Surface Scanning Technique Research Articles

Efficient data acquisition and reconstruction for air-coupled ultrasonic robotic NDE

Non-destructive evaluation of complex parts using surface scanning techniques, such as ultrasonic testing and eddy current testing, requires complex manipulation of such sensors to ensure quantitative results. A robotic arm may function as a complex manipulator for surface scanning, controlling the position and tilt between the probe and specimen’s surface. To ensure accuracy in probe manipulation, accurate geometric information of the specimen is required. This article explores a methodology that uses structured light for physical-to-virtual reconstruction, providing submillimeter scale and accurate surface geometries. Reconstruction aids in path planning through a novel ray-triangle intersection array algorithm, establishing movements for the NDE probe to orient itself on the specimen at a constant probe to specimen surface distance, or lift-off. The proposed technique is demonstrated and validated through experimental air-coupled ultrasonic inspection of automotive CFRP composite samples with simulated flaws such as interlaminar delamination. The proposed method employs guided waves and a pitch-catch configuration of air-coupled ultrasonic probes, enabling single-side access scans. A Fanuc 100ib robot arm was used to manipulate the ultrasonic probes along a sample reconstructed with a CR-Scan 01 structured light sensor. The probes were excited at 200khz from a SonoAir system, while also recovering defect vs background information synchronized with the probe’s orientation. Additionally, a framework for potential automation is proposed, with further details to be explored in future works.

Long-term results of minimally invasive strip craniectomy without helmet therapy for scaphocephaly - a single-centre experience.

Scaphocephaly is the most common type of craniosynostosis and various surgical techniques are used for treatment. Due to late postoperative changes of the head shape, long-term outcome data is important for evaluating any new surgical technique. At our institution, minimally invasive strip craniectomy without regular helmet therapy is the standard treatment in scaphocephalic patients. Between October 2021 and February 2023, we retrospectively examined the skull shape of patients who underwent minimally invasive strip craniectomy for scaphocephaly using a 3D surface scan technique. The cephalic index (CI), the need for helmet therapy and additional cosmetic outcome parameters were investigated. We included 70 patients (72.5% male). The mean follow-up time was 46 (10-125) months and the mean CI was 75.7 (66.7-85.2). In 58 patients, the final cosmetic result was rated as "excellent/good" (mean CI: 76.3; 70.4-85.0), in 11 as "intermediate" (mean CI: 73.3; 66.7-77.6), and in one case as "unsatisfactory" (CI 69.3). The presence of a suboccipital protrusion was associated with a "less than good" outcome. The CI correlated significantly with the overall outcome, the presence of frontal bossing, and the interval between scan and surgery (age at scan). Minimally invasive strip craniectomy is an elegant and safe method to correct scaphocephaly. Our data show good cosmetic results in the long term even without regular postoperative helmet therapy.

Supercapacitance Performance of Mesoporous Mono- and Bi-Metallic Cobalt and Nickel Hydroxides Nanoflakes Chemically Deposited from Foam-Surfactant Liquid Crystal Dual Templates

Mesoporous 2D nanoflakes architectures of mono- and bi-metallic cobalt and nickel hydroxide (meso-Co-Ni(OH)2) hybrids were synthesized using novel chemical precipitation of foam-surfactant liquid crystal dual template (FSDT). The dissolved cobalt and nickel ions within the aqueous region of the Brij®78 surfactant template was reduced by the excess of sodium borohydride reducing agent that simultaneously generates excessive hydrogen foam as a double template. The physicochemical characterizations of the mono- and bi-metallic nanostructured Co-Ni(OH)2 hybrids performed using X-ray diffraction, surface area analyzer, scanning and transmission electrons microscopic techniques showed the formation of highly mesoporous hydroxides 2D nanoflakes architectures having an amorphous structure and surface area up to 253.50 m2/g. The electrochemical and supercapacitance evaluation of the mono-, and bi-metallic mesoporous hydroxides showed excellent Faradaic supercapacitance performance within a wider potential window and a higher charge and discharge rate. In particular the mesoporous monometallic of Co(OH)2, Ni(OH)2, bimetallic Co-Ni(OH)2 with Co/Ni ratios of (1:1), and (1:3), hydroxides showed total capacitances of 204, 869, 943, and 1384, F/g at charging current density of 5.0 A g−1 respectively and capacity retention rate of approximately 99.4% after 300 cycles. This suggests that these materials hold promise as electrode materials for energy storage applications.

