3D Digital Microscope Research Articles

Thermal shock behavior of andalusite‐based refractories: Microstructural investigation of crack bridging and grain‐matrix interactions

AbstractAndalusite‐based refractories are characterized by superior thermal shock resistance. Although the demand for alternative raw materials is increasing, it is proving difficult to replicate the thermal shock behavior of andalusite with alternative materials. The physico‐mechanical properties of andalusite refractories are well‐studied. However, comprehensive chemical and microstructural analysis is still needed to fully understand factors influencing the thermal shock resistance. This investigation highlights the use of complementary microstructural techniques (3D digital microscopy, scanning electron microscopy–energy‐dispersive X‐ray spectroscopy, and micro‐X‐ray fluorescence) to analyze crack propagation as well as glass bridge formation and composition in aluminosilicate‐based refractory castables. Andalusite‐based refractories are compared with chamotte 45 and chamotte 60, before and after a thermal shock, as well as after an additional firing. Factors influencing the thermal shock resistance of aluminosilicate refractory castables include (1) crack shape, size, occurrence, and propagation (2) glass bridge formation, size, occurrence, and composition, and (3) aggregate‐matrix interactions.

Measurement of Pen Pressure of Offline Signatures Using 3D Digital Microscopy and Its Utility in Determining Authorship

Measurement of Pen Pressure of Offline Signatures Using 3D Digital Microscopy and Its Utility in Determining Authorship

3D Holo-tomographic Mapping of COVID-19 Microclots in Blood to Assess Disease Severity.

The coronavirus disease 2019 (COVID-19) has impacted health globally. Cumulative evidence points to long-term effects of COVID-19 such as cardiovascular and cognitive disorders, diagnosed in patients even after the recovery period. In particular, micrometer-sized blood clots and hyperactivated platelets have been identified as potential indicators of long COVID. Here, we resolve microclot structures in the plasma of patients with different subphenotypes of COVID-19 in a label-free manner, using 3D digital holo-tomographic microscopy (DHTM). Based on 3D refractive index (RI) tomograms, the size, dry mass, and prevalence of microclot composites were quantified and then parametrically differentiated from fibrin-rich microclots and platelet aggregates in the plasma of COVID-19 patients. Importantly, fewer microclots and platelet aggregates were detected in the plasma of healthy controls compared to COVID-19 patients. Our imaging and analysis workflow is built around a commercially available DHT microscope capable of operation in clinical settings with a 2 h time period from sample preparation and data acquisition to results.

Determination of mosquito diversity using 3D digital microscope in Cibinong district, Bogor Regency

Bogor Regency is a suburban area with hilly topography and very wet tropical climate. In addition, there are still lot of bushes and the location is crossed by river basin. These conditions create an ideal habitat for mosquitoes, which are the deadliest animal in the world. Despite the high incidence of vector-borne diseases caused by mosquitoes in this area, the information regarding mosquito diversity in Cibinong District, Bogor Regency remains limited. The aim of this study is to determine mosquito diversity in Cibinong District, Bogor Regency. In this study, mosquitoes were collected using human landing catch and sweep nets. Then identification was performed using 3D digital microscope. The study’s findings revealed the presence of eight mosquito species from two genera: Aedes and Culex. In conclusion, this study provides valuable insights into the ecology and diversity of each collected mosquitoes.

Second-Generation Wide-Field Visualization Devices for 5-ALA–Induced Fluorescence and Concepts for Validation in Neurosurgery—A Systematic Review

