3D Model Research Articles

Using Digital Twins for Fault Detection and Root Cause Analysis in Mechanical Systems

The integration of Digital Twin (DT) technology into mechanical systems has shown significant potential for enhancing fault detection, diagnostics, and root cause analysis. By creating real-time virtual replicas of physical systems, DTs facilitate continuous monitoring and provide actionable insights into system behavior. This paper explores the application of DT technology in mechanical systems, focusing on its role in fault prevention, predictive maintenance, and root cause analysis. We investigate key aspects such as real-time data synchronization, predictive maintenance strategies, system optimization, and the use of multi-sensor integration to improve fault detection accuracy. The paper also examines the challenges associated with implementing DTs in complex mechanical systems and discusses future directions for research in this field. By leveraging machine learning and advanced data fusion techniques, Digital Twins enable predictive analytics, improving system reliability, efficiency, and overall performance. This work highlights how DTs can transform traditional maintenance strategies, leading to more proactive, data-driven approaches for fault detection and system recovery. Keywords: Digital Twin, fault detection, root cause analysis, mechanical systems, predictive maintenance, real- time data synchronization, system optimization, fault prevention, machine learning, predictive models, sensor data, system performance, anomaly detection, vibration analysis, remaining useful life (RUL), fault recovery, predictive analytics, system reliability, maintenance strategy, real-time monitoring, virtual model, operational efficiency, mechanical failure, sensor fusion, failure prediction, condition-based maintenance, fault detection algorithms, system behavior simulation, data-driven decision making, root cause identification, industrial applications.

USE OF ACTIVE METHODOLOGIES FOR THE TEACHING OF NEUROANATOMY

In recent decades, more and more in higher education, active methodologies have been applied, playing a significant role in expanding knowledge. There is a consensus on the perception of the need to use practical tools that contribute positively to learning in neuroanatomy. Therefore, the present work aimed to present tools used in teaching practice based on active methodologies, of which the following stand out: - handout with boards for activities in class, where students identify neuroanatomical structures by colors and legends; - synthetic anatomical parts; 2D and 3D models; made in groups by themes; - sample of neuroanatomy; - group dynamics and pedagogical gymkhana of knowledge and social responsibility. Considering the experiences based on more than twenty years of the teaching staff in the exercise of higher education focused on health and aligned with the instruments for evaluating undergraduate courses at the MEC, it is relevant to define innovation as creative ideas that contribute positively to the quality of teaching and learning process. Finally, the activities demonstrated encouraged critical thinking, problem solving, decision-making and the practical application of the contents studied.

Exploration of Three-dimensional Modeling by Unmanned Aerial Vehicles for Application in Practical Engineering

Citing actual engineering cases, this paper aims to enhance the application of the model in actual engineering by describing the experience gained in the process of generating 3D stereo models generated by UAV aerial surveys, as well as the characteristics of the aerial photography and model generation process.

Flood analysis using HEC-RAS 1D model for the delta of Brahmani river, Odisha, India

Flood analysis using HEC-RAS 1D model for the delta of Brahmani river, Odisha, India

Flood inundation and hazard mapping using the HEC-RAS 2D model: a case study of Adoori River, Iran

Flood inundation and hazard mapping using the HEC-RAS 2D model: a case study of Adoori River, Iran

Biofabricated 3D Intestinal Models as an Alternative to Animal-Based Approaches for Drug Toxicity Assays.

The main challenge in new drug development is accurately predicting the human response in preclinical models. In this study, we developed three different intestinal barrier models using advanced biofabrication techniques: (i) a manual model containing Caco-2 and HT-29 cells on a collagen bed, (ii) a manual model with a Caco-2/HT-29 layer on a HDFn-laden collagen layer, and (iii) a 3D bioprinted model incorporating both cellular layers. Each model was rigorously tested for its ability to simulate a functional intestinal membrane. All models successfully replicated the structural and functional aspects of the intestinal barrier. The 3D bioprinted intestinal model, however, demonstrated superior epithelial barrier integrity enhanced tight junction formation, microvilli development, and increased mucus production. When subjected to Ibuprofen, the 3D bioprinted model provided a more predictive response, underscoring its potential as a reliable in vitro tool for drug toxicity testing. Our 3D bioprinted intestinal model presents a robust and predictive platform for drug toxicity assessments, significantly reducing the need for animal testing. This model not only aligns with ethical testing protocols but also offers enhanced accuracy in predicting human responses, thereby advancing the field of drug development.