Theoretical Investigations of the Crystal Structures and Molecular Energetics of High Quality Silicon Carbide (β-SiC) Precursor Compound 1,4-bis(trimethylsilyl)benzene

Over the last decades, the rapidly growing theoretical methods have revolutionized whole scientific paradigm, developed state-of-art analyses, and created substantial computational platforms through the huge support of outstanding mathematical algorithms. The self-consistent-charge density-functional based tight-binding (SCC-DFTB) scheme is one of them that offers versatile and efficient quantum mechanical calculations with some unique features compatible especially to the crystalline solid even at low computational resources. Its effective parametrizations and computational implementations under the Gaussian standardized interface as an "External program" via the users' script (Gaussian- External methodology; GEM) has added an additional value because of which various in-built high-level Gaussian computations are directly accessible. Herewith, the Gaussian offered geometry optimization algorithms and convergence criteria plus the ModRedundant type relaxed potential energy surface (PES) scanning techniques are assessed through the GEM, and characterized the crystal structures with concerned molecular energetics and PES of the experimentally synthesized 1,4-bis (trimethylsilyl) benzene (1,4-BTMSB) compound; a potential precursor for the high quality Silicon Carbide (β-SiC) coating particles, and an ideal "Internal Standard" for the quantitative spectroscopic analyses. The general results reveal that the 1,4- BTMSB molecules in its unit-cell and crystal lattice experience significant non-bonding interactions that induces them to attain the definite molecular geometry with recognizable ring, angle, torsional, and steric strains. The quantitative analyses of its PES depict that the phenylene ring has to overcome multiple yet unidentical energy barriers with the tallest Ea1= 5.3 kcal/mol in order to undergo internal 2π angular rotation around the 1,4-(C-Si) axes. And, exhibiting such type internal rotation of its phenylene ring is energetically highly probable as this compound is widely employed in coating high temperature reactors, and in quantizing analyte in high energy run spectroscopic facilities. The same quantification is referred here in order to underscore the significance of adopting perfectly closed topological molecular architectures while designing/synthesizing amphidynamic type crystalline free molecular gyrotops and their prototypes.

Comparative analysis of Road Scanning Techniques

A three-dimensional road point cloud is not only useful for civil engineers (road rehabilitation, road condition assessment) but can also be useful for vehicle engineers (autonomous vehicle driving scenario, vehicle dynamics simulation). Currently, there are several scanning techniques can be used to obtain these point clouds, such as terrestrial laser scanning (TLS), mobile laser scanning (MLS), airborne laser scanning (ALS), unmanned aerial vehicle (UAV) photogrammetry or UAV laser scanning. This paper discusses the investigation of four road surface scanning techniques by comparing their point clouds and the derived products. The comparison was performed for a section of a road with 1136 m length and 4 m width, the TLS survey provided the reference data. Aspects of point cloud evaluation included geometric accuracy, density, and the parameters of plane-fitting. CRG models were created from all studied point clouds to compare the difference between the final products to be used by the automotive industry. The results show that the MLS and the UAV photogrammetry generated the most accurate point cloud, while UAV laser scanning accuracy was the lowest. Similarly, the CRG models comparison showed that there was no significant difference between MLS and TLS models, and the UAV photogrammetry gave a smoother variation relative to the reference surface. Whereas the largest differences were noted for the CRG model derived from the UAV laser scanning models.
 

MANAGING INTERNATIONAL COLLABORATIVE RESEARCH BETWEEN ACADEMICS, INDUSTRIES, AND POLICY MAKERS IN UNDERSTANDING THE EFFECTS OF BIOFOULING IN SHIP HULL TURBULENT BOUNDARY LAYERS

This report documents a large scale joint research project with the aim of improving the efficiency of ship operations and management by providing a methodology and technology that can quantify the emission and fuel usage penalty due to bio-fouling on ship hull. This can be obtained through better understanding of turbulent boundary layer flows over rough surfaces that cause skin friction drag. Here six different institutions from four countries (Australia, Denmark, Indonesia, and UK) that consist of universities, a passenger ship company, a manufacturer of anti-fouling coatings, and the Indonesian Classification Society are formed. They represent three fields, namely: academic, industrial, and an independent party that supports policy makers. Each of them has different objectives and interests that are interconnected. The research collaboration uses an in-situ laser-based measurement technique of the water flow over the hull of an operating ship combined with under-water image-based surface scanning techniques. The shipboard experiments are accompanied by detailed laboratory experiments to provide further validation. This paper will discuss the importance and challenges of managing such collaboration and the significance of satisfying individual objectives from each three fields in order to achieve the overarching aim.

