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Reducing the volume of manual work improves the processing speed of blanks, along with reducing the number of rejected products and overall production costs in large batches, while increasing repeatability. The concept of lean manufacturing is gaining popularity among manufacturers, with one of its main goals being the continuous elimination of waste. The paper presents a method for enhancing the production technology of cast blanks for gas turbine engine blades. Device designs were developed to minimize losses during the production of castings. [ABSTRACT FROM AUTHOR]

The possibility is studied for a controlled structure to be created by varying parameters of the laser powder bed fusion (LPBF) process when using austenitic stainless steels as an example. On the basis of the results of studying the structure of experimental samples, the influence of a combination of various technological parameters included in the scanning strategy when preparing a 3D-model for the LPBF process on the structure formation processes is demonstrated. The possibility of formation of fragments with different structures within a single part in the course of its manufacture by the LPBF method via changing the processing parameters included in the scanning strategy is shown. It is noted that the use of 3D-models, identical in shape but different in the strategy used for laser beam scanning straight in the laser melting process, leads to the formation of a sample with a profoundly different structure, since microstructure formation strongly depends on metal crystallization conditions directly linked with the scanning strategy. [ABSTRACT FROM AUTHOR]

The construction of the St. Adalbert Church in Gdansk dates to 1310. It is a church of rich history and great historical value, and its care is challenging. In this study, the combination of unmanned aerial vehicle (UAV) photogrammetry and terrestrial laser scanning (TLS) was used to accurately build a 3D model of the church. Together with the collected historical inventory documentation, the historic building information model (HBIM) was generated. The Autodesk-Revit® tool was used for this purpose. On the basis of the generated model, the reflection properties of the laser scanner beam and red–green–blue (RGB) images, a methodology was proposed for analysing the degradation of the church's components. The main hypothesis of this study is based on the analysis of sunlight outside the church. In addition to the importance of the method for determining the risks of church degradation, a high-quality method for model visualization combining two photogrammetric techniques (TLS + UAV) is presented. [ABSTRACT FROM AUTHOR]

The generation of 3D models through Terrestrial Laser Scanning has proved to be valuable tools for the study, documentation and recreation of archaeological remains. In this context, it is described how to generate a physical model to provide not only to researchers, but also as teaching material for teachers for university students, facilitating their access and study. As a practical case, this article describes the acquisition, processing and management of archaeological data in the archaeological site of Cástulo, Jaén, in South Spain. We expound how to get the 3D-printed model of the Muslim tower, showing how it is possible to generate a scale and very reliable reproduction of the structure, being also an useful and tangible material in the teaching of cultural heritage. [ABSTRACT FROM AUTHOR]

Despite the amount of research focussed on the Alpine orogen, different hypotheses still exist regarding varying spatial seismicity distribution patterns throughout the region. Previous measurement-constrained regional 3D models of lithospheric density distribution and thermal field facilitate the generation of a data-based rheological model of the region. In this study, we compute the long-term lithospheric strength and compare its spatial variation to observed seismicity patterns. We demonstrate how strength maxima within the crust (~ 1 GPa) and upper mantle (> 2 GPa) occur at temperatures characteristic of the onset of crystal plasticity in those rocks (crust: 200–400 °C; mantle: ~ 600 °C), with almost all seismicity occurring in these regions. Correlation in the northern and southern forelands between crustal and lithospheric strengths and seismicity show different patterns of event distribution, reflecting their different tectonic settings. Seismicity in the plate boundary setting of the southern foreland corresponds to the integrated lithospheric strength, occurring mainly in the weaker domains surrounding the strong Adriatic plate. In the intraplate setting of the northern foreland, seismicity correlates to modelled crustal strength, and it mainly occurs in the weaker and warmer crust beneath the Upper Rhine Graben. We, therefore, suggest that seismicity in the upper crust is linked to weak crustal domains, which are more prone to localise deformation promoting failure and, depending on the local properties of the fault, earthquakes at relatively lower levels of accumulated stress than their neighbouring stronger counterparts. Upper mantle seismicity at depths greater than modelled brittle conditions, can be either explained by embrittlement of the mantle due to grain-size sensitive deformation within domains of active or recent slab cooling, or by dissipative weakening mechanisms, such as thermal runaway from shear heating and/or dehydration reactions within an overly ductile mantle. Results generated in this study are available for open access use to further discussions on the region. [ABSTRACT FROM AUTHOR]

