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L'article présente le projet ERSAT GGC et les techniques de détection des effets locaux sur les GNSS développées pour l'introduction du GNSS dans le système ERTMS/ETCS

The interaction of millimeter wave radiation, in the 30-300 GHz range, with biological systems is a topic of great interest as many of the vibrational dynamics that occur in biochemical reactions of large macromolecules in living organisms fall in the 1-100 GHz range. Membranes and cellular organelles may have different ways of interacting with this radiation as well. In this article, we investigate the influence of 53.37 GHz of radiation on lipid membrane permeability by using cationic liposomes that contain dipalmitoylphosphatidylcholine (DPPC), cholesterol and stearylamine. Carbonic anhydrase (CA) is loaded inside the liposome and the substrate p-nitrophenyl acetate (p-NPA) is added in the bulk aqueous phase. Upon permeation across the lipid bilayer, the trapped CA catalyzes the conversion of the p-NPA molecules into products. Because the self-diffusion rate of p-NPA across intact liposomes is very low, the CA reaction rate expressed as ΔA/min is used to track membrane permeability changes. A highly significant (P0.0001) enhancement of the CA reaction rate, typically from ΔA/min = 0.0043 ± 0.0017 (n = 26) to ΔA/min = 0.0100 ± 0.0020 (n = 32) resulted at a low-level density power of 0.1 mW/cm(2). The enhancement of the CA reaction rate was observed at a lesser extent on liposomes with a larger diameter and, in turn with leaflets less bent. The different packing of the phospholipid bilayer-due to the higher curvature-could be a critical factor in eliciting membrane permeability changes indicating a possible role for water molecules bound to functional groups in the glycerol region. Since numerical dosimetry indicates that the temperature rise during the exposure was negligible, the observed effects cannot be attributed to heating of the samples.

Time Domain Reflectometry (TDR) is a well-established technique for the development of microwave sensors devoted to the dielectric characterization of materials. In particular the TDR has become the standard method for measuring soil water content. Although the response of the TDR signal is strictly related to the medium moisture content, it is also affected by several others factors related to the physical and chemical composition of samples and to the characteristics of soil solution. This way, for each test-case, the investigation of specific calibration procedures, plays a crucial role. This paper is focused on the feasibility of the adoption of three calibration procedures, and on the investigation of the most representative empirical and partly deterministic TDR calibration methods for real-time moisture monitoring of sand-like materials.

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.

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.

The paper presents a type A (experimental) evaluation of the uncertainty due to systematic effects. After a brief discussion about the general problem of choosing a proper mathematical representation for systematic effects in the context of uncertainty evaluation, a pragmatic approach, based on the familiar random variable theory and the ISO 5725 norm is proposed. The approach is called “interinstrument experiment”, on the analogy of the “interlaboratory experiment” of the ISO 5725. Preliminary experimental results, relevant to commercial digital oscilloscopes, are presented and discussed.

In a previous paper the Authors demonstrated that Time Domain Reflectometry (TDR) can be successfully used for an enhanced real-time qualitative and quantitative monitoring of liquids. In this paper, a metrological characterization of the method is formulated. Results are proposed, demonstrating the robustness and liability of the TDR technique.

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.