1,721,098 research outputs found
Caratterizzazione dielettrica di materiali granulari tramite Riflettometria nel Dominio del Tempo
No full textTDR Moisture Measurements in Sand-Like Materials: a Comparison between Different Calibration Procedures
No full textTime 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
Caratterizzazione statica e dinamica di un nuovo fotorivelatore HMSM con cavita’ risonante per applicazioni optoelettroniche
No full textCaratterizzazione e simulazione di fotorivelatori basati su eterostrutture e contatti eterodimensionali
No full textCaratterizzazione dielettrica di liquidi e sostanze granulari tramite Riflettometria nel Dominio del tempo
No full textType A Evaluation of Uncertainty Due To Systematic Effects in Digital Oscilloscopes
No full textThe 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
Classification and adulteration control of vegetable oils based on microwave reflectometry analysis
No full textOlive oil production represents a big part of the Mediterranean economy, and as such it must be protected
from frauds. For this reason, it is necessary to develop alternative low-cost techniques, applicable on large
scale, for checking the quality of the product and for detecting adulteration. On such bases, the present
work deals with the possibility of adopting microwave reflectometry for obtaining a ‘spectral signature’
of vegetable oils. For this purpose, time domain reflectometry (TDR) measurements, in combination with
specific data processing, are first used for the dielectric characterization of several oil types. Successively,
the acquired data are processed through the principal component analysis (for identifying clusters of oil
types that exhibit common features) and through the partial least square analysis (for identifying a predictive
model for detecting oil adulteration). Results confirm that the proposed procedure holds considerable
potential for quality and anti-adulteration control purposes, especially in view of practical
applications
Qualitative and Quantitative Characterization of Liquids from TDR Measurements
No full textTime-domain Reflectometry (TDR) is a well-established technique for
the development of microwave sensors devoted to the dielectric characterization
of materials. This renders TDR an appealing method for a variety of monitoring
applications. Till now, TDR has been successfully applied to solve hydrological
or soil prospecting problems, though its adoption in many other cases is worth an
investigation. In this paper, it is demonstrated that TDR is a viable approach for
quantitative and qualitaive real-time characterization of liquids inside tanks. In
fact, in one shot the suitable handling of time-domain reflectometry data allows
the determination of the liquid level, as well as the evaluation of dielectric
properties, such as dielectric permittivity and electrical conductivity. Some
applications to real cases are proposed, referred to petrol-chemical mixtures or
water-based liquids, thus validating the approach on a wide range of materials
Caratterizzazione Quantitativa e Qualitativa di Liquidi Tramite Tecnica di Riflettometria nel Dominio del Tempo
No full text"Microwave Reflectometry for Sensing Applications in the Agrofood Industry", contained in "Smart Sensors for Industrial Applications"
No full textThe present chapter describes some of the most promising applications of microwave reflectometry (MR) for monitoring and sensing purposes in the agrofood industry. The present chapter focuses on three specific applications in which MR is employed for monitoring purposes in the agrofood industry. In particular, the following applications are considered: 1. Moisture measurement of granular agrofood materials; 2. Quality control of vegetable oils; 3. Monitoring of dehydration process of fruit and vegetables
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