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According to previous research, shore 40 A casting silicone is currently one of the more suitable materials for simulating the physical behavior of the airways in medicine simulation. This is essential to attain high-fidelity manikins that can perfectly mimic the simulated anatomic region, not just geometrically, but also in terms of haptic feedback. Due to the geometrical complexity of the tracheo-bronchial tree, mold design is a difficult and time-consuming process. An interactive modeling procedure for modeling mold parts for tracheo-bronchial tree casting is proposed in this paper, with the purpose of reducing modeling time without compromising quality. Following the definition of a standard modeling procedure, this was implemented in the Matlab language by using an IGES and STL editing toolbox. By using the interactive procedure it is possible to reduce the time required for virtual modeling from several hours to less than 1 min. Given this preliminary result, the proposed procedure will be further tested and developed in the near future, with the possibility of automating other lower airway modeling steps, such as vent generation and mounting holes/pins. [ABSTRACT FROM AUTHOR]

Research into teachers' concepts and changes over time in digital technologies is crucial for gaining insights into the factors that shape teachers' concepts of technologies and influence their use in the classroom. Numerous studies have indicated that the use of 3D modelling and printing (3DMP) contributes to the modernization of teaching and the achievement of student learning outcomes. Using a three-wave longitudinal study with the application of conceptual metaphors as a theoretical background, this study tracks teachers' concepts of 3DMP after training, three months, and after one year of teaching experience and provides insight into this area. The data for the study was collected from 74 secondary teachers and processed using a mixed-methods research approach. The findings show that as teachers gain experience, their views on using 3DMP in education evolve. The results include a shift in their perception of digital reliance, the pedagogical benefits, the potential for creative expression, and the sensitivity of 3D printing. The findings of our study suggest that teachers need continuous technical support at the beginning of their use of 3DMP in the classroom, so that the application of this technology can successfully contribute to the development of student creativity and knowledge. This research emphasizes the need for comprehensive ongoing support and targeted training to enable teachers to effectively integrate 3DMP into educational practices, while fostering creativity and addressing technical complexities. Furthermore, this research sheds light on teachers' views of 3DMP and has implications for developments in teacher training and courses, the 3DMP platform, software development, education policy, and the 3DMP industry. [ABSTRACT FROM AUTHOR]

Cultural heritage is no longer something that can only be experienced in a museum exhibition. Digital tools have facilitated the distribution of material relating to artefacts, both in its representation and in presenting its context. This paper describes how digital modelling techniques can be synthesised with 3D scanning to digitally restore artefacts and create authentic replicas of their original states. The digital artefacts can then be used to assist the process of interpreting these artefacts in diverse forms, both in the museum and outside the museum. The study looks at Pictish sculpture as a case-study, restoring 3D models of two stones, and creating varying opportunities for their interpretation. As part of this study, new interactive tools, a virtual reality environment, and a virtual tour are built to assist immersive interpretation of the Pictish sculpture. The application of these digitised objects serves as an opportunity for informal learning. These applications were evaluated during a drop-in session. Findings show that all participants enjoyed the immersive mode of learning with 89% also showing a willingness to learn more about the topic. [ABSTRACT FROM AUTHOR]

Medical imaging is a valuable source for facilitating empirical research and provides an accessible gateway for developing novel forensic anthropological methods for analysis including 3D modelling. This is especially critical for the United Kingdom (UK), where methods developed from modern UK populations do not currently exist. This study introduces a new approach to assist in human identification using 3D models of the paranasal sinuses. The models were produced from a database of 500 modern CT scans provided by University College London Hospital. Linear measurements and elliptic Fourier coefficients taken from 1500 three-dimensional models across six ethnic groups assessed by one-way ANOVA and discriminant function analysis showed a range of classification rates with certain rates reaching 75–85.7% (p < 0.05) in correctly classifying age and sex according to size and shape. The findings offer insights into the potential for employing paranasal sinuses as an attribute for establishing the identification of unknown human remains in future crime reconstructions. [ABSTRACT FROM AUTHOR]

At a global scale, deltas are vital economic hubs, in part due to the combination of their access to inland regions via river systems with their proximity to sea. However, with the sea in close vicinity also comes the threat of freshwater contamination by saline seawater, especially during droughts. This study explores the potential of a mitigation measure to estuarine salt intrusion, namely the construction of a (temporary) earthen sill—a measure implemented in the Lower Mississippi River near New Orleans (LA, USA). This study suggests design guidelines on how a sill can be used to mitigate estuarine salt intrusion: the design should focus on the longitudinal placement and the height of the sill, and the mitigating efficiency of the sill reduces with increasing tidal range. Overall, a (temporary) sill has great potential to reduce salt intrusion in salt wedge estuaries if there is sufficient water depth available. [ABSTRACT FROM AUTHOR]

Cephalopods, a diverse class of carnivorous marine predators, exhibit a wide range of feeding behaviours and foraging strategies related to their lifestyle, habitat and morphological adaptations. Their beaks play a crucial role in capturing and processing prey. This study investigates the link between the shape of the rostrum of cephalopod beaks and their function through a mix of experimental and computational approaches. Fourteen upper beak rostrum models from a range of cephalopod species, representing their morphological and ecological diversity, were 3D-printed, and subjected to uniaxial puncture tests. Force and displacement were recorded to estimate puncture ability. Finite Element Analysis (FEA) was used to explore the form–function relationship under loading conditions mimicking biting and pulling, analysing stress patterns across different rostrum morphologies. The results show that rostrum size significantly influenced puncture performance, with smaller rostra requiring less force and displacement for puncturing. However, larger rostra exhibited higher structural stiffness, suggesting increased vulnerability to stress during biting. Morphology-driven tests demonstrated species-specific differences in puncture abilities, with rostrum sharpness playing a crucial role. FEA results further indicated that longer and sharper rostra were more susceptible to stress, potentially impacting their overall structural integrity. The findings highlight the trade-off between rostrum size and sharpness in cephalopod beaks, with implications for prey selection and feeding efficiency. The study contributes to understanding the morpho-functional aspects of cephalopod beaks and their role in prey capture and consumption, shedding light on the evolutionary pressures shaping these remarkable marine predators. [ABSTRACT FROM AUTHOR]

