Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging

A methodology is described for the theoretical-experimental evaluation of the measurement uncertainty of the polar and dispersive components of the surface free energy (SFE) in polypropylene films; these parameters are related to the film wettability of adhesives and inks. The proposed method is based on the measurement by means of a vision system of the contact angles of liquid drops deposited on the film itself, which allows for obtaining, through mathematical models drawn from the literature, the physical quantities of interest. The effect of the principal influence parameters has been experimentally evaluated, and testing has allowed the defining of the technical procedures readily transferable in the industry. The uncertainty assessment is interesting not only to correctly evaluate experimental data but also to characterise the reproducibility of the effects of techniques for improving the wettability of films, such as surface treatments

Calibration of tri-axial MEMS accelerometers in the low-frequency range – Part 1: comparison among methods

Abstract. Two alternative experimental procedures for the calibration of tri-axial accelerometers have been compared with traditional methods, performed according the procedures stated in the standard ISO 16063-21. Standard calibration is carried out by comparison with a laser Doppler vibrometer (LDV), used as a primary reference transducer. The main sensitivities have been investigated and, where applicable, also transverse ones. Many aspects have been evaluated: the hypotheses about transverse sensitivities, the simplicity of the procedure, the number of measurements needed, and the effect of typology of transducer, depending on electrical and geometrical contributions. Two different accelerometers have been tested, a piezo-electric accelerometer and a capacitive MEMS accelerometer. A low-frequency range of vibration has been investigated, 3 and 6 Hz, with amplitude of acceleration ranging from 2 to 20 ms−2. A satisfactory reproducibility of methods has been verified, with percentage differences less than 2.5 %. Anyway, pros and cons of each method are also discussed with reference to their possible use for easy and quick calibration of low-cost tri-axial accelerometers

Calibration of tri-axial MEMS accelerometers in the low-frequency range – Part 2: Uncertainty assessment

Abstract. A comparison among three methods for the calibration of tri-axial accelerometers, in particular MEMS, is presented in this paper, paying attention to the uncertainty assessment of each method. The first method is performed according to the ISO 16063 standards. Two innovative methods are analysed, both suitable for in-field application. The effects on the whole uncertainty of the following aspects have been evaluated: the test bench performances in realizing the reference motion, the vibration reference sensor, the geometrical parameters and the data processing techniques. The uncertainty contributions due to the offset and the transverse sensitivity are also studied, by calibrating two different types of accelerometers, a piezoelectric one and a capacitive one, to check their effect on the accuracy of the methods under comparison. The reproducibility of methods is demonstrated. Relative uncertainty of methods ranges from 3 to 5 %, depending on the complexity of the model and of the requested operations. The results appear promising for low-cost calibration of new tri-axial accelerometers of MEMS type

Dynamic calibration uncertainty of three-axis low frequency accelerometers

In this paper a methodology concerning the static and dynamic calibration of three-axis low-cost accelerometers in the (0 to 10) Hz frequency range is described, to be used for evaluation of existing civil infrastructures. Main and cross sensitivities of the accelerometers have been experimentally estimated by means of the matrix sensitivity concept. The standard deviation of accelerations obtained along all three axes using different calibration data sets in repeatability conditions has been calculated and intended as dynamic calibration uncertainty. The method has been validated by using reference accelerations accurately realized, in order to evaluate the residual bias error. Static and dynamic calibration test benches have been used to realize reference accelerations. In order to create a three-axis acceleration field, a mechanical arm is used in static calibration; a rotary device is used in order to test the accelerometers in dynamic conditions. According to the procedure described in this paper, a great improvement of the low cost accelerometers' metrological characterization could be achieved, especially in dynamic working conditions

Optical system for on line monitoring of welding: a machine learning approach for optimal set up

In this paper a methodology is described for continuous checking of the settings of a low cost vision system for automatic geometrical measurement of welding embedded on components of complicated shape. The measurement system is based on a laser sheet. Measuring conditions and the corresponding uncertainty are analyzed by evaluating their p-value and its closeness to an optimal measurement configuration also when working conditions are changed. The method aims to check the holding of optimal measuring conditions by using a machine learning approach for the vision system: based on a such methodology single images can be used to check the settings, therefore allowing a continuous and on line monitoring of the optical measuring system capabilities.According to this procedure, the optical measuring system is able to reach and to hold uncertainty levels adequate for automatic dimensional checking of welding and of defects, taking into account the effects of system hardware/software incorrect settings and environmental effects, like varying lighting conditions. The paper also studies the effects of process variability on the method for quantitative evaluation, in order to propose on line solutions for this system.</p