BACKGROUND AND OBJECTIVES: Fluorescence-guided resection (FGR) of malignant gliomas with five-aminolevulinic acid (5-ALA) is an established method using surgical microscopes equipped with filter systems for observing fluorescence. Over the past decade, new technologies have been introduced for the same purpose, with available publications evaluating their clinical efficacy based on varying criteria. This study aims to review technologies and concepts of validation in the context of 5-ALA–mediated FGR. METHODS: A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was performed to identify devices capable of detecting 5-ALA–induced fluorescence. Articles found eligible for this review were analyzed, focusing on the methods of validation used for novel devices. A qualitative analysis is presented. RESULTS: Using predefined eligibility criteria, 22 studies were analyzed. Publications on the following visualization devices were reviewed: FL400 (Leica Microsystems), Aeos (Aesculap), BLUE400 and BLUE400 AR Filter System (Carl Zeiss Meditec AG), Endoscope with D-Light C (Karl Storz), Fiberscope N-4L (Machida), ORBEYE 4K 3D Digital Video Microscope (Olympus), and several customized surgical loupe systems. In many cases, validation seemed unstandardized, with inherent biases and limited reproducibility. CONCLUSION: This review illustrates the significance of device validation within the framework of FGR. It emphasizes the criticality of validating devices in accordance with established standard, i.e. the BLUE400 filter system, which was employed in the approval studies of 5-ALA. Furthermore, standardized concepts of validation are required to assess whether new devices are, in fact, a reliable or superior alternative in the field of FGR. Published guidelines should be considered when performing future studies.

Analysis of the ivory remains from the Etruscan tumulus of Carmignano (Central Italy) using 3D digital microscopy

The Tumulus of Montefortini is an Etruscan tomb located in Carmignano (Central Italy), which is believed to date from the 7th century BC. The tumulus is an oval burial mound 80 metres long and 11 metres high, which houses two tombs. More than 10,000 ivory fragments, that were likely part of a rich grave good, were recovered from this site. The main raw material exploited was probably the proboscidean dentine given the presence of the "Schreger lines" on the surfaces of many specimens. In this work we analyzed a sample of this archaeological assemblage using a 3D digital microscope. This noninvasive procedure allowed to investigate the main micromorphological and micromorphometrical features of the proboscidean dentine in a relatively brief time, preserving the integrity of the archaeological finds. Unexpected results regarding to the Schreger structure were obtained from this analysis. Data collected in the present work will be useful to evaluate, through further analysis of the examined sample, the accuracy and reliability of the 3D digital microscopy in the characterization of the proboscidean taxa exploited in the past.

A preliminary study evaluating the relationship between force and incised trauma on pig rib bones

In forensic contexts, understanding of the complicated relationships between level of force, type of knife blade, and dimensions of incisions remains limited. The purpose of this research was to explore how incisions on pig rib bones vary depending on the type of knife blade and quantity of perpendicular force inflicted. A cutting rig (designed to position a bone, knife, and weights) facilitated the creation of incisions on fleshed rib bones (n = 59), defleshed rib bones (n = 77), and synthetic materials (n = 36). Five different masses of weights (measuring 4381, 8861, 13515, 18267, and 23343 g) were applied to four knife blades (two serrated and two non-serrated blades), with each combination of variables repeated thrice. 3D digital microscopy was utilized to model and measure each incision. The two-way ANOVA found significant differences in depth and length between knife types and levels of force across all sample sets (p < 0.05), with greater perpendicular forces and serrated blades creating longer and deeper cuts. These findings demonstrate that there is a complex relationship between force, type of knife blade, and the related dimensions of incisions.

Close-range photogrammetry reveals morphometric changes on replicative ground stones.

The pursuit of a quantitative approach to functional analysis of stone tools is an ongoing endeavour for traceologists. Technological advancements in 3D imaging techniques, such as photogrammetry/3D scanners, CT scanning, 3D digital microscopy, confocal microscopy, AFM and FEG-SEM and micro-topographical scanning, have greatly facilitated the detailed capturing of the geometry and surface texture at multiple levels of observation, from the object-scale to the nano-scale. However, while such technological innovations have predominantly focused on flaked assemblages, ground stone tools have only recently begun to receive due attention, and a standardised protocol for their study is yet to be established. In order to comprehend the function(s) of these tools, analytical techniques that enable a 3D visualisation of the entire item and the wear affecting the used surfaces have proven to be of great support. To this end, an analytical procedure was developed and tested on slabs and pebbles in order to replicate the use-wear traces observed on Upper Palaeolithic tools. The purpose was to assemble a site-specific reference collection tailored on the artefacts from the cultural level III of the Brînzeni I cave in north-west Moldova. Experimental replicas were used to treat different plant organs during controlled sequential experiments. The present article reports on the analysis based on photogrammetric data acquired during two stages of replicative usage. We tested multiple acquisition setups and elaborations to assess the geometry modification and the surface depletion. By exploring various acquisition strategies, a critical evaluation of potential sources of bias in data collection and subsequent elaboration were performed, and the methodology was accordingly adjusted thereby enhancing the reliability and reproducibility of the results. This study highlights the importance of carefully considering the acquisition strategy in archaeological related research to ensure accurate analyses and to validate robust interpretation.