The regions of East Asia, as well as South Asia and the Middle East are rich in cultural heritage of grottoes where a large number of Buddhist niches exist. Three-dimensional (3D) semantic modelling enriches 3D geometric models with an understanding of the historical and cultural value of cultural heritage, facilitating interoperability and analysis beyond mere visualization. 3D models with semantic information act as essential digital infrastructure for heritage management, knowledge dissemination and simulation analysis in cultural heritage. However, due to the lack of standardized data model for the grotto domain, it is difficult to exchange information, share knowledge and the advancement of spatial analysis and simulation. In order to fill the above-mentioned gap, this study develops a data model for niches as a CityGML Application Domain Extension (ADE) based on the CityGML 3.0 standard. In this ADE, niche components and their attributes are defined on two semantic levels, i.e., niche structural component and niche component member. A famous niche in China belonging to the World Heritage was selected as a case study to demonstrate the integration of geometries, semantics and attributes, illustrating that the extended ADE module complies with the CityGML 3.0 standard. This study provides novel insights into the 3D semantic modelling of niches as well as expands the applications scope of CityGML standard within the cultural heritage sector. [ABSTRACT FROM AUTHOR]

This paper reports results of laboratory and 3D numerical modeled pull-out tests with steel ladders and polymeric strip reinforcements. These types of reinforcement are commonly used in reinforced soil walls constructed with concrete facing elements. Laboratory pull-out tests are required to determine accurate and realistic pull-out strength values considering the interaction of specific reinforcement and backfill materials under different confining pressures (i.e., trying to simulate the different reinforcement layer arrangements and load conditions in actual reinforced soil walls). International design Codes for reinforced soil walls provide default values for pull-out strength. However, in many cases, default values are too conservative and/or are not strictly specified for particular reinforcement types. Pull-out tests can be difficult and expensive to perform, thus not being common nor worth for the vast majority of reinforced soil wall projects. Consequently, calibrated numerical models can be useful to predict pull-out response under site-specific conditions, and provide further understanding of the mechanisms involved in the soil-reinforcement interaction. Details of the numerical approach, including relevant aspects of the soil-reinforcement interfaces, are described. Examples of calibrated numerical predictions for pull-out loads, displacements, and soil-dilatancy effects are presented. The influence of reinforcement, soil and interface stiffnesses is shown. Numerical results provide useful insight for future modelling works of the complex interaction between type-specific backfill materials and reinforcement element, relevant for investigation and/or practical design of reinforced soil walls. [ABSTRACT FROM AUTHOR]

Accurate quantification of the jawbone-implant interface plays a pivotal role in assessing the mechanical stability of dental implant structures. This study proposes a methodology integrating the electro-mechanical impedance (EMI)-based technique with a deep learning algorithm to autonomously monitor the bone-implant interface during the osseointegration process. We develop a 1D convolutional neural network (1D CNN) model, which automatically processes raw EMI data and extracts optimal features for predicting osseointegration ratios. To validate our approach, we conduct predictive 3D numerical modelling of the PZT-implant-bone system. This model simulates the implant's EMI response under varying degrees of osseointegration. Next, we employ traditional statistical metrics to monitor osseointegration and discuss their limitations. Finally, we apply the proposed 1D CNN model to predict bone-implant osseointegration rate. We train and test the network using the simulated EMI data with added noise to account for real-world conditions. The results show that the trained model achieves a minimal testing error of just 2.4%. Even when 60% of testing cases are not trained, the model maintains a prediction accuracy exceeding 94%. [ABSTRACT FROM AUTHOR]

Virtual and augmented reality digital twins are becoming increasingly prevalent in a number of industries, though the production of digital-twin systems applications is still prohibitively expensive for many smaller organisations. A key step towards reducing the cost of digital twins lies in automating the production of 3D assets, however efforts are complicated by the lack of suitable automated methods for determining the visual quality of these assets. While visual quality assessment has been an active area of research for a number of years, few publications consider this process in the context of asset creation in digital twins. In this work, we introduce an automated decimation procedure using machine learning to assess the visual impact of decimation, a process commonly used in the production of 3D assets which has thus far been underrepresented in the visual assessment literature. Our model combines 108 geometric and perceptual metrics to determine if a 3D object has been unacceptably distorted during decimation. Our model is trained on almost 4, 000 distorted meshes, giving a significantly wider range of applicability than many models in the literature. Our results show a precision of over 97% against a set of test models, and performance tests show our model is capable of performing assessments within 2 minutes on models of up to 25, 000 polygons. Based on these results we believe our model presents both a significant advance in the field of visual quality assessment and an important step towards reducing the cost of virtual and augmented reality-based digital-twins. [ABSTRACT FROM AUTHOR]

This study presents a web-based application developed for the efficient management of large 3D city models (3DCMs) which are challenging in terms of browsers' memory limits and network traffic management. The application offers functionalities such as 3D tiling, web-based visualization, 3DCM generation from 2D data, and 3D spatial analysis. It complies with international standards and utilizes open-source software components. The application includes a 3D tiling tool that implements the OGC 3D Tiles Standard, allowing users to partition their 3DCMs into optimized tiles for storage, transmission, and rendering. A web-based procedural modeling tool enables users to generate 3DCMs from 2D building footprint data without the need for complex modeling languages. A 3D spatial analysis component empowers users to perform comprehensive spatial analyses within the web-based environment. Leveraging modern web technologies facilitates precise and efficient spatial computations. To provide standardized visualization, the application features a viewer and client application built using HTML5 and WebGL technologies. This viewer adheres closely to the 3D Tiles Standard, enabling immersive navigation and interaction with 3DCMs. By combining these components, this web-based application handles the management of large 3DCMs, offering enhanced visualization, analysis, and model generation capabilities. It represents a milestone in web-based 3D city model management, prioritizing international standards and open-source principles. [ABSTRACT FROM AUTHOR]

Purpose: Acute syndesmotic ankle injuries continue to impose a diagnostic dilemma and it remains unclear whether weightbearing and/or external rotation should be added during the imaging process. Therefore, the aim of this study was to assess if combined weightbearing and external rotation increases the diagnostic sensitivity of syndesmotic ankle instability using weightbearing CT (WBCT) imaging, compared to isolated weightbearing. Methods: In this retrospective study, patients with an acute syndesmotic ankle injury were analysed using a WBCT (N = 21; Age = 31.6 ± 14.1 years old). Inclusion criteria were an MRI confirmed syndesmotic ligament injury imaged by a WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic injuries. Three-dimensional (3D) models were generated from the CT slices. Tibiofibular displacement and talar rotation were quantified using automated 3D measurements (anterior tibiofibular distance (ATFD), Alpha angle, posterior Tibiofibular distance (PTFD) and Talar rotation (TR) angle in comparison to the contralateral non-injured ankle. Results: The difference in neutral-stressed Alpha angle and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and contralateral control (P = 0.046 and P = 0.039, respectively). The difference in neutral-stressed PTFD and TR angle did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (n.s.). Conclusion: Application of combined weightbearing-external rotation reveals an increased ATFD in patients with syndesmotic ligament injuries. This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. In clinical practice, this could enhance the current diagnostic accuracy of subtle syndesmotic instability in a non-invasive manner. However, to what extent certain displacement patterns require operative treatment strategies has yet to be determined in future studies. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Mining industrial areas with anthropogenic engineering structures are one of the most distinctive features of the real world. 3D models of the real world have been increasingly popular with numerous applications, such as digital twins and smart factory management. In this study, 3D models of mining engineering structures were built based on the CityGML standard. For collecting spatial data, the two most popular geospatial technologies, namely UAV-SfM and TLS were employed. The accuracy of the UAV survey was at the centimeter level, and it satisfied the absolute positional accuracy requirement of creating all levels of detail (LoD) according to the CityGML standard. Therefore, the UAV-SfM point cloud dataset was used to build LoD 2 models. In addition, the comparison between the UAV-SfM and TLS sub-clouds of facades and roofs indicates that the UAV-SfM and TLS point clouds of these objects are highly consistent, therefore, point clouds with a higher level of detail and accuracy provided by the integration of UAV-SfM and TLS were used to build LoD 3 models. The resulting 3D CityGML models include 39 buildings at LoD 2, and two mine shafts with hoistrooms, headframes, and sheave wheels at LoD 3. [ABSTRACT FROM AUTHOR]

