761 research outputs found
Secure Communication in Vehicular Networks - PRESERVE Demo
Security and privacy are fundamental prerequisites for the deployment of vehicular communications. The near-deployment status of Safety Applications for Intelligent Transport Systems (ITS) calls for strong evidence on the applicability of proposed research solutions, notably close-to-reality situations and field-operational trials. The contribution of our work is in this direction: We present a demonstration of the integration and the interoperability among components and security mechanisms coming from different Research and Development projects, as per the PRESERVE project. In fact, we show that the components of the SeVeCom and EVITA projects with the PRESERVE architecture lead to strong and practical security and privacy solutions for Vehicular Ad-hoc Networks (VANETs)
Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications
[EN] Spray pyrolised SnS thin films doped with indium were studied using various optical and electrical techniques.Structural analysis shows that all films crystallise in an orthorhombic structurewith (111) as a preferential direction, without secondary phases. The doping of SnS layers with indium results in better morphology with increased grain size. Absorption measurements indicate a dominant direct transition with energy decreasing from around 1.7 eV to 1.5 eV with increased indium supply. Apart from the direct transition, an indirect one, of energy of around 1.05 eV, independent of indiumdoping, was identified. The photoluminescence study revealed two donors to acceptor transitions between two deep defect levels and one shallower one, with an energy of around 90 meV. The observed transitions did not depend significantly on In concentration. The conductivitymeasurements reveal thermal activation of conductivity with energy decreasing from around 165 meV to 145 meV with increased In content.This work was supported by the Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat Valenciana (Prometeus 2014/044).Urbaniak, A.; Pawlowski, M.; Marzantowicz, M.; Sall, T.; MarÃ, B. (2017). Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications. Thin Solid Films. 636:158-163. https://doi.org/10.1016/j.tsf.2017.06.001S15816363
Determinants Influencing the Consumption of Iron-Rich Foods among Senegalese Young Children: A Path Analysis
Background: Anaemia is a public health concern among Senegalese children aged 6-59 months old. One of the potential causes of this situation is the low consumption of iron-rich foods (IRF). Understanding factors that influence the provision of IRF among young children could help prevent and control anemia. Using the extended version of the theory of planned behavior (eTPB), this nationwide study examines psychosocial and environmental determinants of the consumption of IRF in children aged 6-23 months.
Methods and Materials: To this end, an existing questionnaire used for the same purpose was reviewed and re-validated. Using data collected among 418 children's caregivers on each construct of the eTPB, pathways by which individual and environmental constructs may influence the daily IRF consumption were identified. Data on IRF consumption were collected using a food frequency questionnaire.
Results: Overall, 42% of children consumed IRF, while 95% of caregivers intended to provide them with IRF daily. There was no association between the intention and the actual behavior. The daily IRF consumption was instead predicted by the child's age and environmental factors. In turn, the subjective norm and the perceived behavioral control predicted the intention.
Conclusion: By using a valid and reliable tool to collect data on individual and environmental factors affecting the consumption of IRF among Senegalese young children on a national scale, our research highlights potential barriers to their provision. These barriers should be considered in the design and implementation of effective interventions to improve their nutrition
Rift Valley fever outbreak, Mauritania, 1998: seroepidemiologic, virologic, entomologic, and zoologic investigations.
