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A methodology aiming at identifying and removing biofilms from cultural heritage was applied to stones from tuff walls in historical sites. Identification of phototrophic encrusting microorganisms was carried out by optical and electron microscopy, as well as by molecular techniques (DNA analyses and denaturing gradient gel electrophoresis (DGGE)). In all sites, the examination of microbial components of biofilms resulted in the identification of 17 species belonging to Cyanobacteria, Rhodophyta, Bacillariophyta and Chlorophyta, with Cyanobacteria being the dominant components in all biofilms. In order to remove the biofilms, an innovative technique based on the use of nonthermal effects of radiofrequencies was adopted. The source of the electromagnetic fields was a signal generator connected to a horn antenna through an amplifier to provide the power boost required to generate the target field amplitude. Seven days after exposure to radiofrequency electromagnetic field, about 50 % reduction of biofilm was observed; after 14 days, biofilm extension was reduced by about 90 %. DGGE analyses performed after 14 days confirmed these visual inspections. Also, DGGE analyses carried out before and 14 days after treatments showed that 12 out of 17 identified species disappeared. A complete visual disappearance of biofilms was observed a month after the beginning of treatments. DGGE repeated at this time confirmed the total disappearance of biofilm-forming species. Treated stones, when transferred back to their original sites, did not show any microorganism re-growing after 6 months. No alteration in the color and structural consistency of tuff substrata was observed after radiofrequency treatments.

Radiated emissions from arcing between pantograph and overhead lines in electrical transportation systems extend up to the frequency bands currently used for telecommunications and may therefore affect the quality features of telecommunication systems. The paper investigates on the time and frequency characteristics of the disturbances. Transient amplitude, rise time and pulse duration were measured in the time domain to obtain the associated empirical distributions; the power spectrum and the frequency content were calculated in the bands of interest; finally a time-frequency representation has been used to observe the evolution of the power spectra over time and the location of the main contributions.

The paper presents the results of an experimental activity focused on the measurement of electromagnetic fields generated by magnetic resonance imaging systems, carried out with the purpose of assessing exposure of workers to static, low frequency and radio-frequency electromagnetic fields , as required by the EU Directive 2004/40/EC. The main contribution of the paper is that it presents a comparative study of exposure carried out during operation of the MRI system and close to the sources, with different scanning sequences and RF coils. Results show that the static magnetic field follows the theoretical values only close to the magnet due to the effect of the walls, with a few percent variation due to the operating conditions; exposure to the magnetic field in the low frequency band is mainly determined by emissions generated by the power grid at 50 Hz and by the pulses driving the gradient coils; and finally the radio-frequency band only shows contributions by the diagnostic pulses at the resonance frequency, with exposure levels usually below the limits contained in the Directive.

The paper contains a proposal for the estimation of the frequency of a sine signal corrupted by zero-mean additive white gaussian noise. The method resorts to the histogram of the time intervals between adjacent zero-crossing samples. Validation has been carried out for various noise levels and results show that the relative error is much less than other algorithms for frequency estimation. Performances are also compared to those of numeric counters. The method can be easily implemented of low cost devices and is computationally very efficient.

The transient electromagnetic field emissions from the pantograph electric arc captured by a GSM-R antenna mounted on roof top were recorded and used to reproduce the disturbance on a test bench for the evaluation of the Quality of Service under controlled conditions. The arrangement of the test setup and the characteristics of used equipment are presented. The parameters that characterize the noise coupled onto the GSM-R channel are put in relationship with QoS indexes. Finally, the results obtained from preliminary tests are reported.