Could facing techniques be compatible with optimal bone preservation surface?

Bone usually requires conservation treatment during excavation. Some of the most common interventions are facing techniques to reinforce the specimens during their extraction in the field. This consists of the attachment of a fine tissue with a reversible adhesive, usually an acrylic resin, directly over the surface of the specimen. This interacts directly with the surface, which might link to the loss of bone surface information. This experiment focuses on the possible modifications that facing techniques could cause on bone surfaces with cut marks. Experimental bones with cut marks were artificially aged to reproduce the decayed process of archaeological bones. Different groups of bone samples were faced and exposed in two contexts for one year: indoors and outdoors. Bone surface and cut marks were documented before and after the facing and storing phases with 3D Digital Microscopy. In the indoor bones, cut marks show abundant traces of resin. Conversely, bones preserved in an outdoor environment displayed a high modification of their colour and an extremely poor state of preservation. Some cut marks disappeared completely or partially. Visual comparison allowed us to evaluate possible loss of archaeological information produced by the treatments. Facing techniques should be carefully monitored to guarantee its short-term contact with the bone surface and avoid these modifications.

A Comparison of Materials for Dry Surface Cleaning Soot-Coated Papers of Varying Roughness: Assessing Efficacy, Physical Surface Changes, and Residue

ABSTRACT To provide detailed information to aid conservators faced with soot removal, a survey comparing the removal of lamp black pigment, serving as a model soot, from three sample papers of differing roughness is presented. The efficacy of ten different dry surface cleaning materials—including sponges, firm and kneaded erasers, eraser crumbs, a cleaning putty, a solvent-free polydimethylsiloxane elastomer, and a dry swab—have been assessed using a handheld color spectrophotometer and image analysis of photomicrographs. Inspection of the cleaned substrates with a portable optical microscope revealed detailed information into how physical properties of cleaning materials influence the location of residual soot on the surface. 3D digital light microscopy and Fourier-transform infrared spectroscopy were used to assess physical changes to the paper surface and to identify potential residues from the materials after cleaning, respectively. The results of this model study were compared with spot cleaning tests performed on a fire-damaged paper book cover. Limited access to laboratory spaces during Covid-19 lockdown motivated this research to focus on affordable ways to perform hands-on technical research outside of the laboratory, details of which are noted throughout this paper.

Wear Mechanism of Fe/Cu Self-Lubricating Composite Coatings Fabricated by Electro-Explosive Spraying under Dry Friction

In the present work, Fe/Cu composite coatings were fabricated by electro-explosive spraying technology (EEST), with good lubrication performance and high wear resistance. The microstructure and morphology were characterized by an energy-dispersive spectrometer (EDS), 3D digital microscope, and scanning electron microscope (SEM) coupled with electron backscattered diffraction (EBSD). Mechanical properties and tribological performance were measured using a micro Vickers hardness tester, universal testing machine, and universal friction and wear testing machine. The composite coating had low porosity with a minimum value of 0.7%, high microhardness with a maximum value of 729.9 HV0.2, high bonding strength with a maximum average value of 55.25 MPa, and good wear resistance and self-lubrication, and the ratio of soft metal and hard metal in the coatings was controllable. Under dry friction conditions, the friction reduction mechanism was that there were both metallic oxide particles and soft metal attached in the friction pairs. When the ratio of soft metal in the composite coating was higher, the self-lubricating performance of the coating was better, with adhesive wear as the main wear mechanism; when the ratio of hard metal was higher, the wear resistance was better and the wear mechanism was mainly abrasive wear.