A potential method for sex estimation of human skeletons using deep learning and three-dimensional surface scanning.

Deep learning based on radiological methods has attracted considerable attention in forensic anthropology because of its superior classification capacities over human experts. However, radiological instruments are limited in their nature of high cost and immobility. Here, we integrated a deep learning algorithm and three-dimensional (3D) surface scanning technique into a portable system for pelvic sex estimation. Briefly, the images of the ventral pubis (VP), dorsal pubis (DP), and greater sciatic notch (GSN) were cropped from virtual pelvic samples reconstructed from CT scans of 1000 individuals; 80% of them were used to train and internally evaluate convolutional neural networks (CNNs) that were then evaluated externally with the remaining samples. An additional 105 real pelvises were documented virtually with a handheld 3D surface scanner, and the corresponding snapshots of the VP, DP, and GSN were predicted by the trained CNN models. The CNN models achieved excellent performance in the external testing using CT-based images, with accuracies of 98.0%, 98.5%, and 94.0% for VP, DP, and GSN, respectively. When the CT-based models were applied to 3D scanning images, they obtained satisfactory accuracies above 95% on the VP and DP images compared to the GSN with 73.3%. In a single-blind trial, a multiple design that combined the three CNN models yielded a superior accuracy of 97.1% with 3D surface scanning images over two anthropologists. Our study demonstrates the great potential of deep learning and 3D surface scanning for rapid and accurate sex estimation of skeletal remains.

3D Surface Digitization in Scientific Research and Product Development

This comprehensive review participates in the use of three different non-invasive surface scanning techniques directed in scientific research of medical, anthropology, archaeology forensic science, and product designing. 3D surface examining tools speak to a promising technique to provide reproducible data such as map the facial soft or hard tissues of a subject document skeletal remains, and trauma, generating 3D imitations of the components for documented and illustrative purposes while simultaneously holding exactness and unwavering quality. Three-dimensional imaging is rapidly turning into a vital tool for reconstruction and examination in scientific research. The final 3D mesh can be 3D printed or the digital version can be shared online with scientific researchers. This review manuscript highlights several studies utilizing non-invasive scanning techniques, depicts the pro and cons of the 3D scanning techniques, and different features of the scanners irrespective of the cost which would be helpful for future research work. A resourceful review was conducted using 7 databases; PubMed, CENTRAL, Science Direct, Scopus, Google Scholar, Research Gate, and IEEE Xplore from 2002 to 2020. Search terms were; “3D Laser scanning”, “Photogrammetry”, “Skeleton preservation”, “Documentation”, “Surface Scanning”, etc. Papers with quality work and related to the field of forensic science, anthropometry, 3D facial scanning, and product development were selected. From all the studies, 71 studies met the eligibility criteria, and other articles were excluded which were non-relevant, had duplicate records, and did not meet search criteria. This review provides in-depth understanding and discussions into methods, restrictions, and inferences from respective research publications.

An automated cluster surface scanning method for exploring reaction paths on metal-cluster surfaces

