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Parotidectomy can affect facial symmetry. Our study evaluated the symmetry of different facial areas and upper neck after total parotidectomy and filling the area with vascularized fat flap (VFF). Facial symmetry was evaluated in eight patients and a control group matched in terms of gender and age, using a three-dimensional (3D) facial scanner. The operated side was compared with the non-operated side and the symmetry compared with that of the control group. Scanning was performed either within the first year (group 1; n = 5) or after 3 years (group 2; n = 3) postoperatively. The patients' cheek and neck areas were found to be significantly more asymmetric, but the cheek area in group 2 was significantly more symmetrical when compared with group 1. VFF appeared to achieve similar facial symmetry to the matched non-operated group. Time had a positive impact on the facial symmetry. The neck area was the most asymmetric, and proved to be unreliable, regardless of whether any procedure was performed or not. [ABSTRACT FROM AUTHOR]

The black-footed cat (Felis nigripes) is the smallest and one of the rarest cats in Africa. Endemic to the semi-arid regions of South Africa, Namibia and Botswana, this nocturnal carnivore spends daytime in burrows, thus avoiding high temperatures and diurnal predators. Despite the importance of burrows, den usage has never been studied in detail for this species. Here we report on the frequency with which female black-footed cats use burrows of different dimensions and compared with burrow availability. The entrances of 50 dens, used by five radio-collared black-footed cats over four weeks, were scanned with LiDAR to measure tunnel width (mean = 15.2 ± 3.9 cm) and height (mean = 13.9 ± 3.6 cm). Of these, 98% (n = 49) most closely matched the dimensions of springhare (Pedetes capensis) burrows. Each cat used a mean of 11.6 den sites and spent a mean of 2.0 consecutive days in a den before selecting a new one. When kittens reached an age of 44–50 days, mothers switched from using a den for a mean of six days-per-den, to changing dens every day. Our results suggest that female black-footed cats are reliant upon springhares to provide suitable daytime refugia and maternity dens in southern Namibia. Further studies should be conducted to determine what den sites are selected in the absence of springhare, and whether localised persecution of springhare impacts the survival of black-footed cats. [ABSTRACT FROM AUTHOR]

As a result of the thermo-mechanical impact during welding, distortions are generated in welded structures. These distortions significantly influence the geometric and dimensional accuracy of welded structures, in many cases lowering their working characteristics and reliability. An optimal design for welded structures is a prerequisite for increased reliability and reduction in manufacturing cost, and such an optimal design can be achieved knowing the distortions in weldments. Despite the fact that pulsed metal inert gas welding and metal active gas welding have been broadly applied in the last few decades, nowadays, few manufacturers, for instance, Fronius, EWM, Redco, and Perfect Power Welders, offer such an option for manual arc welding. This work aims to determine the influence of the parameters of pulsed welding modes on distortions that are generated during manual arc welding. Two different inverter welding power sources were used, and the welding distortions were measured by 3D scanning. The results showed that the pulsed mode during manual arc welding led to a reduction in distortions compared to the conventional welding mode. The crucial part of the manual welding system proved to be the qualification and performance of the welder. [ABSTRACT FROM AUTHOR]

Introduction. Formation of a contact surface in prosthetics and orthotics is crucial for the restoration of human musculoskeletal functions. This paper considers specific features of methods currently used for denoising of a 3D model surface obtained by optical scanning. An algorithm for manufacturing an individual prosthetic and orthopedic product is developed. The current literature reports no similar methods, which may be explained by the widespread use of gypsum technology for the manufacture of prostheses and orthoses.Aim. Research and development of digital filtration methods for 3D meshes obtained by optical scanning for further modeling of individual prosthesis and orthosis modules.Materials and methods. It is proposed to optimize the pre-processing stage of 3D scanned models by applying denoising and smoothing processes. In total, 50 optical 3D scans were selected for testing via the following denoising algorithms: bilateral filtering, vertex-based anisotropic smoothing, mean and median filtering applied to face normals.Results. The study was conducted using 3D scans of lower limb stumps and Chenault brace orthoses and corsets provided by the Institute of Prosthetics and Orthotics, Albrecht Federal Scientific and Educational Centre of Medical and Social Expertise and Rehabilitation. А method for denoising and smoothing of the 3D model surfaces for the manufacture of prosthetic and orthopedic products is proposed. The SNR metric difference SNR – δ-SNR (with averaging by scans and SNR values) and average execution time were calculated. The bilateral filtration method with δ-SNR = 11.3362 dB and a runtime of 8.8900 s showed the highest efficiency.Conclusion. The proposed methods for the pre-processing stage of 3D optical scans showed high efficiency in the formation of 3D models of prosthesis and orthosis modules. The results obtained can be used for automating the process of manufacturing various prosthetic and orthopedic products, which is particularly relevant in the context of the modern geopolitical situation.