An experimental approach to the analysis of altered cut marks in archaeological contexts from Geometrics Morphometrics

Geometric Morphometrics (GMMs) is a useful tool for the experimental characterization of different taphonomic modifications on bone surfaces, including anthropogenic cut marks. Until now, most research has been conducted evaluating experimental and non-altered cut marks, in order to obtain a better control of the studied variables. However, in archaeological contexts, bones are frequently subject to different taphonomic alterations and, in most cases, bone surfaces and the associated taphonomic signals show different grades of alteration. In this study, we present an experimental approach in which experimental cut marks were produced, mechanically altered, digitized, and analyzed using GMMs, in order to provide an in-depth characterization of how overlying taphonomic traces can alter cut marks. In the experiment, 40 cut marks were subjected to abrasion by a mixture of distilled water, sands, and gravels, using a tumbling machine in a series of cumulative cycles for a total of 4 h: cycle 1 (0.5′), cycle 2 (0.5′), cycle 3 (1 h) and cycle 4 (2 h). Cut mark cross-section profiles were then obtained using 3D digital microscopy, and a 2D 7-landmark designed for cut mark analyses were employed. Our results show a clear statistical differentiation among non-altered cut marks belonging to Cycle 0, and altered cut marks. The depth and opening angle of cut marks appear to be the features with a higher weight in the differentiation between altered and non-altered cut marks. On the other hand, there are no distinctions when differentiating between the diverse altered cycles. These results, like those previously obtained in an experimental approach using a binocular microscope, point to the limitation of the identification of cut marks and other taphonomic signals in archaeological contexts with altered bone surfaces, caused by the fast alteration and the loss of diagnostic criteria of the bone surface modifications.

Foliar Roughness and Water Content Impact on Escherichia coli Attachment in Baby Leafy Greens.

Understanding the relation between the susceptibility of different leafy greens to human pathogen contamination and leaf traits can contribute to increase the food safety of the fresh vegetable industry. The aim of this research was to evaluate the susceptibility to E. coli ATCC 35218 attachment in 30 accessions of baby leaves, and to identify leaf traits potentially involved in the contamination. The accessions were surface inoculated with a bacterial suspension containing 1 × 107 cells/mL and the attachment was measured 1.5 h after inoculation. Significant differences in attachment were detected between the accessions for p ≤ 0.05. The three most and the three least susceptible accessions were selected and characterized for leaf micro-morphological traits (stomata density and size, surface roughness) and water content. Scanning electron microscopy was used to analyse the stomatal parameters. Roughness was measured by an innovative portable 3D digital microscope. No significant correlation between the attachment of E. coli ATCC 35218 and stomatal parameters was detected, while the attachment was positively correlated with roughness and water content. The E. coli ATCC 35218 population in surface-inoculated leaves was also measured after a UV treatment, which was found to be less effective in reducing bacterial contamination in the rougher leaves. This result suggested that roughness offers UV protection, further highlighting its impact on the microbiological safety of baby leafy greens.

EFFECTS OF MACHINING PARAMETERS ON TOOL LIFE

Cutting tools, which are used extensively in machining, are expected to have high performance and longer service life. Tool life term defines the time period between the starting of the cutting tool and the sharpening of the tool so that the tool is actively used. According to international standards, tool deterioration by wear is a specific criterion used to determine tool life. In this study, the effects of cutting parameters on the cutting performance and tool life of standard end mills with diameters Ø6, Ø8, Ø10, Ø12 which are used extensively in the die-making industry, were investigated. Detection of cutting-edge wear conditions was achieved by conducting detailed surface observations with a high-resolution camera of a three-dimensional (3D) digital microscope