Metal-cluster surfaces present a wide variety of unique coordination environments. This complexity makes it difficult to manually probe the surface reactivity of such clusters. Here, we present a simple and automated method to systematically discover reaction pathways on cluster surfaces, based on the automated cluster surface scanning (ACSS) technique for mapping out potential energy surfaces. We showcase our method on 55-atom icosahedral Cu and Ag clusters, where we determine the activation energies of four elementary steps common in heterogeneous catalysis – hydrogen recombination (H* + H* → H2* + *), oxygen recombination (O* + O* → O2* + *), water formation (OH* + H* → H2O* + *), and CO oxidation (CO* + O* → CO2* + *) – with density functional theory calculations (DFT-PBE + D3). We show that the ACSS method requires significantly less human effort than the established manually performed climbing-image nudged elastic band (MP + CI-NEB) technique and locates transition states with comparable accuracy (root-mean-squared error of 0.10 eV) and similar computational cost. Rigorous sampling of the potential energy surface with the ACSS method allows one to locate all lowest-energy reaction pathways obtained via the MP+CI-NEB approach, as well as alternative pathways that one may have missed with the MP+CI-NEB approach due to the many possible pathways available on these clusters. The accuracy and efficiency afforded by the ACSS method could enable high-throughput exploration of the diverse reactivity of metal clusters.

Digital reconstruction of fragmented tooth remains in forensic context

Forensic odontology majorly focuses on the identification of victims through the analyses of oral and para–oral structures. Exposure to high temperatures and trauma can occur in mass disasters and may lead to the fracturing and fragmentation of teeth. These fragments may become very fragile and easily damaged while handling. Conventional methodologies such as the use of transparent nail polish, hair spray, cyanoacrylate or adhesives have been used to stabilize the fragmented pieces. This study introduces a new and innovative digital technique that utilizes three-dimensional surface scanning (3DSS) and rapid prototyping techniques to reconstruct fractured portions of the teeth. The results of qualitative congruency analysis suggest that over all variance of morphological error (0.0526 ± 0.05) mm. These results imply that the reconstructed 3D model can be used for various morphometric analyses.

Spatial energy transfer with observation of bimolecular singlet oxygen emission using quantum dots as donors and zinc-phthalocyanine as acceptors.

This study reports the influence of CdSe-ZnS core-shell quantum dots (QDs) for formation of singlet oxygen using zinc-phthalocyanine (ZnPc) dyes in colloidal solutions. Using a microluminescence surface scan technique it was possible to measure accurately the photon diffusion length, or photon mean free path, inside the medium. Analyses were performed for a range of QD concentrations. Photon diffusion length was assigned to the bimolecular singlet oxygen emission at 707 nm. Related singlet oxygen emission was predicted by observing quenching of the photon diffusion length measured at the specific oxygen emission as a function of QD concentration, being a nontrivial phenomenon related to the QD donors. Diffusion length measured at 707 nm increased with QD concentration; in the absence of QDs, as in pure ZnPc samples, the emission peak at 707 nm was not observed.

Application of three-dimensional confocal x-ray fluorescence equipment in surface topography and depth contour scanning.

Three-dimensional microfocus x-ray fluorescence technology has been used to determine surface topography. The surface scanning technique initially facilitated surface topography reconstruction of the sample. This paper demonstrates the improved performance of its infrastructure, including a higher-precision translation platform, an ultrabright microfocus x-ray source and a rewritten scanning algorithm, leading to a new scanning technology that can depict the surface topography of samples with complex internal structures. The improved scanning technology can analyze the metal element information of layers at different depths. This paper presents studies of the surface and depth of coins and porcelain bottles from ancient times using this technique.

A solid-state sensor based on poly(2,4,6-triaminopyrimidine) grafted with electrochemically reduced graphene oxide: Fabrication, characterization, kinetics and potential analysis on ephedrine

A catalytic surface was fabricated by incorporation of electrochemically reduced graphene oxide (rGO) on poly(2,4,6-triaminopyrimidine) (PTAP) film modified glassy carbon electrode. The surface materials of the constructed electrode (rGO.PTAP/GCE) were characterized by means of electrochemical and surface scanning techniques including Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and X-ray Photoelectrons Spectroscopy (XPS). Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were carried out to identify the preparation of the graphene oxide (GO). The heterogeneous rate constant (ks = 0.149 cm s−1) of the fabricated sensor was evaluated by Nicholson method. The synergistic effect of surface materials promotes the catalytic efficiency of the developed sensor for the detection of ephedrine (EPH) in pharmaceutical samples where the detection limit (DL3σ) of EPH was 1.8 μM (297 ppb). The diffusion coefficient of ephedrine (2.55 × 10−5 cm2·s−1) was also evaluated using theoretical electrochemical approach. The analytical performance of the sensor was successfully applied for real drug sample with acceptable analytical recovery percentage.

