Computer-aided Design Software Package Research Articles

Three-dimensional biofabrication of nanosecond laser micromachined nanofibre meshes for tissue engineered scaffolds.

There is a high demand for bespoke grafts to replace damaged or malformed bone and cartilage tissue. Three-dimensional (3D) printing offers a method of fabricating complex anatomical features of clinically relevant sizes. However, the construction of a scaffold to replicate the complex hierarchical structure of natural tissues remains challenging. This paper reports a novel biofabrication method that is capable of creating intricately designed structures of anatomically relevant dimensions. The beneficial properties of the electrospun fibre meshes can finally be realised in 3D rather than the current promising breakthroughs in two-dimensional (2D). The 3D model was created from commercially available computer-aided design software packages in order to slice the model down into many layers of slices, which were arrayed. These 2D slices with each layer of a defined pattern were laser cut, and then successfully assembled with varying thicknesses of 100 μm or 200 μm. It is demonstrated in this study that this new biofabrication technique can be used to reproduce very complex computer-aided design models into hierarchical constructs with micro and nano resolutions, where the clinically relevant sizes ranging from a simple cube of 20 mm dimension, to a more complex, 50 mm-tall human ears were created. In-vitro cell-contact studies were also carried out to investigate the biocompatibility of this hierarchal structure. The cell viability on a micromachined electrospun polylactic-co-glycolic acid fibre mesh slice, where a range of hole diameters from 200 μm to 500 μm were laser cut in an array where cell confluence values of at least 85% were found at three weeks. Cells were also seeded onto a simpler stacked construct, albeit made with micromachined poly fibre mesh, where cells can be found to migrate through the stack better with collagen as bioadhesives. This new method for biofabricating hierarchical constructs can be further developed for tissue repair applications such as maxillofacial bone injury or nose/ear cartilage replacement in the future.

Utilizing ChatGPT to assist CAD design for microfluidic devices.

ChatGPT is a generative AI model that has garnered tremendous public interest due to its ability to solve diverse problems through high-level reasoning and analysis. Among its features is an ability to create and debug code. While this capability has been explored with conventional programming languages such as Python, it has yet to be applied to computer-aided design (CAD). In this work, we utilized GPT-4 to create functional microfluidic components using OpenSCAD, an open-source CAD software package. Through an iterative dialogue, GPT-4 created functional designs for a helix/spiral, a valve, a t-junction, and a serpentine channel. This concept could facilitate CAD in the future for both technical and non-technical users and can be reasonably extended to other fields.

Computer-aided Design of Distal Femoral Osteotomy for the Valgus Knee and Effect of Correction Angle on Joint Loading by Finite Element Analysis.

Lateral open-wedge distal femoral osteotomy (DFO) has been used to treat valgus deformity of the knee, with good clinical outcomes. However, there is a lack of biomechanical studies regarding the angle of correction. The objective of this study was to apply computer-aided design (CAD) for osteotomy planning in a three-dimensional (3D) anatomical model and to assess the biomechanical differences among the varying correction angles on joint loading by finite element analysis (FEA). To model different angles of lateral open-wedge DFO correction, the CAD software package Mimics 21.0 was used to accurately simulate the operated knee. The femur was cut to 0°, 2°, 4°, 6°, 8°, and 10° of varus (equivalent to hip-knee-ankle angles of 180°, 178°, 176°, 174°, 172°, and 170°, respectively). The original knee model and the corrected models were processed by FE software. Then, the FE models were subjected to an axial force to obtain the von Mises stress (VMS) and shear stress distributions within the femoral cartilages and menisci. Under a compressive load of 740 N, the highest VMS in lateral and medial compartments of the intact knee model was 3.418 and 3.303 MPa. The maximum value of both the VMS and the shear stress in the lateral compartment decreased as the varus angle increased, but the corresponding values in the medial compartment increased. When the hip-knee-ankle (HKA) angle was 180°, the VMS in the lateral and medial compartments was balanced (3.418 and 3.303MPa, respectively). Meanwhile, when the HKA angle was 178° (3.488 and 3.625MPa, respectively), the shear stress in the lateral and medial compartments was balanced. In addition, the magnitude of change in the stress was significantly higher in the medial compartment (90.9%) than in the lateral compartment (19.3%). The optimal correction angle of the valgus knee is close to neutral alignment or slightly varus (0° - 2°). Overcorrection is not recommended, as it can result in a steep increase of the stress within the medial compartment and may accelerate the process of medial compartment OA.

