Computer-aided Design Process Research Articles

Mathematical simulation modeling of an automated system to reduce heat stress and convergence to theoretical values

Relevance. It is known that the productive qualities of animals depend on the genetic component and animal housing conditions. Due to the fact that the microclimate of the room should be perceived as a complex dynamic system, it is necessary to determine a number of factors that have the greatest influence on its relationship with living organisms. In order to create favorable conditions in the premises for keeping cattle, it is necessary to comply with the regulated values from normative documents. The biggest problem at the moment in microclimate regulation is the detrimental effect of heat stress. As a rule, it is caused by uncontrolled temperature increase in the cattle housing. To date, heat stress is combated in several ways: the use of specialized equipment, pharmacological, prevention of harmful effects, genetic. At the same time used methods to reduce the impact of heat stress is still insufficient, in view of which nowadays research is conducted to create new systems.The purpose of the study was to conduct simulation modeling to verify the values obtained from theoretical studies. Computer-aided design and data processing programs such as Compass-3D and Microsoft Office were used.Results. The results of the study allow us to establish that the velocity of the outgoing air flow at the moment of exit from the duct is 1.615 m/s, and the velocity of the air flow when approaching the cattle decreases and reaches 0.450 m/s. These values are lower than the theoretical one by 15% and 10% respectively. The relationship between the results of simulation modeling and theoretical values is direct and has a strong closeness of relationship, convergence is equal to 0.86.

Evaluation of the Accuracy of Intraoral Digital Impression Systems and CAD and CAM Workflows for Fabricating Dental Prostheses

ABSTRACT Background: Dental prosthesis manufacturing has undergone a radical change with the introduction of intraoral digital impression technologies and computer-aided design and computer-aided manufacturing (CAD and CAM) processes. Investigations into these systems’ accuracy in creating dental restorations that adhere to clinical standards are still underway. Materials and Methods: For this investigation, a total of 60 patients in need of single-unit crowns were chosen. They were divided into three groups of 20: Group A used intraoral digital impression systems, Group B used conventional impression procedures, and Group C combined digital impressions with CAD and CAM processes. The marginal fit and internal fit of the crowns were compared to assess the correctness of the dental prosthesis. A stereomicroscope was used to evaluate the marginal fit, and micro-CT imaging was employed to analyze the interior fit. ANOVA and Tukey’s post hoc test were used to examine the data, with a significance threshold of P < 0.05. Results: The mean marginal fit was 120 ± 15 μm for Group A, 80 ± 10 μm for Group B, and 75 ± 8 μm for Group C, according to the data. The internal fit values were 150 ± 20 μm for Group A, 90 ± 12 μm for Group B, and 85 ± 10 μm for Group C. According to statistical analysis, Group B and Group C outperformed Group A in terms of accuracy in both internal and marginal fits (P < 0.01). There was no discernible difference between Group B and Group C. Conclusion: When constructing dental prostheses, intraoral digital impression technologies and CAD and CAM workflows show better accuracy over conventional impression techniques. The greatest clinical results are obtained when digital impressions and CAD and CAM workflows are combined, indicating that these technologies need to be accepted as routine procedures in prosthetic dentistry.

Decoding Electrochemical Interfaces with Computational Approaches: The Case of NiOOH Catalyst

