Non-destructive Investigation Research Articles

The Dutch Apollo 11 Goodwill display contains genuine Moon rocks

In the 1970s, US President Richard Nixon offered moon samples returned by the Apollo 11 and Apollo 17 missions to the leaders of the nations of the World. In this study, we used a combination of advanced X-ray analysis methods, including microtomography, tomosynthesis and hyperspectral chemical mapping to carry out a non-destructive forensic investigation of the Dutch Apollo 11 Goodwill sample, normally on display at the Boerhaave museum in the Netherlands. These powerful methods were uniquely able to non-destructively interrogate the samples encased in plastic without contact, providing 3D images of sample textures and compositional analysis, to assess whether the results agree with archive data on Apollo 11 coarse-grained soil sample number 10085, and to provide new insights on their origins. Our forensic investigation asked the question: were the rocks in the Dutch display actually picked up on the surface of the moon by Neil Armstrong and Buzz Aldrin?

Documentation of Vertical Connectors Between Successive Drums in Ancient Columns-Literature and In-Situ Investigation

The current paper is dedicated to the documentation of the characteristics of vertical connectors (gomfoi) in ancient columns and to the observed pathology. The gathering of the relative information aims to provide the data necessary for decisions related to an experimental program, investigating the behaviour of columns provided with connectors between successive drums. The investigation has been carried out in monuments where the use of connectors is already known, as well as in monuments for which there is insufficient information. Monuments for which it is assumed that there are no connectors have also been studied to confirm the hypothesis. Literature review, in situ observation, and the application of non-destructive investigation methods (geo-radar) have led to the documentation of the use and location of connectors in the monuments under study.

Non-destructive investigations at Neolithic tell-centered settlement complexes on the Great Hungarian Plain

AbstractIn Southeast Europe, recent years have witnessed a notable shift in scholarly focus related to prehistoric tell sites, expanding to encompass both their immediate surroundings and broader contexts. This shift has coincided with, and to a large extent has been generated by, significant methodological advancements in an array of non-invasive methods, including particularly magnetic prospection. This paper presents the methodology and results of an integrated set of non-destructive investigations conducted at Battonya-Parázs-tanya, a Middle/Late Neolithic settlement located in the southeastern part of the Great Hungarian Plain. In addition to various map sources, magnetometry, LiDAR, thermal and multispectral imaging, and surface survey were utilized at this tell-centered settlement complex to locate old excavation blocks and gain insights into settlement size, layout, and land use. Our data indicates that Battonya-Parázs-tanya spanned approximately 110 ha, with two primary ditches surrounding the tell and indications of a possible third enclosure, suggesting significant human alterations to the local landscape. This study underscores the importance of integrating multiple non-invasive techniques to achieve a more comprehensive understanding of the organizational complexities of and variations in large Neolithic settlements, thereby shedding light on socio-cultural dynamics that shaped them.

Magnetic Non-Destructive Evaluation of Reinforced Concrete Structures—Methodology, System, and Identification Results

This paper aims to present a non-destructive magnetic method developed for simultaneously identifying key parameters in reinforced concrete (RC) structures. This method is designed to evaluate concrete structures containing dense reinforcement meshes. The development process of the system is presented step by step. First, the hardware layer of the system is discussed and documented. The proposed modifications to the excitation system enhanced the method’s effectiveness compared to the conventional Magnetic Flux Leakage (MFL) technique. Next, this paper presents the extracted association rules that connect the parameters of the RC structure to the properties of resultant waveforms. The relations are verified with measurement results. Finally, the identification of the model’s design, implementation, and deployment processes are presented. A universal methodology for non-destructive testing investigations was developed and is described throughout the research.

Forensic-geology-based magnetic analysis of beach sediments from the Shimokita Peninsula, Japan.