SOFTWARE ANALYSIS IN THE FIELD OF GEODESY

In connection with the development of modern geodetic technologies, there is a need to quickly and efficiently perform automated processing of source data. Today, the market for surveying software is diverse and is divided into common products and specialized software packages. Geodetic works are not possible without the use of geographic information technologies and software. Therefore, the purpose of this article is a detailed analysis of the software packages used in Ukraine, as well as an analysis of their capabilities, accessibility, clarity and additional functions in the field of geodesy. Geodetic works belong to the tasks of geoinformation analysis, and with the help of modern electronic geodetic equipment increases the accuracy of work, the processing of which is carried out by computer-aided design (CAD). After analyzing the functionality of software products, we can conclude that most of them are not fully functioning automated products of full-scale systems. An important factor when choosing a software package is the ability to use for free or the low cost of a license to use. But, in addition to cost, when choosing a product, considerable attention is paid to the complexity of implementation and operation of such CAD. Among the most famous representatives that have proven themselves in Ukraine, we can highlight such packages as CREDO III, Digitals, and software packages created on the CAD platform. In general, such programs are set up by companies that have direct links with Western firms to facilitate data resolution. Other products can only be used to solve specific tasks of a narrower direction. When choosing a software, it is important that the program meets the objectives and processes all types of topographic and geodetic works. The application and implementation of new software packages in the field of geodesy provides greater accuracy and quality of topographic and geodetic works. When choosing software, many Ukrainian business leaders, as experience shows, focus on CREDO III, Digitals and CAD software packages to be able to work in a single information space at different stages of project development.

Silicon on isolator ribbon field-effect nanotransistors for high-sensitivity low-power biosensor

Silicon nanowire field-effect transistors are discussed as biological sensors due to their excellent sensitivity due to the large surface-to-volume ratio and high selectivity with respect to a large number of analytes. A miniature sensor based on a long-channel fin field-effect transistor as a surface charge detector is being investigated. The three-gate configuration offers undeniable advantages over planar devices, since the edges are about a hundred nanometers wide and are characterized by increased conductivity, which leads to higher sensitivity. The characteristics of the transistor are optimized using 3D modeling performed by the computer-aided design software package TCAD, depending on the topological parameters of the transistor and the level of control voltages. Based on the obtained simulation results, a chip was manufactured on a SOI substrate based on self-aligning CMOS-compatible technological processes from top to bottom. It is established that thin structures with a reduced level of doping and low supply power have promising electrical characteristics for an effective approach to scaling a high-resolution pH sensor, which is of particular interest to integrated pH bioanalytics based on CMOS technology.

Studying the Effect of Light Incidence Angle on Photoelectric Parameters of Solar Cells by Simulation

It is crucial to examine the dependence of photoelectric parameters of solar cells on the light incidence angle. In the present study, two solar cell models have been developed using the Sentaurus Technology Computer-Aided Design software package. The light spectrum AM1.5 has been directed on the frontal surface of solar cells at different angles. It has been found that the angular coefficient of the photoelectric parameters of a solar cell with nanoparticles included, is two times more than that of a simple solar cell. Besides, it has been found that the efficiency of platinum nanoparticles induced solar cells is 2.15 times greater than simple solar cell efficiency. When the light incidence angle has been varied from 0 to 60 degrees, the short-circuit current has changed by 11% for simple solar cells and by 10% for solar cells with nanoparticles. Further, it has been observed that the variation of power for simple solar cells is 12.5%, while it is 10.5% for solar cells with nanoparticles. In addition, the short-circuit current of solar cells with nanoparticles has been found to be linear within a light incidence angle ranging from 0 to 60 degrees.

An Intelligent Approach to Evaluating CAD Software Packages Through Hesitant Fuzzy AHP

The evaluation of computer-aided design (CAD) packages among the rising number of alternatives in the market has been a critical process for companies because it directly affects the performance of their design/engineering-related activities in a new product development (NPD) as well as in R&D departments. Moreover, it is seen as an important step towards the computer-integrated manufacturing (CIM) environment. On the other hand, the evaluation process of CAD software packages is a multiple-criteria decision-making (MCDM) problem in the presence of sets of alternatives and evaluation criteria, which should be solved using one of the MCDM methods in the current literature. Therefore, in this study, the analytic hierarchy process (AHP), successfully implemented in both academic research and practices, is used for CAD software selection problem. The method is also used with the group decision-making approach to reach a more reliable solution. Additionally, due to the fact that the crisp pairwise comparison in the traditional AHP method seems to be insufficient and imprecise to capture the right judgments of decision makers (DMs), the hesitant fuzzy linguistic term-sets are integrated with the AHP approach (the hesitant F-AHP) to model the vagueness and uncertainty on judgments of the DMs. This proposed approach is also supported with a user-friendly Excel template that provides an effective tool for companies to evaluate and rank CAD software packages without many tiresome fuzzy comparisons and complex calculations. Moreover, in the paper, a numerical example is presented to demonstrate the effectiveness and applicability of the proposed approach to potential readers and practitioners. In this example, five CAD software options are evaluated based on six criteria by three DMs; and the best alternative is determined.