Modieslab Innovative Concrete Pavement Structure: From Idea through Research to Implementation

In 1996 the Dutch Ministry of Transport, Public Works and Water Management launched the innovation program ‘Roads to the Future’. One of the developed innovative pavement structures is a Modular Pavement Structure called Modieslab. This structure is designed as a bridge and it merely consists of precast concrete elements. Since 2001 several researches were performed. Along the motorway A50 in the Netherlands a low-risk and not heavily loaded test section was constructed and monitored during 16 months. On this test section mainly the functional properties as well as construction and maintenance techniques were investigated. The main findings of this test section are reported. The structural integrity of the structure was investigated by Accelerated Load Testing of another instrumented test section by means of LINTRACK. Some characteristic measurement results are presented. Insight into the structural behaviour of both the total pavement structure and the most critical upper part of it was further obtained by means of 3D finite element modelling. Some typical calculation results are compared to measurement results. Finally the materials research is briefly described. This research concentrates on the porous concrete wearing course. Research is ongoing to find solutions for skid resistance and ravelling problems that occurred to some extent on the test sections. Given the rather positive experiences, both from a technical and an economical point of view, it was decided to actually construct an in-service road section of the radically innovative Modieslab pavement structure after only 4 to 5 years of research. Probably this project will be realized in 2005 or 2006 in an area with very poor subsoil.

Axially multifocal metalens for 3D volumetric photoacoustic imaging of neuromelanin in live brain organoid.

Optical resolution photoacoustic imaging of uneven samples without z-scanning is transformative for the fast analysis and diagnosis of diseases. However, current approaches to elongate the depth of field (DOF) typically imply cumbersome postprocessing procedures, bulky optical element ensembles, or substantial excitation beam side lobes. Metasurface technology allows for the phase modulation of light and the miniaturization of imaging systems to wavelength-size thickness. Here, we propose a metalens composed of submicrometer-thick titanium oxide nanopillars, which generates an elongated beam of diffraction-limited diameter with an aspect ratio of 286 and a uniform intensity throughout the DOF. The metalens enhances visualization of phantom samples with tilted surfaces compared to conventional lenses. Moreover, the volumetric imaging of neuromelanin is facilitated for depths of up to 500 micrometers within the human midbrain and forebrain organoids that are 3D biological models of human brain regions. This approach provides a miniaturized platform for neurodegenerative disease diagnosis and drug discovery.

Bionic Modeling Study on the Landing Mechanism of Flapping Wing Robot Based on the Thoracic Legs of Purple Stem Beetle, Sagra femorata

Flapping wing micro aerial vehicles (FWMAVs) are recognized for their significant potential in military and civilian applications, such as military reconnaissance, environmental monitoring, and disaster rescue. However, the lack of takeoff and landing capabilities, particularly in landing behavior, greatly limits their adaptability to the environment during tasks. In this paper, the purple stem beetle (Sagra femorata), a natural flying insect, was chosen as the bionic research object. The three-dimensional reconstruction models of the beetle’s three thoracic legs were established, and the adhesive mechanism of the thoracic leg was analyzed. Then, a series of bionic design elements were extracted. On this basis, a hook-pad cooperation bionic deployable landing mechanism was designed, and mechanism motion, mechanical performance, and vibration performance were studied. Finally, the bionic landing mechanism model can land stably on various contact surfaces. The results of this research guide the stable landing capability of FWMAVs in challenging environments.

Functional Imaging Methods for Investigating 3D Choroid Plexus Organoids.

The choroid plexus (ChP) is a vital brain structure that produces cerebrospinal fluid (CSF) and forms a selective barrier between the blood and CSF, essential for brain homeostasis. Composed of secretory epithelial cells, connective stroma, and a fenestrated vascular network, the ChP supports nutrient transport, immune surveillance, and the clearance of toxic by-products. Despite its significance in maintaining cerebral function, the mechanisms underlying its development and maturation remain poorly understood. Recent advancements, such as the creation of stem cell-derived three-dimensional (3D) ChP organoid model, provide a promising platform for studying these processes. The ChP organoid model replicates key developmental stages and functions of the ChP, including CSF secretion and barrier formation. Additionally, they offer unique opportunities to investigate the impacts of drugs, pathogens, and toxins on the blood-CSF barrier. This study highlights imaging techniques critical for the characterization and utilization of ChP organoids, illustrating their value in advancing our understanding of ChP biology and its role in health and disease.

