Search

This paper discusses the bond performance of prestressed carbon fiber reinforced polymer to concrete under service fatigue loading at high temperatures. Fatigue tests were performed in reinforced concrete beams at 4Hz, with minimum and maximum stress corresponding to 50% and 60% of the steel yielding obtained from the static 6-point bending test, and an R ratio of 0.60). The test conditions (5M cycles at ambient temperature, 5M cycles at 50oC, and 2M cycles at 75oC) reflect the typical degradation processes of conventional reinforced concrete bridges, in which the synergy between the high temperatures reached by the asphalt pavement and the service fatigue loading may shorten the frequency of maintenance operations. In the 5 to 10M cycles interval, the decrease of the adhesive's mechanical properties induced a shear stress redistribution with a decrease in the interfacial shear stresses due to the softer behavior of the adhesive. The high temperature raised the stiffness loss and induced local debonding in the 10 to 12M cycles interval, with no damage in the non-mechanical anchorage zone and the adjacent strengthening lengths. The combined effects of fatigue and temperature showed to be strongly influenced by the glass transition temperature of the epoxy resin and cyclic loading conditions and may induce interfacial debonding., Paper 106

Open interoperability delivers on the promise of enabling vendors and developers to interact and interoperate, without interfering with anyone’s ability to compete by delivering a superior product and experience. In the absence of global IoT standards, the INTER-IoT voluntary approach will support and make it easy for any IoT stakeholder to design open IoT devices, smart objects, services, and complex systems and get them to be operative and interconnected quickly, thus creating new IoT interoperable ecosystems by using a bottom-up approach. In particular, INTER-IoT is based on hardware/software tools (INTER-Layer) granting multi-layer interoperability among IoT system layers (i.e. device, networking, middleware, application service, data and semantics), on frameworks for open IoT application and system programming and deployment (INTER-FW), and on a full-fledged CASE tool-supported engineering methodology for IoT systems integration (INTER-Meth). The INTER-IoT approach is notably exemplified through two use cases: INTER-LogP, involving interoperability of port logistics ecosystems, and INTER-Health, encompassing integration between e-Health at home and in mobility infrastructures.

Communications in Wireless Sensor Networks (WSNs) are affected by dynamic environments, variable signal fluctuations and interference. Thus, prompt actions are necessary to achieve dependable communications and meet Quality of Service (QoS) requirements. To this end, the deterministic algorithms used in literature and standards, both centralized and distributed ones, are too slow and prone to cascading failures, instability and sub-optimality. Meanwhile, in recent years, cognitive protocols are gradually being introduced. This chapter provides an overview of the Transmission Power Control (TPC) protocols present in literature, categorized as deterministic (proactive and reactive) and cognitive (Swarm Intelligence, Fuzzy Logic and Reinforcement Learning). Only few solutions have considered TPC based on cognitive approaches, including both energy efficiency and QoS management. Our review identifies key shortcomings in deterministic TPC, pinpointing the benefit of the emerging methods based on computational intelligence.

In this work we describe the fabrication and the characterization of perfluorinated plastic-cladded optical fiber tapers. The heat-and-pull procedure has been used to fabricate symmetric tapers. Devices with different taper ratio have been produced and the repeatability of the process has been verified. The very low refractive indexes of the core-cladding perfluorinated polymers (n = 1.35-1.34) permit a strong enhancement of the evanescent wave power fraction in aqueous environments (n = 1.33), making them very attractive for evanescent wave sensing. The tapers have been characterized carrying out evanescent field absorbance measurements with different concentrations of methylene blue in water and fluorescence collection measurements in an aqueous solution containing Cy5 dye. A good sensitivity, tightly related to the low refractive index of the core-cladding materials and the geometrical profile, has been shown.