Advanced Manufacturing Technology Research Articles

The Impact of Advanced Manufacturing Technology on Achieving Competitive Advantage: A Field Study at Foodstuff Manufactories in the Capital Municipality of Sana’a

The study aimed to investigate the impact of advanced manufacturing technology on comparative advantage of foodstuff manufactories in the Capital Municipality of Sana’a. Using an analytical approach, data were collected from a sample of 90 employees through a questionnaire. The data were analyzed using inferential statistical methods applied with SPSS software. The findings revealed a positive influence of advanced manufacturing technology on the competitive advantage of foodstuff manufacturers in the Capital Municipality of Sana’a. The study also revealed that information technology dimension was the most influential factor affecting the competitive advantage of foodstuff manufactories, while the design and engineering dimension had the least impact. Based on these findings, the study recommends further strengthening the application of advanced manufacturing technology in foodstuff manufactories in the Capital Municipality of Sana’a. Additionally, it emphasizes the importance of robust supervision of the implemented manufacturing systems to ensure product quality. The study underscores the need for higher focus on the quality of raw materials used in the manufacturing process.

‘5D PRINTING’ -THE NEW ERA IN DENTISTRY! -A NARRATIVE REVIEW

3D printing technology has a wide range of applications in various industries. It is widely used to produce complex 3D structures, but it has some limitations such as a limited amount of material, etc., which have been overcome with the introduction of 4D printing technology. In 4D printing, which involves time as a function and the combination of smart materials, this enables properties such as changing form and function.[1]Five-dimensional (5D) printing is a new branch of additive manufacturing (AM) with great potential to solve problems in engineering, medicine, dentistry and other related fields. It is the latest technological advancement used to produce complex and intricately shaped products, implants and devices with much better physical properties than those obtained by three-dimensional (3D) printing. The concept of 5D printing originated from William Yerazunis of the American University of Mitsubishi Electric Research Laboratories (MERL). In 5D printing, the printing plate also moves with the printing head during the printing process. in 3D printing techniques.[1]four-dimensional (4D) printing is the concept of using a smart material that can change the shape of a printed object over time as the temperature changes. [2] One of the advantages of 5D printing is the use of 25% less material than 3D printing. Five-dimensional printing is all about efficiently manufacturing this complex and curved structure with maximum strength. Using computer-aided design (CAD) data to produce super strong dental implants, orthodontic brackets, crowns, aligners, bridges and appliances. This CAD data is created using the dentist's 3D scanner / different design software.[1] 5D printing of five axes: [1], 1.X-axis ;2. Y-axis;3. Z axis; 4. Movable print head and 5. Movable printing base.5D printing is an advanced manufacturing technology that builds on the concept of 3D printing and adds customization options and features. While 3D printing requires the creation of three-dimensional objects layer by layer, 5D printing allows additional functions or features to be added to a printable object, often dynamically or responsively. its role in dentistry may be limited due to the newness of the technology.

Online Orientation Recognition of Single-Crystal Diamond Tools in the Process of Indexing Grinding Based on HMM and Multi-Information Fusion

Single-crystal diamond tools occupy an important position in the field of optical processing as the basis and key to advanced optical manufacturing technology, such as grating manufacturing and optical mirror-turning processing. Single-crystal diamond tools have become the cornerstone of the development of related industries. This paper takes a single-crystal diamond arc tool as the research object. Sound signal analysis technology and vibration signal analysis technology are comprehensively applied to the online orientation identification of a single-crystal diamond tool in the indexing grinding process. The online orientation method of the tool is explored, the sound signal and the vibration signal are taken as the characteristic signals, and a wavelet algorithm (WT) is used to reduce the noise of the vibration signal and sound signal. The kurtosis of the sound signal and the kurtosis and skewness of the vibration signal in the high-order statistics strongly related to the grinding direction of a single-crystal diamond are used as the characteristic parameters, and the online direction recognition model of the tool is established using the Hidden Markov Method (HMM). The above characteristic parameters are used as model input for multi-information fusion. The mapping relationship between the characteristic parameters of the characteristic signal and the crystal orientation of the single-crystal diamond crystal face is obtained, and then the online orientation method of the single-crystal diamond arc tool in the process of indexing grinding is formed. The effectiveness of the method is verified by experiments, and effective orientation information is provided for research on the positioning control strategy of the tool grinding process to ensure the efficiency of grinding and improve the manufacturing level of the tool.

