Thorium divanadate dihydrate, Th(V2O7)(H2O)2

The title compound, Th(V2O7)(H2O)2, was synthesized by a hydro­thermal reaction. The crystal structure consists of ThO7(OH2)2 tricapped trigonal prisms that share edges, forming [ThO5(OH2)2]n chains along [010]. The edge-sharing ThO7(OH2)2 polyhedra share one edge and five vertices with the V2O7 divanadate anions having a nearly ecliptic conformation parallel to [001]. This results in an open framework with the water mol­ecules located in channels. O—H⋯O hydrogen bonding between water molecules and framework O atoms is observed. Bond-valence-sum calculations are in good agreement with the chemical formula of the title compound

UAV-Assisted Reactive Routing for Urban VANETs

International audienceVehicular ad hoc networks (VANETs) are characterized by frequent path failures due to the high mobility caused by the sudden changes of vehicles direction. The routing paths between two different vehicles should be established with this challenge in mind. It must be stable and well connected in order to guarantee a reliable and safe delivery of packets. The aim of this work is to present a new reactive routing technique providing effective and well-regulated communication paths. These discovered paths are created based on a robust flooding discovery process involving UAVs (Un-manned Aerial Vehicles) to ensure the connectivity when the network is sparsely connected. The evaluation of this technique is performed using NS-2 simulator and its performances are compared with on-demand protocols dedicated for VANET. Simulation results show clearly that our approach gives interesting outcomes ensuring a high delivery ratio with a minimum delay. This hybrid communication between the vehicles and UAVs is attractive to initiate more smart connected nodes in the near future

NFK: a novel fault-tolerant K-mutual exclusion algorithm for mobile and opportunistic ad hoc networks

[EN] This paper presents a fault-tolerant algorithm ensuring multiple resources sharing in mobile ad hoc networks (MANETs) that is able to handle the known K-mutual exclusion problem in such mobile environments. The proposed algorithm relies on a token-based strategy, and requires information about resources and their use to be carried in routing protocol control messages. This way, our solution avoids any additional exchange of messages. Furthermore, experimental results show that it offers a fast response time. Moreover, we introduce a dual-layer fault-tolerance mechanism that tolerates the faults of several sites at the same time without affecting the well functioning of the system. Simulation results also evidence the high efficiency of our proposal, which achieves reduced overhead and response delay even in the presence of critical situations where multiple simultaneous faults occur.Allaoui, T.; Yagoubi, MB.; Kerrache, CA.; Tavares De Araujo Cesariny Calafate, CM. (2019). NFK: a novel fault-tolerant K-mutual exclusion algorithm for mobile and opportunistic ad hoc networks. International Journal of Information and Communication Technology. 15(2):176-197. https://doi.org/10.1504/IJICT.2019.102479S17619715

Silicon Sheets By Redox Assisted Chemical Exfoliation

In this paper, we report the direct chemical synthesis of silicon sheets in gram-scale quantities by chemical exfoliation of pre-processed calcium di-silicide (CaSi2). We have used a combination of X-ray photoelectron spectroscopy, transmission electron microscopy and Energy-dispersive X-ray spectroscopy to characterize the obtained silicon sheets. We found that the clean and crystalline silicon sheets show a 2-dimensional hexagonal graphitic structure.Comment: Accepted in J. Phys.: Condens. Matte

Visión de los ganaderos sobre las estrategias de manejo de las explotaciones de ovino para adaptarse al cambio climático en el Mediterráneo

Existen cinco estrategias principales de adaptación al CC de las explotaciones de ovino en el Mediterráneo, cuya importancia relativa varía entre países y sistemas de producción. Aunque algunos factores técnicos (como la presencia de riego) pueden determinar la estrategia idónea, otros aspectos relacionados con la percepción del riesgo por parte de los ganaderos también influyen en su visión sobre las mejores estrategias para adaptarse al CC.Financiación PRIMA-AEI (Proyecto ADAPT-HERD, PCI2019-103533) y Gobierno de Aragón (Grupo de investigación A14_20R

Farmer views of best climate change adaptation strategies for sheep farming in the Mediterranean

Publishe

Exploring climate change adaptation strategies form the perspective of Mediterranean sheep farmers

PRIMA project Adapt-Her

Haar Transform Approximations of Parameter-Dependent Lyapunov and Riccati Equations Matrix Sign-Based Solutions

International audienc

A parametric sensitivity constrained linear quadratic controller

International audienceThe purpose of this paper is to give a new insight on a suboptimal linear quadratic control taking explicitly into account the parametric uncertainties. System sensitivity to parameter variations is handled through including a quadratic trajectory parametric sensitivity term in the cost functional to be minimized. The paper main contribution is twofold: - Using a descriptor system approach, the paper shows that the underlying singular linear-quadratic optimal control problem leads to a non-standard Riccati equation. - A solution to the proposed control problem is given based on a connection to the so-called Lur'e matrix equations. Some examples are given in order to illustrate the interest of the approach