Preoperative planning of comminuted fracture repair using 3D printed anatomical models is enabling surgeons to visualize and simulate the fracture reduction processes before surgery. However, the preparation of such models can be challenging due to the complexity of certain fractures, particularly in preserving fine detail in bone fragments, maintaining the positioning of displaced fragments, and accurate positioning of multiple bones. This study described several key technical considerations for preparing 3D printed anatomical models for comminuted fracture preoperative planning. An optimized segmentation protocol was developed that preserves fine detail in bone fragments, resulting in a more accurate representation of the fracture. Additionally, struts were manually added to the digital model to maintain the positioning of displaced fragments after fabrication, reducing the likelihood of errors during printing or misrepresentation of fragment positioning. Magnets were also used to enable separation and visualization of accurate positioning of multiple bones, making it easier to visualize fracture components otherwise obscured by the anatomy. Finally, the infill for non-target structures was adjusted to minimize print time and material wastage. These technical optimizations improved the accuracy and efficiency of preparing 3D printed anatomical models for comminuted fracture preoperative planning, improving opportunities for surgeons to better plan surgical treatment in advance, reducing the likelihood of errors, with the goal of improving surgical outcomes. [ABSTRACT FROM AUTHOR]

In a large variety of smart city applications, the processes are settled with LOD2 (Level of Details) and the generation of the LOD2 models requires the proper generation of the roof geometries. In general, obtaining roof type information and succeeding generations of the LOD2 models requires expensive aerial surveys and time-consuming construction processes. In this study, a methodology to generate LOD2 building models using only 2D building footprints and aerial imagery is explained to overcome these challenges. The roof type information has been obtained from an aerial image that covers the entire study area using a CNN (Convolutional Neural Network) model. Then, the roof geometries have been constructed procedurally by extending and implementing a well-known Straight Skeleton (SS) algorithm for three main types of roofs: flat, gable and hipped. These constructed roof geometries have been combined with LOD1 block models generated by extruding the 2D footprints according to the height attribute. The overall accuracy of the CNN is 89.9% and the class-wise accuracies are over 84% for all classes. The least recall value is observed for the gable roof class, the enhancement options are discussed in the relevant section. The proposed methodology has been developed as a web-based solution utilizing RESTful web services with modern web technologies. In summary, the main novelty of the study is based on two contributions: using DL for gathering roof-type information without any end-user interference and the extension of the SS algorithm for the construction of roof geometries. The final product of this study is a web-based architecture for the rapid generation of the LOD2 building models. [ABSTRACT FROM AUTHOR]

The paper deals with the unpublished survey and geometric analysis of the circular helical staircase built around 1660 in Palazzo Spada's wing on Via del Polverone in Rome. Its role in the development of the place and the history of its design process are addressed thanks to historical drawings and the reference model proposed both in the treatise and construction between the fifteenth and seventeenth centuries. A description of the 3D digital survey procedures is followed by the reconstruction of a NURBS 3D model that describes the staircase and its geometric properties. Three helical turns of the staircase undergo an in-depth analysis of the slope angle thanks to the development of the helical lines. This leads to the recognition of the main features of this staircase: its unique central structure; the implementation of geometrical proportions descending from Andrea Palladio's treatise; the changes of the slope angle that characterize the staircase flights and the space they generate. [ABSTRACT FROM AUTHOR]

In this work, we study the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) structure in aqueous dispersion with small-angle X-ray scattering (SAXS). In-depth structure analysis is achieved based on a set of complementary and sophisticated algorithms, which provide not only shape and packing of chains but also 3D structure of the colloids. The structure information of the PEDOT chain was extracted from the well-known Guinier, Porod and pair distance distribution function (PDDF) analysis of the SAXS data, while the 3D modelling was achieved with the DAMMIF and DAMAVER programs in ATSAS software package. To the best of our knowledge, we first establish the 3D model of the PEDOT:PSS colloids' structure that will help people to understand the supramolecular assembly in aqueous dispersion, which sheds light on the solution structure study of polymers that are widely used in daily life. [ABSTRACT FROM AUTHOR]

In the present paper, an active landslide located to the southeast of the urban area of Alcoy (Alicante, Spain) is analysed. This landslide affects the N-340 road, as well as an area in which some industrial buildings dated from the fifteenth century and catalogued as Places of Cultural Interest are placed. This region is characterised by the existence of a steep relief composed of materials from the Miocene to the present, on which many gravitational movements are developed. The displacements have been analysed using high-resolution spotlight mode SAR images captured by the Spanish SAR satellite PAZ (which operates at X-band), which were processed by advanced differential SAR Interferometry (A-DInSAR). The behaviour of the instability has been determined using InSAR-derived time series displacement maps. Additionally, the study has been completed with a detailed geomorphological mapping at 1:2000 scale and an analysis of structural damage carried out in situ. The landslide was modelled in 3D, from a deterministic and probabilistic point of view, confirming the global instability of the area and the relationship of the landslide with rainfall and the construction of a new road. The integration of all this information obtained and its subsequent analysis has made possible to precisely define the extension of the instability, its kinematics, and to identify the main triggering factors. This information will be crucial for the proper management of this landslide by the local authorities. [ABSTRACT FROM AUTHOR]