Nowadays, the field programmable analog arrays or FPAAs provides a very promising analog solutions to substitute the most costly analog applications to be implemented into complex systems in the goal of reducing their cost and their prototyping time, in biomedical applications this fact should be very interesting specially for supporting life and portable devices, nevertheless, their parametric characterization to be suitable for this applications is not enough when we take in account the influence of external disturbances on the possible distorted behaviour of such devices, in this paper, we present the results of a functional immunity test of an FPAA-based biomedical application involving ECG signal conditioning to EM radiated energy over a electromagnetic field over frequency range from 80 MHz to 3 GHz‥

In this study bead-on-plate tests on 3 mm-thick Ti6Al4V sheets were performed using a Yb:YAG thin disk laser in continuous mode to evaluate the effects of focus position on the bead characteristics. Among the various solid-state lasers, the disk laser has better beam quality than conventional rod geometries thanks to the absence of thermal lensing effect. An experimental plan was conducted using nine focus positions with constant power and welding speed. The beads were characterised in terms of geometry, defects, hardness and microstructure. This work is a preliminary study to select the best values of the focal position for subsequent butt welding tests. Analysing the results obtained, the best value of defocusing was -4 mm because, among full penetrated beads, it showed lower undercut and excessive penetration, lower melted area and smaller grain size in the melted area.

In order to assess the performance of digital to analog converters (DAC) the attention is generally focused on the integral nonlinearity (INL). Useful diagnostic tools to detect the causes of poor linearity are the linearity and intermodulation errors, which can be evaluated from INL measurements. Linearity and intermodulation errors highlight and quantify erroneous calibration and unwanted interactions between current sources inside the DAC hardware. Unfortunately, their estimates, especially those related to high order intermodulation errors are characterized by high uncertainty. It is thus difficult assessing their relevance on the base of their very uncertain value. It is shown that by means of the analysis of variance (ANOVA) the relevance of intermodulation errors can be assessed from a limited set of INL measurements. ANOVA is in fact capable of distinguishing if the variance in INL measurements has to be addressed to active factors or noise, even if the effect of each factor is widespread upon different elements of the INL array and in different combinations with the other factors.

The expression of the anti-apoptotic protein BAG3 is induced in several cell types by exposure to high temperature, oxidants, and other stressful agents. We investigated whether exposure to 50 Hz electromagnetic fields raised BAG3 levels in the human melanoma cell line M14, in vitro and in orthotopic xenografts. Exposure of cultured cells or xenografts for 6 h or 4 weeks, respectively, produced a significant (P

Characterization of electromagnetic field sensors requires that the behaviour of each sensor is investigated over the whole functional space, i.e., the range in which the device is expected to work. In most cases, for the sake of time reduction, experiments are run only over a subset of the functional space. The reduced extension of the experimental space limits the knowledge of the actual behaviour of the probe represented by the calibration factor K. Linear regression is a common technique to represent measurement data, but it is generally not applied to sensor calibration. Furthermore, no comparative study of experimental plans differing in the number and location of experimental points has ever been carried out nor has a methodology to determine the optimal degree of the regression polynomial been outlined. This paper compares the error variance between experimental points and fitted curve obtained using different experimental plans and regression polynomials.

Tests of field programmable analog arrays (FPAA) are required to assess tolerance to variations of components, due to aging, uncertainty, or external disturbances. The paper focuses on radiated electromagnetic energy as a cause for a possible faulty behavior: results show that input and output channels of the FPAA are affected by the presence of noise due to the coupling of the incident field with the board, and that the susceptibility profile depends on the configuration of the FPAA and the field’s polarization. Therefore, topology and electromagnetic characteristics of the board must be carefully designed. Moreover, the transfer function is susceptible to the incident field to a degree that depends on the configuration of the FPAA and the field’s amplitude and frequency. This limits application of FPAAs in critical applications like in the automotive and aerospace industry, where fields with large amplitudes are likely to be encountered during normal operation.

MIMO measurement systems are measurement systems that collect homogeneous and/or heterogeneous measurement data from several input sources and then process them to achieve multiple output information, possibly exploiting their redundancy to be more robust against disturbances, such as interference and noise. The paper discusses the crucial synchronization issues of MIMO measurement systems, classifies them into two categories depending on how they affect the sampled signals, and proposes a methodology for the synchronization of different acquisition channels.