Identification of Key Amino Acids in the A Domains of Polymyxin Synthetase Responsible for 2,4-Diaminobutyric Acid Adenylation in Paenibacillus polymyxa NBRC3020 Strain.

Developing novel nonribosomal peptides (NRPs) requires a comprehensive understanding of the enzymes involved in their biosynthesis, particularly the substrate amino acid recognition mechanisms in the adenylation (A) domain. This study focused on the A domain responsible for adenylating l-2,4-diaminobutyric acid (l-Dab) within the synthetase of polymyxin, an NRP produced by Paenibacillus polymyxa NBRC3020. To date, investigations into recombinant proteins that selectively adenylate l-Dab─exploring substrate specificity and enzymatic activity parameters─have been limited to reports on A domains found in enzymes synthesizing l-Dab homopolymers (pldA from S. celluloflavus USE31 and pddA from S. hindustanus NBRC15115), which remain exceedingly rare. The polymyxin synthetase in NBRC3020 contains five A domains specific to l-Dab, distributed across five distinct modules (modules 1, 3, 4, 5, 8, and 9). In this study, we successfully obtained soluble A domain proteins from modules 1, 5, 8, and 9 by preparing module-specific recombinant proteins. These proteins were expressed in E. coli BAP-1, purified via Ni-affinity chromatography, and demonstrated high specificity for l-Dab. Through sequence homology analysis, three-dimensional structural modeling, docking simulations to estimate substrate-binding sites, and functional validation using alanine mutants, we identified Glu281 and Asp344 as critical residues for recognizing the side chain amino group of l-Dab, and Asp238 as essential for recognizing its main chain amino group in the A domain. Notably, these key residues were conserved not only across the A domains in modules 1, 5, 8, and 9 of P. polymyxa NBRC3020 but also in those of the P. polymyxa PKB1 strain, as confirmed by sequence homology analysis. Interestingly, in pldA and pddA, the key residues involved in recognizing the side-chain amino group of l-Dab, which are conserved among polymyxin synthetases of NBRC3020 and PKB1 strain, were not observed. This suggests a potentially different mechanism for l-Dab recognition.

Smartphone application-based augmented reality for pre-clinical dental implant placement training: a pilot study.

Precise implant placement is essential for optimal functional and aesthetic outcomes. Digital technologies, such as computer-assisted implant surgery (CAIS), have improved implant outcomes. However, conventional methods such as static and dynamic CAIS (dCAIS) require complex equipment. This study examined the usefulness of smartphone-based augmented reality (AR) for CAIS based on the value addition regarding angulation and positioning of pilot drillings and the potential for training dental students. An in vitro model was created to mimic dental scenarios using three-dimensional datasets. Smartphone technology and AR application (app)-based intraoral tracking were used for dCAIS. The app allowed real-time visualization of implant planning, superimposition of three-dimensional models, and alignment of surgical instruments. Forty dental students performed four pilot drillings each; two were performed freehand, whereas two were performed using the app. The angulation and position of the prepared implant bed preparation were statistically analyzed. Implant angulation was significantly better in the AR-guided group than in the unguided group; however, no significant difference was observed in the implant position. Smartphone-based AR techniques for dCAIS are easily accessible in dental implantology. This may be advantageous for training dental students and potentially improving clinical outcomes, particularly the angulation of dental implants.

Three-Dimensional Modeling of the Behavior of a Blood Clot Using Different Mechanical Properties of a Blood Vessel

Three-Dimensional Modeling of the Behavior of a Blood Clot Using Different Mechanical Properties of a Blood Vessel

Two- and Three-Dimensional Culture Systems: Respiratory In Vitro Tissue Models for Chemical Screening and Risk-Based Decision Making

Risk of lung damage from inhaled chemicals or substances has long been assessed using animal models. However, New Approach Methodologies (NAMs) that replace, reduce, and/or refine the use of animals in safety testing such as 2D and 3D cultures are increasingly being used to understand human-relevant toxicity responses and for the assessment of hazard identification. Here we review 2D and 3D lung models in terms of their application for inhalation toxicity assessment. We highlight a key case study for the Organization for Economic Cooperation and Development (OECD), in which a 3D model was used to assess human toxicity and replace the requirement for a 90-day inhalation toxicity study in rats. Finally, we consider the regulatory guidelines for the application of NAMs and potential use of different lung models for aerosol toxicity studies depending on the regulatory requirement/context of use.

