Nondestructive Characterization Research Articles

Non-destructive characterization of individual particle bunches by a resistive-cooling measurement in a Penning trap

We have developed and operated an electronic system for the non-destructive detection and cooling of charged-particle bunches that are captured and confined in a Penning trap, together with methods for the evaluation of corresponding measurements that allow for a detailed characterization of each individual particle bunch. Once calibrated, from a single measurement of the particles’ induced electronic signal as a function of time directly upon capture, the setup and method allow for a fast determination of the initial and final absolute particle energies, of the cooling rate, and of the absolute number of particles in the bunch. We demonstrate this with highly charged ions (Ne8+) that are injected into the Penning trap of the HILITE experiment.

A novel method of nondestructive characterization via X-ray and high-speed imaging of TiC/IN718 composite materials manufactured by LMD

A novel method of nondestructive characterization via X-ray and high-speed imaging of TiC/IN718 composite materials manufactured by LMD

Machine learning-based prediction of single clad characteristics and non-destructive characterization of multi-layer deposited FeCoNiCrMo HEA on EN24 via laser cladding

The prediction of the proper metallurgical bonding and bead morphology in a laser cladding is very crucial to get a best profile of multi-clad layer. This work explores the laser cladding performance of FeCoCrNiMo high entropy alloy (HEA) on EN24 by analyzing the bead morphology with various process parameters. Machine learning (ML) technique is applied for two set of data where feasibility of the metallurgical bond is predicted and tested. From second set of data mainly three ML models, Support vector machine (SVM) radial kernels, K-Nearest neighbor (KNN), and multilayer perceptron (MLP) were applied to predict the outcomes. Sequential Minimal Optimization (SMO) algorithm is applied to identify the proper bonding between the substrate and cladded materials, which is classification-based ML model. The KNN model consistently attained the highest predictive accuracy across all response variables. It achieved perfect R² values and exhibited the lowest error metrics for clad width (w), clad height (h), clad depth (d), heat affected zone (HAZ), and Microhardness, establishing it as the most reliable and accurate model among the three applied ML model. To minimize the HAZ, the best conditions are lower laser powers, higher scanning speeds, and lower powder feed rate which is observed by contour plot. This reduces thermal diffusion into the substrate, maintaining material properties. Also, a non-destructive approach is used to characterize the multi-layer cladded before and after the deposition. The cladding process has significantly altered the microstructural and magnetic properties of the EN24 substrate, resulting in more refined grain structure and increased microhardness in the cladded region.

Prediction of Temperature‐Dependent Stress in 4H‐SiC Using In Situ Nondestructive Raman Spectroscopy Characterization

Abstract4H‐SiC is widely used in power electronics owing to its superior physical properties. However, temperature‐induced stresses compromise the reliability of 4H‐SiC power devices in high‐temperature applications, warranting precise, and nondestructive stress characterization responsive to temperature variations. Herein, a temperature‐dependent predictive model is proposed for analyzing the Raman shift–stress in 4H‐SiC. The 4H‐SiC epitaxial samples prepared via chemical vapor deposition are characterized using in situ variable‐temperature Raman spectroscopy, resulting in a temperature correction factor of approximately −0.021 cm−1 K−1, which is integrated into the conventional Raman shift–stress relationship to assess stress variations induced by temperature variations. The elastic modulus tensor of 4H‐SiC at various temperatures determined using molecular dynamics simulations indicates a linear reduction in modulus with increasing temperature. This variable temperature modulus is incorporated into the Raman shift–stress relationship. Furthermore, a finite element method is used for model simplification to perform stress calculations in three axial directions. The experimental results confirm the consistency between calculated and experimental values with a 10% error range under the uniaxial stress condition. The study findings provide valuable insights into assessing stress evolution in 4H‐SiC under temperature variations based on Raman spectroscopy, thereby advancing the application of spectroscopic techniques in material stress detection.