Introduction: Large segmental long bone defects are notoriously difficult to manage. Treatment is resource-intensive due to the complexity, cost, and specialized skills required. Truss designs are known for their triangular shapes organized in web configurations. This allows for maximal mechanical strength, the least mass, and a lattice that can be filled with bone graft. Using a truss cage combined with contemporary internal fixation provides immediate stability for bone ingrowth and long-term potential union. The implant is designed using virtual 3D modelling of the patient's bone defect based on a CT scan. The truss cage can be used in a staged procedure combined with Masquelet's induced membrane technique. This study aims to review the outcomes of patient-specific, locally designed 3D titanium truss cages packed with cancellous autograft in treating segmental, long bone defects in the lower limb in a developing country setting. Methods: This retrospective series reviewed cases performed at various institutions between January 2019 and March 2022. Parameters assessed included patient demographics, size and location of the defect, time to clinical and radiological union and complications. Results: Nine cases were included for review, with a mean age of 36 years (range 19–52). Defects ranged from 60 to 205 mm, and eight cases were staged procedures. Eight cases used intramedullary reamings as bone graft. Contemporary intramedullary nails were used for fixation in all cases. No peri- or post-operative complications occurred. All cases progressed to functional union. Conclusion: 3D-printed titanium truss cages combined with bone graft appear to be an effective treatment of large bone defects in the lower limb in a developing country setting in the short term. No complications were encountered, but longer follow-up is needed before definitive recommendations can be made. Level of evidence.: Level IV (retrospective case series). [ABSTRACT FROM AUTHOR]

The sedimentary architecture of the Middle Sanaga deposits in the Central Cameroon Region was studied by combining sedimentological and surface geoelectrical techniques. Lithologic columns from hand augers and pits were correlated to geoelectrical profiles. All of these data were analysed to determine the volumes of lithological units that constitute significant potential geomaterial deposits (gravels, sands, and clays). From surface to depth, geoelectrical results show four main units: conductive GU1 (100 Ωm), semi-resistive GU2 (800 Ωm), resistive UG3 (1000–2000 Ωm), and highly resistive GU4 (over 2000 Ωm). The calibration results identify three lithological units: LU1 composed of poorly sorted pebbles and gravels; LU2 consisting of well-classified medium to coarse sands, asymmetry towards fine to coarse elements; and LU3 consisting of silty clays and clayey sands. Correlation of results assigns UG1 and LU3 to low hydrodynamics, GU2 and LU2 to medium hydrodynamics, and GU3 with LU1 to high hydrodynamics. A 3D filling model has been developed. This model shows that the volume of GU1-LU3 is estimated of 33,549,496 m3, for GU2-LU2 is estimated of 18,352,728 m3, and of GU3-LU1 of 7,687,875m3. This study has important implications for the knowledge and characterization of lithological units, especially geomaterials. [ABSTRACT FROM AUTHOR]

Neighbouring buildings, even though disconnected from the structural viewpoint, may interact through the underlying soil especially when they are founded on very soft soils. Despite some pioneering studies since the early 1970's, structure–soil–structure interaction has yet to be further investigated to reveal the effects that could be exerted on both the static and dynamic response of nearby structures. The present work aims at expanding the theoretical knowledge on this phenomenon through an extensive parametric study based on a truly 3D continuum approach solved through the Flac3D finite difference software. The impedance functions of two closely-spaced shallow foundations have been numerically calculated by varying the distance between the nearby footings and the subsoil configuration (homogeneous or layered). The numerical results have elucidated important effects of cross interaction between two neighbouring foundations. The static stiffness reduces, and this effect is increasingly significant as the foundations are closer whatever the subsoil conditions are. The dynamic coefficients increase with respect to those corresponding to the single footing over halfspace. Such effect is less important for the layer-over-halfspace soil configuration, for which the dynamic coefficients are mainly affected by the frequency response of the stratum. Finally, in the realm of the sub-structure approach, a novel simplified design approach, based on group factors for closely-spaced shallow foundations, was proposed to compute the soil-foundation impedance matrix englobing the foundation–foundation interaction in addition to the soil–foundation interaction. [ABSTRACT FROM AUTHOR]

The recording and measurement of information on research objects has always been one of the most important concerns of archaeologists, both in terms of preserving complete information on the objects and in terms of not stopping further excavation work. With the rapid development of photogrammetry and 3D modelling techniques, 3D reconstruction techniques have now become an important tool for recording and measuring information in archaeology today. In this study, the SFM-MVS computer vision technique was used to take continuous photographs of a small scene with overlapping images under normal lighting conditions and to attempt to record rapid 3D modelling of the small scene and to measure parameters related to rock features. Firstly, based on the application of SFM-MVS technology, small-scene 3D models are rapidly created to recover accurate surface model records of the suspected fossil outcrop rock masses. Secondly, the 3D model of the fossil outcrop was separated into rock monoliths, and the suspected fossil contour lines were outlined and measured to extract an orthographic projection vector map of the rock monoliths. Finally, the shape of the rock monoliths was measured and statistically analysed in conjunction with geometric morphological analysis, and multi-view visual observations of the suspected fossil monoliths were recorded and their surface features accurately measured. The research work process and results show that the use of mobile phone imaging point cloud modelling method can not only quickly obtain 3D records of small scenes of rock masses, but also extract orthographic projection planes of suspected fossil monoliths and surface fine feature parameter measurements to realise digital mapping of archaeological objects, and this technical method is a realistic reference guide for similar archaeological research on small scenes and the conservation of cultural heritage. [ABSTRACT FROM AUTHOR]

This work proposes the virtual restoration of the Bodhidharma polychrome sculpture from the Lingyan Temple in China. Based on scientific analyses and simulation experiments, exterior colours and textures were virtually restored by combining 3D scanning and multi-view 3D reconstruction. At the same time, an efficient cultural relics high-fidelity information 3D modelling method was proposed. Colours and textures are essential for polychrome cultural relics, reflecting the historical appearance and technology. Due to long periods of natural ageing and the destruction of environmental factors, the colours and textures of polychrome sculptures are often altered or radically changed, making it difficult for people to appreciate the initial appearance. With the rapid development of digital technology and high-fidelity 3D modelling, virtual reality technology allows us to restore the appearance of cultural relics. This study expands the dimension of cultural relics exhibition, provides new perspectives for archaeology, art history and cultural heritage research, and provides a reference for the virtual restoration and digitalised archive of other cultural relics. [ABSTRACT FROM AUTHOR]