Modeling Temperature and Moisture Dynamics in Corn Storage Silos: A Comparative 2D and 3D Approach

Grain storage in silos plays a fundamental role in preserving the quality and safety of agricultural products. This study presents a comparative evaluation of two-dimensional (2D) and three-dimensional (3D) mathematical models to predict the temperature and moisture distribution during unventilated corn storage in cylindrical silos with conical roofs. The models incorporate external temperature fluctuations, solar radiation, grain moisture equilibrium with air humidity via sorption isotherm (water activity), and grain respiration to simulate real-world storage conditions. The 2D model offers computational efficiency and is suitable for preliminary assessments but simplifies natural convection effects and underestimates axial temperature gradients. Conversely, the 3D model provides a detailed representation of heat and moisture transfer phenomena, capturing complex interactions such as buoyancy-driven flow and localized effects of solar radiation. The results reveal that temperature and moisture accumulation are more pronounced in the upper regions of the silo, driven by solar radiation and natural convection, with significant implications for large-scale silos where thermal inertia plays a key role. This dual modeling approach demonstrates that while the 2D model is valuable for quick evaluations, the 3D model is essential for comprehensive insights into thermal and moisture gradients. The findings support informed decision-making in silo design, optimization, and management, enhancing grain storage strategies globally.

3D modelling and simulation of thermal effects and dispersion of particles carrying infectious respiratory agents in a railway transport coach

Even though the COVID-19 pandemic now belongs to the long history of infectious diseases that have struck humanity, pathogenic biological agents continue to pose a recurring threat in private places, but also and mainly in places where the public congregates. In our recent research published in this journal in 2022 and 2023, we considered the illustrative example of a commuter train coach in which a symptomatic or asymptomatic passenger, assumed to be infected with a respiratory disease, sits among other travellers. The passenger emits liquid particles containing, for example, COVID-19 virions or any other pathogen. The size spectrum of particles varies depending on whether they are produced during breathing, speaking, coughing or sneezing. More specifically, droplets associated with breathing are in the range of 1–10 µm in aerodynamic diameter, while at the other end of the spectrum, drops associated with coughing can reach 100–1000 µm. In the first part of our research, we used Computational Fluid Dynamics (CFD) to model and simulate in 3D the transport and dispersion of particles from 1 µm to 1 mm in the turbulent flow generated by the ventilation of the railway coach. We used both the Eulerian approach and the Lagrangian approach and showed that the results were strictly similar and illustrated the very distinct aerodynamics, on one hand, of the aerosol of droplets suspended in the air and, on the other hand, of the drops falling or behaving like projectiles depending on their initial speed. In the second part of our research, we developed a model of filtration through a typical surgical mask and possible leaks around the mask if it is poorly adjusted. We resumed the twin experiment of the railway coach and compared the distribution of droplets depending on whether the passengers (including the infected one) wear masks or not and whether the masks are perfectly fitted or worn loosely. Our method made it possible to quantify the particles suspended in the air of the railway coach depending on whether the infected passenger wore their mask more or less well. In this third article, we specifically explore how thermal effects due to the presence of passengers influence the spatio-temporal distribution in the railway coach of aerosols produced by the breathing infected person. We demonstrate that the influence of thermal effects on aerodynamics is very significant and can be very favourable for air decontamination if the ventilation system is judiciously configured. Beyond its application to a commuter train, our work confirms the value of validated CFD tools for describing the airflow and dispersion of particles in complex spaces that do not always allow experimentation. The models that we have developed are applicable to any other semi-confined, ventilated public place, such as a classroom, a hospital room or a performance hall, and they enable the objective assessment of whether the occupation of these spaces could be critical with regard to infectious contamination and of how to limit this ubiquitous risk.