The purpose of an EM shield is to prevent undesired electromagnetic coupling between an EM source and a susceptible EM device. The mechanism of electromagnetic coupling is by radiation, inductive and capacitive coupling. The radiation of energy by electromagnetic waves characterizes the EM coupling in the far field region, while inductive (or lowimpedance) and capacitive (or high-impedance) couplings are the driving mechanism of coupling in the near field region. In all the cases, a complete analysis of the shielding performances of an EM shield should require a full-wave solution of the electromagnetic problem. This means to solve a classical eddy current problem and in presence of magnetically permeable materials the analysis shall combine the Maxwell’s equations with the magnetic properties of the shield. Numerous studies of shielding problems can be found in the literature showing how this topic has been the subject of great interest to the scientific community for many years (Moser; 1988; Schelkunoff; 1943; Schulz et al.; 1988). Several analytical and numerical techniques have been developed during the years especially with the advent and proliferation of the electronic devices. Different materials with a wide range of electrical and magnetic properties are used for shielding applications. As a matter of fact, an accurate knowledge of the electromagnetic properties of the material is an important task for a correct modeling and design phase. Further, shields have different shapes and contain apertures and all these parameters influence the shielding effectiveness, thus the electromagnetic susceptibility of the combined shieldelectronic equipment system. In a first part, this chapter reports on basic aspects of the shielding theory and standard measurement methods of shielding effectiveness in the frequency and time domain. Concepts and measurement techniques are discussed with reference to basic shield configurations and following the relevant standards (IEEE Std 299; 2006). A basic configuration of the experimental setup and instrumentation chain for shielding effectiveness measurements is reported.

Functional tests of field programmable analog arrays (FPAA) are required to assess tolerance to uncontrolled and unintentional variations in the components characteristic parameters, like for example a change in the values of capacitances and gains of the differential amplifiers which may be due to aging, uncertainty (i.e., a difference between the actual and nominal values), or to an outer disturbance like radiated electromagnetic energy. The paper focuses on the latter as a cause for a possible faulty behavior: experimental results have shown that the expected performances are distorted by the presence of noise added to the useful signals due to the coupling of the external electromagnetic field with the circuitry. The results indicate that the susceptibility features depend only marginally on the specific configuration given to the FPAA, leading to the conclusion that the topology and electromagnetic characteristics of the board on which the device is mounted must be carefully designed.

A ground monitoring system that exploits electromagnetic field properties of accounting of both physical and geometrical features of the surrounding medium is proposed. The system is based on TDR tests, assisted by a control and processing unit, and aims at detecting starting cavities underground in the soil. The digital signal processing approach deployed for waveform analysis, which plays a fundamental role in detecting and characterizing underground anomalies, is described.

The paper presents an original methodology for testing the data acquisition system immunity to conducted disturbances and for evaluating the typical uncertainty intervals to be assigned to these kinds of measurements. As in any data measurement system, even in those consisting of a desktop computer equipped with a PCI data acquisition board, several devices and components are involved in the process of acquiring, sampling and digitizing the analogue signal, and eventually presenting the digital values to the user. Therefore, there are many possible coupling paths between the measurement system and external electromagnetic disturbances, in principle both radiated and conducted, which would require a large number of configurations to be tested. Indeed, with particular reference to radiated couplings, their effects generally depend on the adopted test setup. In addition, the electromagnetic boundary conditions of the test site can significantly affect the measurement results. Both these aspects should be carefully taken into account because they are the main cause for ambiguous results and well-known issues in inter-laboratory comparisons. In this framework, the aims of this study are (i) to investigate which components or component configurations influence the data acquisition system immunity most significantly; (ii) to provide a practical way to effectively test these types of measurement system and (iii) to assess the related uncertainty budget in order to qualify the test results. Finally, the site-to-site reproducibility of the measurements has been evaluated by comparing results obtained in two different laboratories.

A distributed system of sensors for surveying the electromagnetic (EM) field exposure is presented, and its main design characteristics and performance are discussed. The system overcomes the coverage restrictions of commercial measurement systems by adopting fully mobile sensors that communicate with a central unit through the cellular network, so that the widest area can be monitored with the smallest possible number of probes by mounting them onto transportation means. The system also benefits from the low cost per unit area served and for maintenance, which make it of great interest both for administrations that need to deploy field measurement activities and for researchers involved in statistical characterization of an EM urban environment. Communication between sensors has been planned according to such specifications that could allow integration of sensors built by different manufacturers, and it largely relies on the use of open transmission control protocol/internet protocol (TCP/IP). The sensor network has been used in a broadband measurement campaign over a typical urban environment, and results obtained are shown together with specific statistical analysis of both sampled and root-mean-square values.