Fundamental understanding of electrochemical interfaces is a prerequisite for designing well performing and economically viable electrocatalyst materials. The rapid increase in supercomputing power accompanied by methodical improvements in atomistic simulations enables an accelerated computer-aided materials design process. Our research in this context integrates theory and advanced simulation methods to decipher the relations between structure, properties and performance of electrochemical interfaces [1-4]. The presentation emphasizes the necessity of combining novel computational schemes [1,2,5,6] with knowledge from solid state chemistry and computational mineralogy in order to be able to rationalize the tremendous enhancement in the activity for the oxygen evolution reaction (OER) under alkaline conditions that is achieved upon Fe-doping of NiOOH [4,7]. Significant research has been dedicated to understanding the enhanced electrocatalytic activity of this material with different, often contradicting mechanisms proposed [7-11]. On the computational side, we identified the severe overestimation of the occupancy of d-orbitals by the widely used DFT+U computational approach as the origin of the problem and corrected it by employing localized Wannier functions as projectors for calculating the occupations of d-orbitals [4,2]. This approach allowed us to correctly compute the band gap of NiOOH and to reveal a realistic electronic structure of Fe-doped NiOOH. It occurred that Fe exists in the low-spin state for Fe contents below the solubility limit in Fe:NiOOH solid solution. The low-spin state of Fe dopant is responsible for lowering the OER overpotential relative to the value for pure NiOOH by ~300 mV, which agrees with the measured decrease [7] . The discovered state allows for the consistent explanation of measured data on ionic and electronic structure as well as magnetic and electrochemical properties. We will show that the miscibility of Fe in NiOOH is related to the sizes of Ni3+ and Fe3+ cations and that it is the closely matching cation radii of Ni and Fe in the low spin state that enable the formation of a mixed phase. Our results reconcile catalyst composition and structure with the mixing behavior in solid solution and the electrocatalytic activity.[1] Tesch, Kowalski & Eikerling, J. Phys.: Condens. Matter 33, 444004 (2021)[2] Ting & Kowalski, Electrochim. Acta 443, 141912 (2023)[3] He et al., Angewandte Chemie 136, e202315371 (2023)[4] He et al., Nat, Commun. 14, 3498 (2023)[5] Nishihara & Otani Phys. Rev. B 96 115429 (2017)[6] Kowalski et al. Front. Energy Res. 10, 1096190 (2023)[7] Friebel et al., J. Am. Chem. Soc. 137, 1305 (2015)[8] Conesa, J. Phys. Chem. C 120, 18999 (2016)[9] Martirez & Carter, Chem. Mater. 30, 5205 (2018)[10] Tkalych et al., Phys. Chem. Chem. Phys., 20, 19525 (2018)[11] Rajan et al., J. Am. Chem. Soc. 142, 3600 (2020)

Design and simultaneous analytical optimization of microwave filters with superimposed rectangular cavities for radar applications

In this paper, a method for the rapid design of filters with superimposed rectangular cavities is proposed. It starts with a good initialization of the filter dimensions from the targeted coupling matrix, which serves as the basis for calculating the bandwidth of the inter-cavity couplings (CBW) and the group delay (GD) of the input/output couplings. Next, an analytical and simultaneous optimization of all filter dimensions is applied. It is based on the extraction of the S-parameter coupling matrix from Model-based Vector Fitting (MVF) coupled to the Generalized Isospectral Flow Method (GIFM). The differences between the coefficients of the targeted matrix and the extracted matrix are then calculated, and depending on their positive or negative signs, appropriate adjustments are applied to the filter dimensions. This computer-aided design (CAD) process was successfully used to design one single-band and one dual-band 6th-order microwave filters with superimposed-cavity , with respective center frequencies of 10 GHz and 9.99 GHz, and taking into account milling constraints for eventual manufacture.

Design and 3D simulation of weft-knitted jacquard plush fabrics

Abstract Weft-knitted jacquard plush fabrics are widely used and have a wide variety of varieties, but the design and production process is complicated, time-consuming, and labor-intensive. To reduce the time and cost of fabric sampling and production, a method for designing and simulating these fabrics is proposed based on an analysis of their structural characteristics. Following the design principles of weft-knitted jacquard plush fabrics, mathematical models for pattern design and structural design were established sequentially, leading to the generation of a mathematical model for the knitting diagram. Arrays for raw material editing and threading editing were created to set various parameters. Second, loop models were established based on plush loop shapes, including a forming loop model, a U-shaped loop model, a Henkel plush loop model, a “8”-shaped plush loop model, and a O-shaped plush loop model. Finally, the effects of lighting and number of segments were investigated in THREE.Tube Geometry on the simulation’s effectiveness and speed. By comparing actual fabric images with simulation images, the feasibility of the design and simulation method was verified. This resulted in a computer-aided design process for weft-knitted jacquard plush fabrics, providing an effective method for their design and simulation. The proposed method holds significant theoretical and practical values.