The Isabel II dam is a monumental hydraulic structure built in the middle of the nineteenth century in Spain. In this study, unmanned aerial vehicle (UAV) photogrammetry was used as a data acquisition technique to carry out a survey of the dam's current state and its surrounding constructions. The point cloud obtained by the photogrammetric process, together with the collected historical in-formation, served as the basis to generate an historic building information model (HBIM) that is the central core containing all the graphical, structural and archaeological information. The HBIM was validated by means of the As-Built for Autodesk Revit®-FARO® plug-in, and shows the high accuracy obtained with respect to the point cloud. The results show that with this methodology it is possible to obtain models representative of reality with an accuracy of ± 0.05 m. In addition, in order to improve the visualization, texture adjustments are made to obtain a photorealistic rendering of the model. [ABSTRACT FROM AUTHOR]

Purpose: The goal of this study was to develop a complete workflow allowing for conducting computational fluid dynamics (CFD) simulation of airflow through the upper airways based on computed tomography (CT) and cone-beam computed tomography (CBCT) studies of individual adult patients. Methods: This study is based on CT images of 16 patients. Image processing and model generation of the human nasal cavity and paranasal sinuses were performed using open-source and freeware software. 3-D Slicer was used primarily for segmentation and new surface model generation. Further processing was done using Autodesk® Meshmixer TM. The governing equations are discretized by means of the finite volume method. Subsequently, the corresponding algebraic equation systems were solved by OpenFOAM software. Results: We described the protocol for the preparation of a 3-D model of the nasal cavity and paranasal sinuses and highlighted several problems that the future researcher may encounter. The CFD results were presented based on examples of 3-D models of the patient 1 (norm) and patient 2 (pathological changes). Conclusion: The short training time for new user without a prior experience in image segmentation and 3-D mesh editing is an important advantage of this type of research. Both CBCT and CT are useful for model building. However, CBCT may have limitations. The Q criterion in CFD illustrates the considerable complication of the nasal flow and allows for direct evaluation and quantitative comparison of various flows and can be used for the assessment of nasal airflow. [ABSTRACT FROM AUTHOR]

A numerical three-dimensional model for computing residual stresses generated in cross section of steel 42CrMo4 after nitriding is presented. The diffusion process is analyzed by the finite-element method. The internal stresses are computed using the obtained profile of the distribution of the nitrogen concentration. The special features of the intricate geometry of the treated articles including edges and angles are considered. Comparative analysis of the results of the simulation and of the experimental measurement of residual stresses is performed by the Waisman-Philips method. [ABSTRACT FROM AUTHOR]

Pavement performance of asphalt is an important criterion for road engineering quality evaluation. Proposed research paper designed an orthogonal experiment using three asphalt mixtures, including SMA-13, AC-20 and ATB-25 to get their relation models and evaluate pavement performances. Totally twenty-seven samples from private companies have been selected and seven crucial parameters are analyzed via factor analysis. Further analysis concluded three main factors corresponding to the three main pavement performance parameters (i) high-temperature stability (ii) durability and (iii) shear resistance. Based on scores of each asphalt mixture's 3D scatter-map is plotted. Analysis found the relationship between three above-mentioned parameters. Relationship between the three main performance parameters has been established using graphical analysis. A separation plane can define the different types of asphalt mixtures' scatter distribution area, and get the regression equation for the plane. Based on the equation for the plane a more intuitionistic model has been made which describes the relationship of asphalt pavement performance. [ABSTRACT FROM AUTHOR]