This paper describes the use of video and digital image processing in investigation of the impact between a rigid hemispherical shape impactor and Hybrid Polyurea-Polyurethane-MWCNTs Nanocomposite Coatings. An experimental study was performed for six sample configurations: single aluminum plates (reference test), multilayer plates with 4 types of coatings and double aluminum plates. The impact phenomenon was recorded with a high-speed video camera and the variation of the projectile's velocity during the impact was obtained through digital analysis. Additionally, the test was instrumented using a force sensor specially designed and mounted on the impactor. The video processing was used to draw the velocity curves and to estimate the evolution of the contact forces between the impactor and the multilayer structures, the results obtained being compared with the force sensor data. Some differences between these two types of measurements are observed, so in order to analyze the configurations behavior, a numerical study of the phenomena was performed in LS-DYNA software using a 2D axial symmetric model. The simulations showed that the profile of the force evolution measured with the sensor is affected by the chosen constructive solution and the data obtained based on the video images are more accurate. The deformations were analyzed, the maximum deformation based on image processing and the residual deformation based on 3D Scan post-test. The video technique combined with 3D Scan are precise enough to study the impact at low velocities and the numerical simulations provide results according to reality. The hyperelastic coatings contribute to a better resistance of the aluminum plates. [ABSTRACT FROM AUTHOR]

The Chinese pangolin（Manis pentadactyla) is a typical nocturnal burrowing mammal, with a very low direct observation rate in the field, and its burrow is important material for ecological research. However, there are few quantitative studies on the burrow structure characteristics of Chinese pangolin, and the verification of burrow classification criteria (resting burrows, foraging burrows) has not been reported. In order to explore the morphological structure differences between the resting burrows and the foraging burrows of Chinese pangolin, four foraging burrows and three resting burrows abandoned by Chinese pangolins were selected for model casting, and 3D digital models were constructed by 3D scanning technology. The results show that the burrow entrance all face west and the tunnel diameters are generally larger than burrow entrance diameters. The average length of the first section of the burrow tunnel, total length of the burrow, bending angle of the burrow tunnel (the first bending from burrow entrance), and the volume of the burrow were 147.5cm, 322.7cm, 130.0°, and 0. 0732 m³, respectively. There were structural differences between the resting burrows and foraging burrows. The entrance to the resting burrow faces further north, its tunnel and entrance diameters, first section length, total length, and the volume of the resting burrows were larger than that of the foraging burrows. The tunnel bending angle and the number of termite nests of the foraging burrows were larger than that of the resting burrows. The study results accurately quantified the burrow structure of the Chinese pangolin, verified the accuracy of the burrow category classification criteria, and provided a theoretical basis for further research on the ecology of the Chinese pangolin burrows. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku is the property of Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku is the property of Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science of Gymnastics Journal is the property of Science of Gymnastics Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arising out of the heightened sensory perceptions of extended lockdown, this creative investigation began with contemplation of flowering street-trees. Through 262 days of lock down, residents of Melbourne retreated to the hyper-local, often reinforced by a 5-km travel bubble and a one-hour daily time limit outdoors. The sublime ephemeral springtime flowers of street-trees were amplified by the extreme sensory and social constraints of social distancing. Drawing us into a suspended moment of slow encounter, we attuned to the contained glowing pulse of plants. The works were created using photogrammetry, a technique for generating 3D models from a large set of photographs taken from all angles of the botanical specimen. Whilst the point-cloud models remain the central artefact of vegetal/digital, it has been presented in a range of formats throughout 2022–23, including multichannel video loops, augmented reality, webXR, gestural interactive works and still prints. This work invites an embodied experience of attuning to both the vegetal and the digital. This is consistent with my alignment with queer and autistic politics, of siding with the object. Increasingly, queer cultural practices are employing new materialism and posthumanism to interrogate the agency of things and the culturally constituted hierarchies of objects and subjects. The reconfiguration of embodied relations is necessary in order to reconceive a viable future. [ABSTRACT FROM AUTHOR]

Foot morphology and arch integrity do not remain constant during a running bout. Previous studies have reported inconsistent changes in foot sizes and arch parameters and this discrepancy may be related to the variation in their test duration, e.g., 15-min treadmill run vs. 30 KM trial. Hence, this study sought to evaluate the change in foot morphology, arch integrity and bilateral symmetry after a 10 KM run among 19 male recreational runners. Before and after the run, a portable foot scanner was used to capture the 3-dimensional foot images and measure foot dimensions in both weight-bearing and non-weight-bearing conditions. Foot arch integrity was quantified by arch height ratio, arch height index, and arch stiffness index (ASI). Bilateral symmetry was evaluated by calculating the symmetry index. Increased foot length (p = 0.007; ηp2 = 0.18) and decreased ball girth (p = 0.038; ηp2 = 0.11) were demonstrated following the run with absolute differences of less than 2 mm. Navicular height, dorsum height, arch height ratio and arch height index significantly decreased after the run (p < 0.001; ηp2 ≥0.30) whereas ASI increased (p < 0.001, ηp2 = 0.33) and navicular height drop reduced (p < 0.001, ηp2 = 0.37). Significances of symmetry index were only demonstrated for navicular height (p = 0.019, effect size = 0.37) and arch height ratio (p = 0.019, effect size = 0.42). A few changes in foot morphology were detected but a reduction in foot arch height was demonstrated, which may give shoe manufacturers insights into shoe design. Male recreational runners were recommended to choose shoes with arch support for maintaining foot arch function during a 10 KM run.