Analytic Solutions for Volume, Mass, Center of Gravity, and Inertia of Wing Segments and Rotors of Constant Density

In the preliminary design of aircraft lifting surfaces, accurate mass and inertia properties can be difficult to obtain. Typically, such methods as computer-aided design or statistical processes are used to determine these properties. These methods require significant time and effort to implement. The present paper presents an exact analytic method for calculating the volume, mass, center of gravity, and inertia properties of wing segments and rotors of constant density. The influence of taper, spanwise thickness distribution, airfoil geometry, and sweep are included. The utility of the method is presented, and the accuracy is evaluated with various test cases via percent difference with a corresponding computer-aided design model. These case studies demonstrate the present method to be accurate to within about 1% for typical wing geometries and within about 1.3% for typical propeller geometries.

Zeolite-Y-catalyst production from locally sourced Meta-kaolin: Computer-Aided scale-up process design and economic analysis with Monte-Carlo-Simulation

Production of zeolite-Y catalyst from natural substrate has been a research trend in the scientific community. Published articles revealed that zeolite-Y recovery from locally sourced metakaolin is confined to laboratory practice. Scale-up process design and its economic feasibility for zeolite-Y catalyst recovery are rarely found in the scientific bibliography. Therefore, this study presented conceptual scale-up process design, base-case techno-economics and Monte-Carlo simulation of zeolite Y recovery from Nigerian metakaoline. ASPEN Base Case Simulation (ABCS), scale-up design and economics were accomplished using inherent design and costing algorithms in ASPEN Batch Process Developer (ABPD) V10. Process economic parameters: Net Present Value (NPV), Internal Rate of Return (IRR), Return on Investment (ROI) and Payback Time (PBT), were modelled and optimized using Design Expert V13 software; while zeolite Unit Production Cost (UPC), Annual Production Cost (APC), Total Capital Investment (TCI) and interest/discount rate were considered as model inputs. Monte-Carlo Simulation (MCS) in Crystal Ball Oracle software was used to perform the sensitivity and uncertainty analyses. The base-case techno-economic results of process design of 600,000 kg/year zeolite production gave batch size 5000 kg/batch with 104 batches/year, batch time (4149 min), TCI ($15,930,306), APC ($147,145), NPV ($41,983,375), ROI (38.13 %) and PBT (2.14 years). The coefficient of determination (R2) of the economic models were 0.9978, 0.9989 and 0.9986 for NPV, ROI and IRR respectively. The optimum economic variables that maximized synthesis of 5000 kg/batch zeolite Y are UPC ($11.68), APC ($100,033) and TPC ($15,930,200). MCS uncertainty for NPV, IRR and ROI are negligible. Therefore, this study demonstrated that scale-up zeolite-Y production from the local substrate is economically feasible.

Prediction of stability constants of metal-ligand complexes by machine learning for the design of ligands with optimal metal ion selectivity.

The new LOGKPREDICT program integrates HostDesigner molecular design software with the machine learning (ML) program Chemprop. By supplying HostDesigner with predicted logK values, LOGKPREDICT enhances the computer-aided molecular design process by ranking ligands directly by metal-ligand binding strength. Harnessing reliable experimental data from a historic National Institute of Standards and Technology (NIST) database and data from the International Union of Pure and Applied Chemistry (IUPAC), we train message passing neural net algorithms. The multi-metal NIST-based ML model has a root mean square error (RMSE) of 0.629 ± 0.044 (R2 of 0.960 ± 0.006), while two versions of lanthanide-only IUPAC-based ML models have, respectively, RMSE of 0.764 ± 0.073 (R2 of 0.976 ± 0.005) and 0.757 ± 0.071 (R2 of 0.959 ± 0.007). For relative logK predictions on an out-of-sample set of six ligands, demonstrating metal ion selectivity, the RMSE value reaches a commendably low 0.25. We showcase the use of LOGKPREDICT in identifying ligands with high selectivity for lanthanides in aqueous solutions, a finding supported by recent experimental evidence. We also predict new ligands yet to be verified experimentally. Therefore, our ML models implemented through LOGKPREDICT and interfaced with the ligand design software HostDesigner pave the way for designing new ligands with predetermined selectivity for competing metal ions in an aqueous solution.