BaTiO3 modified 3Y-TZP with self-lubricating property for dental application

The present study aimed to evaluate the wear behavior of BaTiO3 (BT) modified 3Y-TZP ceramic composites compared to commercially available 3Y-TZP products and provided evidence relevant to its clinical use. A set of BT-modified 3Y-TZP (BT/3Y-TZP) ceramic composites was prepared. The mechanical properties and wear behavior of BT/3Y-TZP ceramic composites were investigated. The 3D digital microscopy, scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM) analyses of the worn surface helped to reveal the underlining mechanisms. In comparison with commercially available 3Y-TZP ceramics, the mechanical properties of the BT/3Y-TZP composite ceramics could meet the clinical requirements. More importantly, the 5 mol% BT/3Y-TZP showed the best wear properties against natural tooth enamel for the dry and saliva lubrication tests. The SEM and STEM analyses confirmed a stable transfer enamel layer formed on the surface of 5 mol% BT/3Y-TZP ceramic composite under dry as well as saliva environments. The in site formed tribofilm with self-lubricating function contributed to the reduced wear of the antagonist teeth. Therefore, the enamel-friendly 5 mol% BT/3Y-TZP may be a new material option for restorative dentistry. Moreover, the interface transfer theory could provide a new way of thinking to find more enamel-friendly dental restorative materials in the future.

Using 3D Microscope for Hepatic Artery Reconstruction in Living Donor Liver Transplant.

Introduction: This study compares the intraoperative process of hepatic artery anastomosis using conventional microscope and novel 3D digital microscope and discusses our technique and operative set-up. Method: A retrospective comparative cohort study with 46 hepatic artery reconstructions in living donor liver transplant patients. Either an operational microscope (control group) or a 3D digital microscope Mitaka Kestrel View II (study group) was used for hepatic artery anastomosis. We then discuss and share our institution’s experience of improving surgical training. Results: Both operation instruments provide effective and comparable results. There was no statistical difference regarding operational objective results between conventional microscope and exoscope. Both instruments have no hepatic artery size limit, and both resulted in complete vessel patency rate. Conclusions: There was no statistical differences regarding hepatic artery anastomosis between microscope and exoscope cohorts. Microsurgeons should perform hepatic artery anastomosis efficiently with the instruments they are most proficient with. Yet, exoscope provided better ergonomics in the operation room and lessened musculoskeletal strain, allowing surgeons to work in a more neutral and comfortable posture while allowing the first assistant to learn and assist more effectively. Using exoscope with micro-forceps and modified tie technique make artery reconstruction easier.

Wounded to death. Holistic, multimodal reconstruction of the dynamics in a case of multiple perimortem cranial injuries from a medieval site in northern Italy

The current study focuses on the remains of an adult male individual unearthed during archaeological excavations inside the church of San Biagio in Cittiglio (Northern Italy). The skull displayed four lesions in the form of defects in the cranium that involved the occipital squama, the right nuchal portion, the right parietal, and the right occipito-mastoid area. At macroscopic observation, the lesions showed polished surfaces, sharp margins, V-shaped cross-sections, and evidence of parallel microstriations.The investigation required a multi-analytical approach, which combined macroscopic assessment, computed tomography, photogrammetric three-dimensional reconstruction, and 3D digital microscopy that allowed us to obtain a morphometric characterization of the evidence. Our objective was to reconstruct the dynamics of an ancient violent event by applying a modern scientific approach to the analysis of the injuries observed in the skull of an osteoarchaeological individual.Digital microscopy allowed us to evaluate the micromorphometric aspect of the lesions, and to obtain microscopic quantitative data such as linear and angular measurements in the three dimensions. The complete absence of bone reaction at the site of the lesions revealed the perimortem nature of the injuries. Through the holistic, combined approach employed in the current study it was concluded that this individual was most likely struck four times in rapid succession from behind with a straight bladed implement, consistent in form with a long sword of the time. At the end of our study, it was possible to reconstruct the dynamics for each lesion and to hypothesize the reconstructive sequence of the violent event.

Optimization of milling parameters based on five-axis machining for centrifugal impeller with titanium alloy

The centrifugal impeller is the core component of a turbojet engine. Due to its complex geometry, it is difficult to generate machining paths. Moreover, a lot of material is removed between the blades during the manufacturing process. This study investigates the optimization parameters of a titanium alloy centrifugal impeller for five-axis milling. Rough grooving toolpaths are obtained using Siemens NX software, and the NC program is obtained after post-processing conversion. VERICUT can perform cutting simulations to determine whether there is an interference or collision. During the initial cutting parameter experiment, a sensory tool holder is used to measure the tool bending moment during milling. After milling, a 3D digital microscope is used to observe the flank and face of the cutter to analyze the cutting bending moment and tool wear. Finally, the optimal cutting parameters are determined through a full-factor experiment, and the tool life parameters are verified. According to the cutting parameter experiment, the cutting depth is 1 mm, the cutting speed and feed rate is the same, and the maximum bending moment increases proportionally with depth. In addition, a tool life experiment is performed using the optimal cutting parameters: cutting speed of 50 m/min, feed rate of 250 mm/min, and cutting depth of 2 mm. The maximum cutting moment is below the wear limit of 27 Nm. The tool could cut seven grooves, and the machining time is 41 min 46 s.

Analysis of surface quality and optimization of process parameters in laser-assisted cutting of SiC ceramics

In order to improve the surface quality of laser-assisted turning silicon carbide (SiC) ceramics, the effects of laser power, rotational speed, cutting depth and feed speed on surface quality are investigated. Taking the surface roughness as the characterization value, the reasonable selection range of each factor is determined by the numerical simulation results of temperature field and the single factor experiment results; orthogonal experiments and range analysis are performed on laser power, rotational speed, cutting depth and feed speed, the primary and secondary order of influence on surface roughness and the optimal combination of process parameters are obtained. The surface topography of the cutting area was observed by 3D digital microscope and the surface roughness is calculated. Taking surface roughness as the evaluation index, the reasonable selection range of each factor is obtained through temperature field simulation and single factor experiment results analysis as follows: laser power 230 ∼ 245 W, rotational speed 1500 ∼ 1650 r min−1, cutting depth 0.1 ∼ 0.2 mm, and feed speed 2 ∼ 4 mm min−1. Through orthogonal experiment and range analysis, the order of the significant degree of the influence of various process parameters on surface roughness and the optimal combination of process parameters are obtained. The order of the significant degree of the influence of various process parameters on surface roughness Ra is as follows: laser power (P) > cutting depth (ap) > feed speed (f) > rotational speed (n); the optimal combination of process parameters is as follows: laser power 235 W, rotational speed 1620 r min−1, cutting depth 0.1 mm and feed speed 2 mm min−1. Compared with the surface quality of original workpiece, the surface of the SiC workpiece processed under the optimal combination of process parameters has no cracks and damage marks, and the surface roughness is reduced to 0.293 μm, which significantly improves the surface quality of the SiC workpiece.

Study on surface wettability of nickel coating prepared by electrodeposition combined with chemical etching

Nickel coatings with different surface characteristics were prepared on copper substrate by electrodeposition. Subsequently, the as-coating surface was etched with a mixed solution of FeCl3, HCl and H2O2 at different times, to obtain different surface morphologies and special microstructures. The surface morphologies, element composition, roughness and liquid contact angle were characterized by scanning electron microscope, energy dispersive X-Ray spectroscopy, 3D digital microscope and contact angle measurement. The van Oss-Chaudhury-Good method was used to calculate the solid surface free energy and discuss the variation of surface wettability. The results show that etching time has a significant effect on surface morphology, roughness and wettability. After long-time physical aging, the multiple polygonal-layered architectures and larger-sized layered microstructure can maintain high surface free energy and keep the liquid metal in a good hydrophilic state, which provides a reference for optimizing the surface morphologies of the casting roll. This will improve the heat transfer efficiency and promote heterogeneous nucleation during twin-roll continuous casting.