Imaging in forensic science: Five years on

Abstract The Journal of Forensic Radiology and Imaging was launched in 2013 with the aim to collate the literature and demonstrate high-quality case studies on image-based modalities across the forensic sciences. Largely, the focus of this journal has been on the transmissive aspect of forensic imaging, and therefore a significant number of high-quality case studies have been published focusing on computed tomography and magnetic resonance imaging. As a result, the ‘and imaging’ aspect is often neglected. Since 2013, technology has fundamentally evolved, and a number of new techniques have become accessible or have been demonstrated as particularly useful within many sub-disciplines of forensic science. These include active and passive surface scanning techniques, and the availability of three-dimensional printing. Therefore, this article discusses non-contact techniques, their applications, advantages, and considerations on the current state of play of imaging in forensic science.

The Affordances of 3D and 4D Digital Technologies for Computerized Facial Depiction.

3D digital technologies have advanced rapidly over recent decades and they can now afford new ways of interacting with anatomical and cultural artefacts. Such technologies allow for interactive investigation of visible or non-observable surfaces, haptic generation of content and tactile experiences with digital and physical representations. These interactions and technical advances often facilitate the generation of new knowledge through interdisciplinary and sympathetic approaches.Scientific and public understanding of anatomy are often enhanced by clinical imaging technologies, 3D surface scanning techniques, 3D haptic modelling methods and 3D fabrication systems. These digital and haptic technologies are seen as non-invasive and allow scientists, artists and the public to become active investigators in the visualisation of, and interaction with, human anatomy, remains and histories.Face Lab is a Liverpool John Moores University research group that focuses on creative digital face research; specifically the further development of a 3D computerized craniofacial depiction system, utilizing 3D digital technologies in facial analysis and identification of human remains for forensic investigation, or historical figures for archaeological interpretation.This chapter explores the affordances of such interactions for the non-destructive production of craniofacial depiction, through a case-study based exploration of Face Lab workflow.

Centrifuge testing to verify scaling of offshore pipeline ploughs

Offshore pipeline ploughs have previously been modelled at 1g with small 1:50 scale models designed to derive the parameters required for prediction of ploughing in terms of tow force requirements and potential advance rates. This was scaled up to prototype with the validity of the scaling verified through ‘modelling of models’ and with comparison to typical prototype tow forces but without direct validation. To allow further validation, a long centrifuge box and actuation system was developed for use on a medium-sized beam centrifuge. Previous approaches to 1g ploughing were also improved through the use of micro-electro-mechanical systems accelerometers and new low-cost surface scanning techniques. A wide range of ploughing velocities were explored through increasing actuation speeds and the use of pore fluids of different viscosities. The study has shown that although there may be initial concerns over low effective stress scaling issues at 1g, in shallow problems with small-scale models, the large deformation nature of the ploughing problem can be replicated with appropriate scaling. This allows the use of 1g modelling for more efficient parametric studies for this application and has given further confidence to performance parameters for prototype modelling derived from 1g and centrifuge studies.

A Novel Approach to Investigating Transport of Lost Circulation Materials in Rough Fracture

The drilling fluid loss or lost circulation via fractures is one of the critical engineering problems in the development of deep oil and gas resources. The conventional treatment is to introduce granular lost circulation material (LCM) into the drilling fluid system to plug fractures. In this work, a method incorporating the fracture surface scanning technique and coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) numerical simulation is proposed for the first time to investigate how the LCM particles plug rough fractures. The rough fracture model is built utilizing a high resolution and high precision measurement system. The LCM particle transport and plugging process in rough fractures are captured in the CFD-DEM numerical simulations. The results show that the local fracture aperture has a significant influence on LCM particle transport and the distribution of the plugging zone. The drilling fluid loss rate will decrease, and the drilling fluid pressure will redistribute during the accumulation of LCM particles in the fracture. The fracture plugging efficiency of nonspherical LCM is improved as a result of formation of multi-particle bridges. This study provides a novel approach and important theoretical guidance to the investigation of LCM particle transport in rough fractures.