Computed tomography (CT)-angiography is routinely performed prior to catheter-based and surgical treatment in congenital heart disease. To date, little is known about the accuracy and advantage of different 3D-reconstructions in CT-data. Exact anatomical information is crucial. We analyzed 35 consecutive CT-angiographies of infants with congenital heart disease. All datasets are reconstructed three-dimensionally using volume rendering technique (VRT) and threshold-based segmentation (stereolithographic model, STL). Additionally, the two-dimensional maximum intensity projection (MIP) reconstructs two-dimensional data. In each dataset and resulting image, measurements of vascular diameters for four different vessels were estimated and compared to the reference standard, measured via multiplanar reformation (MPR). The resulting measurements obtained via the STL-images, MIP-images, and the VRT-images were compared with the reference standard. There was a significant difference ( p < 0.05) between measurements. The mean difference was 0.0 for STL-images, −0.1 for MIP-images, and −0.3 for VRT-images. The range of the differences was −0.7 to 1.0 mm for STL-images, −0.6 to 0.5 mm for MIP-images and −1.1 to 0.7 mm for VRT-images. There was an excellent correlation between the STL-, MIP-, VRT-measurements, and the reference standard. Inter-reader reliability was excellent ( p < 0.01). STL-models of cardiovascular structures are more accurate than the traditional VRT-models. Additionally, they can be standardized and are reproducible. [ABSTRACT FROM AUTHOR]

Analysis of thermal stresses in tubes and a compensator, taking into account water heating in each heater bunch and temperature at which its mounting is implemented, and of stresses on pressure is presented. The 3D-model of the horizontal delivery water heater of PSG-4900-0.3-1.14 type is used. The tube plate is represented as the 3D-body with 6863 holes with offset center of the perforated area, the steam space shell is represented as a cylindrical casing, the bottoms of water chambers are considered as elliptical casings, the four-lens compensator is represented in the form of toroidal casings, and the tubes are considered as beams operating in tensile-compression and bending in two planes. Calculations were carried out for different temperatures of superheated steam and a steam space shell, respectively, as well as designs with compensator and without it. Various temperature values of the tubes on the passes were calculated and set. The studies were carried out taking into account nonaxis-symmetrical spacing the tube plate and compensator deformation. The calculation results of tensile-compression stresses in the tubes are presented. Furthermore, the central tubes experience compressive stresses, whose maximal values take place on the border between the tubes of the fourth and of the first passes. For its decrease, it is recommended to increase the distance between the tubes of these passes. The tension stresses in the peripheral tubes are the maximal stresses. To reduce the stresses and, therefore, increase service life of the delivery water heater at using wet or superheated (not more than by 30-50°C) steam in it (the larger value refers to the brass tubes and the water pressure of 1.6-2.5 MPa), it is necessary to recommend the noncompensatory design at using the steam superheated by more than 30-50°C (at Ural Turbine Works, it is the turbines of T-250/300-23.5 and T-113/145-12.4 types with intermediate superheating) and to recommend the installation of the compensator operating only at compression. [ABSTRACT FROM AUTHOR]

A 3-D model of an equilibrium polyhedral structure of a homogeneous solid solution is presented for α-titanium alloys. The variety of shapes and sizes of polygons is considered and arbitrary sections of a plane mapping of the spatial model are constructed. An analytical dependence relating the specified size of a crystallite to the mean diameter of its plane mapping is obtained. Relations between the specific surface, specific volume and the size of a crystallite at the micro-, submicro- and nanostructural (0.01 - 100 μm) levels are derived. [ABSTRACT FROM AUTHOR]

On the example of the forest resource areas located within the territory of the Lisinsky educational and experimental forestry of the St. Petersburg State Forest Technical University (SPbGLTU), the influence of the form of the topographical surface on the structure and productivity of the forest and plant cover was studied. Based on the 3D-model of the topography of the studied surface and the GIS created in the MAPINFO PROFESSIONAL ver. 6.0 environment, there were four territorial entities distinguished that differ by their absolute height. The landscape interpretation of territorial entities was carried out on the basis of the joint analysis of topographical, geological, geochemical and forest management information by means of GIS. It is shown that the respective landscape areas are naturally distinguished on the basis of the considered territorial entities. Relationships between the structure and productivity of forests of different landscape areas were established, and their digital map was compiled, which makes it possible to establish unambiguously the boundaries of the areas in nature. Applications of the results of conducted research are proposed. [ABSTRACT FROM AUTHOR]