The occurrences of various illegal activities on beaches require effective geological and environmental investigation methods. Among these methods, the room-temperature magnetic analysis of soils and sediments represents a nondestructive investigation method for various amounts, types, and grain sizes of magnetic minerals. Here, to verify the usefulness of magnetic analysis in forensic geology research, beach sediment samples from nine sites in the Shimokita Peninsula, Japan, were measured using magnetic analysis to determine the correlations between their concentration-dependent magnetic parameters and actual regional characteristics. The results revealed that the values of various parameters, namely the low-field magnetic susceptibility, anhysteretic remanent magnetization, and isothermal remanent magnetization (IRM), were relatively higher at sites near Ti and Fe sedimentary ore deposits. Further, thermomagnetometry results revealed that magnetite was the main magnetic carrier of the sediments. Moreover, pyrrhotite was detected around Ti-Fe mine sites. Furthermore, the results of the investigated parameters reflected the regional characteristics of the amount of magnetic minerals in the beach sediments. Low-temperature IRM curves and the magnetic grain size parameter also displayed sample-site-reflective characteristics. Thus, we believe that magnetic analysis represents an effective method for estimating the provenance of beach sediments in forensic geology research.

A Non-Destructive Investigation Method of Granite in Taiwan’s Cultural Heritage Sites: Image Analysis for Calculating Mineral Proportions in Granites

<p>臺灣古蹟、歷史建築中有相當多由石材建造的建築和碑碣，當這些文化資產需要修復時，選擇與原物件相匹配的替換材料對於保護文化真實性至關重要。然而，對石材原件和替換材進行定量比較以往需要破壞性分析，但文化資產通常禁止採樣。為了解決這個問題，本文研發了一項非破壞性影像處理程序，得出花崗岩主要礦物的比例，以定量比較其外觀。在建築石材中，選擇花崗岩來開發這種影像處理程序法，因為它具有高辨識度顏色的礦物，並且是一種廣泛應用於文化資產的建築材料。因此，礦物比例是描述花崗岩影像的主要參數，從外觀上看，花崗岩可分為灰白色系和粉棕色系兩大類，再藉由拉曼光譜儀證實影像中顏色與各主要礦物的對應關係。在影像處理程序中，利用紅色、綠色和藍色（R-G-B）色彩空間模型中，粉紅、棕色像素與灰、白色（斜長石）和黑色（黑雲母）像素R值（紅色）的差異性，並利用2R/（G+B）– δ（RGB）關係圖分辨圖形序列中的淺色和深色像素，最後應用灰階來解析序列中的白色和灰色像素，最終將影像中顏色的像素數量轉換為礦物比例。影像處理所得之數據再與需要破壞性程序取得的理想礦物比例與進行比較，兩者誤差在10%以內。因此，影像處理程序被驗證為一種可有效辨識文化資產中花崗岩的非破壞性調查方法。最後，將此方法實際應用於「湯德章紀念公園」與「南鯤鯓代天府」兩處文化資產並進行相關討論，證實影像處理法可有效提升現場調查之效能與廣度及深度，是非常值得繼續研究開發及推廣之調查方法。</p> <p> </p><p>Heritage sites often comprise buildings and monuments constructed from stone materials. When these heritage sites require restoration, selecting replacement materials that match originals is crucial for preserving cultural authenticity. Nevertheless, sampling is generally prohibited at heritage sites, preventing destructive analyses for quantitatively comparing originals and replacements. To address this issue, we established a non-destructive image analysis protocol to derive proportions of constituent minerals for quantitatively comparing the appearance of stone materials. Among the construction stones, granite was selected for developing this color differentiation algorithm because it is a ubiquitous construction material and it comprises minerals with distinctive colors. Mineral proportions are, therefore, prime parameters for describing the images of granites. By appearance, granites were sorted into the gray-white group and the brown-pink group. The corresponding relationship between the colors in the image and the main minerals is confirmed by a Raman spectrometer. In image analysis, the brown and pink pixels were distinct from the gray, white (plagioclase), and black (biotite) ones for higher R (red) values in the red, green, and blue (RGB) color model. Moreover, the dark colored pixels had a standard deviation from the mean of RGB values [δ (RGB)] extending to higher values. Granite pixels were, therefore, first separated using a 2R/(G+B) versus δ (RGB) plot. The brown and pink pixels formed a high R array with a positive 2R/(G+B) – δ (RGB) slope, whereas the gray, white, and black pixels defined a low R array showing an inverse 2R/(G+B)–δ(RGB) correlation. The combination of δ (RGB) and (R+G+B) further separated light and dark colored pixels in a 2R/(G+B) – δ (RGB) array. At last, grayscale was applied to resolve the white and gray pixels in a low R array after isolating the black pixels. The numbers of pixels for each color were then converted to mineral proportions. More precise mineral proportions were acquired for comparison through composition 2 analyses that required destructive procedures. The comparator values were derived by solving a matrix equation that described a bulk composition as the sum of the products of the constituent mineral compositions and their corresponding proportions. The mineral proportions from image analysis and composition analyses were within 10%. Hence, our new protocol was validated as a method for selecting proper replacement materials for restoring granite-based cultural heritage sites. Finally, the image analysis procedures were applied to the restoration of two monument in southern Taiwan.</p> <p> </p>

