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cosRMC is a three dimensional neutron photon transport Monte Carlo code based on the stochastic statistical method of neutral particle transport. At present, the cosRMC geometry model is imported by writing the input file manually...
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cosRMC is a three dimensional neutron photon transport Monte Carlo code based on the stochastic statistical method of neutral particle transport. At present, the cosRMC geometry model is imported by writing the input file manually, which leads to time-consuming, inefficient and error-prone problems. This will limit application of cosRMC in fusion neutronics calculations because of the complex geometry in fusion devices. Therefore, in order to improve the modeling efficiency and meet the requirements of calculation and analysis of advanced nuclear facilities, a visual modeling platform, cosVMPT-Visual Modeling Platform for Particle Transport, is developed based on Open Cascade (OCC) as CAD geometry engine and FreeCAD framework as graphical user interface. This platform can realize the complete process from modeling to calculation, then to visualization. In this article, the conversion algorithm from CAD models to cosRMC geometry models is introduced in detail. The reliability of the conversion algorithm is preliminarily verified with some representative models by comparing volumes change before and after conversion. The result shows that the geometries after conversion are in good consistency with the original geometries.
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Flexural strength (FS) and translucency (Contrast Ratio-CR) of three different factory crystallized silica-based glass ceramics, Celtra Duo (CD), N!ce (NI) and Li-Si Block, a lithium disilicate, IPS e.max CAD (LD), and a leucite-r...
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Flexural strength (FS) and translucency (Contrast Ratio-CR) of three different factory crystallized silica-based glass ceramics, Celtra Duo (CD), N!ce (NI) and Li-Si Block, a lithium disilicate, IPS e.max CAD (LD), and a leucite-reinforced feldspathic ceramic, Empress CAD (EM), in two different translucencies (HT and LT) for use in chairside dental restorations have been compared. CAD blocks of the materials were cut into beams and tiles and processed following manufacturers’ instructions. The beams were tested (3-PBT) to determine flexural strength, Weibull characteristic strength, and Weibull modulus; and tiles were tested to determine CR. All data were statistically analyzed. In addition, SEM analysis of the materials was performed. Differences in flexural strength (FS) and translucency (CR) between the materials were found to be statistically significant. FS decreased as follows (MPa) LDHT 350.88 ± 19.77 (a) = LDLT 343.57 ± 18.48 (a) > LSLT 202.15 ± 17.41 (b) = LSHT 196.93 ± 8.87 > NIHT 186.69 ± 13.06 (c) = CDLT 184.73 ± 13.63 (c) = CDHT 174.15 ± 21.76 (c) = NILT 172.12 ± 11.98 (c) > EMHT 131.16 ± 13.33 (e) = EMLT 127.65 ± 11.09. CR decreased as follows (mean ± sd) CDLT 74.1 ± 1.1 (a); LSLT 74.0 ± 1.1 (ab); NILT 73.3 ± 0.8 (ab); EMLT 73.0 ± 1.5 (ab); NIHT 72.4 ± 1.0 (bc); LDLT 71.3 ± 1.1 (bc); LTHT 65.2 ± 0.9 (de); LSHT 63.8 ± 1.1 (def); EMHT 636 ± 1.2 (ef); CDHT 62.2 ± 0.8 (f). Our findings show that factory-crystallized lithium silicate glass ceramics fulfill ISO standards for Classes 1 and 2. Therefore, they can be considered viable alternatives to produce single-unit restorations with a chairside procedure not requiring thermal treatment.
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Accelerator driven system (ADS) is an advanced nuclear system with high inherent safety feature, which can transmute the nuclear waste including minor actinides (MA) and long-lived fission products (LLFPs) into short-lived fission...
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Accelerator driven system (ADS) is an advanced nuclear system with high inherent safety feature, which can transmute the nuclear waste including minor actinides (MA) and long-lived fission products (LLFPs) into short-lived fission products. In order to accomplish the neutronic simulation in ADS, a conventional way can be divided into two steps, namely the physical process of proton beam bombarding spallation target (FLUKA) and the neutron transport process in subcritical reactor coupling with a spallation neutron source (OpenMC). However, there are some difficulties in the modeling process for ADS, such as the inconsistent modeling process between FLUKA and OpenMC codes, and the error-prone process of constructing complex geometries. Therefore, it is imperative to build a code system that can convert the CAD modeling files into the input cards of Monte Carlo codes. In this context, a code system named CAD-PSFO (FreeCAD based parsing script for FLUKA and OpenMC) has been developed to solve the modeling conversion problem in ADS, in which basic geometry and boolean logic classes have been established with a mapping relationship to FLUKA and OpenMC codes, and ray-casting technology based iteration method has been proposed to solve the problem of higher-order surfaces in complex geometries. Finally, CAD-PSFO has been verified and validated by comparing with a reference model, two benchmarks, and two simulation tests. (C) 2017 Elsevier Ltd. All rights reserved.
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MCNPX is a general purpose Monte Carlo radiation transport code designed to track many particle types over broad ranges of energies and it has the potential to deal with Accelerator Driven System (ADS) problems. The neutronics des...
