Monitoring and simulating humidity profiles in concrete elements during drying

Integrated approaches towards the measurement and simulation of the internal humidity of cement based materials, in which the same team accomplishes all the tasks are scarce in the literature. Furthermore, the measurement of humidity in cement-based materials is a subject that requires experience and significant care to obtain reliable data. In view of this reasoning, the research here reported pertains to an integrated approach that focuses in two main topics: (a) several issues regarding the experimental measurement of internal humidity in cement based materials through sleeved humidity probes, with test series devoted to each issue (namely the type of sensor, the existence of Gore Tex fabric to protect the sensor and the influence of the permanence time of probes within measuring sleeves); (b) an experimental program for humidity measurement in concrete specimens, followed by the simulation through the formulation forwarded in the MC1990/2010. The successful achievement of the measurements and simulations reported herein corroborate the validity of the adopted strategies and assumptionsFEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT within the scope of the projects POCI-01-0145-FEDER-007633 and POCI-01-0145-FEDER-016841 (IntegraCrete - PTDC/ECM-EST/1056/2014). The PhD grant of the second author is also gratefully acknowledged (SFRH/BD/80682/2011

Bender-extender elements for characterization of cement paste at early ages

The embedment of bender-extender elements in cement-based materials for assessment of the early development of mechanical properties is a relatively unexplored field. This technique provides the opportunity of embedding piezoelectric elements (emitter and receiver) into the tested material at the fresh state, generate waves and assess the velocity of propagation. It has the interesting feature of allowing distinct frequencies of wave to be explored at the several stages of stiffening of the testing material, thus maximising signal intensity and facilitating the identification of velocities. This paper presents an exploratory application of bender- extender elements to cement paste specimens, in parallel with other established experimental techniques, such as the Vicat needle, ultrasound pulse velocity measurements (with external probes), measurement of E-modulus through cyclic compressive testing and continuous assessment of the E-modulus of the cement paste through EMM-ARM. The results are evaluated and discussed in an integrated manner and conclusions are drawn in regard to the potential of using bender-extender elements in cement-based materialsFEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the projects POCI-01-0145-FEDER-007633 and POCI-01-0145-FEDER-016

N1 responses to images of hands in occipito-temporal event-related potentials

Hands, much like faces, convey social information, instructions and intentions to an observer. While the neural processes of face perception have been widely studied, it was only recently that fMRI identified occipito-temporal areas sensitive to static images of hands as body parts. To complement these studies with fine-grained timing information, we measured event-related EEG potentials (ERPs) from 33 subjects who were presented with static images of hands versus faces, whole bodies, and inanimate objects as controls. Already at N1 latency, ~ 170 ms, hand-related ERP patterns were manifest in two results: (1) significant differences in amplitudes for images of hands versus bodies in occipito-temporal N1 responses; (2) left lateralization of responses to images of hands, and also of the difference waveforms (hands minus bodies), quantifying hand-related responses. In line with fMRI studies of hand-sensitive areas distinct from extrastriate body area (EBA), the current findings provide electrophysiological evidence for hand-sensitive brain activation, occurring at a similarly early latency as N1 responses to faces

A new methodology for assisting quality control of NSM-CFRP systems since very early ages

The performance of NSM systems directly depends on the performance of the adhesive which can only be reached if a proper curing conditions and time are assured. In order to assess the curing process of the adhesives, as well as the corresponding bond behavior, adequate non-destructive testing approaches are required. Nonetheless, scarce information could be found in the literature in concern to this relevant topic. To fill such gap, the present paper proposes a new method for continuous quality control of epoxy adhesives, based on adaptations of an existing technique originally devised for continuous monitoring of concrete E-modulus since casting, called EMM-ARM (Elasticity Modulus Monitoring through Ambient Response Method). This work reports the simultaneous study of the adhesive through EMM-ARM, together with direct pullout tests at several ages on concrete specimens strengthened with NSM CFRP laminate strips using the same epoxy. The tests are described, and the obtained results are presented and discussed, highlighting the potential of applying EMM-ARM for quality control and decision-making assistance of NSM systems.FCT -Fuel Cycle Technologies(undefined

Estandarización de un protocolo de recolección de muestras y PCR en tiempo real para la detección e identificación de especies de leptospira patógenas en muestras de agua de río.

Leptospirosis is a zoonotic disease of worldwide distribution, and a considerable public health problem in Ecuador. This disease, caused by bacteria from the genus Leptospira, is commonly transmitted through water and soil contaminated with urine from infected mammals. For this reason, monitoring commonly usable water sources from risk areas is an important tool for understanding the development of leptospirosis outbreaks. This study presents a conventional PCR and real time PCR strategy for the detection of pathogenic species of Leptospira in water samples from two Ecuadorian provinces. For this purpose, Leptospira specific primers were used targeting the secY and lipL32 genes. Additionally, the presence of intermediate specieswas determined using primers that target a sequence of the 16S ribosomal gene. Our results show the presence of pathogenic species in 8 samples: 6 corresponding to the province of Esmeraldas and 2 corresponding to the Province of Manabí. The sequence analysis of these samples for the lipL32 PCR products allowed for the identification of the species present in 8 out of 9 samples. We also found the presence of 13 positive water samples for intermediate species, out of which 9 samples were also positive for pathogenic species of Leptospira. The results of this project provide with an important tool for future studies of pathogenic Leptospira monitoring in water sources.La leptospirosis es una enfermedad zoonótica de distribución mundial, y un problema de salud considerable en el Ecuador. Esta enfermedad, causada por bacterias del género Leptospira, se transmite comúnmente a través de fuentes de agua y suelos contaminados con orina de mamíferos infectados. Por esta razón, el monitoreo de fuentes de agua de uso común en zonas de riesgo es una herramienta importante para comprender la aparición de brotes de esta enfermedad. El presente estudio utilizó una estrategia de PCR convencional y PCR en tiempo real (Real Time PCR) para determinar la presencia de especies patógenas de Leptospira en muestras de agua de río en dos provincias ecuatorianas. Se utilizaron cebadores específicos para los genes secY y lipL32 de especies patógenas de Leptospira. Adicionalmente se determinó la presencia de especies intermedia de Leptospira utilizando cebadores específicos para una secuencia del gen que codifica para el 16S rRNA. Los resultados mostraron la presencia de especies patógenas en un total de 8 muestras: 6 correspondientes a la provincia de Esmeraldas y 2 correspondientes a la provincia de Manabí. El secuenciamiento de los productos de PCR del gen lipL32 permitió identificar la especie de Leptospira presente en 8 de las 9 muestras. También se encontró la presencia de 13 muestras de agua positivas para especies intermedias, de las cuales 9 fueron también positivas para especies de Leptospira patógena. Los resultados de este proyecto proveen una herramienta importante para futuros estudios de monitoreo de Leptospira patógena en fuentes de agua

Effects of curing temperature on pull-out behavior and stiffness evolution of epoxy adhesives for NSM-FRP applications

The efficiency of the FRP-concrete strengthening system is strongly influenced by the mechanical properties of the epoxy adhesive, which depend on the curing temperature.In the present work, the influence of temperature on the curing process of the epoxy was examined. Two different temperatures were studied: 20 and 30 °C. The elastic modulus of the adhesive was continuously monitored by using a variant of the classical resonant frequency methods, called EMM-ARM (Elasticity Modulus Monitoring through Ambient Response Method). A simultaneous study of direct pull-out tests with concrete specimens strengthened with NSM carbon FRP laminate strips was carried out at the same two different temperatures to compare the evolution of bond performance with the E-modulus of epoxy since early ages. The results showed that increasing the curing temperature significantly accelerated both the curing process of the epoxy adhesive and the evolution of bond performance. Moreover, the EMM-ARM technique revealed its ability in clearly identifying the hardening kinetics of epoxy adhesives, allowing measurements since very early ages and in different environmental conditions