Wide-Field Polarimetric Second-Harmonic Imaging for Rapid and Nondestructive Investigation of Laser-Induced Crystallization Phenomena.

The selective and controlled formation of nanocrystals in glass is emerging as a versatile method to achieve functional photonics, optoelectronics, and quantum devices, such as single-photon emitters. Here, we investigate the use of wide-field polarimetric second-harmonic (SH) microscopy as a method to rapidly and nondestructively examine nanoscale crystal arrangements in laser-processed glass. As a case study, we investigate tellurite glass, where the formation of a trigonal tellurium (t-Te) nanocrystalline phase after femtosecond laser exposure was recently demonstrated. Combined with theoretical models, we show that wide-field polarimetric SH microscopy offers comprehensive information on the nanocrystals' orientation, distribution, and chirality. With its high imaging throughput and spatial resolution, this method has the potential not only to significantly accelerate investigations on laser-induced glass crystallization processes but also to provide a valuable tool for in situ process monitoring.

Developing a quantitative multimodal and multi-scale, fully non-destructive technique for the study of iron archaeological artefacts

This article presents the methodology and initial findings of the SNSF Sinergia project CORINT. The project's objective is to elucidate the corrosion mechanisms affecting iron-based structures entrapped in various porous media. This paper focuses specifically on iron archaeological artefacts (IAAs) in soil. A novel multimodal quantitative imaging technique, which integrates neutron and X-ray computed tomography (NX-CT), is under development for non-destructive examination of corrosion processes. The method involves registering and fusing neutron and X-ray tomography data, followed by Gaussian mixture model (GMM) clustering for phase segmentation. Imaging was conducted on two IAAs, Vrac C and BdC1. Additionally, random cross-sections of these samples underwent analysis through optical microscopy, µRaman spectroscopy, and SEM-EDS to characterize and correlate corrosion layers with NX-CT results. This study yields valuable insights into the corrosion of IAAs, enabling the non-destructive investigation of corrosion processes in porous media. The implications extend beyond the preservation of cultural heritage, to the examination of long-term corrosion behaviors in contemporary iron structures, steel within concrete, and nuclear waste disposal plans.

Anomaly detection via improvement of GPR image quality using ensemble restoration networks

Ground penetrating radar (GPR) has been commonly applied for the non-destructive investigation of underground anomalies. This study proposes a robust anomaly detection method for GPR images that overcomes harsh noisy conditions by employing an ensemble image-restoration network. The ensemble network exploits SwinIR, RCAN, and MSRN to improve extreme GPR images. Furthermore, the restored higher-quality GPR images were employed for anomaly detection using different classification networks. The experimental results indicated that the ensemble network with combination factors 0.2:0.4:0.4 (SwinIR, RCAN, and MSRN, respectively) significantly improves low-quality GPR images with peak signal-to-noise ratio of 42.9 dB and 44.0 dB and structural similarity index measure of SSIM = 0.980 and 0.989 for denoising and deblurring, respectively. The restored GPR images significantly reduce the misclassification and increases the classification accuracy as much as that of the ideal GPR images. This study suggests that an ensemble restoration network can effectively restore GPR images and improve anomaly detection.

