FIRST EVIDENCE OF OPUNTIA FICUS INDICA LEAVES USED AS SURFACE FINISHING TREATMENTS ON THE PIETRA LECCESE

Lecce stone belongs to the group of Miocene limestone and is distributed in many areas of the Salento peninsula. The great part of the historical buildings, both religious and civil, in this area have been constructed with this porous and soft material. In the past, various methods and recipes have been used to protect the surfaces and ensure their longevity. However, these ancient "recipes" are unidentified, because these techniques were known only by the artisans who used them [2]. For this purpose, selected religious and civil buildings in the territory of the province of Lecce, made of Lecce stone, not yet restored and possibly treated with some of these unknown recipes because of their good conservation state, were studied and the presence of surface treatments was investigated. Samples were analysed by Py/GC-MS with and without thermally assisted hydrolysis and methylation using tetramethylammonium hydroxide (TMAH). The results of the analyses showed that these buildings have been protected with different natural products. Moreover, for the first time, chemical biomarkers demonstrating the use of prickly pear leaves (Opuntia ficus indica [3]) as protective surface finishes have been identified

Practical implementation of diffused sensing elements for TDR-based monitoring of rising damp in building structures

This paper describes the operating and technical details of the practical implementation of an innovative time domain reflectometry (TDR)-system for monitoring rising damp in building structures. The proposed system employs wire-like, passive, diffused sensing elements (SE's) that are embedded, at the time of construction or renovation, inside the walls of the building to be monitored. The SE's remain permanently inside the wall, ready to be interrogated when necessary

Moisture content measurements through TDR: A metrological assessment for industrial applications

In this paper a metrological assessment on the accuracy provided by a Time Domain Reflectometry (TDR)-based method for the estimation of moisture content of granular materials is proposed. In particular, comparative moisture content measurements are carried out through two different TDR instruments: an inexpensive portable unit and a high-performance unit. The main goals are first to assess a robust procedure for TDR moisture monitoring (in particular for sand-like materials), and second to provide a deep metrological analysis for minimizing and characterizing error contributions. This feature is particularly important when considering the proposed measurement procedures for industrial applications, where both accuracy and low cost must be guaranteed

On the use of dielectric spectroscopy for quality control of vegetable oils

Quality control of vegetable oils is becoming more stringent, and related laws are being enforced especially for avoiding adulteration. As a result, there is a substantial need for methods of analysis that could provide real-time in-situ monitoring, especially for quality control purposes during production process. In this regard, the present paper investigates the possibility of monitoring qualitative characteristics of vegetable oils through microwave dielectric spectroscopy, which is a highly versatile investigative approach. In particular, the Cole & Cole frequency-domain dielectric parameters are known to be strongly related to the compositional characteristics of various substances. This way, starting from traditional Time Domain Reflectometry measurements performed on oils, the corresponding frequency domain information is retrieved. Successively, through a minimization routine, the Cole & Cole parameters of each considered oil are extrapolated. Results show that different dielectric characteristics can be associated with different oils. It is important to point out that the characteristics of the proposed procedure can be automated and, therefore, it may represent a promising solution for practical monitoring applications

Noninvasive patch resonator-based measurements on cultural heritage materials

In this work, a noninvasive microwave-based system for monitoring water content in stone materials used in Cultural Heritage structures is presented. By placing a planar resonator in contact with the considered stone sample, through reflection scattering parameter measurements, it is possible to associate the resonant frequency of the resonator to the moisture content of the stone sample. In this way, an experimental relationship between resonant frequency and moisture content can be obtained. Experimental tests are carried out on two types of materials, namely gentile and carparo stones: which are typically found in Cultural Heritage structures in Southern Italy and they are particularly affected by deterioration and decay phenomena. Measurements were performed for five levels of water content of the stone samples, and the empirical relationship between each considered level of water content and the corresponding measured quantity were derived. The obtained results demonstrate that this solution appears robust

An inverse validation for detecting pipe leaks with a TDR-based method

Recently, an innovative system based on time domain reflectometry (TDR) for the individuation of leaks in underground pipes has been proposed and validated. Starting from the results obtained so far, the present works aims at further investigating the practical applicability of the aforementioned system. In particular, the goal of this work is to assess the system in the detection of two close leaks (i.e. leakages that may occur on the same length of pipe). To this purpose, an experimental setup was arranged: two "leakage conditions" were imposed, and the position of the leaks were considered as unknown and calculated through the dedicated developed algorithm. Results show that, differently from traditional leak detection methods (in which the presence of a leak may "mask" the presence of other leaks), the TDR-based system successfully individuates and correctly localizes the presence of two leaks

Accuracy improvement in the TDR-based localization of water leaks

A time domain reflectometry (TDR)-based system for the localization of water leaks has been recently developed by the authors. This system, which employs wire-like sensing elements to be installed along the underground pipes, has proven immune to the limitations that affect the traditional, acoustic leak-detection systems. Starting from the positive results obtained thus far, in this work, an improvement of this TDR-based system is proposed. More specifically, the possibility of employing a low-cost, water-absorbing sponge to be placed around the sensing element for enhancing the accuracy in the localization of the leak is addressed. To this purpose, laboratory experiments were carried out mimicking a water leakage condition, and two sensing elements (one embedded in a sponge and one without sponge) were comparatively used to identify the position of the leak through TDR measurements. Results showed that, thanks to the water retention capability of the sponge (which maintains the leaked water more localized), the sensing element embedded in the sponge leads to a higher accuracy in the evaluation of the position of the leak

Latest Advancements in SSVEPs Classification for Single-Channel, Extended Reality-based Brain-Computer Interfaces

This work details the latest advancements on a single-channel, reactive Brain-Computer Interfaces developed at the Interdepartmental Research Center in Health Management and Innovation in Healthcare (CIRMIS) of the University of Naples Federico II. The proposed instrumentation is based on Extended Reality (XR) and exploits the acquisition and classification of the Steady-State Visually Evoked Potentials (SSVEPs). In particular, an XR headset is employed for generating the flickering stimuli necessary to the SSVEP elicitation. The users brain signals are captured by means of a highly wearable and portable electroencephalografic acquisition unit, which is connected to a portable processing unit in charge of processing in real time the incoming data. In this way, a deeper interaction between users and external devices with respect to traditional architectures is guaranteed. The classification capability of the proposed instrument has been significantly improved over the years. Currently, in fact, a classification accuracy up to 90 % is obtained with at least 2 s of acquisition time

An Augmented Reality-Based Solution for Monitoring Patients Vitals in Surgical Procedures

In this work, an augmented reality (AR) system is proposed to monitor in real time the patient's vital parameters during surgical procedures. This system is characterised metrologically in terms of transmission error rates and latency. These specifications are relevant for ensuring real-time response. The proposed system automatically collects data from the equipment in the operating room (OR), and displays them in AR. The system was designed, implemented and validated through experimental tests carried out using a set of Epson Moverio BT-350 AR glasses to monitor the output of a respiratory ventilator and a patient monitor in the OR

Diffused capacitance-based sensing for hydric control and watering optimization

Soil moisture measurements are essential especially in the agricultural field, where it is crucial to guarantee that the optimal amount of water is provided to the cultivations. Most soil moisture measurement systems are local sensors; hence, a multitude of sensors must be distributed all over the field to obtain a comprehensive picture of the soil condition. Starting from these considerations, the present work addresses the feasibility of employing diffused sensing elements (in a wire-like configuration) for sensing soil moisture variations, based on capacitance measurements. To this purpose, for a preliminary validation of the proposed methodology, several experiments were carried out, thus identifying the suitable setup configurations and the potential of the method