An automated sonic tomography system for the inspection of historical masonry walls.

The conservation of the built masonry heritage requires a comprehensive understanding of its geometrical, structural, and material characteristics. Non-destructive techniques are a preferred approach to survey historical buildings, given the cultural value of their fabric. However, currently available techniques are typically operated manually, consuming much time at operational and processing level and thus hindering their use for the on-site inspection of heritage structures.

Ultrasonic Propagation in Liquid and Ice Water Drops. Effect of Porosity.

This work studies ultrasonic propagation in liquid and ice water drops. The effect of porosity on attenuation of ultrasonic waves in the drops is also explored. The motivation of this research was the possible application of ultrasonic techniques to the study of interstellar and cometary ice analogs.

A full-scale experimental study of sub-slab pressure fields induced by underground perforated pipes as a soil depressurisation technique in radon mitigation.

Sub-slab depressurisation systems have proven to effectively mitigate radon entry. A poor understanding of the fluid physics underlying the technique has been shown to lower the success rate substantially. This article describes a study of pressure fields in a sub-slab gravel bed induced by a soil depressurisation system consisting of perforated pipes run under the slab at a depth of 75 cm.

A Multisensor System for the Characterization of the Field Pressure in Terrain. Accuracy, Response, and Adjustments.

In different disciplines of science, the knowledge of the resulting pressures in the subsoil can help to understand physical phenomena of mass exchange between the atmosphere and the terrain. The measurement of lower differential pressures is complicated given the low range of detected values. In this paper, a multisensor system has been designed and developed to measure differential pressures in radon gas transport studies.

Routing Topologies of Wireless Sensor Networks for Health Monitoring of a Cultural Heritage Site.

This paper provides a performance evaluation of tree and mesh routing topologies of wireless sensor networks (WSNs) in a cultural heritage site. The historical site selected was San Juan Bautista church in Talamanca de Jarama (Madrid, Spain). We report the preliminary analysis required to study the effects of heating in this historical location using WSNs to monitor the temperature and humidity conditions during periods of weeks.

Nonplanar fiber-optic sensing head for the compensation of bending-induced birefringence in Faraday current sensors.

We demonstrate the compensation of bending-induced linear birefringence in single-mode fibers coiled in a nonplanar path by alternating orthogonal bending planes. This effect can be applied for the construction of birefringence-free fiber coils in Faraday sensor heads (e.g.

Monitoring of freeze-thaw cycles in concrete using embedded sensors and ultrasonic imaging.

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches-the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles.