3D Analysis Research Articles

3D analysis of soft tissue dimensional changes after dental implant placement with butt-joint vs. conical connection: a 12-month randomized control trial.

to quantify the soft tissue dimensional changes after single-gap implant placement, during healing abutment and crown delivery phase for butt-joint and conical implant-abutment connection type. forty patients were enrolled in the study and received randomly allocated implants with butt-joint and conical implant-abutment connection type. A standard healing abutment was placed after 6 months for two weeks. The definitive screw retained full-ceramic crowns were manufactured in a digital workflow. The soft tissue profile was digitized using IOS on following stages: pre-op, immediately, two, 7 and 14 days post-op, pre-exposure, immediately after exposure, two weeks after exposure (pre-delivery), immediately after crown delivery, 6 and 12 months after delivery. The intraoral scans were matched in the metrology software (Geomagic Control X). The mean maximum and mean average differences in mm were gathered to assess the soft tissues change. Various anamnesis parameters have been taken into account. the conical connection implant system exhibited more soft tissue gain and less recession, compared to the butt-joint connection type within the 12 months follow-up period. A higher loss of soft tissue was observed in the distal papilla than in the mesial one. the implant-abutment connection type may influence the reaction of peri-implant soft tissue within the 12 months follow-up period.

Spectra of standing kink waves in loops and the effects of the lower solar atmosphere

Understanding the effects of the lower solar atmosphere on the spectrum of standing kink oscillations of coronal loops, in both the decaying and decayless regime, is essential for developing more advanced tools for coronal seismology. We aim to reveal the effects of the chromosphere on the spatial profiles and frequencies of the standing kink modes, create synthetic emission maps to compare with observations, and study the results using spatial and temporal coronal seismology techniques. We excited transverse oscillations in a 3D straight flux tube using (a) a broadband footpoint driver, (b) a sinusoidal velocity pulse, and (c) an off-centre Gaussian velocity pulse, using the PLUTO code. The flux tube is gravitationally stratified, with footpoints embedded in chromospheric plasma. Using the FoMo code, we created synthetic observations of our data in the Fe IX 17.1 nm line and calculated the spectra with the Automatic Northumbria University Wave Tracking code. We also numerically solved the generalised eigenvalue system for the 1D wave equation to determine the effects of the stratification on the kink modes of our system. The synthetic observations of the loops perturbed by the velocity pulses show a single dominant mode that our 1D analysis reveals to be the third harmonic of the system. For the broadband driver, the synthetic emission shows multiple frequency bands, associated with both the loop and the driver. Finally, using seismological techniques, we highlight the possibility of misidentifying the observed third, sixth, and ninth harmonics with the first, second, and third harmonics of the coronal part of the loop. Unless more advanced techniques of spatial seismology are used with many data points from observations along the entire loop length, this misidentification can result in overestimating the mean magnetic field by a factor equal to the period ratio of the fundamental over the third harmonic. For longer coronal loops it is easy to misidentify the detected standing kink modes for lower-order modes of the system, which can have important seismological implications. To prevent these errors and properly constrain the value of the estimated mean magnetic field, additional observations of the loops footpoints using transition region and chromospheric lines are necessary.

Analysis of differential weathering patterns and causes on the top of hollow enemy towers’ facades of the Great Wall – a case study of section in Haigang District, Qinhuangdao City

ABSTRACT The hollow enemy towers are iconic structures of the Great Wall. During a survey of the Ming Great Wall in Haigang District of Qinhuangdao, researchers observed differential weathering phenomena in the facade tops of 21 out of 51 well-preserved hollow enemy towers. Initially, high-precision 3D data of enemy towers was acquired using close-range photogrammetry from drones. The 3D surface metrology analysis software Mountains was introduced, in which the particle analysis module can use false-color images to calibrate and measure depressions on the 3D model surface, thereby enabling the identification and quantitative analysis of weathering and erosion areas on the top of the enemy towers’ facades. The study revealed that the upper regions of facades with the drainage troughs exhibited more pronounced weathering erosion compared to the areas without drainage troughs. Upon conducting an analysis of the structural integrity of the top drainage components and evaluating the slope and surface of the drainage system, it was determined that the primary water collection zones were located near the drainage troughs at both ends of enemy tower tops. Differential weathering at the top of enemy towers’ facades is primarily influenced by the varying amount of water accumulation, which serves as the decisive factor.

Preliminary study: Evaluating the reliability of cone-beam computed tomography images for upper airway volume in orthodontics

Objectives: The primary aim of this study was to evaluate the reliability of cone-beam computed tomography (CBCT) in measuring upper airway volume in orthodontics. The secondary aim was to compare the upper airway volumes between laypeople and military personnel (physically fit individuals). Material and Methods: This study included 36 male participants aged 21–29 years who had no upper airway pathology or history of upper airway surgery. CBCT scans had been previously obtained as part of routine dental checkups using a standardized protocol by the same operator. The digital imaging and communications in the medicine files of the subjects were imported into the 3D analysis software SimPlant® 17 Pro (Materialize Dental, Leuven, Belgium) to facilitate the measurement of upper airway volume. The upper airway volume was divided into three sections and measured on days 0 and 14 by the same operator. The intrarater intra-class correlation coefficient (ICC) and Bland-Altman plot were used to assess reliability. The upper airway volumes of the laypeople and military personnel were compared using Tukey’s pairwise test. Results: The variables demonstrated excellent reliability across all sections of the upper airway; the Superior part of the upper airway has an ICC of 0.993, the middle part of the upper airway has an ICC of 0.995, and the inferior part of the upper airway has an ICC of 0.989. The ICC for the entire upper airway was 0.987. The intrarater plot for superior airway measurement showed that 8 out of 8 measurements (100%) fell within the limits of agreement. Similarly, the intrarater plot for the middle airway measurements indicated that 8 out of 8 measurements (100%) fell within the limits of agreement. For inferior airway measurement, the intrarater plot revealed that 7 out of 8 measurements (87.5%) fell within the limits of agreement. No significant differences were found between the upper airway volumes of the laypeople and military personnel. Conclusion: Preliminary evidence suggests that CBCT using a standardized protocol is reliable for measuring upper airway volume. Separating the upper airway into three different parts also demonstrated high reliability and reproducibility among the raters. The ability to accurately measure the upper airway enhances the evaluation of the effects of orthodontic treatment by comparing the pre-and post-upper airway volume.

Association study of the JAK/STAT signaling pathway with susceptibility to COVID-19 in moroccan patient and in-silico analysis of rare variants.

The goal of our study was to explore the association of the polymorphisms in the JAK/STAT pathway among Moroccan COVID-19 patients, using a case-control approach. Next-generation sequencing was employed to investigate the IFNAR1, IFNAR2, JAK1, TYK2, STAT2, and IRF9 genes within the JAK/STAT pathway. We also performed an in silico study to examine the rare variants in this pathway. Statistical analyses were conducted using MedCalc software. Protein 3D structures were determined via the I-TASSER server, with variant structures generated using PyMOL. YASARA View allowed local 3D analysis comparing native and variant structures for pathogenic rare variants. The study encompassed 206 COVID-19 patients, averaging 45.70 ± 12.73 years and a control group (N=118). Among the examined genes, 15 common polymorphisms and 7 rare variants were identified. Adjustment for age and gender revealed a significant association between TYK2 p.Gly363Ser (p=0.036) and COVID-19 infection, where the GA variant exhibited protective effects (0.6361 [0.3405-1.1884], p=0.035). Additionally, STAT2 p.Met594Ile showed an association to COVID-19 risk (p=0.042), with heterozygous GC being linked to infection (p=0.037, OR=2.7135 [0.5684 -12.9532]). Notably, IFNAR1 p.Val168Leu mutated C allele was significantly associated with reduced susceptibility to COVID-19 severity (p=0.028, OR=0.5936 [0.3725 - 0.9461]), under the additive model (p=0.045, OR=0.626 [0.3958 - 0.9899]). Rare variants IFNAR1 p.Trp318Cys, p.Ser476Phe, and IFNAR2 p.Cys271Tyr were predicted deleterious, impacting protein structure via hydrogen bond and hydrophobic interaction alterations. Burden analysis of rare variants revealed a protective cumulative effect against COVID-19 severity for TYK2 (p=0.0013, OR=0.1438 [0.04237 - 0.4803]) under the dominant model. This study underscores the role of genetic factors in COVID-19 susceptibility and advocates further explorations regarding functional impacts of JAK/STAT pathway rare variants.

Quantitative assessment of refrigerant impact on vehicle air-conditioning systems via Z-Freq 2D statistical analysis

In this study, the impact of refrigerant types on the performance and efficiency of vehicle air-conditioning (AC) systems was quantitatively assessed using a novel two-dimensional Z-Freq 2D statistical analysis method. Wireless vibration accelerometers, capturing both horizontal and vertical vibrations, were utilized to measure the dynamic response of the air-conditioning compressor. Before data collection, meticulous calibration of sensors was conducted to ensure the accuracy and reliability of measurements. The introduction of the Z-Freq 2D statistical analysis technique, developed specifically for this research, allowed for a comprehensive examination of the vibrational data, facilitating a deeper understanding of the effects of different refrigerants on AC system performance. To validate the effectiveness and reliability of the Z-Freq 2D analysis, machine learning techniques were employed. These techniques provided a robust framework for the analysis of the statistical data, with performance evaluation indicators demonstrating the efficacy of the newly developed method. The experimental setup was based on an actual vehicle air-conditioning test rig, designed to simulate real-world operating conditions accurately. The findings of this research offer significant insights into the selection of refrigerants for vehicle AC systems, highlighting the potential for enhanced system performance and efficiency through the application of advanced statistical analysis and machine learning validation techniques. This study not only contributes to the field of automotive thermal management but also paves the way for future research in the optimization of vehicle AC systems.

Understanding the stress field at the lateral termination of a thrust fold using generic geomechanical models and clustering methods

Abstract. This study employs numerical simulations based on the limit analysis (LA) method to calculate the stress distribution in a model that includes a basal detachment, featuring the lateral termination of a generic fault under compression. We conduct 2500 2D and 500 3D simulations with varying basement and fault friction angles to analyze and classify the results into clusters representing similar failure patterns to understand the stress fields. Automatic fault detection methods are employed to identify the number and positions of fault lines in 2D and fault surfaces in 3D. Clustering approaches are utilized to group the models based on the detected failure patterns. For the 2D models, the analysis reveals three primary clusters and five transitional ones, qualitatively consistent with the critical Coulomb wedge theory and the influence of inherited structural and geometric aspects over rupture localization. In the 3D models, four different clusters portray the lateral prolongation of the inherited fault. High stress magnitudes are detected between the compressive boundary and the activated or created faults and at the root of the inherited active fault. Tension zones appear near the outcropping surface relief, while stress decreases with depth at the footwall of the created back thrusts. A statistical cluster-based stress field analysis indicates that for a given cluster, the stress field mainly conserves the same orientations, while the magnitude varies with changes in friction angles and compressive field intensity, except in failure zones where variations are sparse. Small parametric variations could lead to significantly different stress fields, while larger deviations might result in similar configurations. The comparison between 2D and 3D models shows the importance of lateral stresses and their influence on rupture patterns, distinguishing between 3D analysis and 2D cross-sections. Lastly, despite using small-scale models, stress field variations over a span of a couple of kilometers are quite large.

A 3D Model-Based Framework for Real-Time Emergency Evacuation Using GIS and IoT Devices

Advancements in 3D modelling technology have facilitated more immersive and efficient solutions in spatial planning and user-centred design. In healthcare systems, 3D modelling is beneficial in various applications, such as emergency evacuation, pathfinding, and localization. These models support the fast and efficient planning of evacuation routes, ensuring the safety of patients, staff, and visitors, and guiding them in cases of emergency. To improve urban modelling and planning, 3D representation and analysis are used. Considering the advantages of 3D modelling, this study proposes a framework for 3D indoor navigation and employs a multiphase methodology to enhance spatial planning and user experience. Our approach combines state-of-the art GIS technology with a 3D hybrid model. The proposed framework incorporates federated learning (FL) along with edge computing and Internet of Things (IoT) devices to achieve accurate floor-level localization and navigation. In the first phase of the methodology, Quantum Geographic Information System (QGIS) software was used to create a 3D model of the building’s architectural details, which are required for efficient indoor navigation during emergency evacuations in healthcare systems. In the second phase, the 3D model and an FL-based recurrent neural network (RNN) technique were utilized to achieve real-time indoor positioning. This method resulted in highly precise outcomes, attaining an accuracy rate over 99% at distances of no less than 10 metres. Continuous monitoring and effective pathfinding ensure that users can navigate safely and effectively during emergencies. IoT devices were connected with the building’s navigation software in Phase 3. As per the performed analysis, it was observed that the proposed framework provided 98.7% routing accuracy between different locations during emergency situations. By improving safety, building accessibility, and energy efficiency, this research addresses the health and environmental impacts of modern technologies.

A comparison of super-resolution microscopy techniques for imaging tightly packed microcolonies of an obligate intracellular bacterium.

Conventional optical microscopy imaging of obligate intracellular bacteria is hampered by the small size of bacterial cells, tight clustering exhibited by some bacterial species and challenges relating to labelling such as background from host cells, a lack of validated reagents, and a lack of tools for genetic manipulation. In this study, we imaged intracellular bacteria from the species Orientia tsutsugamushi (Ot) using five different fluorescence microscopy techniques: standard confocal, Airyscan confocal, instant Structured Illumination Microscopy (iSIM), three-dimensional Structured Illumination Microscopy (3D-SIM) and Stimulated Emission Depletion Microscopy (STED). We compared the ability of each to resolve bacterial cells in intracellular clumps in the lateral (xy) axis, using full width half-maximum (FWHM) measurements of a labelled outer membrane protein (ScaA) and the ability to detect small, outer membrane vesicles external to the cells. Comparing the techniques readily available to us (above), 3D-SIM microscopy, in combination with the shortest-wavelength dyes, was found overall to give the best lateral resolution. We next compared the ability of each technique to sufficiently resolve bacteria in the axial (z) direction and found 3D-STED to be the most successful method for this. We then combined this 3D-STED approach with a custom 3D cell segmentation and analysis pipeline using the open-source, deep learning software, Cellpose to segment the cells and subsequently the commercial software Imaris to analyse their 3D shape and size. Using this combination, we demonstrated differences in bacterial shape, but not their size, when grown in different mammalian cell lines. Overall, we compare the advantages and disadvantages of different super-resolution microscopy techniques for imaging this cytoplasmic obligate intracellular bacterium based on the specific research question being addressed.

Comparison of 2D and 3D lung lobe quantification with Ventilation/Perfusion Ratio.

In this study, standard 2D lung lobe quantification is compared with two 3D lung lobe quantification software tools to investigate the clinical benefit of a 3D approach. The accuracy of 2D versus 3D lung lobe quantification is evaluated based on the calculated numerical ventilation-perfusion ratio (VQR) using a receiver operating curve (ROC) analysis.A study group of 50 consecutive patients underwent a planar lung scintigraphy (anterior/posterior) as well as ventilation/perfusion single photon emission computed tomography (SPECT/CT) to exclude acute pulmonary embolism. All data were acquired with SPECT OPTIMA NM/CT 640 (GE Healthcare). 2D analysis was performed for all ventilation/perfusion scans using a lung analysis tool (Syngo Workstation, Siemens Healthineers). 3D quantification analysis was performed using QLUNG (Q. Lung, Xeleris 4.0, GE Healthcare) and LLQ (Hermes Hybrid 3D Lung Lobar Quantification, Hermes Medical Solutions). The area under the ROC curve (AUC) served as a decision criterion to find the best agreement between clinical PE findings and calculated PE candidates of the 2D and 3D methods. The significance of the ROC curves was evaluated using the DeLong comparison.A significant difference between 2D/3D could be determined. Both 3D approaches showed robust and comparable results. The AUC range of [0.10, 0.67] was given for 2D lobar analysis, QLUNG AUC range revealed in [0.39,0.74] and LLQ AUC range was [0.42,0.72]. Averaged over all lung lobes an AUC=0.39 was given for 2D analysis and AUC=0.58 was given for LLQ/QLUNG.We could demonstrate the better performance of 3D analysis compared to 2D analysis. Consequently, is recommended to use a 3D approach in clinical practice.

Design innovative perspectives of thermally radiative flow of chemically reactive magnetized nanofluid capturing bioconvection and Joule heating aspects

The distinguishing thermophysical features of nanofluids make them possibly advantageous in enhancing transfer of heat. The applications of nanofluids in industrial cooling, cooling tower detection, imaging, microelectronic cooling, crossbreed motor proficiency, transparent sunscreen, crack-resistant paint, nuclear reactor cooling, thermal transport, enhanced oil recovery, and architecture have diversified extensively in recent years. Scientific research has shown an enormous spike in fascination with non-Newtonian nanofluids in the past few decades. The stress in non-Newtonian fluids varies nonlinearly with the rate of deformation. These fluids are used in material processing, bioengineering, polymeric fluids, oil reservoir design, and the chemical and nuclear industries. There have been several non-Newtonian models presented forth. The Williamson fluid model is one example of such a model that has a shear-thinning behavior. The current article explanate analysis of (3D) Williamson fluid flow considering various physical features which plays vital role to raise the heat transportation rate. Through transformations procedure the governing physical problem is simplified and then solved via bvp4c in MATLAB. Acquired data are tabulated and graphically presented, and the impacts of relevant parameters on concentration-microorganisms and temperature have been examined numerically. According to the accomplishments, the concentration profile is anticipated to decline as the stretching rate parameter and Brownian motion parameter values grow. By boosting the magnetic parameter, the microorganism profile advances, but the bioconvection Peclet number reveals an opposite tendency.

Experimental simulation of friction and wear between carbon fiber tow and heddle eye under periodic tension during the 3D weaving process

AbstractWeaving is the predominant technology for fabricating carbon fiber composite preforms. Carbon fibers are subjected to various forms of reciprocating friction in the weaving process. Especially, the friction between carbon tow and heddle eyes is difficult to describe due to the complex conditions of variable tension. In this study, a novel experimental simulator was developed to characterize the friction behavior between warp yarn and heddle eye under periodic tension variation. The friction force (Ff) and coefficient of friction (COF) under variable tension conditions were tested. To investigate the variation of real contact area between carbon tow and heddle eyes under variable tension conditions, a silicon‐film indentation method was developed, and the effect of pre‐tension on carbon tow was obtained by combining three‐dimensional micro surface morphology and Hertz analysis methods. The results indicated that both the COF and Ff decreased with increasing pre‐tension. 3D morphology analysis suggested that the tow contact area reached its maximum when the pre‐tension was 1.2 N. In the Hertzian calculation of the actual contact area, the change of the contact area and the pre‐tension was generated by taking into account the evolving contact length, which differed from the measured friction force value by a constant factor.Highlights A variable tension device was designed and developed. The friction between carbon tow and heddle eye was simulated under variable tension. The Ff and COF under different pre‐tensions were tested. A silicon‐film indentation method was proposed. The relationship between contact area and friction was studied.

3D variability analysis reveals a hidden conformational change controlling ammonia transport in human asparagine synthetase

Advances in X-ray crystallography and cryogenic electron microscopy (cryo-EM) offer the promise of elucidating functionally relevant conformational changes that are not easily studied by other biophysical methods. Here we show that 3D variability analysis (3DVA) of the cryo-EM map for wild-type (WT) human asparagine synthetase (ASNS) identifies a functional role for the Arg-142 side chain and test this hypothesis experimentally by characterizing the R142I variant in which Arg-142 is replaced by isoleucine. Support for Arg-142 playing a role in the intramolecular translocation of ammonia between the active site of the enzyme is provided by the glutamine-dependent synthetase activity of the R142 variant relative to WT ASNS, and MD simulations provide a possible molecular mechanism for these findings. Combining 3DVA with MD simulations is a generally applicable approach to generate testable hypotheses of how conformational changes in buried side chains might regulate function in enzymes.

Investigating the Effects of Remapping Method in Explosion

Using real explosives to detect explosion effects is a difficult and impractical method due to its danger and cost. Performing numerical analyses based on previously conducted experimental studies allows for the diversification of studies on this subject. Since the elaboration of numerical analyses causes an increase in the amount of processing, it requires the devices that need to perform these operations to be very advanced. It is an important optimization that the solutions are shorter and closer to reality, and this can be done with the remapping method. With this method, the explosion loads obtained from 1D analysis can be integrated into 2D and 3D analyses with certain methods, and the duration of these analyses is reduced and their accuracy is increased. Within the scope of this study, the methods and approaches for the application of this method are explained. As a result of this study, it will help those who want to perform explosion simulations to obtain more accurate results in a shorter time with less processing power, and it will pave the way for many scientific studies to be carried out.

Comparative analysis of 3D and 2D in vitro models of the permanent fish liver cell line RTL-W1: Metabolic capabilities and responses to xenobiotics

In vitro models based on permanent fish liver cell lines have proven to be versatile tools for examining chemical biotransformation and toxicity. However, their in vivo relevance remains uncertain due to their potentially de-differentiated phenotype. Here, we investigate whether a 3D cell culture environment can restore hepatocyte-like properties of the Rainbow trout liver cell line RTL-W1. Utilizing ultralow attachment (ULA) microwell plates, we achieved controlled sizing and extended culture (3 weeks) of spheroidal aggregate cultures (spheroids). RTL-W1 cells within the spheroids remained viable and metabolically active, as confirmed by the CellTiter-Glo 3D assay. Transmission electron microscopy revealed that spheroids exhibit tissue-like arrangements, such as interdigitations, cell-cell junctions, and endo- or exocytic activity at the cell-cell interface. They also displayed ultrastructural characteristics typical of metabolically active cells/hepatocytes, including abundant endoplasmic reticulum (ER), Golgi apparatus, and mitochondria. RT-qPCR analysis showed upregulation of genes involved in xenobiotic and endogenous (lipid) metabolism in 3D cultures over time. Notably, for several genes, especially cyp1a, expression levels were significantly higher in spheroids than in monolayers cultured for the same duration. This was corroborated at the enzyme level by increased Cyp1a-dependent catalytic activity (EROD). Interestingly, increased Cyp1a expression did not lead to heightened susceptibility to benzo[a]pyrene toxicity, which requires bioactivation. However, RTL-W1 3D and 2D cell cultures exhibited differential susceptibility to toxicity from other model chemicals, such as the surfactant SDS and the metal copper (Cu). These findings support the hypothesis that RTL-W1 cells can re-differentiate to a hepatocyte-like phenotype when cultured in a 3D configuration and may exhibit distinct biological responses upon exposure to xenobiotics. Overall, this study advances our understanding of the potential of cell line-derived 3D in vitro models for research and providing more physiologically relevant data for regulatory contexts.

The mandible of Salbatore II: A new Ursus deningeri site in the northern Iberian Peninsula

Ursus deningeri, together with Ursus spelaeus sensu lato, are chronospecies that belong to the Quaternary iconic cave bear lineage. They inhabited Iberia from the late Early to the late Middle Pleistocene. Here we describe a complete bear mandible recovered from Salbatore II cave (Basque Country). To assess its taxonomy, we compared it with other European Pleistocene cave and brown bears. Comparisons were made concerning its morphology and using both traditional and 3D geometric morphometrics analyses. The mandible has several morphological similarities with the cave bears such as a high corpus and deep masseter fossa. However, it exhibits a coronoid process that leans backwards, a pointed pterygoid process, and the p1 and p3 are present. These are characteristics customarily associated with U. deningeri and U. arctos. Metric analyses show that Salbatore II fits within the cave bears variation, with a minimum overlap with brown bears once size is accounted for. However, geometric morphometric analyses show that Salbatore II is similar to U. arctos, but within U. deningeri variation. Based on the overall size and the morphological characteristics, Salbatore II displays U. deningeri affinities with many ancestral characteristics, suggesting a minimum mid-Middle Pleistocene age rarely recorded in the Cantabrian region.

Dynamic 3D Point Cloud Sequences as 2D Videos.

Dynamic 3D point cloud sequences serve as one of the most common and practical representation modalities of dynamic real-world environments. However, their unstructured nature in both spatial and temporal domains poses significant challenges to effective and efficient processing. Existing deep point cloud sequence modeling approaches imitate the mature 2D video learning mechanisms by developing complex spatio-temporal point neighbor grouping and feature aggregation schemes, often resulting in methods lacking effectiveness, efficiency, and expressive power. In this paper, we propose a novel generic representation called Structured Point Cloud Videos (SPCVs). Intuitively, by leveraging the fact that 3D geometric shapes are essentially 2D manifolds, SPCV re-organizes a point cloud sequence as a 2D video with spatial smoothness and temporal consistency, where the pixel values correspond to the 3D coordinates of points. The structured nature of our SPCV representation allows for the seamless adaptation of well-established 2D image/video techniques, enabling efficient and effective processing and analysis of 3D point cloud sequences. To achieve such re-organization, we design a self-supervised learning pipeline that is geometrically regularized and driven by self-reconstructive and deformation field learning objectives. Additionally, we construct SPCV-based frameworks for both low-level and high-level 3D point cloud sequence processing and analysis tasks, including action recognition, temporal interpolation, and compression. Extensive experiments demonstrate the versatility and superiority of the proposed SPCV, which has the potential to offer new possibilities for deep learning on unstructured 3D point cloud sequences.

Observation of biological and emulsion samples by newly developed three-dimensional impedance scanning electron microscopy

Imaging at nanometre-scale resolution is indispensable for many scientific fields such as biology, chemistry, material science and nanotechnology. Scanning electron microscopes (SEM) are widely used as important tools for the nanometre-scale analysis of various samples. However, because of the vacuum inside the SEM, a typical analysis requires fixation of samples, a drying process, and staining with heavy metals. Therefore, there is a need for convenient and minimally invasive methods of observing samples in solution. Recently, we have developed a new type of impedance microscopy, multi-frequency impedance SEM (IP-SEM), which allows nanoscale imaging of various specimens in water with minimal radiation damage. Here, we report a new IP-SEM system equipped with a linear-array terminal, which allows eight tilted images to be observed in a single capture by applying eight frequencies of input signals to each electrode. Furthermore, we developed a three-dimensional (3D) reconstruction method based on the Simulated Annealing (SA) algorithm, which enables us to construct a high-precision 3D model from the 8 tilted images. The method reported here can be easily used for 3D structural analysis of various biological samples, organic materials, and nanoparticles.

The Combination of X-ray Ct and Multi-particle Finite Element Method for Powder Compaction

Abstract The macroscopic mechanical properties of granular materials are closely related to their microscopic properties, and studying the compression problem of powder is helpful for establishing a constitutive law of powder compaction process. This study utilized X-ray CT technology to investigate the 3D numerical analysis model of loose particle stacking and compaction based on MPFEM, and investigated the mechanical behavior of powder under compression. The results of MPFEM were experimentally verified through powder uniaxial compression experiments, and the results showed that the calculated results of MPFEM were in good agreement with the experimental results. The method of X-ray CT can effectively capture the geometric characteristics of powder particles, and the MPFEM can obtain the true characteristics of plastic deformation of powder bodies, which is an important means of developing powder compaction constitutive models.

Advanced Detection of Underwater Gas Seep Sites Through Multibeam Echosounder Water Column Data and Numerical Analysis

Abstract Water column imaging of multibeam echosounder systems (MBES) are sensitive and potential devices for investigating free gas bubbles release and their ascent up the water column. These data could demonstrate previously undetected characteristics on the water’s surface and seabed which are related to Sustainable Development Goal 14 about life below water. The research utilizes a MBES to map the volume of seabed gas emission bubbles in the Adriatic Sea, Italy, using water column data. The survey covered 1.5 km2 around a four-legged gas platform at a depth of 77 meters. To achieve a 50% overlap, ten parallel transects of 1.5 km each were used, with a vessel speed range of 2-2.6 m/s and a transect spacing of 100 m. Acoustic waves from seabed seepage were visualized using water column data, with reflection intensities ranging from −63.5 dB to 29 dB, reflecting the acoustic reflectance of various suspended materials. More precise thresholds were obtained by filtering and clustering the gas bubbles using the point weight approach to separate them from the noise and water bubbles. The uneven Digital Terrain Model (DTM) indicates gas emissions through water column data. The volume of gas bubbles was determined by visualizing the points in a 3D format using XYZ coordinates. Through interpolation techniques and 3D volumetric analysis, six bubble locations were obtained with volumes of 651.12 m3, 108.30 m3, 42.00 m3, 167.20 m3, 186.00 m3, 287.81 m3, and 45.00 m3. This study is crucial because it questions the methods of Carbon Capture and Storage (CCS) by investigating the discharge of carbon into the sea. Furthermore, this study helps to identify emission sources, measure the volume of released gas, and explain the depth distribution of emissions, providing essential data for marine CCS assessment.