Although personalized polymethylmethacrylate (PMMA) implant production molds for cranioplasty are costly and time-consuming, they allow for better-quality implants. The researchers quantitatively tested the contribution of simplified, low-cost techniques to cosmetic improvement. PMMA prosthesis was placed in a 25-year-old male patient due to osteolysis in the bone flap removed after decompression surgery. A single-sided mold was three-dimensional (3D) printed before the surgery, and the prosthesis was produced during the surgery. In addition, the change in cranial asymmetry was evaluated using a 3D surface scanner after surgery. The mold took half an hour to design and 5 hours to print. The mold cost about 2 dollars. The root means square (RMS) value measured to determine cranial asymmetry decreased from 5.4 mm to 2.8 mm postoperatively. The patient stated that he was pretty satisfied with the cosmetic result. Simple design techniques developed can offer low-cost, fast-design alternative solutions with satisfactory cosmetic results for low-income countries and patients. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine if body symmetry influences establishing stand balance after drop jump. Thirty-two healthy sports students participated in this study, with an average age 19.8 ± 1.4 years, height of 182.9 ± 6.8 cm and weight of 79.1 ± 8.1 kg. Morphological characteristics were assessed by measuring the differences between the left and right side of forearm girth, upper arm girth, calf girth, thigh girth, long shoulder height, lean mass of legs and lean mass of arms. The standing balance result was calculated based on factor scores obtained from nine measurements taken for 30 seconds after jumping from a 25 cm height platform. These measurements included three for normal stand, three for blind stand, and three for deaf stand. The data was collected using a pressure insoles system and by measuring the difference in ground reaction force between the left and right leg. Regression analysis revealed that 27% of the differences in leg load could be explained by differences in morphological characteristics between the left and right side. Two significant predictors were identified: the difference in long shoulder height (explaining 16% of the variance) and the differences in arm lean mass (explaining 11% of the variance). Both variables showed a negative relationship with the factor jump standing. It was observed that imbalances in body symmetry could increase the long-term risk of acute or chronic injuries.

In this study, the effectiveness of an experimental clinical technique for the reproduction of attachments during an orthodontic treatment with clear aligners was evaluated using a new index (CorAl) for quality assessment that exploits the differential entropy of point clouds. The procedure involves the use of a pre-drilled template and a second pre-loaded template with a high-viscosity composite and is compared with the standard technique. Attachment planning was conducted on four prototypes of dental arches with extracted teeth which were divided into two groups according to the proposed operating procedures. Digital scans were utilized to capture dental impressions for both the purposes of virtual planning and to reproduce the clinical outcomes post-procedure. The point clouds obtained after the reproduction of the attachments were aligned with those from the virtual planning, and the deviation analysis was conducted using the quality index of the CorAl method. Though no significant discrepancies were found among the groups regarding morphological flaws, detachments, or maximum defect values, the differential entropy analysis revealed that the experimental technique offers good alignment in attachment placement. The outcome supports that the innovative procedure of the clinical reproduction of attachments proved to be reliable and operationally simple, with additional benefits derived from using the CorAl index. The advantages of CorAl include the use of a single comparison index, no problem of comparison commutativity, noise immunity, low influence from the presence of holes, and point cloud densities. This allows for the drawing of quality maps that show areas with the highest deviation. [ABSTRACT FROM AUTHOR]

Aims: Visualization of the subtalar joint surface in surgical management of calcaneal factures remains a big challenge and anatomic reduction of the articular surface is essential for a good clinical outcome. We hypothesize that video-assistance can provide superior fracture reduction compared to fluoroscopy and that nanoscopy (NSC) achieves more extensive visualization compared to fracturoscopy (FSC). Methods: Ten human cadaveric feet with artificially pre-fractured intraarticular calcaneal fractures with involvement of the posterior facet were treated via a minimal invasive subtalar approach. After initial control of reduction by 2D fluoroscopy, the reduction was further analyzed intraoperatively by FSC and NSC. 3D Scan served as gold standard control of reduction. Need of revision of reduction after the different visualization techniques was recorded and the extent of visualization of the subtalar joint surface in the medio-lateral dimension was compared for FSC and NSC. To quantify access and visualization of the medial and posterior facet, a depth gauge was used to measure from laterally at the clinically widest portion of the calcaneus targeted to the sustentaculum tali. The distance in millimetres was referred to the complete medio-lateral distance seen on paracoronal CT at the widest portion of the calcaneus. Results: Fracture analysis in preoperative CT-scans according to Sanders classification revealed four type IC, two IIA, three IIC and one IIIAC fractures. Mean visualization of the medial and posterior facet was significantly improved with NSC (30.4 ± 3.78 mm) compared to FSC (23.6 ± 6.17 mm) (p = 0.008). An imperfect reduction requiring revision was more often required with NSC compared to FSC. Insufficient reduction using video-assistance was found in two cases. Conclusion: In order to optimize subtalar joint reduction and congruency, video-assisted techniques, especially NSC, provide superior visualization and thus can improve reduction in the surgical treatment of intraarticular calcaneal fractures. [ABSTRACT FROM AUTHOR]