Development of a Hyperspectral Imaging Protocol for Painting Applications at the University of Seville

In the last decade, the hyperspectral imaging (HSI) method allowed performing non-invasive analysis in the field of cultural heritage. However, a considerable limitation was given by redundant and time-consuming features, with the necessary application of statistical algorithms and image-processing tools to extract relevant information. In this study, the Centro Nacional de Aceleradores (CNA) and the Group of Interdisciplinary Physics (GFI) of the School of Engineering (ETSI) of the University of Seville tested the application of three different hyperspectral cameras in the visible and near-infrared (VNIR) and short-wave infrared (SWIR) range for the investigation of an ancient painting. A reference-based procedure was realised to build a starting personal library and to evaluate the best working conditions for non-invasive and non-destructive characterisation with data treatment using the commercially available software Evince® and Specim IQ® to apply, respectively, the Principal Component Analysis (PCA) model functions and the classification method. The evaluation of the protocol was tested by acquiring complementary information by X-ray fluorescence (XRF), Ultraviolet Luminescence (UVL) imaging, and Infrared Reflectography (IRR). This exploration established a simplified protocol to analyse the large collection of paintings of the Archbishop’s Palace and the Cathedral of Seville.

On the Use of Reflection Polarized Optical Microscopy for Rapid Comparison of Crystallinity and Phase Segregation of P3HT:PCBM Thin Films.

Rapid, nondestructive characterization techniques for evaluating the degree of crystallinity and phase segregation of organic semiconductor blend thin films are highly desired for in-line, automated optoelectronic device fabrication facilities. Here, it is demonstrated that reflection polarized optical microscopy (POM), a simple technique capable of imaging local anisotropy of materials, is capable of determining the relative degree of crystallinity and phase segregationof thin films of polymer:fullerene blends. While previous works on POM of organic semiconductors have largely employed the transmission geometry, it is demonstrated that reflection POM provides 3× greater contrast. The optimal configuration is described to maximize contrast from POM images of polymer:fullerene films, which requires Köhler illumination and slightly uncrossed polarizers, with an uncrossing angle of ±3°. It is quantitatively demonstrated that contrast in POM images directly correlates with 1) the degree of polymer crystallinity and 2) the degree of phase segregation between polymer and fullerene domains. The origin of the bright and dark domains in POM is identified as arising from symmetry-broken liquid crystalline phases (i.e., dark conglomerates), and it is proven that they have no correlation with surface topography. The use of reflection POM as a rapid diagnostic tool for automated device fabrication facilities is discussed.

Precision Phenotyping in Crop Science: From Plant Traits to Gene Discovery for Climate‐Smart Agriculture

ABSTRACTThe global population is placing unprecedented demand on food systems, which can be met only through a complex interplay of technology, sustainable food production intensification methods and climate resilience. To address such compounded requirements, developing high‐yielding crop varieties using precise plant breeding methods bolstered with efficient and nondestructive plant trait documentation approaches is vital. High‐throughput crop phenotyping (HTCP) platforms have prominently emerged as a mainstream approach for reducing the phenotyping bottleneck in breeding programmes. HTCP has the potential to provide detailed quantitative information of large plant populations under different growth stages across diverse environmental regimes, facilitating accelerated plant breeding strategies. New imaging platforms also enable nondestructive characterization of a wide range of above and below‐ground crop parameters. The specificity in use of sensors, automation of data collection, large‐scale data handling systems and accurate analytical tools have a substantial role in dynamic crop monitoring and big data interpretation. HTCP platforms are capable of making precise measurements of a wide range of physiological, morphological, biochemical and stress responses in plants. Developments of sensors with improved precision, intervention of unmanned aerial vehicles, robotics, computed tomography and machine learning have given a dramatic developmental leap to precise and large‐scale crop phenotyping. This review provides an avenue for understanding various high‐throughput phenotyping platforms, working principles, current developments and contributions to high‐throughput phenotyping of various crops under laboratory and field conditions. A detailed comparative idea on the advantages and pitfalls of these available platforms can help researchers in choosing the right technology suiting specific practical requirements. Furthermore, the review aims to provide novel future prospects and developmental requirements that can potentially widen the application and utilization of these HTCP technologies in agriculture.