РАЗРАБОТКА ПРОГРАММНО-ТЕХНИЧЕСКОГО КОМПЛЕКСА ДЛЯ ПРОЕКТИРОВАНИЯ ХИМИКО-ТЕХНОЛОГИЧЕСКИХ СИСТЕМ

The problems of constructing a software package for computer-aided design of mathematical models of complex chemical and technological processes are considered.

ОБГРУНТУВАННЯ ВИКОРИСТАННЯ МЕТАЛУРГІЙНИХ ШЛАКІВ ЯК ЗАКЛАДНОГО МАТЕРІАЛУ КАР’ЄРНИХ ПУСТОТ

Purpose. Experimental studies of the interaction of blast-furnace and steel-making slags with open pit waters during their direct contact and assessment of the volume of filling of the formed man-made cavities during mining of mineral deposits. Methods. Based on the analysis, the current low level of metallurgical slag and the lack of real and effective directions of their large-scale utilization were determined. The laboratory studies of the interaction of metallurgical slags with open pit water at a certain time of interaction, generally accepted methods for studying the chemical composition and concentration of substances in water, computer-aided design software packages and drawings to determine the volumes of the open pit mined-out area were used. Results. The dynamics of changes in the products of interactions of steel-smelting slags with open-pit waters at a certain ratio and period of interaction was investigated. It was found that the concentration of pollutants upon contact of water with steel-making slag changes according to polynomial dependences on the time of their interaction, decreasing by the 30th day, which eliminates the danger for the aquifer. The safest type of metallurgical slag was recommended for the formation of the bottom layer of the backfill massif. The volumes of the mined-out area of the open pit were determined in detail to assess the volumes of placement of the backfill material based on metallurgical slags. Scientific novelty. The safety of the contact of backfill materials based on steelmaking slags with open pit water was scientifically proven, which is confirmed by the established polynomial patterns of changes in concentrations and pollutants from the ratio and time of interaction. Practical significance. The formation of the backfill massif on the basis of blast-furnace dump and steel-smelting slags will allow achieving an environmental effect, such as their safe disposal as a reclamation of technologically disturbed lands by mining and restoration of the economic value of the land plot, as well as preventing the formation of new dumps.

A helical gear with discrete ring-involute teeth

This study produces a skewed-imaginary planar rack cutter with discrete conical teeth that is used to create a helical gear with discrete ring-involute teeth. A mathematical equation for the skewed-imaginary rack cutter with discrete conical teeth is firstly solved. The coordinate system for the rack cutter and gear pair is then established and a family of the rack-cutter surfaces is obtained using homogeneous coordinate transformation. The relative velocity method is used to produce the equation for meshing between the rack cutter and the gear pair. Substituting the equation of meshing into the family of the rack-cutter surfaces gives the mathematical models for the gear pair with discrete ring-involute teeth. The transmission error for the gear pair is calculated using the assembly error and a tooth contact analysis. A computer-aided design software package is used to establish solid model for the gear pair. A software interference function is used to simulate the contact condition for the gear pair for various assembly errors. Finite element analysis software is then used to determine the contact stress for the gear pair. The transmission error and the contact stress for the gear pair are insensitive to any horizontal misalignment in the assembly errors.

Digitisation of traditional product using computer aided design technology: a case study on desiccant compressed air dryer

In order to face the competition, traditional manufacturing companies are required to digitise the products by applying computer-aided design (CAD) for infusing innovative features in them. In the context of this realisation, a case study on digitising a traditional product by name 'desiccant compressed air dryer' (DCAR) by applying CAD technology which is presented in this paper was carried out. The procedures adopted to create the CAD models of six subassemblies of DCAR and its assembly by using a CAD software package namely Creo Parametric 2.0 are described. Then the advantage of digitising the traditional products using the CAD technology is described. The article is concluded by stating that utilising this kind of facilities that are available in CAD software packages will enable traditional manufacturing companies to become agile by quickly adding amazing features that will delight the customer.