Reverse engineering methods like 3D scanning are becoming common in engineering practice. These methods enable engineers to reproduce the original shape of a scanned part. If other properties are required, then other reverse engineering methods can follow. Estimation of fatigue is a tricky task even if the material properties of the base material are known. Fatigue is influenced not only by material properties and the part's shape but also by technological processes. Fast fatigue life estimation of stamped parts using reverse engineering methods is the target of this paper. The forming process, which has a crucial impact on the fatigue of stamped parts, is considered via inverse stamping. Adaptation of inverse stamping method from shell FEM meshes to volumetric meshes is included. The article also discusses the application of two methods, the Material Law for Steel Sheets (MLSS) and the Method of Variable Slopes (MVS). These methods adjust the fatigue curve based on effective plastic strain calculated by inverse stamping. Calculated results were compared with experimental results. In most situations, there is a good agreement between the calculations and the tests of the specimens without surface coatings. Sometimes, the calculated results are more conservative than the experiments. This is acceptable in component design in terms of reliability. When a Zn-Ni surface coating was applied, the fatigue life of the specimen decreased. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a method for simulating the deformation of concrete surfaces due to weathering employing an example-based approach to replicate shape changes observed in real-world objects. A key challenge in implementing this approach is the scarcity of opportunities to measure shapes both before and after the weathering process. To overcome this limitation, we utilize concrete bricks collected from real-world environments as standardized examples, allowing for an analysis of erosion. By measuring erosion based on the estimated original shape, we correlate the characteristics of erosion with geometric features such as curvature and accessibility. We then apply this analysis to simulate new weathering effects in a given input model in alignment with its own geometric features. Our method yields visually compelling results while reproducing the variation of geometric weathering effects. [ABSTRACT FROM AUTHOR]

Remote sensing technologies such as laser scanning and photogrammetry have advanced significantly in the field-to-BIM workflow in recent years, becoming key instruments for modeling as-built frameworks. They can be utilized to collect dense 3D measured data on the condition of a building, and the derived point cloud can be processed to generate the as-built BIM. It provides building information to report as-built conditions and serves as a skill set for data on problem-solving issues in civil engineering. This research presents an efficient and automated workflow for modifying and evaluating point cloud data, focusing on supporting scan-to-BIM operations. The workflow utilizes cubic voxel mesh creation and voxel subsampling techniques to ensure precise representation of scanned data. The validation of this reconstruction methodology using Grasshopper and Volvox demonstrates its potential to reduce manual labor and analysis typically required in conventional scan-to-BIM methodologies. The presented workflow simplifies the critical task of acquiring building profiles, an essential BIM result, and streamlines the overall process. The integration of the Volvox plugin has further augmented the capabilities of Grasshopper and Rhino, providing users with intuitive tools for manipulating point clouds. Automating certain operations through the presented workflow has significant potential to enhance the efficiency and accuracy of the scan-to-BIM methodologies. These findings have implications in architecture and design, demonstrating how technology can be leveraged to unlock new possibilities and streamline critical processes. [ABSTRACT FROM AUTHOR]

Surface deterioration of concrete subjected to freezing and thawing in combination with deicing salts is one of the most important factors determining the durability of concrete infrastructure in cold climates. The freeze–thaw deicing salt (FTDS) resistance of cementitious materials can be determined by the capillary suction of de‐icing chemicals and freeze–thaw (CDF) test. Specimens are subjected to repeated freeze–thaw cycles with simultaneous addition of deicing salt and the amount of material scaled off near the surface is determined. For concretes with adequate FTDS resistance, this test method works very well. However, specimens with unknown performance often experience increased edge scaling. This leads to a falsification of results and consequently to an underestimation of the actual freeze–thaw resistance. In materials research, however, concretes with high levels of surface deterioration are studied in order to investigate various factors of influence on the freeze–thaw resistance of concretes in a targeted manner. This article presents a novel methodology that delivers new information regarding surface deterioration of CDF samples using high‐resolution 3D scan data. Change of volume is used to support deterioration results of the standard CDF methodology. Increase of surface area is used to estimate change in roughness of samples. [ABSTRACT FROM AUTHOR]

Abstract Sometimes cranioplasty is necessary to reconstruct skull bone defects after a neurosurgical operation. If an autologous bone is unavailable, alloplastic materials are used. The standard technical approach for the fabrication of cranial implants is based on 3D imaging by computed tomography using the defect and the contralateral site. A new approach uses 3D surface scans, which accurately replicate the curvature of the removed bone flap. For this purpose, the removed bone flap is scanned intraoperatively and digitized accordingly. When using a design procedure developed for this purpose creating a patient-specific implant for each bone flap shape in short time is possible. The designed skull implants have complex free-form surfaces analogous to the curvature of the skull, which is why additive manufacturing is the ideal manufacturing technology here. In this study, we will describe the intraoperative procedure for the acquisition of scanned data and its further processing up to the creation of the implant.