The water turnover of two coastal areas, Forsmark and Laxemar-Simpevarp, has been modeled for 13 selected years between 6500 bc and 9000 ad by utilizing information about past, present, and future bathymetry. The Forsmark area can be described as an open-ended funnel, and is analyzed with a 3D-model (MIKE 3-FM); the Laxemar area is partitioned into clusters of sub-basins treated with a discrete coupled basin model (CouBa). In all simulations, the main variation factor is the land uplift. The 3D-model domain is successively modified. For the CouBa approach the successive basin configurations are objectively deduced based on the 3D domain modifications. The average age (AvA) of the resident water relative to the open coast is generally lower for the Forsmark area. A typical progression is that the AvA values increase until a sub-basin ceases to be connected to the coastal zone. This disconnection is often preceded by a lowered AvA. [ABSTRACT FROM AUTHOR]

ion potentials in neurons are generated on the plasma membrane through depolarization, i.e. exchange of charges through the membrane. Hodgkin and Huxley developed a mathematical model which describes the interaction of ions through an active plasma membrane. In Vossen et al. (Comput Visual Sci 10:107-121, ) we developed a passive three-dimensional (3D) model for signal propagation in dendrite. We now combine this model with a generalized Hodgkin-Huxley model to obtain a 3D-model that describes active signal processing on realistic cell morphologies. Time dependent changes of the neuron's intra- and extracellular potential is regulated by the Ohmic flux of charges. These fluxes are balanced in membrane-near areas by the capacitory and Hodgkin-Huxley flux. The active model we present consists of five non-linear, coupled integro-differential equations which are solved numerically with a finite volume approach, implicit time stepping and Newton's method for solving the underlying non-linear system of equations with multigrid solver methods. We present numerical results as well as axon behavior in a biological setting. This model can be considered as a three-dimensional expansion of existing state of the art one-dimensional models, with the significant advantage of being able to investigate the morphological influence of neuron cell types on their specific signaling properties. [ABSTRACT FROM AUTHOR]

This paper presents a 3D-modeling numerical method using finite element method (FEM) to simulate the electromagnetic behavior of high-temperature superconductors (HTSC). The models are formulated by the magnetic field vector method (H-method). The resolving code was written by FROTRAN language. The electromagnetic properties of HTSC are described though Kim critical-state model. The magnetic fields and current distribution in the bulk HTSC in the applied non-uniform external magnetic fields generated by the permanent magnetic guideway (PMG) are obtained using the proposed method. The magnetic levitation forces by the interaction between the bulk HTSC and the PMG are calculated. In order to validate the method, measurement of the vertical force between a bulk YBaCuO(YBCO) and a PMG is obtained. The measurement and simulation results show good matching. This method could be used in the HTSC magnetic levitation transportation system optimization design. [ABSTRACT FROM AUTHOR]

Adenosine is a naturally occurring purine nucleoside that has a wide variety of well-documented regulatory functions and physiological roles. Selective activation of the adenosine A1 receptor has drawn attention in drug discovery for the therapeutic effects on neural and cardiovascular disorders. We have developed a model of the human A1 adenosine receptor using bovine rhodopsin as a template. A flexible docking approach has been subsequently carried out for evaluating the molecular interactions of twenty-one selective A1 agonists with the receptor model. The results of these studies are consistent with mutational and biochemical data. In particular, they highlight a wide hydrogen-bonding network between the nucleoside portion of the ligands and the A1 receptor as well as key amino acids for hydrophobic interactions with the different N6-groups of the agonists. The models presented here provide a detailed molecular map for the selective stimulation of the adenosine A1 receptor subtype and a steady basis for the rational design of new A1 selective ligands. [ABSTRACT FROM AUTHOR]