The defining of upper crustal structures is an essential process for understanding the tectonic evolution and geodynamics of a region. In this context, the paper aims to determine basement depth and upper crustal structures through the Bouguer gravity anomalies and seismic reflection sections in Denizli Graben located in the western part of Turkey. The gravity data have been analyzed using the power spectrum technique. The results from this technique show that the average Moho depth, basement depth of the middle layer, and the depth of sediment basin in the region have been calculated as 33.6, 12.8, and 3.9 km, respectively. Furthermore, the Moho depth of the region has been estimated using gravity anomalies and is computed to be about 33 km in Denizli Graben. As such, it is shown that the depth values obtained from power spectrum analysis and Moho depth calculations are consistent with each other. Bouguer gravity anomalies have been also modeled three-dimensionally (3D). In the model map, the basement depth of the Denizli Graben has been calculated as approximately 9–10 km. Besides these, by interpreting the seismic section, the depth of the interface in the Denizli Graben has been obtained as approximately 2634 m for one-way travel time. This depth is quite shallow compared to the one (i.e., around 10 km) obtained from the gravity model. Thus, the interface seen in the seismic section is not considered to be the deepest part of the Denizli Graben. From the geothermal and oil exploration perspectives, the obtained basement and interface depths are quite beneficial, especially for the drilling planning. [ABSTRACT FROM AUTHOR]

Purpose: Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature.Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests.Average GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01).Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA.Methods: Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature.Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests.Average GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01).Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA.Results: Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature.Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests.Average GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01).Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA.Conclusion: Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature.Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests.Average GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01).Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA. [ABSTRACT FROM AUTHOR]

The evaluation of 3D printed osteological materials has highlighted the difficulties associated with accurately representing fine surface details on printed bones. Moreover, there is an increasing need for reconstructions to be demonstrably accurate and reliable for use in the criminal justice system. The aim of this study was to assess the surface quality of 3D prints (n = 9) that presented with micromorphological alterations from trauma, taphonomy and pathology processes. The archaeological bones were imaged using micro-CT scanning and 3D printed with selective laser sintering (SLS) printing. A multi-method experimental approach subsequently identified: (1) the 3D printed bones to be metrically accurate to within 1.0 mm; (2) good representation of micromorphological surface features overall, albeit with some loss of intricate details, depths, and fine textures that can be important for visual processing; (3) five of the nine 3D printed bones were quantitatively scored as accurate using the visual comparison method; and, (4) low mesh comparison distances (± 0.2 mm) between the original models and the digitised 3D print models. The findings offer empirical data that can be used to underpin 3D printed reconstructions of exhibits for use in courts of law. In addition, an adaptable pathway was presented that can be used to assess 3D print accuracy in future reconstructions. [ABSTRACT FROM AUTHOR]

We present 3D thermal and rheological models of a key intra-plate locality of South America: the southernmost limit of the Río de la Plata Craton area (which encompasses the Claromecó Basin, the Sierras Australes, and the Colorado Basin). Both models were calculated on the basis of a previously published 3D lithospheric scale density model, after the population of the different units with thermal and rheological properties. Firstly, the steady-state conductive thermal field was modelled using different thermal properties in accordance with the assumed lithological composition of the units. Moving forward, the strength distribution was calculated considering the resulting thermal field and published rheological properties for common rock types as input for the different layers that compose the 3D density configuration of the area. Our main results suggest that the thickness and composition of the crust exert a first-order control on the present-day thermal field of the area and, subsequently, on the lithospheric strength. Particularly, we identified a rheologically weak lithospheric zone that coincides with previously proposed inherited Paleozoic structures of Gondwana. This inherited lithospheric fabric could have controlled the opening of the Colorado Rift Basin during the early Late Jurassic. In that sense, the present day high strength of the Rio Negro and Colorado transfer zones associated with the mafic infill of Colorado rifting in the Mesozoic suggests that the weak zones should have necessarily been developed during (at least) Paleozoic to early Mesozoic times. This supports the hypothesis that the reactivation and interaction of the latter with the Gondwanic weak lithospheric zone could have deformed and uplifted the Sierras Australes during the Gondwanides Orogeny. [ABSTRACT FROM AUTHOR]

The role of 3D virtual reconstruction of lost heritage artefacts is acquiring ever-greater importance, as a support for archaeological research and art history studies, as well as a vehicle for the cultural and evocative involvement of the end-user. The main risk of virtual reconstruction is the lack of a faithful restitution but, conversely, very often the artefact conservation state does not allow a complete 3D reconstruction. Therefore, 2D sources, both textual and iconographic, represent a precious integration and completion of the existing 3D sources. This paper proposes an operating systematic workflow to integrate retrieved 2D and 3D sources and assess their compatibility for the virtual reconstruction of lost heritage artefacts using and integrating 3D survey and digital modelling. As a case study, we virtually reconstructed the lost equestrian monument of Duke Francesco III d'Este, 7 m high, built in 1774 in Modena, Italy, by the sculptor Giovanni Antonio Cybei and completely destroyed a little over 20 years later during the revolutionary uprisings. Following the proposed workflow, we integrate data coming from: a still preserved preparatory stucco model, paintings and engravings showing the missing details of the 3D model, a series of urban views returning the proportion and positioning of the monument (statue, pedestal and base), a fragment of the right foot providing the statue size and the appearance of the original white Carrara marble. The final 3D digital model shows a faithful correspondence to the 2D sources and guarantees an effective user's fruition thanks to dedicated virtual applications. Besides the scientific and cultural goal, we highlight the evocative role of this work, which has contributed to the restitution of a monument that is unknown to most citizens and visitors. [ABSTRACT FROM AUTHOR]

Despite major improvements over the past several decades in computer methods for analyzing and synthesizing exploration and site investigation geological data for engineering purposes, which should have decreased project risk, unexpected failures and construction problems still occur. Often, this unexpectedness can be tied back to inadequate structural geological understanding of actual site-specific conditions. Part of this diminished appreciation of structural geological controls on rockmass behaviour can likely be attributed to inappropriate use of computational geostatistics, block modelling and geomechanics computer codes, without significant structural geological input. Part may be because of inadequate domaining in the raw data analysis phase, such that no differentiation was ever made between uncertainties due to true natural variability versus those due to data inadequacy. Modelled data error issues cannot easily be resolved once mixing and smearing of parameters have occurred as a result of earlier inappropriate synthesis of an uncontrolled database. The increased use, industry-wide, of inadequately calibrated, often totally unverified, geomechanics computer modelling for design of civil or mining projects is a worrying trend that needs reversing. Much more attention needs to be paid to properly sub-dividing project sites into realistic geological entities through use of rigorous geological structural domaining techniques, such that much better understanding is gained of project-specific geological risk. This in turn will lead to improved reliability and representativeness in project geomechanical parameter selection for use in design. This paper attempts to set out some guidelines to help practitioners undertake more rigorous domaining, as an aid to parameter selection for design. [ABSTRACT FROM AUTHOR]