The proposed work deals with the production of a thumb prosthesis from ASA (Acrylonitrile-styrene-acrylic) material using FDM (Fused deposition modeling) additive manufacturing technology. The prosthesis serves as a substitute for the deformity of the hand (absence of the thumb including the metacarpal bone) and as a support point for grasping objects to restore the lost opposition function of the thumb. The shape of the thumb and the socket of the prosthesis are designed individually based on a 3D scan of the subject’s healthy hand. The design of the prosthesis was developed according to the anatomically correct condition and the user's requirements. The socket of the prosthesis sufficiently copies the relief of the subject's hand, which results in a sufficient attachment of the prosthesis to the hand segment and the comfort of the subject while wearing the prosthetic aid. [ABSTRACT FROM AUTHOR]

This article's primary goal was to analyze the effect of texture on skid resistance. Surface texture was recorded with a revolutionary device designed to create 3D surface scans, the Static Road Scanner. The skid resistance was represented by a pendulum test value. Measurements were made on three different groups of surfaces. Reference surfaces with known standard grain sizes represented the first group. The second group consisted of specimens made from a different type of aggregate. The last group of surfaces consisted of asphalt specimens made from different sizes and types of aggregates used in a mixture. The test results shed some more light on understanding texture's effect on surface friction. Although some results were expected, not all of them were proven. For instance, a high level of texture doesn't necessarily mean high friction. A relatively strong relationship was found between friction and microtexture on the reference surfaces with grain sizes up to 125 µm. However, the relationships between texture and skid resistance on the aggregate and asphalt specimens turned out to be shallow for the investigated samples. For this reason, it was recommended to expand the number of investigated surfaces in further research to ensure sufficiently different levels of texture. [ABSTRACT FROM AUTHOR]

Small-angle scattering (SAS) is a powerful tool for the detailed structural analysis of objects at the nanometer scale. In contrast to techniques such as electron microscopy, SAS data are presented as reciprocal space information, which hinders the intuitive interpretation of SAS data. This study presents a workflow: (1) creating objects, (2) 3D scanning, (3) the representation of the object as point clouds on a laptop, (4) computation of a distance distribution function, and (5) computation of SAS, executed via the computer program Phone2SAS. This enables us to realize SAS and perform the interactive modeling of SAS of the object of interest. Because 3D scanning is easily accessible through smartphones, this workflow driven by Phone2SAS contributes to the widespread use of SAS. The application of Phone2SAS for the structural assignment of SAS to Y-shaped antibodies is reported in this study. [ABSTRACT FROM AUTHOR]

Sometimes cranioplasty is necessary to reconstruct skull bone defects after a neurosurgical operation. If an autologous bone is unavailable, alloplastic materials are used. The standard technical approach for the fabrication of cranial implants is based on 3D imaging by computed tomography using the defect and the contralateral site. A new approach uses 3D surface scans, which accurately replicate the curvature of the removed bone flap. For this purpose, the removed bone flap is scanned intraoperatively and digitized accordingly. When using a design procedure developed for this purpose creating a patient-specific implant for each bone flap shape in short time is possible. The designed skull implants have complex free-form surfaces analogous to the curvature of the skull, which is why additive manufacturing is the ideal manufacturing technology here. In this study, we will describe the intraoperative procedure for the acquisition of scanned data and its further processing up to the creation of the implant. [ABSTRACT FROM AUTHOR]

The application of frequency-resonance method (FRM) for precise log bending testing is limited by complex geometry; usually the cone with variable cross. This case study presents the relationship among non-destructively tested material parameters of sugar maples and the numerical analysis of effect of simplifications in FRM. Four standing stems were measured to find basic geometry parameters, 3D scanned for precise geometry description, tested by pulling test (PT) to obtain elastic parameters, and, finally, cut down to process the logs. Four logs were measured by stress wave propagation (SWP) using an acoustic tomography (AT) device to obtain longitudinal sound velocities and then evaluated by the FRM to obtain natural frequencies in bending and longitudinal vibrations. Comparison was made between the dynamic moduli of elasticity (MOE), calculated from SWP and the FRM, and the static MOE calculated from the PT. In-situ experimental evaluation was accompanied by modal analysis by finite element method (FEM) working at three levels of geometry simplification (beam model, simplified solid model, and scan-based solid model); the natural frequencies of bending and longitudinal mode shapes were analyzed. The influence of geometry precision on the resulting dynamic response of logs was found regarding comparison to the experimental values. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effectiveness of 360-degree panorama-based Virtual Reality (360VR) as a tool to simulate real-world site visit experiences in interior design education. In the first stage of evaluation, the online survey was implemented to ask students about their learning experience of using 360VR. The second stage of 360 VR effectiveness evaluation focused on the objective comparison of students learning outcomes between the 360VR method and the traditional approach. The students' experience survey results indicated that 360VR and virtual walkthrough experiences benefited students' understanding of the site during the design process. Students reflected positive 360 VR experiences on their engagement in learning, special layout, visualization, and educational effectiveness. The result of the student learning outcome evaluation showed no significant difference between 360 VR compared to no site visit. However, there was a significant improvement in students' spatial planning, finish selection, and total scores when using the 360 VR method compared to an on-site visit. [ABSTRACT FROM AUTHOR]