Characterization of sustainable biocompatible materials based on chitosan: cellulose composites containing sporopollenin exine capsules

In this work, photothermal beam deflection spectrometric technique (BDS) is applied for non-contact and non-destructive characterization of chitosan (CS): cellulose (CEL) biocomposites with incorporated sporopollenin exine capsules (SEC). The objective was to determine the structural and thermal properties of synthesized CS:CEL:SEC composites with varying amounts of SEC, and to validate the BDS by photopyroelectric calorimetry (PPE) as an independent technique. It was found that CS:CEL biocomposites without SEC exhibit low porosities, which are on the order of 0.005 %, but can be increased by augmenting the content of CEL in the composite and/or by incorporation of SEC. By increasing the SEC content of CS:CEL composites to 50 % (w/w), the porosity increased up to 0.17 %. SEC also increases the surface roughness of biocomposite by over 2000-times to reach the roughness amplitude of 6 μm in composites with 50 % SEC. The thermal conductivities of investigated biocomposites were in the range of 40–80 mWm−1 K−1, while the thermal diffusivities were on the order of fractions of mm2s−1. With first validation of BDS results for thermal properties of CS:CEL-based composites, which show agreement with PPE results to within 5 %, this study confirms BDS technique as a perspectives tool for non-destructive characterization of CS:CEL:SEC biocomposites.

Use of Computerised X-ray Tomography in the Study of the Fabrication Methods and Conservation of Ceramics, Glass and Stone Building Materials

This work will review and discuss the use of computerised X-ray tomography (CXT) for analysing ancient, manufactured items, like stone building materials, glass and ceramics. It will consider particular techniques required, and/or of benefit, for CXT of heritage materials, such as special precautions during the experimentation to ensure there is no damage to the materials, special imaging methods such as elemental-specific imaging, and sample-specific image analysis requirements. This study shows how the knowledge of internal features, particularly pores, discerned from CXT can be used to reverse engineer the artefact fabrication process. CXT can be used to obtain information on both the raw materials (such as types and impurities) and fabrication techniques used. These abilities can then be used to establish technological evolution and the incidence of ancient behaviours like recycling and allow the linking of particular items to specific production sites. It will also be seen how CXT can aid the development of effective conservation techniques. This work will also consider how conclusions drawn from CXT data can be amended or augmented by the use of complementary non-destructive characterisation methods, such as gas overcondensation.

Design, fabrication, and characterization of 1–3 piezoelectric composite air-coupled ultrasonic transducers with micro-membrane filter matching layer

Air-coupled ultrasonic transducers are widely used in various fields of nondestructive material characterization. This paper presents the fabrication and performance characterization of 1–3 piezoelectric composite air-coupled ultrasonic transducers operating at frequencies ranging from 400 kHz to 600 kHz. The transducers are fabricated using a dice-and-fill method with PZT-5 as the active material. A double-layer matching strategy is employed, utilizing hollow glass microsphere filled epoxy resin as the first matching and bonding layer. Additionally, micro-membrane filters with different pore sizes are used as the second matching layer. Thermoplastic adhesive TPU is utilized to bind the micro-membrane filter and the first matching layer. Due to the low acoustic impedance of the hollow glass microsphere filled epoxy resin and micro-membrane filter, acoustic impedance mismatch is reduced. Finite element simulation is used to determine the optimal ceramic volume fraction and ceramic pillar height of the 1–3 piezoelectric composites. When the pore size of the micro-membrane filter is 0.8 μm, the transducer achieves the lowest two-way insertion loss of −56.86 dB and the highest −6 dB bandwidth of 15.6 %, making it feasible for through mode applications.