Comparison of three-dimensional surface scanning techniques for capturing the external ear

ABSTRACTCongenital facial anomalies, such as microtia (malformation of the external ear), lead to significant psychosocial effects starting from early childhood. Three-dimensional (3D) scanning and advanced manufacturing are being investigated as a cheaper and more personalised method of fabricating reconstructive treatments for patients compared to traditional approaches. To date, most case studies have used expensive 3D scanners, yet, there is potential for low-cost devices to provide comparable results. This study aimed to investigate these different approaches. Both ears of 16 adult participants were scanned with three devices: Artec Spider (Artec Group), Intel® RealSense™ (Intel), and the Apple iPhone® 7 (Apple Inc.) combined with photogrammetry using 90, 60 and 30 photographs. The scanning time, processing time, accuracy, completeness, resolution and repeatability of each technique were assessed using the Artec Spider as a reference scanner. Our results show that the iPhone had the longest processing time however, this decreased nine-fold when reducing the number of photos from 90 to 30. There was no significant difference in the accuracy, completeness or repeatability of the iPhone scans with 90 photographs (1.4 ± 0.6 mm, 79.9%, 1.0 ± 0.1 mm), 60 photographs (1.2 ± 0.2, 79.3%, 0.9 ± 0.2 mm) or 30 photographs (1.2 ± 0.3 mm, 74.3%, 1.0 ± 0.2 mm). The Intel RealSesne performed significantly worse in each parameter (1.8 ± 03 mm; 46.6%, 1.4 ± 0.5). Additionally, the RealSense had significantly lower resolution with not enough detail captured for the application. These results demonstrate that the ear can be accurately 3D scanned using iPhone photographs. We would recommend capturing between 30 and 60 photographs of the ear to create a scan that is accurate but without the downfall of long processing time. Using these methods we aim to provide a more comfortable setting for the patient and a lower-cost and more personalised ear prosthesis.

Managing International Collaborative Research Between Academics, Industries, and Policy Makers in Understanding the Effects of Biofouling in Ship Hull Turbulent Boundary Layers

This report documents a large scale joint research project with the aim of improving the efficiency of ship operations and management by providing a methodology and technology that can quantify the emission and fuel usage penalty due to bio-fouling on ship hull. This can be obtained through better understanding of turbulent boundary layer flows over rough surfaces that cause skin friction drag. Here six different institutions from four countries (Australia, Denmark, Indonesia, and UK) that consist of universities, a passenger ship company, a manufacturer of anti-fouling coatings, and the Indonesian Classification Society are formed. They represent three fields, namely: academic, industrial, and an independent party that supports policy makers. Each of them has different objectives and interests that are interconnected. The research collaboration uses an in-situ laser-based measurement technique of the water flow over the hull of an operating ship combined with under-water image-based surface scanning techniques. The shipboard experiments are accompanied by detailed laboratory experiments to provide further validation. This paper will discuss the importance and challenges of managing such collaboration and the significance of satisfying individual objectives from each three fields in order to achieve the overarching aim.

The Effect of Carbonate Precursors on the Capacitance Properties of MnCO3

MnCO3 is gaining attention of the scientific community as a potential electrode material for supercapacitor applications. It can be easily synthesized by simple, cost effective method using manganese and carbonate precursors. In this article, we report the effect of carbonate precursors on the capacitive storage performance of MnCO3. Carbonate precursors used for the synthesis of MnCO3 were (NH4)HCO3, (NH4)2CO3, K2CO3, Li2CO3, NaHCO3 and Na2CO3. The effect of carbonate precursors on the physico-chemical properties of MnCO3 was studied using powder X-ray diffraction (PXRD), infra-red spectroscopy (IR), surface area analysis, scanning and transmission electron microscopic techniques. PXRD and IR spectral studies revealed that carbonate precursors do not affect the crystal structure. However, they influence significantly the morphology, surface area and porosity of MnCO3 as revealed by morphological and sorption studies. The capacitance properties of MnCO3 were evaluated in an aqueous 0.1 M Mg(ClO4)2 electrolyte. Specific capacitance value of 103, 116, 120, 121, 123 and 141 F g-1 was obtained for MnCO3 synthesized using (NH4)HCO3, (NH4)2CO3, K2CO3, Li2CO3, NaHCO3 and Na2CO3 as carbonate precursor, respectively. Difference in the specific capacitance is attributed to difference in the morphology and other surface properties.