relevant performance indexes. The evaluation pertains to a standard case study of an industrial warehouse, tested through practical simulations. The results demonstrate that TSN provides notable advantages, but it requires meticulous coordination with the Wi-Fi MAC layer protocol to guarantee improved performance
A Comprehensive Review on Time Sensitive Networks with a Special Focus on Its Applicability to Industrial Smart and Distributed Measurement Systems
The groundbreaking transformations triggered by the Industry 4.0 paradigm have dramati-cally reshaped the requirements for control and communication systems within the factory systems of the future. The aforementioned technological revolution strongly affects industrial smart and distributed measurement systems as well, pointing to ever more integrated and intelligent equipment devoted to derive accurate measurements. Moreover, as factory automation uses ever wider and complex smart distributed measurement systems, the well-known Internet of Things (IoT) paradigm finds its viability also in the industrial context, namely Industrial IoT (IIoT). In this context, communication networks and protocols play a key role, directly impacting on the measurement accuracy, causality, reliability and safety. The requirements coming both from Industry 4.0 and the IIoT, such as the coexistence of time-sensitive and best effort traffic, the need for enhanced horizontal and vertical integration, and interoperability between Information Technology (IT) and Operational Technology (OT), fostered the development of enhanced communication subsystems. Indeed, established tech-nologies, such as Ethernet and Wi-Fi, widespread in the consumer and office fields, are intrinsically non-deterministic and unable to support critical traffic. In the last years, the IEEE 802.1 Working Group defined an extensive set of standards, comprehensively known as Time Sensitive Networking (TSN), aiming at reshaping the Ethernet standard to support for time-, mission-and safety-critical traffic. In this paper, a comprehensive overview of the TSN Working Group standardization activity is provided, while contextualizing TSN within the complex existing industrial technological panorama, particularly focusing on industrial distributed measurement systems. In particular, this paper has to be considered a technical review of the most important features of TSN, while underlining its applicability to the measurement field. Furthermore, the adoption of TSN within the Wi-Fi technology is addressed in the last part of the survey, since wireless communication represents an appealing opportunity in the industrial measurement context. In this respect, a test case is presented, to point out the need for wirelessly connected sensors networks. In particular, by reviewing some literature contributions it has been possible to show how wireless technologies offer the flexibility necessary to support advanced mobile IIoT applications
A learning model for battery lifetime prediction of LoRa sensors in additive manufacturing
Today, an innovative leap for wireless sensor networks, leading to the realization of novel and intelligent industrial measurement systems, is represented by the requirements arising from the Industry 4.0 and Industrial Internet of Things (IIoT) paradigms. In fact, unprecedented challenges to measurement capabilities are being faced, with the ever-increasing need to collect reliable yet accurate data from mobile, battery-powered nodes over potentially large areas. Therefore, optimizing energy consumption and predicting battery life are key issues that need to be accurately addressed in such IoT-based measurement systems. This is the case for the additive manufacturing application considered in this work, where smart battery-powered sensors embedded in manufactured artifacts need to reliably transmit their measured data to better control production and final use, despite being physically inaccessible. A Low Power Wide Area Network (LPWAN), and in particular LoRaWAN (Long Range WAN), represents a promising solution to ensure sensor connectivity in the aforementioned scenario, being optimized to minimize energy consumption while guaranteeing long-range operation and low-cost deployment. In the presented application, LoRa equipped sensors are embedded in artifacts to monitor a set of meaningful parameters throughout their lifetime. In this context, once the sensors are embedded, they are inaccessible, and their only power source is the originally installed battery. Therefore, in this paper, the battery lifetime prediction and estimation problems are thoroughly investigated. For this purpose, an innovative model based on an Artificial Neural Network (ANN) is proposed, developed starting from the discharge curve of lithium-thionyl chloride batteries used in the additive manufacturing application. The results of experimental campaigns carried out on real sensors were compared with those of the model and used to tune it appropriately. The results obtained are encouraging and pave the way for interesting future developments
Spatial distribution of macro- and micro-litter items along rocky and sandy beaches of a Marine Protected Area in the western Mediterranean Sea
In this study, the spatial distribution and physical characteristics of beach macro- and micro-litter within the Cabrera Archipelago Maritime-Terrestrial National Park (Cabrera MPA), in the Balearic Islands have been analysed. For macro-litter items, a mean concentration of 1.9 ± 2.4 items/m2 weighing a total of 13 kg was quantified. In terms of beach composition, cobble beaches with deposited seagrass had almost twice as much marine litter as other beaches. For beach micro-litter items, white and transparent microplastics within the size class of 1–2 mm were the most abundant on all the beaches, and the most common polymer types were polyethylene (64%) and polypropylene (17.2%). Overall, for both macro- and micro-litter items, plastic was the most dominant material (90%) identified on all beaches surveyed within Cabrera MPA, indicating areas of low anthropogenic pressures are increasingly becoming sinks for marine litter.En prens
Reproducción y hábitat de desove del jurel dentón, Pseudocaranx dentex, en las Azores, Atlántico norte central
Reproductive biology and habitat preferences of the white trevally, Pseudocaranx dentex (Carangidae), were studied in the Azores islands, central north Atlantic, to determine the spatial and seasonal dynamics of habitat use of immature and mature fish. The sex ratio was close to 1:1 and fish matured at about 30 cm fork length. There were no differences in the maturation or length-weight relationships between sexes. The spawning season lasts from June to September. Underwater visual censuses showed that schools of mature individuals preferentially aggregate around the summits of offshore reefs during the spawning season. In contrast, schools of smaller, immature fish use inshore habitats all year round. Our data support the hypothesis that offshore reefs are a preferential spawning habitat of larger white trevally, and most possibly for a number of visitor pelagic predators as well. Inverse relationships between exploitation levels, abundance and size composition at the two different islands suggest that the summer fishery targeting trevally schools around offshore reefs has negatively impacted the population. These findings bring additional ecological and management relevance to offshore reefs.Se realizó un estudio de la biología reproductiva y las preferencias de hábitat del jurel dentón, Pseudocaranx dentex (Carangidae),en las islas Azores, Atlántico norte central, con el objetivo de comprender la dinámica espacial y estacional de individuos inmaduros y maduros en el uso del hábitat. Se observó un sex ratio próximo a 1:1 y una talla de primera madurez de 30 cm longitud de furca, sin diferencias entre sexos respecto a la talla de madurez, ni tampoco en la relación talla-peso. La época de reproducción se prolongó de junio a septiembre. Los muestreos visuales revelaron que durante la época de reproducción los individuos maduros se agregan preferentemente en torno de las coronas de arrecifes en mar abierto, mientras que los cardúmes de individuos inmaduros utilizan los hábitats costeros durante todo el año. Nuestros datos apoyan la hipótesis de que los arrecifes en mar abierto constituyen el hábitat preferente para el desove del jurel dentón y, muy probablemente, de otros predadores pelágicos. Una relación inversa entre los niveles de explotación y la abundancia y talla del jurel dentón en dos islas distintas sugiere que la pesquería de verano del jurel dentón ha afectado negativamente la población. Estos resultados ponen de manifiesto la relevancia, tanto ecológica como para la gestión, de los arrecifes en mar abierto
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