A Rift Valley fever outbreak occurred in Mauritania in 1998. Seroepidemiologic and virologic investigation showed active circulation of the Rift Valley fever virus, with 13 strains isolated, and 16% (range 1.5%-38%) immunoglobulin (Ig) M-positivity in sera from 90 humans and 343 animals (sheep, goats, camels, cattle, and donkeys). One human case was fatal
Monitoring and Forecasting of Coastal Erosion in the Context of Climate Change in Saint Louis (Senegal)
Owing to its unique physical and socio-economic characteristics, the Saint Louis region stands out as one of the most susceptible areas in Senegal to the adverse impacts of coastal erosion. The dynamics of erosion in this region are significantly influenced by the Langue de Barbarie (LB), a sand spit formed at the mouth of the Senegal River. Initially, in 2003, a 4 m wide artificial breach was strategically introduced to mitigate flooding; however, sediment dynamics expanded it to 6 km by 2020, thereby affecting the entire region. This study delves into the coastline change of the LB, specifically divided into three zones (LB-1, LB-2, and LB-3), spanning the period from 1994 to 2042. Leveraging Geographic Information System (GIS) and remote sensing techniques, our investigation reveals that, prior to the breach’s creation, the average dynamic coastline rates in zones LB-1, LB-2, and LB-3 were estimated at 4.4, 5.9, and 4.4 m/year, respectively. Subsequent to the breach, these rates shifted to −1.2, 8.4, and −2.7 m/year, with the most significant erosion observed alongshore of LB-3 at −6.6 m/year during the period 2002–2012. Projecting into 2032, LB-1 and LB-3 are anticipated to experience erosion rates of −11.5 and −26.8 m/year, respectively, while the LB-2 records an estimated accretion rate of 8.41 m/year. Eroded areas are expected to total 571,458 m2, while accumulated areas are expected to total 67,191 m2. By 2042, zones LB-1, LB-2, and LB-3 are expected to experience erosion rates of −23 and −53.6 m/year, resulting in the erosion of 1,021,963 m2 and the accumulation of 94,930 m2 with a dynamic rate of 168.2 m/year in zone LB-3. These results have significant implications for solving the urgent issue of coastal erosion in LB. © 2024 by the authors
Influence of post-treatment on the microstructural and tribomechanical properties of suspension thermally sprayed WC-12 wt%Co nanocomposite coatings.
The potential to improve the tribomechanical performance of HVOF-sprayed WC-12Co coatings was studied by using aqueous WC-12Co suspensions as feed-stock. Both as-sprayed and hot-isostatic-pressed (HIPed) coatings were studied. Mathematical models of wear rate based on the structure property relationships, even for the conventionally sprayed WC-Co hardmetal coatings, are at best based on the semiempirical approach. This paper aims to develop these semiempirical mathematical models for suspension sprayed nanocomposite coatings in as-sprayed and heat-treated (HIPed) conditions. Microstructural evaluations included transmission electron microscopy, X-ray diffraction and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. The nanohardness and modulus of the coated specimens were investigated using a diamond Berkovich nanoindenter. Sliding wear tests were conducted using a ball-on-flat test rig. Results indicated that the HIPing post-treatment resulted in crystallization of amorphous coating phases and increase in elastic modulus and hardness. Influence of these changes in the wear mechanisms and wear rate is discussed. Results are also compared with conventionally sprayed high-velocity oxy-fuel hardmetal WC-Co coatings
Phylogeography of Rift Valley Fever Virus in Africa Reveals Multiple Introductions in Senegal and Mauritania
Rift Valley Fever (RVF) virus (Family Bunyaviridae) is an arthropod-borne RNA virus that infects primarily domestic ruminants and occasionally humans. RVF epizootics are characterized by numerous abortions and mortality among young animals. In humans, the illness is usually characterized by a mild self-limited febrile illness, which could progress to more serious complications. RVF virus is widespread and endemic in many regions of Africa. In Western Africa, several outbreaks have been reported since 1987 when the first major one occurred at the frontier of Senegal and Mauritania. Aiming to evaluate the spreading and molecular epidemiology in these countries, RVFV isolates from 1944 to 2008 obtained from 18 localities in Senegal and Mauritania and 15 other countries were investigated. Our results suggest that a more intense viral activity possibly took place during the last century compared to the recent past and that at least 5 introductions of RVFV took place in Senegal and Mauritania from distant African regions. Moreover, Barkedji in Senegal was possibly a hub associated with the three distinct entries of RVFV in West Africa
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