Rapid on-site nondestructive surface corrosion characterization of sintered nanocopper paste in power electronics packaging using hyperspectral imaging

Sintered nanocopper (nanoCu) paste, exhibiting excellent electrical, thermal, and mechanical performances, offers promise for interconnections in wide bandgap (WBG) semiconductors operating at higher temperatures. However, sintered nanoCu is prone to severe corrosion in environments containing H2S, with on-site characterization methods for the composition of corrosion products currently lacking. In this study, a novel method was proposed for the rapid characterization of corrosion products during the corrosion process based on hyperspectral imaging (HSI) technology. Sintered nanoCu samples were subjected to 336 h H2S gas corrosion tests with bulk Cu as the reference, followed by correlating the corrosion element content with hyperspectral characteristic parameters. Then, the morphology and composition of corrosion products were researched using focused ion beam scanning electron microscope (FIB-SEM) and transmission electron microscope (TEM) analysis. The results showed that (1) during the corrosion process, a linear relationship was established between the Cu, O elemental atomic contents on the sample surfaces and their hyperspectral characteristic parameters. (2) The elemental atomic content of S exhibited an exponential relationship with the characteristic parameter. (3) The change rate in the spectral characteristic parameters during the corrosion process reflected the severity of corrosion, which was confirmed by comparing the thickness of the corrosion products of the sintered nanoCu and bulk Cu. This study offers a foundation for the further investigation of rapid on-site characterization of sintered nanoCu corrosion involving H2S.

Thin-film dielectric characterization by bound state in the continuum in high contrast grating

Subwavelength high contrast grating (HCG) is renowned for its remarkable ability to produce sharp optical resonance, known as the bound state in the continuum (BIC). Due to the strong surface field enhancement, the resonant wavelength and quality factor (Q factor) are highly sensitive to the dielectric properties of the surrounding medium. We propose utilizing this extraordinary phenomenon for thin-film dielectric characterization based on a film-substrate-grating configuration. By optimizing the geometrical parameters to control the cross-interference between guided modes in the grating and self-interference of propagating wave in the substrate slab, an accidental BIC with a Q factor reaching 104 is excited. Using this BIC, two retrieval methods based on contour mapping of resonant wavelength and Q factor are proposed to extract the complex permittivity (εf) of the film under test. It has been demonstrated that with a film thickness as thin as 10−5 times the grating period, the error in the retrieved Re[εf] is below 2%, and that of Im[εf] is below 10%. The proposed design is a strong candidate for non-destructive dielectric characterization of thin films with thicknesses below one-thousandth of the operating wavelength. This characterization technique can facilitate the development of high-frequency devices for the 6 G high-speed communication.

Demonstration of shape analysis of neutron resonance transmission spectrum measured with a laser-driven neutron source

Laser-driven neutron sources (LDNSs) can generate strong short-pulse neutron beams, which are valuable for scientific studies and engineering applications. Neutron resonance transmission analysis (NRTA) is a nondestructive technique used for determining the areal density of each nuclide in a material sample using pulsed thermal and epithermal neutrons. Herein, we report the first successful NRTA performed using an LDNS driven by the Laser for Fast Ignition Experiment at the Institute of Laser Engineering, Osaka University. The key challenge was achieving a well-resolved resonance transmission spectrum for material analysis using an LDNS with a limited number of laser shots in the presence of strong background noise. We addressed this by employing a time-gated 6Li\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{6}{\ extrm{Li}}$$\\end{document}-glass scintillation neutron detector to measure the transmission spectra, reducing the impact of electromagnetic noise and neutron and gamma-ray flashes. Output waveforms were recorded for each laser shot and analyzed offline using a counting method. This approach yielded a spectrum with distinct resonances, which were attributed to 115In\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{115}\\,{\ extrm{In}}$$\\end{document} and 109Ag\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{109}{\ extrm{Ag}}$$\\end{document}, as confirmed through neutron transmission simulation. The spectrum was analyzed using the least-square nuclear-resonance fitting program, REFIT, demonstrating the possibility of using an LDNS for nondestructive areal-density material characterization.