Three-dimensional reconstruction of high latitude bamboo coral via X-ray microfocus Computed Tomography

The skeletons of long-lived bamboo coral (Family Keratoisididae) are promising archives for deep-water palaeoceanographic reconstructions as they can record environmental variation at sub-decadal resolution in locations where in-situ measurements lack temporal coverage. Yet, detailed three dimensional (3D) characterisations of bamboo coral skeletal architecture are not routinely available and non-destructive investigations into microscale variations in calcification are rare. Here, we provide high-resolution micro-focus computed tomography (µCT) data of skeletal density for two species of bamboo coral (Acanella arbuscula: 5 specimens, voxel size, 15 µm (central branch scans) and 50 µm (complete structure scan); Keratoisis sp.: 4 specimens, voxel size, 15 µm) collected from the Labrador Sea and Baffin Bay deep-water basins, Eastern Canadian Arctic. These data provide reference models useful for developing methods to assess structural integrity and other fine-scale complexities in many biological, geological, and industrial systems. This will be of wider value to those investigating structural composition, arrangement and/or composition of complex architecture within the fields and subdisciplines of biology, ecology, medicine, environmental geology, and structural engineering.

Mapping the elemental distribution in archaeological findings through advanced Neutron Resonance Transmission Imaging

This work highlights recent application of energy-selective neutron imaging at the ISIS Neutron and Muon Source, specifically focusing on the development of Neutron Resonance Transmission Imaging (NRTI) at the INES instrument. NRTI is a nuclear technique based on resonant neutron absorption reaction, which combines the sensitivity to elemental and isotopic composition with detailed morphological information, using the epithermal portion of the neutron flux available on the INES instrument at the ISIS facility. Unlike standard neutron radiography and tomography methods, NRTI preserves detailed time and energy information for each detector pixel, enabling enhanced visualisation of elemental distribution inside an object’s volume, with the potential for quantitative elemental analysis. These features combined with the non-destructiveness of NRTI make the method promising for applications in the field of Cultural Heritage, especially when it is employed in a multi-technique approach to provide complementary information about the composition and the crystalline structure of archaeological artefacts. A study related to Heritage Science is presented to demonstrate the effectiveness of NRTI in non-destructive investigations of inhomogeneous artefacts, specifically focusing on the excavation finds related to the first evidence of ancient brass production in Milan, Italy, during Roman times.

Inline CT-Analysis of the Melting Area during Fused Filament Fabrication

In the 21st century, 3D printing has become a mainstream process for prototyping and low-volume production. Fused Filament Fabrication is the most commonly used process for 3D printing plastics. A plastic filament is melted in a nozzle and a component is built up layer by layer. As with all manufacturing processes, there is an interest in continuously optimizing and improving the FFF process. One approach is based on process simulation, which provides a better understanding of the process. Subsequently, it is always necessary to validate the simulation models with the real process. This validation has only been possible to a limited extent in the case of FFF. In this work, a method is presented that allows a non-destructive investigation of the melt behaviour during the printing process. For this purpose, a 3D printer nozzle with an extruder was integrated into an X-ray computed tomography system. Thus, a computed tomography scan can be performed during the extrusion process. By using highly absorbent tungsten filaments, sufficient contrast can be created between the metal nozzle and the plastic filament to allow analysis of the melt behaviour. This setup makes it possible to distinguish between the solid filament area and the melt area, as well as to determine the contact between the filament and the die wall. In doing so, simulations can be validated and nozzle geometries can be improved.

High-Frequency and High-Current Transmission Techniques for Multiple Earth Electrical Characteristic Measurement Systems Based on Adaptive Impedance Matching through Phase Comparison.