This paper presents a method for generative design of decorative architectural parts such as corbel, moulding and panel, which usually have clear structure and aesthetic details. The method is composed of two components: offline learning and online generation. The offline learning trains a 2D CurveInfoGAN and a 3D VoxelVAE that learn the feature representations of the parts in a dataset. The online generation proceeds with an evolution procedure that evolves to product new generation of part components by selecting, crossing over and mutating features, followed by a feature-driven deformation that synthesizes the 3D mesh representation of new models. Built upon these technical components, a generative design tool is developed, which allows the user to input a decorative architectural model as a reference and then generates a set of new models that are "more of the same" as the reference and meanwhile exhibit some "surprising" elements. The experiments demonstrate the effectiveness of the method and also showcase the use of classic geometric modelling and advanced machine learning techniques in modelling of architectural parts. [ABSTRACT FROM AUTHOR]

Spatial visualization ability is an important factor in a child's cognitive development. Its development is affected by numerous factors such as general intelligence, problem-solving skills, gender, playing building games, experience with engineering drawing and 3D modelling, etc. The study aimed to explore how engineering 3D modelling with SketchUp computer programme affects the development of students' spatial thinking and visualization in consideration of previous experience with 3D modelling and students' grades in Technics and Technology. The study included 166 11–14-year-old students who were assigned to an experimental and a control group. A pre-and post-test were applied for initial and final testing. To test students' spatial visualization abilities, an experimental tool with the following elements was assembled: Picture Rotation Test, Form Board Test, The Punched Holes Test, Differential Aptitude Test: Space Relations, The Surface Development Test, Mental Rotation Test, Purdue Spatial Visualization Test: Rotations. The experimental group was included in 30-h training in 3D modelling with SketchUp. The results have shown an excellent response of students in the experimental group to the training and confirmed the expectations concerning the improvement of spatial visualization abilities of these students irrespective of their previous experience and school grades in Technics and Technology. The study has shown that introducing spatial modelling with SketchUp in early technics and technology education enables more effective development and improvement of children's spatial visualization ability skills. [ABSTRACT FROM AUTHOR]

Glial scars are a common pathological occurrence in a variety of central nervous system (CNS) diseases and injuries. They are caused after severe damage and consist of reactive glia that form a barrier around the damaged tissue that leads to a non-permissive microenvironment which prevents proper endogenous regeneration. While there are a number of therapies that are able to address some components of disease, there are none that provide regenerative properties. Within the past decade, neural stem cells (NSCs) have been heavily studied due to their potent anti-inflammatory and reparative capabilities in disease and injury. Exogenously applied NSCs have been found to aid in glial scar healing by reducing inflammation and providing cell replacement. However, endogenous NSCs have also been found to contribute to the reactive environment by different means. Further understanding how NSCs can be leveraged to aid in the resolution of the glial scar is imperative in the use of these cells as regenerative therapies. To do so, humanised 3D model systems have been developed to study the development and maintenance of the glial scar. Herein, we explore the current work on endogenous and exogenous NSCs in the glial scar as well as the novel 3D stem cell–based technologies being used to model this pathology in a dish. [ABSTRACT FROM AUTHOR]

In the geomatics field, modelling and georeferencing complex speleological structures are some of the most challenging issues. The use of conventional survey methods (for example, those employing total stations or terrestrial laser scanner) becomes more difficult, especially because of the space constraints and the often critical light conditions. In this work, a flexible and swift methodology to survey an in-progress excavation is presented, through image-based modelling techniques. The proposed approach allows obtaining a reliable and georeferenced three-dimensional model of the underground environments, preserving the integrity of the scene. The 3D model is scaled and georeferenced through three ground control points located just outside the cave, using data acquired by a double-frequency GNSS receiver in static session mode. Further targets were employed to check the deformation of the model inside the cave. The surveys were conducted on two archaeological sites: La Sassa cave and Guattari cave, both located in southern Latium. [ABSTRACT FROM AUTHOR]

Background: In patients with acetabular fractures, the reconstructed three-dimensional (3D) model of the contralateral acetabulum could be used as a mirrored template for the anatomical configuration of the affected joint. This has not been validated. Objective: To investigate whether the right and left acetabula, as reconstructed 3D models, are valid mirrored duplicates that can be used as a reference model for the contralateral side. Methods: CT scans of twenty patients with unaffected acetabula were used. The symmetry of the generated 3D models was evaluated through: (1) mirroring of the acetabulum; (2) initial rough matching; (3) automatic optimisation of the matching via surface-based matching; (4) calculation of distances between surfaces by evaluating the Euclidean (straight-line) error distance between the closest points between left and right. The percentages of surface points of the left and right acetabulum with a distance smaller than 0.5, 1.0, 1.5 and 2.0 mm were calculated and evaluated, in relation to Matta's criteria, for acetabular fracture reductions. Results: The mean distance deviation was less than 0.75 mm in all 40 comparisons. The calculated distances in 90.7% of the surface points of the left and right acetabulum were below the tolerance threshold of 1.0 mm, based on Matta's anatomical reduction criteria, and 98.7% of the surface points scored below Matta's imperfect tolerance threshold of 2.0 mm. Conclusion: This study demonstrates 3D reconstructed models of healthy left and right acetabula are highly similar and could potentially be used as mirrored duplicates. The next step will be to investigate these results in patients with reduced acetabular fractures. [ABSTRACT FROM AUTHOR]

The management and the safeguard of existing buildings and infrastructures are actual tasks for structural engineering. Non-invasive structural monitoring techniques can provide useful information for supporting the management process and the safety evaluation, reducing at once the impact of disturbances on the structure's functionality. This paper focuses on the exploitation of advanced multi-temporal differential synthetic aperture radar interferometry (DInSAR) products for the structural monitoring of buildings and infrastructures, subjected to different external actions. In this framework, a methodological approach is proposed, based on the integration of DInSAR measurements with historical sources, accurate 3D modelling and consistent positioning of the reflecting targets in the GIS environment. Documentary sources can prove particularly helpful in collecting technical information, to reconstruct an accurate 3D geometry of the building under monitoring, limiting in-situ surveys. The analysis of DInSAR-based displacements time series and mean deformation velocity values allows the identification of possible critical situations for buildings to be monitored. The paper presents different approaches, with increasing accuracy levels, to study the active deformative processes of the examined buildings and the related damage assessment. An insight into these interpretative approaches is given through the application of the proposed procedure to two case studies in the city of Rome (Italy), the residential building named Torri Stellari in Valco San Paolo (1951–1953) and the housing complex referred to as Corviale (1967–1983), by exploiting the whole COSMO-SkyMed data archive (both ascending and descending acquisitions), collected during the 2011–2019 time interval. Pros and cons of the various approaches are deeply discussed, together with an estimation of the required computational effort. [ABSTRACT FROM AUTHOR]