DEM investigation into the small-strain stiffness of bio-cemented soils

AbstractBio-mediated methods, such as microbially induced carbonate precipitation, are promising techniques for soil stabilisation. However, uncertainty about the spatial distribution of the minerals formed and the mechanical improvements impedes bio-mediated methods from being translated widely into practice. To bolster confidence in bio-treatment, non-destructive characterisation is desired. Seismic methods offer the possibility to monitor the effectiveness and mechanical efficiency of bio-treatment both in the laboratory and in the field. To aid the interpretation of shear wave velocity measurements, this study uses the discrete element method to examine the small-strain stiffness of bio-cemented sands. Bio-cemented specimens with different characteristics, including properties of the host sand (void ratio, uniformity of particle size distribution) and properties of the precipitated minerals (distribution pattern, content, Young’s modulus), are modelled and subjected to static probing. The mechanisms affecting the small-strain properties of cemented soils are investigated from microscopic observations. The results identify two mechanisms controlling the mechanical reinforcement associated with bio-cementation, namely the number of effective bonds and the ability of a single bond to improve stiffness. The results show that the dominant mechanism varies with the properties of the host sand. These results support the use of seismic measurements to assess the mechanical efficiency and effectiveness of bio-mediated treatment.

Intellectual fitting of hard X-ray resonant reflectance maps obtained for low-contrast oxide multilayers across L absorption edges of Eu and Gd

The present work describes an intellectual computational approach to X-ray resonant reflectometry – a synchrotron-based method aimed at non-destructive characterization of epitaxial nanoscale multilayers with low optical contrast between the sublayer materials. Resonant reflectance from specially designed bilayer structures was measured as a function of grazing angle and photon energy across the L absorption edges of rare earth elements and then modeled with the aid of a specially developed software utilizing OpenCL high speed computations performed on a graphical processing unit. The map fitting was carried out in the blind mode in which the spectral shapes of the optical constants of the sublayers were reconstructed by the fitting routine without initial knowledge of the chemical composition and without using any reference spectra. The model uses stepped Lorentzian line shape for the imaginary part of the scattering length density and the Kramers-Kronig consistent line shape for the corresponding real part. Epitaxially grown Eu2O3 / Gd3Ga5O12 bilayers were used as a test bench system to demonstrate the benefits of the proposed 2D mapping technique over conventional X-ray reflectometry. To increase reliability, the map fitting was carried out simultaneously at the absorption edges of two different chemical elements. The derived shapes and positions of the absorption peaks were used to uniquely identify rare earth elements within the corresponding sublayers and provide information on their oxidation states. The method was experimentally tested on the bilayers having different material order to show that not only the chemical composition but also the layer sequence can be effectively reconstructed in the automatic way from the 2D resonant reflectance maps.

Three-Dimensional (3D) Nondestructive Characterization of the Spatial Distribution and Complex Properties of Polytypes on 4H-SiC Wafers

Three-Dimensional (3D) Nondestructive Characterization of the Spatial Distribution and Complex Properties of Polytypes on 4H-SiC Wafers

Non destructive qualification of bovine meat tenderness

Tenderness is one of the most important criteria in bovine meat, as it determines whether the meat is used for grilling, long-time cooking or post-processing. It is therefore of great interest for the industry to measure it. Common systems require the extraction and destruction of samples, inducing time and material expenses. In this article, a new nondestructive characterization apparatus, based on monitored indentation, relaxation, and recovery, is proposed. Samples from two cuts known for their difference in tenderness were used from the same carcass. Their tenderness were assessed via compression tests and then compared to indicators from the force–displacement measurements. Results showed that the indentation and recovery speed, and the force relaxation enable the differentiation of the two cuts (p<0.05). These results were obtained on samples from a single carcass. Measurements on other carcasses should be performed to ensure that the results presented in this article can be generalized to bovine meat.