With the increase in groundwater exploration, underground mineral resource exploration, and non-destructive investigation of cultural relics, high-resolution earth electrical characteristic measurement has emerged as a mainstream technique owing to its advantageous non-destructive detection capability. To enhance the transmission power of the high-frequency transmitter in high-resolution multiple earth electrical characteristic measurement systems (MECS), this study proposes a high-frequency, high-current transmission technique based on adaptive impedance matching and implemented through the integration of resonant capacitors, a controllable reactor, high-frequency transformers, and corresponding control circuits. A high-current precisely controllable reactor with a 94% inductance variation range was designed and combined with resonant capacitors to reduce circuit impedance. Additionally, high-frequency transformers were employed to further increase the transmission voltage. A prototype was developed and tested, demonstrating an increase in transmission current at frequencies between 10 and 120 kHz with a peak active power of 200 W. Under the same transmission voltage, compared to the transmission circuit without impedance matching, the transmission current increased to a maximum of 16.7 times (average of 10.8 times), whereas compared to the transmission circuit using only traditional impedance matching, the transmission current increased by a maximum of 10.0 times (average of 4.2 times), effectively improving the exploration resolution.

A probabilistic interpretation of corrosion state through half-cell potential and electrical resistivity measures: The Flaminio Bridge in Rome

During the last decades, non-destructive investigation approaches have played an essential role in preserving structural integrity, capacity, and finding early defects in reinforced concrete (RC) heritage affected by time-dependent degradation. One of the most widespread structural RC damages belongs to corrosion phenomena. Electro-chemical approaches stand out among the non-destructive techniques presently available for identifying corrosive problems in-situ. The latter gives some knowledge in terms of physical quantities aiming to evaluate structural conditions by collecting indirect measures. Nevertheless, results are correlated to strong interpretative scale codes, which may not always provide appropriate interpretation of the defect's identity. In the paper a probabilistic degradation model, based on a statistical interpretation of the in situ electro-chemical measurements, has been proposed with the aim to give a contribution for structural diagnosis. Finally, results are validated through structural visual inspection.

Fiber optics passive monitoring of groundwater temperature reveals three-dimensional structures in heterogeneous aquifers

Alluvial aquifers often exhibit highly conductive embedded formations that can act as preferential pathways for the transport of solutes. In this context, a detailed subsurface characterization becomes crucial for an effective monitoring of groundwater quality and early detection of contaminants. However, small-scale heterogeneities are seldom detected by traditional nondestructive investigations. Heat propagation in porous media can be a relatively inexpensive tracer for groundwater flow, potentially offering valuable information in various applications. In this study, we applied passive Fiber Optics Distributed Temperature Sensing (FO-DTS) to a group of observation wells in a highly heterogeneous phreatic aquifer to uncover structures with different hydraulic conductivity, relying on their response to temperature fluctuations triggered by natural and anthropogenic forcings. A comprehensive data analysis approach, combining statistical methods and physics-based numerical modeling, allowed for a three-dimensional characterization of the subsurface at the experimental site with unprecedentedly high resolution.

In-situ detection on near-infrared spectra fingerprints of asphalt mixture after laboratory short- and long-term aging

Although Fourier transform infrared spectroscopy has been widely used in research on the aging of asphalt binders, it is a cumbersome, time-consuming, and environmentally polluting process using toxic solvents to extract and recover asphalt binders from asphalt mixtures for spectral measurement and analysis. However, little effort has been devoted towards its non-destructive spectral measurement, which is important for intelligent monitoring of pavement deterioration conditions. This paper focused on the non-destructive investigation of comparative near-infrared spectra of asphalt mixture specimens designed using the Marshall method after laboratory short- and long-term aging with a portable near-infrared spectrometer. The near-infrared spectra showed that asphalt mixtures from different aging states appeared significantly different fingerprints. The near-infrared fingerprints and aging states were also statistically significantly different according to the analysis of one-way analysis of variance. These distinctive near-infrared fingerprints could be attributed to the varied amounts of chemical functional groups, mainly hydrogen-containing groups during oxidative aging. This study provided a non-destructive and in-situ detection of the aging of asphalt mixtures.

