Search results for "nondestructive"
showing 10 items of 86 documents
Impulsive Tests on Historical Structures: The Dome of Teatro Massimo in Palermo
2016
Cultural heritage is the set of things, that having particular historical cultural and aesthetic are of public interest and constitute the wealth and civilization of a place and its people. Sharpen up methodologies aimed at safeguarding of monuments is crucial because the future may have in mind the historical past. Italy is a country that has invested heavily on its historical memory returned in large part by the historical building or the monuments. Furthermore, culture represents a fundamental indicator of the growth of the culture of a country. Consider a monitoring project of one of the most Impressive theater in the world, like “Teatro Massimo” in Palermo (Italy), means to add value t…
Battery characterization via eddy-current imaging with nitrogen-vacancy centers in diamond
2021
Sensitive and accurate diagnostic technologies with magnetic sensors are of great importance for identifying and localizing defects of rechargeable solid batteries in a noninvasive detection. We demonstrate a microwave-free AC magnetometry method with negatively charged NV centers in diamond based on a cross-relaxation feature between NV centers and individual substitutional nitrogen (P1) centers occurring at 51.2 mT. We apply the technique to non-destructive solid-state battery imaging. By detecting the eddy-current-induced magnetic field of the battery, we distinguish a defect on the external electrode and identify structural anomalies within the battery body. The achieved spatial resolut…
Multi-aperture beamforming for automated large structure inspection using ultrasonic phased arrays
2019
Increasing the inspection quality and speed is essential in manufacturing applications, especially for large structures (e.g. modern aircrafts). Traditional ultrasonic manual scanning can be comprehensive, but lacks repeatability and is time-consuming. Several robotic non-destructive testing systems have been developed in recent years. Although high inspection rates have been achieved by the use of robotic arms, there is the need to furtherly increase the inspection speeds, to cope with the current industrial demands. For systems delivering robotic ultrasonic inspection through phased array probes, the current bottleneck is given by the time required to electrically fire all elements of the…
Ultrasonic nondestructive testing of building materials for the diagnosis and characterization of the decay due to salts crystallization
2020
The possibility to use ultrasonic nondestructive testing for the diagnosis and characterization of decay in building materials due to salts crystallization is here investigated. Salts crystallization is one of the main sources of decay for stone materials, especially for cultural heritage items underwater or exposed to water, and its early detection as well as a continuous monitoring is highly desirable. Currently, this often requires the use of destructive methods and the sampling of the items under inspection. This work shows promises to the successful use for this purpose of ultrasonic nondestructive testing.
Chronological development of element concentrations in grapes during growth and ripeness and during fermentation of must determined by instrumental n…
2014
Abstract The chronological development of element concentrations during growth and ripeness of grapes described in the literature has only been concerned with the macro elements Mg, K, and Ca. Concentrations of trace elements in must are only described as a snapshot at the end of the ripeness. Therefore, the motivation for the present work was to accompany the growth and the ripening process of grapes successively by systematically determining element concentrations in grapes of Riesling and Cabernet Sauvignon by neutron-activation analyses. While for a number of elements, the concentrations in the grapes increased as a function of grape development (e.g., Na, K, Rb, Al), other concentratio…
Solitary Waves for the Assessment of Thermal Stress and Neutral Temperature in Slender Structures
2015
Slender columns and continuous welded rails subjected to compressive stress are common in many civil structures. The rapid in-situ measurement of this stress may be of interest to prevent structural anomalies such as buckling. In this article, the authors describe the coupling mechanism between highly nonlinear solitary waves (HNSWs) propagating along an L-shaped granular system and a beam in contact with the granular medium. The aim is the evaluation of HNSWs as a tool to measure stress in thermally loaded structures and to estimate the neutral temperature, i.e. the temperature at which this stress is null. The authors investigated numerically and experimentally one chain of spherical part…
On real-time algorithms for the location search of discontinuous conductivities with one measurement
2008
We discuss, and compare, two simple methods that provide coordinates of a point in the vicinity of one inclusion within some object with homogeneous electrical properties. In the context of nondestructive testing such an inclusion may correspond to a material defect, whereas in medicine this may correspond to a lesion in the brain, to name only two possible applications. Both methods use only one pair of voltage/current measurements on the entire boundary of the object to determine a single pair of coordinates that is considered to be close to the center of the inclusion. The first method has been proposed previously by Kwon, Seo and Yoon; the second method, called here the effective dipole…
An unsupervised Learning Algorithm for Fatigue Crack Detection in Waveguides
2009
Ultrasonic guided waves (UGWs) are a useful tool in structural health monitoring (SHM) applications that can benefit from built-in transduction, moderately large inspection ranges, and high sensitivity to small flaws. This paper describes an SHM method based on UGWs and outlier analysis devoted to the detection and quantification of fatigue cracks in structural waveguides. The method combines the advantages of UGWs with the outcomes of the discrete wavelet transform (DWT) to extract defect-sensitive features aimed at performing a multivariate diagnosis of damage. In particular, the DWT is exploited to generate a set of relevant wavelet coefficients to construct a uni-dimensional or multi-di…
Forensic comparison of PVC tape backings using time resolved LA-ICP-MS analysis
2019
Abstract Adhesive tapes are common tools for criminal acts such as the construction of improvised explosive devices. Hence, tape samples can be used as evidence to link a suspect to a scene of crime or different crime scenes to each other. A set of 87 black electrical tapes was the subject of a study evaluating a LA-ICP-MS method for the characterization of tape backings regarding their elemental composition in a forensic context. LA-ICP-MS is a powerful tool in forensic investigations due to fast, quasi nondestructive analysis of small samples and detection or determination of elements up to the ultra-trace range. In this study, the development of a semiquantitative LA-ICP-MS method for fo…
Conformable eddy current array delivery
2016
The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path…