3D modelling of man-made objects is widely used in the cultural heritage sector, among others. It is relevant for its documentation, dissemination and preservation. Related to historical fabrics, weaves and weaving techniques are still mostly represented in forms of 2D graphics and textual descriptions. However, complex geometries are difficult to represent in such forms, hindering the way this legacy is transmitted to new generations. In this paper, we present the design and implementation of SILKNOW's Virtual Loom, an interactive tool aimed to document, preserve and represent in interactive 3D forms historical weaves and weaving techniques of silk fabrics, dating from the 15th to the 19th centuries. To that end, our tool only requires an image of a historical fabric. Departing from this image, the tool automatically subtracts the design, and allows the user to apply different weaves and weaving techniques. In its current version, the tool embeds five traditional weaving techniques, 39 weaves and six types of yarns, which have been defined thanks to close collaboration of experts in computer graphics, art history and historical fabrics. Additionally, users can change the color of yarns and produce different 3D representations for a given fabric, which are interactive in real time. In this paper, we bring the details of the design and implementation of this tool, focusing on the input data, the strategy to process images, the 3D modelling of yarns, the definition of weaves and weaving techniques and the graphical user interface. In the results section, we show some examples of image analysis in order to subtract the design of historical fabrics, and then we provide 3D representations for all the considered weaving techniques, combining different types of yarns. [ABSTRACT FROM AUTHOR]

This paper reports the results of 3D numerical modelling of a 6-m-high mechanically stabilised earth (MSE) wall constructed with concrete panels and steel or polymeric strip reinforcement. These systems pose numerical challenges as a result of the discontinuous reinforcement arrangement which is not the case for MSE walls constructed with continuous reinforcement layer configurations. Details of the numerical approach including modelling of the reinforcement strips, concrete facing panels and compressible bearing pads between panels are described. Examples of numerical predictions for facing deformations, toe loads due to soil down-drag behind the panels, soil and reinforcement settlements, and reinforcement tensile loads are presented. The influence of reinforcement stiffness is demonstrated by comparing numerical predictions for the same MSE wall with relatively inextensible steel strips and with relatively extensible polymeric strips. Of particular interest are the results showing the disruption of earth pressures along vertical and horizontal planes in the reinforced soil zone as a result of the discontinuous strip inclusions, and the vertical load that accumulates on the reinforcement strips close to the connections due to soil settlement behind the facing. The details of the modelling approach used here and the lessons learned provide a benchmark for future similar lines of investigation and for practitioners, particularly as the computational power of desktop computers continues to increase. [ABSTRACT FROM AUTHOR]

The digitized image has an important role in the compression. Compression encodes the image using a certain algorithm with less number of bits and decompression decoded this image in original form using a different algorithm. The clinical environment and hospitals are moving towards digitization, computerization and centralization in the field of medical image processing. Content based compressions (CBC) techniques turns more considerable in the field of medical image processing and multimedia. However, CBC techniques alone are not adequate for all medical image processing applications. Therefore, in this paper, the EZW algorithm has been discussed with Haar wavelet and Bior4.4 technique on skeleton images with different type of image quality parameters. The analysis shows that the compression ratio (CR) of EZW with Bior4.4 on skeleton image is 44.19%, MSE is 527.73 and PSNR is 45.45. While, the CR of EZW with Haar on the same image is 40.31%, MSE is 699 and PSNR is 35.34 db. Further EZW can help precise capacity of amount, exterior area and other morph metric capacity of organic stuff, lacking removing them commencing the sea or in the marine environment. [ABSTRACT FROM AUTHOR]

Watasenia scintillans, a sparkling enope squid, has bioluminescence organs to illuminate its body with its own luciferase activity. To clarify the molecular mechanism underlying its scintillation, we analysed high-throughput sequencing data acquired previously and obtained draft genome sequences accomplished with comparative genomic data among the cephalopods. The genome mapped by transcriptome data showed that (1) RNA editing contributed to transcriptome variation of lineage specific genes, such as W. scintillans luciferase, and (2) two types of luciferase enzymes were characterized with reasonable 3D models docked to a luciferin molecule. We report two different types of luciferase in one organism and possibly related to variety of colour types in the W. scintillans fluorescent organs. [ABSTRACT FROM AUTHOR]

This article focuses on analysing and modelling geometrically a complex vault typology known as single-row spherical dome, which was defined in several classic stereotomy treatises. The peculiarity of this kind of dome is that all their stone pieces are different, since there is a helical directrix defining the upper and lower edges of the pieces. Different solutions will be compared and analysed, both from a graphical and a mathematical point of view, by describing the spatial helixes. The accuracy of the different methods described in the treatises for tracing the stone templates will be also tested. To conclude, some examples of virtual 3D modellings and 3D printed models will be exposed. [ABSTRACT FROM AUTHOR]

Archaeologists usually see, and understand, rock shelters as taphonomically active, but pre-existing, physical structures onto which people undertake a variety of actions including rock art. Our aim in this paper is not only to document the changes undergone by rock shelters but also to identify traces of anthropic actions that have intentionally led to these changes. Recent research in northern Australia provides empirical evidence that for thousands of years, Aboriginal peoples altered the physical shape of rock shelters by removing masses of rock to create alcoves, restructure internal spaces and create stone-worked furniture. Through archaeomorphological research, this paper presents evidence from Borologa in Australia's Kimberley region, where hard quartzite monoliths were shaped and engaged as architectural designs by Aboriginal people prior to painting many surfaces, making us rethink what have traditionally been distinguished as natural versus cultural dimensions of archaeological landscapes and rock art sites. [ABSTRACT FROM AUTHOR]

Arboreal nests of eusocial insects are typically roughly egg- or pear shaped with superficial irregularities, which makes the correct determination of their volume or surface area in the field difficult. Here, we evaluated the accuracy (benefit) of different geometric proxies with varying number of underlying measurements (cost) when assessing the volume and surface area of arboreal termite nests of Microcerotermes indistinctus and Constrictotermes cyphergaster. We compared size measures based on the 3D models with the most common shape models in literature: spheres (1–3 parameters), ellipsoids (3 parameters), cylinders (3 parameters), and a combination of superimposed cylinders with spherical caps (at least 9 parameters). The most complex model returned the most accurate results (low estimation error and low error variability). However, estimation errors did not differ from simpler shape models, based on only three (ellipsoids, spheres using half of the arithmetic mean of height, width and depth as radius) or even a single parameter (spheres using half of depth as radius). Cylindric proxies and spheres based on nest height or width, on the other hand, returned far less accurate results with estimation errors of up to almost 300%. Although nests of M. indistinctus showed a higher variation in shape and more surface irregularities than those of C. cyphergaster, each geometric proxy tested in the present study determined the nest size of both termite species with equal precision. This suggests that each shape model may generate similarly accurate estimates of volume and surface area over a wider range of termite species that build egg-shaped arboreal nests. [ABSTRACT FROM AUTHOR]