Nondestructive Spectroscopic Investigation of N-Type 4H-SiC Defects Irradiated With Low Fluence 16.5 MeV/u Ta Ions

Nondestructive Spectroscopic Investigation of N-Type 4H-SiC Defects Irradiated With Low Fluence 16.5 MeV/u Ta Ions

Provenance of Neolithic Stone Artefacts through Minimally Invasive or Absolutely Non-Destructive Petroarchaeometric Investigations: Some Cases from Calabria (Southern Italy)

In the present work, more than one hundred and thirty lithic artefacts rediscovered in several archaeological sites dating from the Upper Palaeolithic to the Middle Ages from Calabria (Southern Italy) were petroarchaeometrically characterised through minimally invasive techniques. In more detail, 110 specimens were found in the Grotta della Monaca site (Sant’Agata di Esaro), and the other 23 belong to a collection kept in the Museo Nazionale Preistorico ed Etnografico “Luigi Pigorini” (Roma), coming from several localities (Longobucco, Spezzano della Sila, Cicala, Gimigliano, Roccaforte del Greco, and Bova). For preservation needs, 2 small axes in polished stone and 2 obsidians collected from Grotta della Monaca were analysed by absolutely non-destructive techniques. Optical and electron microscopic investigations, sometimes integrated with wavelength-dispersive X-ray fluorescence spectroscopy and X-ray diffraction spectrometry, allowed us to ascertain that the source area of all the lithic tools was in Calabria, except for obsidians, which come from the island of Lipari (Messina, Southern Italy). For a small number of particularly favourable cases, it was possible to define with great precision the outcrop area of the used rocks given their textural and mineralogical features. The specific source area contained a pickaxe originating from Cetraro–Fuscaldo metabasalt (lawsonite–albite facies) outcrops and two small axes in polished stone, one derived from migmatitic metapelites from Palmi and the other from meta-ultramafic rocks from Curinga. The choice of the used lithologies, harder or softer, had to be linked to the use that humans had to make of the lithic artefacts.

Non-destructive investigation of thermophysical properties on the China's space station: In-orbit experiment measurements and analysis

This paper discusses the current state of non-destructive research on the density, surface tension and viscosity of molten samples using the electrostatic levitation furnace (ELF) aboard the China Space Station (CSS). To address the challenges posed by the microgravity environment during the non-destructive testing process of containerless technology, we have developed several solutions. These include a temperature correction for infrared temperature measurement, a dual-camera position correction technique for density testing, a double electrode synchronous excitation, semi-frequency excitation and fine-sweeping approach for surface tension testing, and a signal demodulation method for viscosity testing. The uncertainties of the three thermophysical properties were 0.51 %, 3.10 %, and 9.78 %, respectively. This study highlights the feasibility and accuracy of measurements conducted in the ELF on the CSS, offering valuable insights into the behavior of molten materials under microgravity conditions. The findings from this study significantly contribute to our understanding of the thermophysical properties of molten materials.

Spectroscopic and imaging considerations of THz-TDS and ULF-Raman techniques towards practical security applications.

Nitrogen-containing high-energy organic compounds represent a class of materials with critical implications in various fields, including military, aerospace, and chemical industries. The precise characterization and analysis of these compounds are essential for both safety and performance considerations. Spectroscopic characterization in the far-infrared region has great potential for non-destructive investigation of high energetic and related compounds. This research article presents a comprehensive study of common organic energetic materials in the far-infrared region (5-200 cm-1), aiming to enhance security measures through the utilization of cutting-edge spectroscopic techniques. Broadband terahertz time-domain spectroscopy and ultra-low frequency Raman spectroscopy are employed as powerful tools to probe the vibrational and rotational modes of various explosive materials. One of the key objectives of this present work is unveiling the characteristic spectral features and optical parameters of five common nitrogen based high energy organic compounds towards rapid and accurate identification. Further, we have explored the potential of terahertz reflection imaging for non-contact through barrier sensing, a critical requirement in security applications. Based on the spectral features obtained from the spectroscopic studies and using advanced imaging algorithms we have been able to detect these compounds under various barriers including paper, cloth, backpack, etc. Subsequently, this study highlights the capabilities of the two techniques offering a pathway to enhance their utility over a wide range of practical security applications.