Textile reinforcements are increasingly establishing their position in the construction industry due to their high tensile properties and corrosion resistance for concrete applications. In contrast to ribbed monolithic steel bars with a defined form-fit effect, the conventional carbon rovings' bond force is transmitted primarily by an adhesive bond (material fit) between the textile surface and the surrounding concrete matrix. As a result, relatively large bonding lengths are required to transmit bond forces, resulting in inefficient material utilization. Novel solutions such as tetrahedral profiled rovings promise significant improvements in the bonding behavior of textile reinforcements by creating an additional mechanical interlock with the concrete matrix while maintaining the high tensile properties of carbon fibers. Therefore, simulative investigations of tensile and bond behavior have been conducted to increase the transmittable bond force and bond stiffness of profiled rovings through a defined roving geometry. Geometric and material models were thus hereby developed, and tensile and pullout tests were simulated. The results of the simulations and characterizations could enable the optimization of the geometric parameters of tetrahedral profiled rovings to achieve better bond and tensile properties and provide basic principles for the simulative modeling of profiled textile reinforcements. [ABSTRACT FROM AUTHOR]

More than half of the people on the planet use eyewear to correct or protect their vision. Eyewear products that fit poorly cause discomfort, dizziness, or blurred vision. One method to improve fit is to create custom-fit eyewear frames on an individual basis. In this paper we propose a new parametric design method to customize the eyewear frames based on individual 3D scanned data of head-and-face measurements. We take the eyeglasses frame as the case study to establish the landmark-product relationship and develop the parametric algorithm in Rhino/Grasshopper software. The results of the case study can generate custom-fitted eyeglass frame models for the two selected subjects, one 33% percentile Asian female and one 90% percentile Caucasian male. The future study will continue validating the eyewear frame fit and optimizing the parametric design method.

Several excavations at the Hemudu site in Zhejiang Province have led to the discovery of more than 100 pieces of bird bones that were likely used to create a kind of musical instrument. However, in contrast to the Jiahu bone flute, it is not clear for what the Hemudu bone whistle was used, although it was probably used for musical purposes. In this paper, the 7000-year-old Hemudu bone whistle is reproduced with 3D scanning and printing technology. Therefore, we propose a robust scan point detection and tracking method that includes three main stages. First, we conducted robust point detection and selection where noise and irrelevant points were removed. Then, we propose to track the key points and conduct 3D model optimization. With the above efforts, we obtained the 3D model of the bone whistle, and the audio of the bone whistle is replicated. The purpose of the bone whistles is inferred and evaluated through audio analyses. The experimental results show that the method is feasible.

While three-dimensional measurement technology is spreading fast, its meaningful application to sedimentary geology still lacks content. Classical shape descriptors (such as axis ratios, circularity of projection) were not inherently three-dimensional, because no such technology existed. Recently a new class of three-dimensional descriptors, collectively referred to as mechanical descriptors, has been introduced and applied for a broad range of sedimentary particles. First-order mechanical descriptors (registered for each pebble as a pair {S, U} of integers), refer to the respective numbers of stable and unstable static equilibria and can be reliably detected by hand experiments. However, they have limited ability of distinction, as the majority of coastal pebbles fall into primary class { S , U } = { 2 , 2 } . Higher-order mechanical descriptors offer a more refined distinction. However, for the extraction of these descriptors (registered as graphs for each pebble), hand measurements are not an option and even computer-based extraction from 3D scans offers a formidable challenge. Here we not only describe and implement an algorithm to perform this task, but also apply it to a collection of 271 pebbles with various lithologies, illustrating that the application of higher-order descriptors is a viable option for geologists. We also show that the so-far uncharted connection between the two known secondary descriptors, the so-called Morse–Smale graph and the Reeb-graph, can be established via a third order descriptor which we call the master graph. [ABSTRACT FROM AUTHOR]