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MCNPX is a general purpose Monte Carlo radiation transport code designed to track many particle types over broad ranges of energies and it has the potential to deal with Accelerator Driven System (ADS) problems. The neutronics design and analysis of ADS using MCNPX code is significantly complex mainly on constructing the three dimensional geometry model, especially when there is an additional spallation target coupled with the subcritical reactor constructed by abundant nested repeated structures in several levels. This modeling process has long been recognized as a time consuming, tedious and error-prone task, which is hard to master for novice users. Therefore, it is imperative to build a code system that can translate CAD models of ADS to the native language of MCNPX code. In this context of demand, a code system named CAD-PSMC (FreeCAD based parsing script for MCNPX code) has been developed to solve the ADS modeling conversion problems. In the framework of this code, hierarchical tree-based basic geometry classes and Boolean&Affine operations have been established with a mapping relationship to MCNPX code. Additionally, ray-casting technology and Markov chain based iteration method have been proposed to solve the problem of spline surfaces in complex geometries. Finally, the applicability and accuracy of CAD-PSMC code have been demonstrated by comparing with various reference models and numerical calculation results.
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MCNPX is a general purpose multi-particle Monte Carlo transport code with board ranges of energies, which has already been widely employed in the fields of radiotherapy, nuclear engineering, and nuclear fusion research. The neutro...
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MCNPX is a general purpose multi-particle Monte Carlo transport code with board ranges of energies, which has already been widely employed in the fields of radiotherapy, nuclear engineering, and nuclear fusion research. The neutronics design and analysis of fusion reactor facilities using MCNPX have been considered as the time consuming and error prone tasks. For example, the ITER-type models include a lot of nested structures and complicated high-order curve surfaces, which can not be easily described in the mathematics expressions, and the spline surfaces are also not supported by the native syntax of MCNPX. In this context, a code system called CAD-PSMC (FreeCAD based parsing script for MCNPX) has been developed in IMPCAS (Institute of Modern Physics, Chinese academy of Sciences) for the study of modeling conversion problem in ITER-type neutron calculations. Two kinds of methods have been provided and discussed in the framework of this code, including the establishing of the mapping relationship between the specification tree and the build-in boolean operations in consideration of the complicated hierarchical structures, and the demonstration of fast ray-casting technology based iteration method coupling with the mesh-oriented optimized CAD geometries in solving the high-order curve surfaces related problems. Finally, the stability and feasibility of the CAD-PSMC have been verified and validated through the comparison with the selected reference models and the neutronic simulation results of the ITER-type benchmark model.
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Die neue Version der Gratis-Permanentlizenz BobCAD - FreeCAD von DataCAD, Bad Kreuznach, ist bereit zum Download. BobCAD - FreeCAD ist der CAD-Teil des CAD/CAM Systems BobCAD. Die aktuelle Version weist folgende Neuerungen auf: > ...
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Die neue Version der Gratis-Permanentlizenz BobCAD - FreeCAD von DataCAD, Bad Kreuznach, ist bereit zum Download. BobCAD - FreeCAD ist der CAD-Teil des CAD/CAM Systems BobCAD. Die aktuelle Version weist folgende Neuerungen auf: > Ansichtssteuerung: Wenn diese Option aktiviert ist, werden Standardansichten am jeweiligen Benutzerkoordinatensystem (BKS) ausgerichtet. Dadurch soll das Zeichnen auf verschiedenen Ebenen einfacher machen.
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This paper explores the functional modules of railway alignment design in the open source FreeCAD software, and makes a foundation development for other railway majors in the open source software. The interactive interface is desi...
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This paper explores the functional modules of railway alignment design in the open source FreeCAD software, and makes a foundation development for other railway majors in the open source software. The interactive interface is designed by pyside. The geometric elements of the railway alignment, the coordinates of the main point (ZH, HY, YH, HZ, QZ) and the elevation of end or start point in vertical curve are calculated according to the intersection data, so as to realize the design of the horizontal and vertical section for the alignment. OCC interface is accessed through part module to realize the synthesis of railway baseline. Comparing the baseline generated by FreeCAD with the pile-by-pile coordinates of a project bid section, the coordinate error is less than millimeters, which can well meet the needs of railway construction.
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Open source hardware for scientific equipment needs to provide source files and enough documentation to allow the study, replication and modification of the design. In addition, parametric modeling is encouraged in order to facili...
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Open source hardware for scientific equipment needs to provide source files and enough documentation to allow the study, replication and modification of the design. In addition, parametric modeling is encouraged in order to facilitate customization for other experiments. Parametric design using a solid modeling programming language allows customization and provides a source file for the design. OpenSCAD is the most widely used scripting tool for parametric modeling of open source labware. However, OpenSCAD lacks the ability to export to standard parametric formats; thus, the parametric dimensional information of the model is lost. This is an important deficiency because it is key to share the design in the most accessible formats with no information loss. In this work we analyze OpenSCAD and compare it with FreeCAD Python scripts. We have created a parametric open source hardware design to compare these tools. Our findings show that although Python for FreeCAD is more arduous to learn, its advantages counterbalance the initial difficulties. The main benefits are being able to export to standard parametric models; using Python language with its libraries; and the ability to use and integrate the models in its graphical interface. Thus, making it more appropriate to design open source hardware for scientific equipment.
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