Measurement uncertainty estimation of gap and profile in the automotive sector

Abstract In this paper, a methodology is described aiming at assessing the variability causes, affecting the measurement instruments typically used in the automotive sector for the analysis of dimensional defects of coupled components, to check the conformity of the width of the gap between two adjacent parts and the profile, i.e. the alignment of the two surfaces. The inspection may be performed by means of different gap/flush tools, such as feeler gages, calipers and Laser scanner devices; depending on the choice, a different measurand has to be considered. The obtained measurements need to be consistent, because these devices are used indistinctly, depending on the severity of the control and on the typology of the control itself. The paper proposes a methodology to verify the metrological conformity of measurements provided by both traditional and laser-based instruments, so that it is possible to interpret them in an interchanging manner. A 3D geometric model is realized, used as a basis for the analysis of the most influencing uncertainty causes and measurement biases. The methodology will demonstrate to be able to identify and evaluate in a parametric way, the typical variability causes of the instruments considered. It will also highlight possible improvements in the integration of the obtained results

Use of plant growth promoting bacteria (PGDB) for promoting tomato growth and its evaluation as biological control agent.

The plant growth promoting effect of some bacteria usable to control plant diseases has a potential for resolving technical problems of plant production. The effects of Burkholderia gladioli pv. agaricicola ICMP11096 on development of tomato seedlings development and control of their infection by Fusarium oxysporum and Sclerotinia sclerotiorum were evaluated in the present study. Bacterized plants showed a higher shoot and root weight and a more extended root system in terms of total length and root density than non-bacterized plants. The bacter-izing treatments gave rise to significant reduction of disease symptoms such as leaf wilting induced by F. oxysporum infection and/or root ne-crosis and leaf yellowing by S. sclerotiorum. The potential use of Burkholderia gladioli pv. agaricicola ICMP11096 in biocontrol of fungal patho-gens and to enhance seedling growth parameters is underlined as a tool to achieve a high commercial quality of nursery tomato plants

Uncertainty assessment for measurement and simulation in selective laser melting: a case study of an aerospace part

In this work, the additive manufacturing process selective laser melting is analysed with the aim of realising a complex piece for aerospace applications. In particular, the effect of the manufacturing process and of the following thermal treatments on the dimensions of the workpiece is evaluated. The study is based on a hybrid approach including a simulation of the whole manufacturing process by advanced software packages and the dimensional measurements of the realised pieces taken by a coordinate measuring machine (CMM). The integrated use of simulation and measurements is carried out with the aim of validating the simulation results and of identifying the operational limits of both approaches; this analysis is based on metrological evaluation of the results of both the simulation and the tests, taking into account the uncertainty of the data. In addition, the main causes of uncertainty for the simulation activity and the experimental data have been identified, and the effects of some of them have also been experimentally evaluated. Based on the experimental validation, the simulation seems to predict the absolute displacement of the supports of the piece in a satisfactory way, while it is unable, in the actual configuration, to assess the conformity of the surface to its very tight shape tolerances. Conformity assessment of the surface should be carried out by CMM measurement. Integrated use of simulation and experimental results is expected to strongly improve the accuracy of simulation results for the effective and accurate design and control of the additive manufacturing process, including dimensional control and thermal treatments to mitigate induced thermal stresses.</p

Validation of a measurement procedure for the assessment of the safety of buildings in urgent technical rescue operations

This work would like to provide a preliminary contribution to the draft of standard procedures for the adoption of Total Stations by rescuers in emergency situations, so as to offer a reliable and effective support to their assessment activities. In particular, some considerations will be made regarding the effect of the number and positioning of monitoring points on the tilt determination of a building façade, in order to set up simplified procedures, which are quick and easy to implement in emergency situations, at the same time guaranteeing the reliability of the results. Two types of building will be taken into account as test cases, which have different characteristics in terms of height, distance and angle with respect to the Total Station. Some considerations will be made about the aspects to be explored in future work, for the calibration of the method as a whole and the definition of all the steps of a procedure for the evaluation of the safety of a building

Il fenomeno delle dipendenze patologiche nella Provincia di Siracusa. Anno 2005. I Rapporto

Report on the state of legal and illegal substances use in the territory of Siracusa ProvinceIl Report analizza il fenomeno delle dipendenze nel territorio della Provincia di Siracusa. La descrizione del fenomeno si sviluppa intorno all\u27analisi degli indicatori individuati dall\u27Osservatorio Europeo delle Dipendenze di Lisbona (OEDT): 1-uso di sostanze nella popolazione generale (questo indicatore va a rilevare i comportamenti nei confronti di alcol e sostanze psicoattive da parte della popolazione generale); 2-prevalenza d\u27uso problematico delle sostanze psicoattive; 3-domanda di trattamento degli utilizzatori di sostanze; 4-mortalit? degli utilizzatori di sostanze; 5-malattie infettive. Altri due importanti indicatori che si stanno sviluppando, e che vengono qui illustrati, sono l\u27analisi delle Schede di Dimissione Ospedaliera (SDO) e gli indicatori relativi alle conseguenza sociali dell\u27uso di droghe (criminalit? droga correlata). Inoltre sono state applicate diverse metodologie standard di stima sia per quantificare la quota parte sconosciuta di utilizzatori di sostanze che non afferiscono ai servizi, sia per identificarne alcune caratteristiche