On the Design of Broadband Hybrid Amplifiers Using Non-Uniform Transmission Lines as Impedance Matching Networks

In this paper, an approach for the practical design of broadband amplifiers in hybrid technology is presented. It is based on the use of non-uniform transmission lines to implement impedance matching networks, which are synthesized exploiting the powerful optimization tools available in the most common computer-aided design software packages. The versatility of the proposed technique makes it suitable for the design of a wide variety of broadband amplifiers. Furthermore, it is easily implementable in most microwave simulators and allows a considerable design time reduction, since it can be applied in a systematic way and avoids the use of external tools. To validate the technique, it is applied to the design of a low noise amplifier using a single encapsulated transistor. A prototype was implemented, providing 10-dB flat gain from 1 to 12 GHz, noise figure under 2.5 dB, and acceptable input and output matching, which agrees with the simulation data.

An open source, 3D printed preclinical MRI phantom for repeated measures of contrast agents and reference standards

In medical imaging, clinicians, researchers and technicians have begun to use 3D printing to create specialized phantoms to replace commercial ones due to their customizable and iterative nature. Presented here is the design of a 3D printed open source, reusable magnetic resonance imaging (MRI) phantom, capable of flood-filling, with removable samples for measurements of contrast agent solutions and reference standards, and for use in evaluating acquisition techniques and image reconstruction performance. The phantom was designed using SolidWorks, a computer-aided design software package. The phantom consists of custom and off-the-shelf parts and incorporates an air hole and Luer Lock system to aid in flood filling, a marker for orientation of samples in the filled mode, and bolt and tube holes for assembly. The cost of construction for all materials is under $90. All design files are open-source and available for download. To demonstrate utility, B0 field mapping was performed using a series of gadolinium concentrations in both the unfilled and flood-filled mode. An excellent linear agreement (R2 > 0.998) was observed between measured relaxation rates (R1, R2) and gadolinium concentration. The phantom provides a reliable setup to test data acquisition and reconstruction methods and verify physical alignment in alternative nuclei MRI techniques (e.g. carbon-13 and fluorine-19 MRI). A cost-effective, open-source MRI phantom design for repeated quantitative measurement of contrast agents and reference standards in preclinical research is presented. Specifically, the work is an example of how the emerging technology of 3D printing improves flexibility and access for custom phantom design.

Programming of the search algorithm for point belonging to the polygon and the mutual non-intersection of the figures

The object of research is shoe parts of various configurations. At the enterprises of the footwear industry, there is a problem of densely stacking shoe parts in the nesting pattern. To solve this problem, the hodograph of the vector function of the dense distribution of geometric figures is applied. Ray tracing method is used for the formation of rational nesting patterns. These methods are introduced into the developed software package for computer-aided design of nesting patterns. Three main algorithms for finding the point belonging to the polygon are analyzed. There are much more algorithms that solve this problem, but these algorithms have optimal complexity parameters: O(2*N) against O(N^2) in other algorithms. Based on the analysis of the three main algorithms, an algorithm for exclusion of the part from the nesting pattern is created. This algorithm is modified and adjusted to the requirements of the task – leaving 4–6 parts of one configuration in the nesting pattern. A characteristic feature of the algorithm is that instead of constructing a single point for the ray, the pole of the part is used.

A software package for computer-aided design of spintronic nanodevices

Spintronics is a new trend in the development of nanoelectronics and, therefore, requires the development of new software tools for modeling aimed at the development and further miniaturization of spintronic devices. In this paper, we present a new software package for the technology computer aided design modeling of spintronic devices based on magnetic tunnel junctions. The theoretical models and scenarios of the software package are described. Examples of application of the software package to solving the main problems arising in the design of magnetoresistive memory elements and consistent miniaturization of these devices are considered.

Post-traumatic zygomatic osteotomy and orbital floor reconstruction

Purpose Post-traumatic zygomatic osteotomy, fracture reduction, and orbital floor reconstruction pose many challenges for achieving a predictable, accurate, safe, and aesthetically pleasing result. This paper aims to describe the successful application of computer-aided design (CAD) and additive manufacturing (AM) to every stage of the process – from planning to surgery. Design/methodology/approach A multi-disciplinary team was used – comprising surgeons, prosthetists, technicians, and designers. The patient’s computed tomography scan data were segmented for bone and exported to a CAD software package. Medical models were fabricated using AM; for diagnosis, patient communication, and device verification. The surgical approach was modelled in the virtual environment and a custom surgical cutting guide, custom bone-repositioning guide, custom zygomatic implant, and custom orbital floor implant were each designed, prototyped, iterated, and validated using polymer AM prior to final fabrication using metal AM. Findings Post-operative clinical outcomes were as planned. The patient’s facial symmetry was improved, and their inability to fully close their eyelid was corrected. The length of the operation was reduced relative to the surgical team’s previous experiences. Post-operative scan analysis indicated a maximum deviation from the planned location for the largest piece of mobilised bone of 3.65 mm. As a result, the orbital floor implant which was fixed to this bone demonstrated a maximum deviation of 4.44 mm from the plan. Originality/value This represents the first application of CAD and AM to every stage of the process for this procedure – from diagnosis, to planning, and to surgery.