TEM Image Analysis and Simulation Physics for Two-Step Recrystallization of Discretely Amorphized C3H5-Molecular-Ion-Implanted Silicon Substrate Surface

In this study, we investigate the initial rapid recrystallization of a discretely amorphized C3H5-molecular-ion-implanted silicon (Si) substrate surface in the subsequent thermal annealing treatment through the analysis of plan-view transmission electron microscopy (TEM) images and technology computer-aided design (TCAD) process simulation. In the approach of the analysis of the plan-view TEM image of the Si substrate surface, we found that initial rapid recrystallization occurs in the intermediate regions between the residual crystalline and discrete amorphous regions formed in the C3H5-molecular-ion-implanted Si substrate surface. In addition, the TCAD process simulation results indicate that the intermediate regions correspond to the amorphous pockets formed around the discrete amorphous regions in the C3H5-molecular-ion-implanted Si substrate surface and are recrystallized preferentially during the short thermal annealing time. These plan-view TEM image analysis and TCAD process simulation results reveal a two-step recrystallization of the discretely amorphized C3H5-molecular-ion-implaned Si substrate surface. After the initial rapid recrystallization of amorphous pockets in the 1st step, the recrystallization of discrete amorphous regions starts in the 2nd step. The incubation period between the 1st and 2nd steps is the time required to recrystallize the amorphous pockets around the discrete amorphous regions completely and redefine the amorphous/crystalline interface.

Translucency and Strength of Lithium Disilicate for Computer-Aided Design and Manufacturing at Different Thermal Temperatures and Thicknesses: An In Vitro Study.

To manufacture dental restorations composed of lithium disilicate (LD) through the computer-aided design and manufacturing (CAD/CAM) process, thermal refinement is an essential process that can affect the optical and mechanical properties of ceramics. In this study, we aimed to evaluate the translucency and flexural strength of lithium disilicate glass-ceramic for CAD/CAM using different thermal refinement schedules and thicknesses by measuring the total transmission of light through the specimen and calculating the peak load of the specimen until fracture in a piston-on-three-ball test, respectively. The results showed that a lower translucency was exhibited in thicker specimens, and the flexural strength decreased in the order of 1.0, 0.5, and 2.0 mm (p < 0.05). The lithium disilicates thermally refined at a heat of 820 degrees were shown to have the highest biaxial flexural strength (p < 0.05). These findings suggest that it is possible to adjust transparency and strength according to the clinical situation by choosing an appropriate thickness and thermal refinement process.

Is dynamic occlusal design necessary for anterior guidance recovery in the computer-aided design process? An in vitro study

ObjectivesThis study aimed to assess the effectiveness of patient-specific motion in restoring anterior guidance and to investigate the influence of occlusal plane position within a virtual articulator on the design of the anterior guide slope for incisors. MethodsTwenty participants' intraoral scan, occlusal plane position, and jaw motion data were recorded. The maxillary anterior teeth were virtually prepared, and the crowns were designed based on average virtual articulator (AVR), personalized virtual articulator (ART), and patient-specific motion (PSM). The anterior guide slope of maxillary central incisors (S1, S2, Sc, Sp) and the mesio-distal angle (MDA) of the canine of prostheses were compared to that of natural teeth (NAT). One-Way ANOVA was utilized to evaluate the effectiveness of the three methods in restoring the anterior guidance of maxillary anterior teeth. ResultsThe comparison of Sp and MDA showed no significant difference between the PSM and NAT groups (p > 0.05). However, Sp of the ART group was significantly smaller, while MDA was higher than that of the NAT group (p < 0.05). Sp did not differ significantly (p > 0.05) when the angle of the occlusal plane (AOP) was small. As the AOP increased, Sp of the ART and AVR groups were significantly smaller than that of the NAT group (p < 0.05). With a large AOP, Sp of the ART group was notably smaller than that of the NAT group (p < 0.05), while there was no significant difference between the AVR and NAT groups (p > 0.05). ConclusionsOcclusal design based on patient-specific motion proved more effective in restoring natural anterior guidance. The anterior guidance of prostheses designed using a virtual articulator was influenced by occlusal plane position. Clinical SignificanceThe utilization of a jaw motion tracer facilitated the transfer of personalized occlusal plane positions and recorded jaw motion, which can be integrated into the digital prosthetic workflow for virtual occlusion adjustment. Occlusal design based on patient-specific motion more effectively restored lingual guidance of maxillary anterior crowns.