Three-dimensional boundary element sensitivity analysis of anisotropic thermoelastic materials

Abstract The fundamental goal of this research is to develop a new three-dimensional boundary element method (BEM) for solving thermal stress sensitivity problems in anisotropic materials with a heat source. The problem at hand is incredibly tough to address analytically. As a result, we devised a novel boundary element technique to address this problem. The use of quadratic isoparametric elements and constant volume heat source to depict displacement and temperature fields is one of the driving forces behind the requirement to quantify thermal stresses in engineering structures. In three-dimensional scenarios, the impacts of isotropic, orthotropic, and anisotropic due to the presence or absence of a heat source on thermal stress sensitivity are investigated. The resulting linear systems were solved using the three-block splitting (TBS) iteration strategy, which reduced both the number of iterations and CPU time. The new TBS iteration method converges quickly and does not require complex calculations. It exceeds the other iterative methods for solving the resulting BEM linear system. To compare with other articles in the literature, we only considered the two-dimensional model as a subset of our three-dimensional model. The numerical data illustrate the accuracy, precision, and effectiveness of our proposed BEM methodology, as the BEM results are highly consistent with the finite difference method (FDM) and finite element method (FEM) results.

Three-dimensional linkage analysis with digital PCR for genome integrity and identity of recombinant adeno-associated virus

Recombinant adeno-associated virus (rAAV) has emerged as the vector of choice for in vivo gene delivery, with numerous clinical trials underway for the treatment of various human diseases. Utilizing rAAV in gene therapy requires a highly precise quantification method to determine the viral genome titer and further establish the optimal therapeutic dosage for a rAAV product. The conventional single-channel droplet digital PCR (1D ddPCR) method offers only partial information regarding the viral vector genome titer, lacking insights into its integrity. In our pursuit of further advancing rAAV analysis, we have developed a novel 3D ddPCR assay with advanced 3D linkage analysis. We have designed the three amplicon sites targeting both ends of the viral genome, as well as the center of key therapeutic gene of interest (GOI). This study aims to offer a more comprehensive and insightful assessment of rAAV products which includes not only quantity of viral genome titer but also the quality, distinguishing between partial ones and intact full-length viral genomes with the right GOI. Importantly, due to the random partitioning property of a digital PCR system, the 3D linkage analysis of rAAV viral genome requires a proper mathematical model to identify the true linked DNA molecules (full-length/intact DNA) from the population of false/unlinked DNA molecules (fragmented/partial DNA). We therefore have developed an AAV 3D linkage analysis workflow to characterize genomic integrity and intact titer for rAAV gene therapy products. In this study, we focus on evaluating our 3D linkage mathematical model by performing DNA mixing experiments and a case study using multiple rAAV samples. Particularly, we rigorously tested our algorithms by conducting experiments involving the mixing of seven DNA fragments to represent various AAV viral genome populations, including 3 single partials, 3 double partials, and 1 full-length genomes. Across all 37 tested scenarios, we validated the accuracy of our workflow’s output for the percentages of 3D linkage by comparing to the known percentages of input DNA. Consequently, our comprehensive AAV analytical package not only offers insights into viral genome titer but also provides valuable information on its integrity and identity. This cost-effective approach, akin to the setup of traditional 1D or 2D dPCR, holds the potential to advance the application of rAAV in cell and gene therapy for the treatment of human diseases.

Research status of simulation modeling technology for the 3D braiding process

Three-dimensional (3D) braiding has excellent mechanical properties due to its unique spatial organization, in which simulation modeling of the braiding process is a key technology to study the complex spatial structure of 3D braided fabrics. The paper first summarizes the research methods of 3D braiding simulation modeling technology in recent years; second, it focuses on the analysis of numerical method modeling based on geometric dynamics, geometric modeling based on the braiding process, and modeling based on the finite-element method; then, based on the existing technology and application status quo, it sums up the advantages and shortcomings of the current 3D braiding process simulation modeling technology; and, finally, it describes the challenges and opportunities of the 3D braiding simulation modeling technology. The future development direction of the three modeling methods and the new idea of mutual coupling of the three methods are proposed and future development prospects are described. The paper provides technical support for the simulation modeling of the braiding process in 3D braiding technology.

Relationship between left ventricular shape and cardiovascular risk factors: comparison between the Multi-Ethnic Study of Atherosclerosis and UK Biobank

BackgroundStatistical shape atlases have been used in large-cohort studies to investigate relationships between heart shape and risk factors. The generalisability of these relationships between cohorts is unknown. The aims of...