Development of simulation tools for numerical investigation and computer-aided design (CAD) of gyrotrons

As the most powerful CW sources of coherent radiation in the sub-terahertz to terahertz frequency range the gyrotrons have demonstrated a remarkable potential for numerous novel and prospective applications in the fundamental physical research and the technologies. Among them are powerful gyrotrons for electron cyclotron resonance heating (ECRH) and current drive (ECCD) of magnetically confined plasma in various reactors for controlled thermonuclear fusion (e.g., tokamaks and most notably ITER), high-frequency gyrotrons for sub-terahertz spectroscopy (for example NMR-DNP, XDMR, study of the hyperfine structure of positronium, etc.), gyrotrons for thermal processing and so on. Modelling and simulation are indispensable tools for numerical studies, computer-aided design (CAD) and optimization of such sophisticated vacuum tubes (fast-wave devices) operating on a physical principle known as electron cyclotron resonance maser (ECRM) instability. During the recent years, our research team has been involved in the development of physical models and problem-oriented software packages for numerical analysis and CAD of different gyrotrons in the framework of a broad international collaboration. In this paper we present the current status of our simulation tools (GYROSIM and GYREOSS packages) and illustrate their functionality by results of numerical experiments carried out recently. Finally, we provide an outlook on the envisaged further development of the computer codes and the computational modules belonging to these packages and specialized to different subsystems of the gyrotrons.

Rigorous evaluation of propagation losses in arbitrarily shaped waveguide structures using boundary integral – resonant mode expansion and perturbation of boundary conditions

The accurate consideration of propagation losses in arbitrarily shaped waveguide-based structures is studied in this paper. For such a purpose, a software tool based on the perturbation of the boundary conditions on the waveguide metallic walls and on the boundary integral – resonant mode expansion method has been developed. To show the advantages of the proposed technique with respect to the classic power-loss method, the complex propagation wavenumbers of a double ridge and an elliptical waveguide have been first computed and compared with results of a commercial software based on the finite element technique. Next a circular, a sectorial shaped and a triangular shaped waveguide have been considered. Then, a computer-aided design software package based on this modal analysis tool has been applied to predict the propagation loss effects in complex waveguide structures, such as an evanescent mode ridge waveguide filter, a traditional dual mode filter with circular cavities and a twist component for K-band applications.

Image-Based Modeling Approaches to 2D and 3D Digital Drafting in Archaeology at Tel Akko and Qasrin

ABSTRACT As archaeologists continue to adopt geographic information systems and computer-aided design software packages to record and store spatial data, excavations have begun to forgo hand-drawn plans in favor of digital recording. The purpose of this article is to present two case studies that have successfully utilized digital drafting techniques to create architectural plans at multiple scales. The first presents on-site 2D and 3D documentation at the site of Tel Akko, Israel, at the square, field, and tell scales. The second study combines orthophotos and legacy data to create an accurate site plan of Qasrin on the Golan Heights. Both harness image-based modeling to produce 2D and 3D spatial data in order to produce top plans with unprecedented spatial accuracy.

Computer-aided design of tooth preparations for automated development of fixed prosthodontics

BackgroundThis paper introduces a method to digitally design a virtual model of a tooth preparation of the mandibular first molar, by using the commercial three-dimensional (3D) computer-aided design software packages Geomagic and Imageware, and using the model as an input to automatic tooth preparing system. MethodsThe procedure included acquisition of 3D data from dentate casts and digital modeling of the shape of the tooth preparation components, such as the margin, occlusal surface, and axial surface. The completed model data were stored as stereolithography (STL) files, which were used in a tooth preparation system to help to plan the trajectory. Meanwhile, the required mathematical models in the design process were introduced. ResultsThe method was used to make an individualized tooth preparation of the mandibular first molar. The entire process took 15min. DiscussionUsing the method presented, a straightforward 3D shape of a full crown can be obtained to meet clinical needs prior to tooth preparation.