Research on Teaching Reform and Innovation of Computer-aided Process Planning Courses

The innovative research on the teaching reform of computer-aided process design course aims to improve the quality and effectiveness of teaching, and cultivate talents who are more in line with social needs. By introducing the latest technology and theories in the industry, adopting various teaching methods, and strengthening practical teaching, measures are taken to stimulate students' interest and enthusiasm in learning, and improve their practical ability and comprehensive quality.

3D process simulation-assisted device failure analysis with virtual defect injection in IC layout

The development and use of nanotechnology has enabled the creation of submicron electronic devices with unprecedented levels of functionality, speed, and efficiency. While most of the semiconductor industry and its consumers are becoming increasingly dependent on nanoelectronics, these devices are becoming more susceptible to defects and transient faults. Non-Visual Defects (NVD) is a category of semiconductor material and process induced defect that cause electrical failures but are not detected with visual wafer inspection tools (Findlay et al., 2016 [1] and Kim et al., 2009 [10]) or with fault localization tools. Devices with NVD may fail at any stage of their life cycle and may benefit from complex Failure Analysis (FA) investigations including software support to analyze design and diagnostic data. For a higher FA success rate, these investigations can be further supplemented with Technology Computer-Aided Design (TCAD) Process Simulation software to simulate a failure prior to actual physical analysis on limited device samples. In this work, we will showcase an innovative technique for simulating NVD using a 3D process model to pinpoint the exact process step where the defect was introduced. By injecting a new virtual defect layer (which can be autonomously introduced by an FA engineer) in the original device data, we can emulate the failing device. We also present a real-life case study where defect simulation correlates well with the actual Transmission Electron Microscope (TEM) cross-section results.

Extrusion-based 3D printing of osteoinductive scaffolds with a spongiosa-inspired structure.

Critical-sized bone defects resulting from trauma, inflammation, and tumor resections are individual in their size and shape. Implants for the treatment of such defects have to consider biomechanical and biomedical factors, as well as the individual conditions within the implantation site. In this context, 3D printing technologies offer new possibilities to design and produce patient-specific implants reflecting the outer shape and internal structure of the replaced bone tissue. The selection or modification of materials used in 3D printing enables the adaption of the implant, by enhancing the osteoinductive or biomechanical properties. In this study, scaffolds with bone spongiosa-inspired structure for extrusion-based 3D printing were generated. The computer aided design process resulted in an up scaled and simplified version of the bone spongiosa. To enhance the osteoinductive properties of the 3D printed construct, polycaprolactone (PCL) was combined with 20% (wt) calcium phosphate nano powder (CaP). The implants were designed in form of a ring structure and revealed an irregular and interconnected porous structure with a calculated porosity of 35.2% and a compression strength within the range of the natural cancellous bone. The implants were assessed in terms of biocompatibility and osteoinductivity using the osteosarcoma cell line MG63 and patient-derived mesenchymal stem cells in selected experiments. Cell growth and differentiation over 14days were monitored using confocal laser scanning microscopy, scanning electron microscopy, deoxyribonucleic acid (DNA) quantification, gene expression analysis, and quantitative assessment of calcification. MG63 cells and human mesenchymal stem cells (hMSC) adhered to the printed implants and revealed a typical elongated morphology as indicated by microscopy. Using DNA quantification, no differences for PCL or PCL-CaP in the initial adhesion of MG63 cells were observed, while the PCL-based scaffolds favored cell proliferation in the early phases of culture up to 7days. In contrast, on PCL-CaP, cell proliferation for MG63 cells was not evident, while data from PCR and the levels of calcification, or alkaline phosphatase activity, indicated osteogenic differentiation within the PCL-CaP constructs over time. For hMSC, the highest levels in the total calcium content were observed for the PCL-CaP constructs, thus underlining the osteoinductive properties.