Archaeological site mapping is important for both understanding the history and protecting the sites from excavation during developmental activities. As archaeological sites are generally spread over a large area, use of high spatial resolution remote sensing imagery is becoming increasingly applicable in the world. The main objective of this study is to map the land cover of the Itanos area of Crete and of its changes, with specific focus on the detection of the landscape's archaeological features. Six satellite images were acquired from the Pleiades and WorldView-2 satellites over a period of 3 years. In addition, digital imagery of two known archaeological sites was used for validation. An object-based image analysis classification was subsequently developed using the five acquired satellite images. Two rule sets were created, one using the standard four bands which both satellites have and another for the two WorldView-2 images with their four extra bands included. Validation of the thematic maps produced from the classification scenarios confirmed a difference in accuracy amongst the five images. Comparing the results of a 4-band rule set versus the 8-band rule set showed a slight increase in classification accuracy using extra bands. The resultant classifications showed a good level of accuracy exceeding 70%. Yet, separating the archaeological sites from the open spaces with little or no vegetation proved to be challenging. This was mainly due to the high spectral similarity between rocks and the archaeological ruins. The high resolution of the satellite data allowed for the accuracy in defining larger archaeological sites, but still there was difficulty in distinguishing smaller areas of interest. The digital image data provided a very good 3D representation for the archaeological sites, assisting as well as in validating the satellite-derived classification maps. To conclude, our study provides further evidence that use of high resolution imagery may allow for archaeological sites to be located, but only where the archaelogical features are of an adequate size. [ABSTRACT FROM AUTHOR]

Damage to elevated water tanks in past earthquakes can be attributed to the poor performance of their supporting frame staging. In order to ascertain the performance of these elevated water tanks, it is crucial to categorize the damage in quantifiable damage states. Among various parameters to quantify the damage states, the top drift of frame staging can be conveniently correlated to the different damage levels. In literature, drift limits corresponding to different damage states of the frame staging of the elevated water tank are not available. In the present study, drift limits for RC frame staging in elevated water tanks corresponding to different seismic damage states have been proposed. Various damage states of the elevated water tank have been determined using the Park and Ang damage index. The Park and Ang damage index utilizes results of both pushover analysis and incremental dynamic analysis. Twelve models of elevated water tanks have been developed considering variation in staging height and tank capacity. Incremental dynamic analysis has been performed using the suite of twelve actual earthquake ground motions. Based on the regression analysis between damage indexes and drift, limiting drift values for each damage state are proposed. [ABSTRACT FROM AUTHOR]

Although the phylum Gastrotricha is known and studied for more than 150 years, some cell types, tissues and organ systems are still not well understood in terms of their morphology, ultrastructure, function and role. One of these features is the epidermal gland system (EGS). As yet, there is just a single detailed electron microscopic investigation of the epidermal glands of the species Turbanella cornuta Remane, 1925, plus scattered ultrastructural data of few additional species. We comprehensively investigated the epidermal glands of Tetranchyroderma suecicum Boaden, 1960 by means of serial sectioning and transmission electron microscopy (TEM) and with scanning electron microscopy. Furthermore, light microscopical, confocal laser scanning microscopical and micro-computed tomographical (µCT) techniques were additionally used for this investigation. Computer programs for 3D-reconstructions were used to analyse the data obtained by TEM and µCT. Tetranchyroderma suecicum possesses up to 100, mostly pairwise arranged, glandulocytes. Each single-celled gland contains a large anastomosing secretory cistern with granular content, has a very electron-dense cytoplasm, a basally positioned nucleus, peripherally arranged mitochondria and a cuticulated, 'chimney-like' apical neck, which carries the cellular pore. Each merocrine glandulocyte is associated with an adjacent ciliated sensory cell. There is currently no coherent hypothesis of the glandulocytes' functional role, but different ideas are discussed. We refer to evidence that the secretory product of the EGS of Tetranchyroderma suecicum most likely acts as a repellent against potential predators. [ABSTRACT FROM AUTHOR]

The geophysics application is indicated procedure in mineral exploration activities, by the quickness and possible global reduction of project cost. This work presents the results of the DC resistivity and induced polarization methods joint application, integrated to geological and structural data from a potentially mineralized area with copper sulfides, located in the Northern border of the Camaquã Sedimentary Basin, Brazil Southern. The mineral occurrence is characterized by malachite and azurite impregnation on silicified Neoproterozoic metarenite outcrop of Passo da Promessa Formation (Marica Group). The geophysics acquisition consists in six electrical tomography lines in Schlumberger arrangement with 440 m each, the lines were separated on two groups disposed at orthogonal form where the center area is located the mineral occurrence in surface. The results indicate a low resistivity and high chargeability zone 60 m deep, related to a sulfided zone and surrounded by elevated resistivity, which point silicification areas. The structural analysis has revealed two main fracture systems in the crystalline basement (NE–SW and NW–SE), one in the metarenite (NE-SW) and fold with a N20 axis. The 3D visualization model reveals that the mineralization is oriented in the N125 direction (NW–SE). The NW–SE fracture family is secondary but is present in the occurrence area and coincident with the relaxing direction of the folding event. This context corroborates with the hypothesis of filling NW–SE fractures, result which indicates the relevance of this preferential direction in future mineral research campaigns in the Camaquã Basin. [ABSTRACT FROM AUTHOR]

3D surface scanning is a technique brought forward for wound documentation and analysis in order to identify injury-causing tools in legal medicine and forensic science. Although many case reports have been published, little is known about the methodology employed by the authors. The study reported here is exploratory in nature, and its main purpose was to get a first evaluation of the ability of an operator, by means of 3D surface scanning and following a simple methodology, to correctly exclude or associate an incriminated tool as the source of a mock wound. Based on these results, an assessment of the possibility to define a structured methodology that could be suitable for this use was proposed. Blunt tools were used to produce 'wounds' on watermelons. Both wounds and tools were scanned with a non-contact optical surface 3D digitising system. Analysis of the obtained 3D models of wounds and tools was undertaken separately. This analytical phase was followed by a qualitative and a quantitative comparison. Results showed that in more than half of the cases, we obtained a correct association but the prevalence of wrong association was still high due to mark deformation and other limitations. Even if the findings of this exploratory study cannot be generalised, they suggest that the simple and direct comparison process is not reliable enough for a systematic routine application. The article highlights the importance of an analysis phase preceding the comparison step. Limitations of the technique, ensuring needs and possible paths for improvement are also expounded. [ABSTRACT FROM AUTHOR]