This paper presents an experimental study about the effects that various operating conditions have on conducted emissions by variable-speed drives. The objective of the research is to determine what quantities most significantly affect emissions so that electromagnetic compatibility test procedures can be carried out under the most appropriate conditions according to the specific destination of the equipment under test. The obtained measurements would so match the standard's requirement that they represent the worst case for the disturbance emission levels. A quantitative analysis has been made possible by introducing two indexes with values determined by emissions over the measurement band. The effects of voltage asymmetry and amplitude, motor operating frequency, and torque applied to it have been investigated. Results show a strong dependence on motor operating frequency and torque and that the fluctuations in the measured emissions largely depend on the measurement configuration adopted.

Reduction in energy consumption in electrical railway traction systems has become a vital need. The effort spent in providing better quality services implies increasing speed and, therefore, an increase in energy consumption. Various techniques are usually adopted to improve train performances. They span from modifying the vehicle structure to improving the motor. In this paper, a different way to reduce power absorption is presented, which is based on an appropriate interpretation of the traction diagram, along with the absorption curves. Measurement data are available by means of an onboard monitoring system that measures all the electromechanical quantities of the train course and sends them through a network connection to a remote control station. The evaluation of measurement uncertainty, the procedure to obtain the optimized protocol for train operation, and the experimental data obtained when the optimized protocol is applied are also presented.

The aim of this paper is to propose an improved approach for the measurement of the severity of power quality phenomenon called light flicker which is the disturbance caused by luminance variations due to supply voltage fluctuations. The proposed approach is based directly on light intensity measurements, unlike usual standard approach (IEC EN 61000-4-15), which indirectly determines flicker severity from measuring voltage fluctuations and accounting the response of a standard incandescent lamp (230 V/60 W). Only adopting a direct measurement of light fluctuation is possible to asses flicker severity whatever illuminating device is present, in this way, the implemented sensor is considered to perform an objective measurement of light flicker. To compare performances and metrological characteristics with current standard requirements, a testing station has been implemented and results compared to a standard IEC flickermeter (Norma D6000). Thanks to its small dimensions and weight, the instrument can be used to measure light flicker over a wide range of environments spanning from home/office to industrial locations.

Modeling clutter signal is a major task in characterizing radar performances. Clutter distributions pertaining classical radar systems have been widely investigated, but in the past few years passive radars have raised interest among researchers for some specific features that make them very appealing in modern applications, thus bringing about the need for researching appropriate models for the noise signal received under no-target conditions. The paper proposes a new two- state model for the statistical distribution of clutter signal in a passive radar based on the GSM cellular system. A dedicated measurement station has been set up to carry out experiments in a real environment. Results give evidence of the suitability of the proposed model.

Passive radars are not at all new to the radar community though they lately raised interest among researchers for some specific features that make them more appealing than classic active radar systems. In fact, having the TX and RX located at two different positions, and the adoption of signals carrying other kinds of information such as GSM (either classical or the 1800/1900 MHz version) or FM modulated carriers, makes passive radar virtually undetectable and economically advantageous. In the paper a measurement system used to characterize the clutter from a GSM/DCS-based passive radar is presented. The main objective is to study the statistical properties of the clutter signal and to find a theoretical model fitting the measured clutter data.

The paper presents the experimental activity carried out to test the immunity characteristics to conducted disturbances of a digital acquisition system made of a desktop computer equipped with a PCI DAQ board. Like any other numerical measurement system, many devices and components are involved in the process of acquiring the analog signal, sampling, quantizing and presenting the result to the user, and therefore many are the possible coupling paths between the measurement system and the disturbing signal. The aim of the presented study is to investigate which components most influence immunity characteristics, and which path, i.e., whether conducted or radiated one, prevails in the coupling of disturbances with the equipment under test.