Computer-aided batch process design, techno-economic and uncertainty analyses of bio-clarified water recovery from south-eastern Nigerian brewery wastewater

Biocoagulation-flocculation-sedimentation (bioclarification) is one of the main wastewater treatment techniques. Despite its effectiveness in treating brewery wastewater for water reuse, the scale-up process for the reclaimed brewery water from wastewater has rarely been documented in the literature. This study presents the computer-aided process design, techno-economic and uncertainty analyses of bioclarified water production from brewery wastewater. The base-case simulation model, process scale-up design and economics were performed in Aspen Batch Process Developer. Process profitability indices (Net Present Value: (NPV), Internal Rate of Return: (IRR) and Payback Time: PBT) were evaluated in a user-defined developed Microsoft-excel version 2018. Monte-Carlo-Simulation in Crystal-Ball-Oracle software was used to perform the sensitivity and uncertainty analyses. The process scale-up simulation results gave annual production capacity (45,000,000 L/year), batch size (9800 L/batch) and annual number of batches produced (4564 batches/year). Base case capacity results showed that the total capital investment, NPV, IRR and PBT are $2,416,358.62, $2,790,608, 36% and 3.27years respectively. Sensitivity analysis shows that production capacity and product selling price have the highest contribution for both NPV and IRR respectively. Certainties of base-case model were 90.27% for the IRR and 99.51% for the NPV. This study showed that brewery wastewater bioclarification scale-up design is feasible.

Removable complete denture with a metal base: Integration of digital design and conventional fabrication techniques.

Digitally-designed removable complete dentures are typically composed of a resin denture base without a metal framework. However, metal denture bases are preferable as resin bases are more susceptible to fracture. Therefore, this article introduces a unique technique that integrates computer-aided design (CAD) and conventional resin processing for the fabrication of removable complete dentures with a metal framework. A maxillary complete denture with a metal base and a mandibular implant-retained overdenture reinforced with a metal framework were fabricated. The dentures were designed using CAD software and a tooth library. The denture bases were milled from wax disks, and artificial teeth were placed to complete the wax dentures. The metal frameworks were also designed using CAD software and produced via casting of printed resin patterns. Finally, conventional denture processing techniques were applied to obtain dentures with metal frameworks. A digitally designed, removable complete denture with a metal base can be successfully fabricated using the described technique, which merges digital design and conventional methods. This article demonstrates the feasibility and potential advantages of this innovative approach in denture fabrication. The presented technique provides the following advantages: digital design features, precise space above implant overdenture attachments for a metal framework, convenience of esthetic evaluation with printed trial dentures, long-term data storage and duplication, reliable bond between the artificial teeth and denture base, and enhanced strength of the removable complete denture due to the metal reinforcement.

Design and Development of a Novel 3-D Printed External Fixation Device for Fracture Stabilization

BackgroundAn external fixator is an orthopaedic device used to stabilize long bone fractures after high energy trauma. These devices are external to the body and fixed to metal pins going into non-injured areas of bone. They serve a mechanical function to maintain length, prevent bending, and resist torque forces about the fracture area. The purpose of this manuscript is to describe a design and prototyping process creating a low-cost entirely 3-D printed external fixator for fracture stabilization of extremity fractures. The secondary objective of this manuscript is to facilitate future advancements, modifications, and innovations in this area of 3-D printing in medicine.MethodsThis manuscript describes the computer aided design process using desktop fused deposition modeling to create a 3-D printed external fixator system designed for fracture stabilization. The device was created using the orthopaedic goals for fracture stabilization with external fixation. However, special modifications and considerations had to be accounted for given the limitations of desktop fused deposition modeling and 3-D printing with plastic polymers.ResultsThe presented device accomplishes the goals of creating a construct that can be attached to 5.0 mm metal pins, allows for modularity in placement orientations, and facilitates adjustable lengths for fracture care. Furthermore, the device provides length stability, prevention of bending, and resists torque forces. The device can be printed on a desktop 3-D printer using standard low-cost polylactic acid filament. The print time is less than two days and can be completed on one print bed platform.ConclusionsThe presented device is a potential alternative for fracture stabilization. The concept of a desktop 3-D printed external fixator design and method of production allows for numerous diverse applications. This includes assisting areas with remote or limited access to advanced medical care and large-scale natural disasters or global conflicts where large volumes of fractures exceed the local medical supply chain capabilities. The presented device creates a foundation for future devices and innovations in this fracture care space. Further research is needed on mechanical testing and clinical outcomes with this design and initiative in fracture care before clinical application.