A new multi-analytical procedure for radiocarbon dating of historical mortars

The overarching challenge of this research is setting up a procedure to select the most appropriate fraction from complex, heterogeneous materials such as historic mortars in case of radiocarbon dating. At present, in the international community, there is not a unique and fully accepted way of mortar sample preparation to systematically obtain accurate results. With this contribution, we propose a strategy for selecting suitable mortar samples for radiocarbon dating of anthropogenic calcite in binder or lump. A four-step procedure is proposed: (I) good sampling strategies along with architectural and historical surveys; (II) mineralogical, petrographic, and chemical characterization of mortars to evaluate the feasibility of sample dating; (III) a non-destructive multi-analytical characterization of binder-rich portions to avoid geogenic calcite contamination; (IV) carbonate micro-sample preparation and accelerator mass spectrometer (AMS) measurements. The most innovative feature of the overall procedure relies on the fact that, in case of positive validation in step III, exactly the same material is treated and measured in step IV. The paper aims to apply this procedure to the ancient mortar of the Florentine historical building (Trebbio Castle), selecting micro-samples suitable for dating in natural hydraulic mortars. The discussion of the mortar dating results with the historical-archaeological hypotheses provided significant insights into the construction history of the building.

Imaging the intramuscular pressure of living muscles with shear waves

Shear wave elastography (SWE) is an innovative method that allows for the nondestructive and quantitative characterization of muscular mechanical properties. This method finds extensive utility in fields such as sports medicine, sports rehabilitation, and the diagnosis of muscle-related ailments. Existing studies have demonstrated the promise of SWE in probing intramuscular pressure (IMP), a factor intimately tied to muscular physiological functions and the onset of certain diseases. Nonetheless, there remains a lack of a SWE method grounded in an appropriate biomechanical model capable of effectively imaging IMP in vivo. Addressing this issue, we propose a shear wave imaging method relaying on a porohyperelastic model encompassing well-defined parameters for both muscular active behavior and intramuscular pressure. Drawing upon wave motion analysis, we establish a correlation between shear wave velocities and IMP in analytical form. This theoretical solution on one hand help understand the interplay between IMP and muscle active stress and the impact of muscle contraction on IMP. On the other hand, it enables us to develop an elastography method to assess IMP in vivo. We conducted a series of experiments to underscore the applicability of our theory and elastography method. Ex vivo experiments were performed on porcine muscles, while in vivo tests were carried out on human skeletal muscles. The results from the ex vivo tests validate the efficacy of our method. Meanwhile, the in vivo outcomes suggest that our approach holds potential to assess the variation of IMP with muscle fatigue and injuries, inspect intramuscular injections, and diagnose acute and chronic compartment syndrome.

In Situ Annealing Effect on Thermally Co-Evaporated CsPbI2Br Thin Films Studied via Spectroscopic Ellipsometry.

All-inorganic cesium lead halide perovskites possess excellent thermal stability, a feature that renders them highly favorable for optoelectronic applications with an elevated thermal budget. Employing a coevaporation approach for their deposition holds promise for manufacturing at an industrial level, owing to improvements in device scalability and reproducibility. For unlocking the full potential of vacuum-evaporated perovskite thin films, it is crucial to delve deeper into their crystallization process, which, as a solid-state reaction, has been less investigated compared to the crystallization process of, most commonly used, solution-based methods. In this work, we employ spectroscopic ellipsometry, a nondestructive, high speed, and high accuracy characterization method, to study the real time annealing effect on thermally coevaporated CsPbI2Br thin films in a temperature range between 25 and 300 °C. We achieve this by developing a singular dynamic model that can be fitted in real time as a function of temperature, providing insights into how thermal annealing influences the perovskite film's morphology and optical constants. Based on the latter, we derive the temperature dependence of the thermo-optic coefficient and Urbach energy as well as analyze the interband transition energies via critical point analysis. We demonstrate that the γ- to β-phase transition can be identified through a pronounced shift in the bandgap energy, whereas the β- to α-phase transition can be discerned by a sharp increase in the film's roughness. We corroborate the obtained fit results with additional in- and ex situ measurements, such as in situ grazing incidence wide-angle X-ray scattering, atomic force microscopy, reflectance/transmittance, and profilometry.