In this paper, the authors propose a methodology to guide the verification of single-phase energy meters under sinusoidal and nonsinusoidal conditions. At first, a brief review is presented about definitions of the quantities that should be measured of monitored for revenue purposes and their relationship with electrical quantities that are recognized to be important in terms of metering accuracy. Then, a design of an experiment that allows the testing meters under a combination of disturbances showing positive and negative correlations are described. Finally, a hardware and software system to perform verification procedures in complex situations is presented with some preliminary analyses.

Energy saving in electrical railway traction systems has gained more and more relevance in the last years. As a matter of fact, the need for increasing speed in order to provide better quality services, implies an increase in energy consumption, and in operational costs. To keep the latter at the lowest level possible, it is possible to adapt the train's operating conditions according to appropriate rules based on measurements of characteristic train's and system's quantities. In this way, it is possible to have thorough information about train's course, and then take decisions in order to improve service and reduce consumptions at the same time. In the following is presented an on-board monitoring system that measures electrical quantities of the train and sends acquired data to a control station through network connection. The application of such system to the optimization of the train course protocol is also presented.

An experimental study about uncertainty in measurements of conducted emissions of variable speed drives due to variations of operating conditions is presented in this paper. The research is part of a wider experimental program aimed at determining what quantities affect emissions most significantly so that electromagnetic compatibility test procedures are performed under appropriate conditions according to the specific destination of the equipment under test, in such a way that results represent the worst case scenario for compliance testing. A global index based on the average weighted distance between measurements and standard limits is introduced to help determine which parameters show predominant influence. Effects of voltage asymmetry and amplitude, motor's frequency, and applied torque have been investigated. Results show that frequency of motor and load applied cause the most relevant changes in emissions

Measurement of light flicker according to current standard EN ISO 61000-4-15 is performed through measurement of voltage variations filtered by a model of a 60 W/230 V incandescent lamp. Hence, differences in current illumination systems technology can determine discrepancies between light flicker measurements performed under the same voltage flicker. In the paper, a method to measure light flicker with a low cost digital device, based on light intensity measurements, is proposed, thus including the lamp itself in the measurement process. In this way an objective measurement of light flicker is obtained. The metrological characterization of the device has been implemented by means of an automatic testing station which includes a standard IEC flickermeter (Norma D6000) as reference instrument. Thanks to its portability, the instrument can be used to measure light flicker no matter the illumination system used, over a wide range of environments spanning from home/office to industrial locations, and including the environmental condition (i.e., ambient light and reflection by walls and objects) in the measurement process.

In this paper the authors propose a methodology to guide verification of energy meters under sinusoidal and non sinusoidal conditions. At first, it is presented a brief review about definitions of the quantities that should be measured or monitored for revenue purposes and their relationship with electrical quantities that are recognized to be important in terms of metering accuracy. Then, a design of experiment that allows testing meters under a combination of disturbances showing positive and negative correlation is described. Finally, a hardware and software system to perform verification procedures in complex situation is presented with some preliminary analyses.

Reduction in energy consumption in electrical railway traction systems has become a vital need. The effort spent in providing better quality services implies increasing speed and in turn an increase in energy consumption. Various techniques have been adopted to improve train performances, some regarding vehicle structure, some other related to motor improvements. In this paper a different way to reduce power absorption is presented. It is based on the studies of the traction diagram jointly with the absorption curves. The data are made available by an on-board monitoring system which measures all the electromechanical quantities of the train course and sends them through network connection to a control station. Starting from them it is possible to run an optimization procedure in order to get appropriate rules to drive in energy-efficient way the train. The procedure which get the optimized protocol with and the experimental data related to the train optimized protocol are presented. © 2006 IEEE.