Background: Optical scanning technologies are increasingly being utilised to supplement treatment workflows in radiation oncology, such as surface-guided radiotherapy or 3D printing custom bolus. One limitation of optical scanning devices is the absence of internal anatomical information of the patient being scanned. As a result, conventional radiation therapy treatment planning using this imaging modality is not feasible. Deep learning is useful for automating various manual tasks in radiation oncology, most notably, organ segmentation and treatment planning. Deep learning models have also been used to transform MRI datasets into synthetic CT datasets, facilitating the development of MRI-only radiation therapy planning. Aims: To train a pix2pix generative adversarial network to transform 3D optical scan data into estimated MRI datasets for a given patient to provide additional anatomical data for a select few radiation therapy treatment sites. The proposed network may provide useful anatomical information for treatment planning of surface mould brachytherapy, total body irradiation, and total skin electron therapy, for example, without delivering any imaging dose. Methods: A 2D pix2pix GAN was trained on 15,000 axial MRI slices of healthy adult brains paired with corresponding external mask slices. The model was validated on a further 5000 previously unseen external mask slices. The predictions were compared with the "ground-truth" MRI slices using the multi-scale structural similarity index (MSSI) metric. A certified neuro-radiologist was subsequently consulted to provide an independent review of the model's performance in terms of anatomical accuracy and consistency. The network was then applied to a 3D photogrammetry scan of a test subject to demonstrate the feasibility of this novel technique. Results: The trained pix2pix network predicted MRI slices with a mean MSSI of 0.831 ± 0.057 for the 5000 validation images indicating that it is possible to estimate a significant proportion of a patient's gross cranial anatomy from a patient's exterior contour. When independently reviewed by a certified neuro-radiologist, the model's performance was described as "quite amazing, but there are limitations in the regions where there is wide variation within the normal population." When the trained network was applied to a 3D model of a human subject acquired using optical photogrammetry, the network could estimate the corresponding MRI volume for that subject with good qualitative accuracy. However, a ground-truth MRI baseline was not available for quantitative comparison. Conclusions: A deep learning model was developed, to transform 3D optical scan data of a patient into an estimated MRI volume, potentially increasing the usefulness of optical scanning in radiation therapy planning. This work has demonstrated that much of the human cranial anatomy can be predicted from the external shape of the head and may provide an additional source of valuable imaging data. Further research is required to investigate the feasibility of this approach for use in a clinical setting and further improve the model's accuracy. [ABSTRACT FROM AUTHOR]

Scanning real 3D objects face many technical challenges. Stationary solutions allow for accurate scanning. However, they usually require special and expensive equipment. Competitive mobile solutions (handheld scanners, LiDARs on vehicles, etc.) do not allow for an accurate and fast mapping of the surface of the scanned object. The article proposes an end-to-end automated solution that enables the use of widely available mobile and stationary scanners. The related system generates a full 3D model of the object based on multiple depth sensors. For this purpose, the scanned object is marked with markers. Markers type and positions are automatically detected and mapped to a template mesh. The reference template is automatically selected for the scanned object, which is then transformed according to the data from the scanners with non-rigid transformation. The solution allows for the fast scanning of complex and varied size objects, constituting a set of training data for segmentation and classification systems of 3D scenes. The main advantage of the proposed solution is its efficiency, which enables real-time scanning and the ability to generate a mesh with a regular structure. It is critical for training data for machine learning algorithms. The source code is available at https://github.com/SATOffice/improved_scanner3D. [ABSTRACT FROM AUTHOR]

Manual removal of burrs on castings introduces health, safety, and environmental concerns. Automated removal of highly variable casting burrs could improve safety, but requires a solution based on robots, smart sensors, and advanced algorithms to tackle the problem in a flexible and cost-effective way. This paper presents a system for automatic tool trajectory generation for robotic deburring of cast parts with a specific focus on the robotic tool trajectory generation algorithm. The system generates a robotic trajectory adapted to the specific workpiece based on CAD model and 3D scans of the workpiece. The registered 3D scans and CAD model is used to generate a 3D model of each individual workpiece. This is fed into the tool trajectory generation algorithm. The algorithm uses the generated 3D model as well as a priori knowledge of the casting process to generate the tool trajectory. The tool trajectory planning algorithm has been tested on a set of various 3D models of cast parts, and the generated robotic tool path has been both simulated and tested on a KUKA KR 60. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the wear resistance of stainless steel crowns, (SSCs), zirconia crowns (ZRCs), and nanohybrid crowns (NHCs) using a 3D tomography method. Methods: Prefabricated SSCs, ZRCs, and NHCs (n equals 80) were worn for 400,000 cycles, equivalent to three years of simulated clinical wear, at 50 N and 1.2 Hz using the Leinfelder-Suzuki wear tester. Wear volume, maximum wear depth, and wear surface area were computed using a 3D superimposition method and 2D imaging software. Data were statistically analyzed using one-way analysis of variance with the least significant difference post hoc test (P<0.05). Results: After a wear simulation of three years, NHCs had a 45 percent failure rate; NHCs also had the greatest wear volume loss (0.71 mm3 ), maximum wear depth (0.22 mm), and wear surface area (4.45 mm2 ). SSCs (0.23 mm3, 0.12 mm, 2.63 mm2 ) and ZRCs (0.03 mm3, 0.08 mm, 0.20 mm2 ) had less wear volume, area, and depth (P<0.001). ZRCs were the most abrasive to their antagonists (P<0.001). The NHC (against SSC wearing group) had the greatest total wear facet surface area (4.43 mm2 ). Conclusions: Stainless steel crowns and zirconia crowns were the most wear-resistant materials. Based on these laboratory findings, in the primary dentition, nanohybrid crowns are not recommended as long-term restorations beyond 12 months (P=0.001). [ABSTRACT FROM AUTHOR]