Experimental investigation of the effect of lubricant change on automotive component

Manufacturing problems resulting from lubricant supplier changes are relatively common in automotive press shops. Simulations using computer-aided design (process and tool) detect a significant proportion of manufacturing problems before tools are physically produced. In modern forming codes, an enhanced Coulomb model is used to numerically model the friction phenomena associated with lubrication. In the laboratory condition, determining model parameters through physical measurement is challenging. As a result, it became necessary to design a device that could be utilized in industrial environments. In this study, we present the prediction of a manufacturing problem resulting from a change in the lubricant of an industrial sheet metal part. The measuring device has been developed based on the parameters of the friction model of the lubricant materials. The developed measuring device may be used to determine the pressure and velocity dependent friction model parameters. The measuring device can only measure a limited range of pressures and velocities, so the results are extended to a wider range using a mathematical method. The results are used to demonstrate the effect of lubricant material changes on the forming process using the AutoForm code.

Custom Silicone Distal Cup Designed and Fabricated Using 3D Optical Scanning and Additive Manufacturing to Improve Socket Fit of an Individual with Tranfemoral Amputation with Irregular Distal Residual Limb Morphology

ABSTRACT Introduction The study presents the design and manufacturing of a custom silicone distal cup, with a high spatial resolution, to fit inside the prosthetic liner for the treatment of irregular morphology at the distal residual limb of a patient with lower-limb amputation. This distal cup for the inside of the prosthetic liner has intricate interior features matching the shape of the distal residual limb to prevent localized high-pressure regions. Methods High-resolution 3D optical scanning, computer-aided design (CAD), and material extrusion (MEX) process for additive manufacturing of molds are three key techniques for designing and manufacturing this custom distal cup. A three-part mold for molding the distal cup with matching features was designed by CAD and fabricated by MEX. The subject evaluated the distal cup by walking using the distal cup before wearing the prosthetic liner in the lower-limb prosthesis. Results A custom silicone distal cup was fabricated using a 3D-printed mold and evaluated using a Prosthetic User’s Survey. Based on the survey, the insert has an acceptable comfort, suspension requirement, and ease of use. Conclusions The scan by high spatial resolution Space Spider optical scanner could capture detailed features of the distal residual limb. The resulting distal cup had the protrusion that functioned to separate the invaginations. The subject was satisfied with the distal cup based on the Prosthetic User’s Survey. Clinical Relevance The approach to fabricate the custom silicone distal cup using a high-resolution 3D optical scanner and a 3D-printed mold can be applied to fabricate the distal cup with intricate features for a patient with irregular morphology at the distal residual limbs.

A Scoping Review of Voxel-Model Applications to Enable Multi-Domain Data Integration in Architectural Design and Urban Planning

Although voxel models have been applied to address diverse problems in computer-aided design processes, their role in multi-domain data integration in digital architecture and planning has not been extensively studied. The primary objective of this study is to map the current state of the art and to identify open questions concerning data structuring, integration, and modeling and design of multi-scale objects and systems in architecture. Focus is placed on types of voxel models that are linked with computer-aided design models. This study utilizes a semi-systematic literature review methodology that combines scoping and narrative methodology to examine different types and uses of voxel models. This is done across a range of disciplines, including architecture, spatial planning, computer vision, geomatics, geosciences, manufacturing, and mechanical and civil engineering. Voxel-model applications can be found in studies addressing generative design, geomatics, material science and computational morphogenesis. A targeted convergence of these approaches can lead to integrative, holistic, data-driven design approaches. We present (1) a summary and systematization of the research results reported in the literature in a novel manner, (2) the identification of research gaps concerning voxel-based data structures for multi-domain and trans-scalar data integration in architectural design and urban planning, and (3) any further research questions.