Availability of low cost and high efficiency sensors and of both wired and wireless transmission networks discloses new opportunities in the field of distributed and collaborative networks devoted to system and environmental monitoring. In the paper such a new architecture is presented which employs smart sensors connected to the transmission infrastructure through TCP/IP protocol aimed at providing a real-time, multi-sensor and multi-purpose network. Preliminary results about the monitoring campaign of the environmental electromagnetic field over the range 100 kHz to 3 GHz are shown together with the evaluation of the statistical distribution of both sampled and rms values

Mass customization can be approached from many points of view. When the focus is centered on the order acquisition and on the fulfillment process, the recourse to a computer support system, called Product Configurator, is widely adopted. To use it as a support to the design and the development of new products is a challenging application, seldom implemented in current industrial systems. Here, concepts taken from object programming are applied: namely the hereditariness of the class attributes by the children classes. The aim is to implement a hierarchic approach to the customization of the product with the advantage of a thorough applicability of postponed operations along the entire supply chain. In the work the conceptual framework and the application issues of the hierarchic Product Configurator are detailed. In order to evaluate the advantages (simplicity, flexibility and quickness) and the drawbacks (explosion of varieties and difficult stock minimization) of this methodology, it has been applied to case studies taken from production.

An environmental electromagnetic field measurement system that is characterized by a mobile distributed architecture is proposed. The system allows to monitor a wide area in an urban environment, and to analyze measurements so that potential 'critical' locations can be singles out like those where the measured data overcome fixed warning levels, so that suitable corrective actions can be taken. The main advantage of the proposed system is the capability to monitor the spatial and temporal evolution of electromagnetic field over a larger area than using fixed probes. Moreover the architecture allows to collect data from different clients and to send them to a remote server for analysis purposes, which in turn leads to the evaluation of possible correlations that are useful to the process study. The measurement system also provides the integration of data with information like population density: the aggregated information qualifies the results, when areas with different population densities are put in comparison. Eventually, interpretation of acquired data is performed by an innovative fuzzy decision-making procedure, using suitable decision rules in order to minimize risks and costs according to metrological and statistical features of measurement system.

Passive radars have been known to the scientific community since their first application as a system to detect bombers by means of shortwaves radiated by radio broadcasting towers in 1935, although they lately raised a renewed interest among researchers for some specific features that make them more appealing than classic active radar systems. In fact, having the transmitter and receiver located at two different positions, and the adoption of signals carrying other kinds of information such as GSM (either classical or the 1800/1900 MHz DCS version) or UMTS waveforms, makes passive radar virtually undetectable and economically advantageous. A measurement system used to characterise the clutter from a GSM/DCS and UMTS-based passive radar is presented. The main objective is to study the statistical properties of the clutter signals, find theoretical models fitting the measured clutter data and analyse the differences between the modulated carriers of the two different standards.

The propagation channel aboard trains is investigated with reference to the propagation path loss within cars, the delay spread and the coherence bandwidth. Results show that the path loss exponent is slightly smaller than in free space, possibly due to reflections by metal walls, and that it does not depend significantly on the position of transmitter and receiver. The delay spread and coherence bandwidth depend on both the polarization and distance between transmitter and receiver while the effect of interaction is not statistically significant. The best fit for both delay spread’s and coherence bandwidth’s experimental distribution is also investigated. Results show that it does not always match models suggested in the literature and that the fit changes with the values of the input parameters. Finally, the functional law between coherence bandwidth and delay spread is determined. Results typically match expectations although the specific measurement configuration effects the model parameters.

Statistical characterization of the maximum power received in the GSM band is presented. Results show a large unexpected variability of BCCH channel power over time. Such evidence results in a large uncertainty related to the measurement of the average power through use of the α24 parameter as required by the Italian standards to assess average exposure to electromagnetic fields and compliance with limits

Measurement of light flicker with a low cost digital device, based on light intensity measurements, is proposed. Unlike current standard instrument based on IEC EN 61000-4-15, which determines flicker severity by filtering powering voltage measurements with a standard lamp model (230V/60W), the presented methodology measures directly the disturbances caused by light intensity variations including the lamp itself in the measurement process. In this way an objective measurement of light flicker is obtained. The metrological characterization of the device has been implemented by means of an automatic testing station which includes a standard IEC flickermeter (Norma D6000) as reference instrument. Thanks to its portability, the instrument can be used to measure light flicker independently of the lighting system, over a wide range of environments spanning from home/office to industrial locations