Between the 17th and 20th centuries, polychrome beeswax anatomical models played an important role in the transmission of anatomical knowledge thanks to the high degree of accuracy and realism they were able to achieve in the representation of the most delicate structures of the organism. However, due to the fragility of this material, some of these artefacts now survive in a rather precarious state of conservation. Due to the lack of consistency of some of the internal support structures, some of these figures have been damaged or their integrity has been seriously compromised. In this article we show a case of stabilisation using a polymethylmethacrylate support of a model from the Complutense Veterinary Museum, representing the head of a horse, which has suffered the loss of some parts and shows significant cracks and fractures due to the partial collapse of the internal metal framework. The methodology used was based essentially on the use of digital technologies, to minimise the handling of the work. Based on a virtual copy obtained by 3D scanning, a specific support that fits perfectly to the surface of the figure has been designed. Subsequently, some of the pieces were produced using 3D printing in order to subject them to functional and aesthetic tests and, finally, the support was manufactured using numerical control machining. The result meets the requirements of stability and minimum aesthetic impact. [ABSTRACT FROM AUTHOR]

Lightweight porous composites have been widely explored to improve their acoustic and thermal performances. Hempcrete can serve as thermal insulating or soundproofing material by utilising its high porosity. However, the rigorous correlation between hempcrete thermal and acoustic performance and its pore structure remains poorly understood due to its different pore types. In this study, three hempcrete pore types [i.e., i) inter-pore between hemp and mortar, ii) hemp intra-pore, and iii) mortar intra-pore] were modified by tamping, delignification, and foaming agent conditions, respectively. Then the volumes of three types of pores were estimated using X-ray micro-computed tomography (μCT) and mercury intrusion porosimetry. The new segmentation methods were developed and their reliability and accuracy were validated. Then, the pore volumes were correlated to the thermal and acoustic properties of hempcrete. Low tamping and high delignification conditions are recommended to increase inter-pore volume and enhance hempcrete performances relating to both thermal insulation and sound absorption for real-world hempcrete applications. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a method for simulating the deformation of concrete surfaces due to weathering employing an example-based approach to replicate shape changes observed in real-world objects. A key challenge in implementing this approach is the scarcity of opportunities to measure shapes both before and after the weathering process. To overcome this limitation, we utilize concrete bricks collected from real-world environments as standardized examples, allowing for an analysis of erosion. By measuring erosion based on the estimated original shape, we correlate the characteristics of erosion with geometric features such as curvature and accessibility. We then apply this analysis to simulate new weathering effects in a given input model in alignment with its own geometric features. Our method yields visually compelling results while reproducing the variation of geometric weathering effects.

Reverse engineering methods like 3D scanning are becoming common in engineering practice. These methods enable engineers to reproduce the original shape of a scanned part. If other properties are required, then other reverse engineering methods can follow. Estimation of fatigue is a tricky task even if the material properties of the base material are known. Fatigue is influenced not only by material properties and the part’s shape but also by technological processes. Fast fatigue life estimation of stamped parts using reverse engineering methods is the target of this paper. The forming process, which has a crucial impact on the fatigue of stamped parts, is considered via inverse stamping. Adaptation of inverse stamping method from shell FEM meshes to volumetric meshes is included. The article also discusses the application of two methods, the Material Law for Steel Sheets (MLSS) and the Method of Variable Slopes (MVS). These methods adjust the fatigue curve based on effective plastic strain calculated by inverse stamping. Calculated results were compared with experimental results. In most situations, there is a good agreement between the calculations and the tests of the specimens without surface coatings. Sometimes, the calculated results are more conservative than the experiments. This is acceptable in component design in terms of reliability. When a Zn-Ni surface coating was applied, the fatigue life of the specimen decreased.

In this study, the effectiveness of an experimental clinical technique for the reproduction of attachments during an orthodontic treatment with clear aligners was evaluated using a new index (CorAl) for quality assessment that exploits the differential entropy of point clouds. The procedure involves the use of a pre-drilled template and a second pre-loaded template with a high-viscosity composite and is compared with the standard technique. Attachment planning was conducted on four prototypes of dental arches with extracted teeth which were divided into two groups according to the proposed operating procedures. Digital scans were utilized to capture dental impressions for both the purposes of virtual planning and to reproduce the clinical outcomes post-procedure. The point clouds obtained after the reproduction of the attachments were aligned with those from the virtual planning, and the deviation analysis was conducted using the quality index of the CorAl method. Though no significant discrepancies were found among the groups regarding morphological flaws, detachments, or maximum defect values, the differential entropy analysis revealed that the experimental technique offers good alignment in attachment placement. The outcome supports that the innovative procedure of the clinical reproduction of attachments proved to be reliable and operationally simple, with additional benefits derived from using the CorAl index. The advantages of CorAl include the use of a single comparison index, no problem of comparison commutativity, noise immunity, low influence from the presence of holes, and point cloud densities. This allows for the drawing of quality maps that show areas with the highest deviation.