Resistance Welding of CF/PEI Composites by a Novel Implant of Flame-grown Carbon Nanotubes Grafted Carbon Fibers

Objective: Interface enhancement between resin and fiber has been a longstanding goal for manufacturing composite material. Using carbon nanomaterials in combination with macro-materials for composite materials is an important application of advanced manufacturing technology. Methods: This study examined the use of carbon nanotubes (CNTs) wrapped carbon fibers (CFs) (CFs@CNT), a cross-scale composite component incorporating CNTs and CFs, as an implant for resistance welding of composites containing carbon-fiber-reinforced polyetherimide (CF/PEI). Results: The correlation of growth time (tg) on growth morphology of CNTs on implant and strengths of joints were studied. The surface of CF was gradually covered by CNTs and finally completely wrapped, and CNTs appeared as multi-walled CNTs. The interface structure of resistance welded joints and their mechanical properties were evaluated. The PEI resin was sufficiently melted and obtained a perfect bonding joint with stronger mechanical properties when tg was 2min and 3min. The cracks were found at the edge of the bonding interface and a collapse first appeared in joint when tg was 4min and 5min, respectively. The defects were caused by the accumulation of amorphous carbon at the top of the CNTs. The strength of joint welded by CFs@CNT implant increased to 37.8MPa compared with the joint obtained by pure CFs implant alone only 24.2MPa when tg was 3min. Conclusion: The purpose of strengthening the joint was achieved by improving the wettability of PEI resin on CFs@CNT lead to the CFs was fully wrapped by molten resin during welding process.

Industry 4.0 and Lean Manufacturing, using the MAUT Method

Industry 4.0 covers a wide range of areas, such as production processes, efficiency, data management, consumer relationships, and competitiveness. It is also becoming a topic of academic study, with researchers and scholars exploring various questions related to this revolution. Furthermore, the text mentions the Toyota Production System, which promotes efficiency and effective communication in production operations and introduces the concept of Lean Manufacturing, which aims to reduce costs and increase efficiency. The integration of Industry 4.0 with Lean Manufacturing is referred to as “Lean 4.0”. The method used in this article was a questionnaire sent to manufacturing companies in southern Brazil and analyzed the data obtained through the Multi-Attribute Utility Theory (MAUT), which is presented as a decision-making tool that allows comparing alternatives taking into account multiple criteria. The conclusions of this study show that both the views of senior management and those surveyed consider that the companies involved in this research will be in 5 years, with their Industry 4.0 well developed. On the Lean Manufacturing side, considering only the view of those surveyed, they consider that the companies involved in this study will be in 5 years, with Lean Manufacturing quite developed. The practical contribution of this study shows that the companies participating in the study are committed to adopting advanced manufacturing technologies and practices. This conclusion is important because it indicates that companies are aware of the opportunities and challenges of Industry 4.0 and Lean Manufacturing.

State-of-the-Art Lightweight Implementation Methods in Electrical Machines

The demand for high-power density motors has been increasing due to their remarkable output capability and compact construction. To achieve a significant improvement in motor power density, lightweight design methods have been recognized as an effective enabler. Therefore, extensive investigations have been conducted to reduce motor mass and achieve lightweight configurations through the exploration of lightweight materials, structures and manufacturing techniques. This article provides a comprehensive review and summary of state-of-the-art lightweight implementation methods for electrical machines, including the utilization of lightweight materials, structural lightweight design, and incorporation of advanced manufacturing technologies, such as additive manufacturing techniques. The advantages and limitations of each approach are also discussed in this paper. Furthermore, some comments and forecasts on potential future methodologies for motor lightweighting are also provided.

Microstructural characteristics and properties of wire arc additive manufactured 304L austenitic stainless steel cylindrical components by different arc welding processes

Wire arc additive manufacturing (WAAM) is an advanced additive manufacturing (AM) technology that offers low cost and high deposition rates, making it suitable for building large metal parts for structural engineering applications. However, various welding procedures result in differing heat inputs and repetitive heating treatments throughout the deposition process, which can affect the microstructural and mechanical characteristics of the parts. In the current study, cylindrical parts made of 304L austenitic stainless steel (ASS) were manufactured using the WAAM technique, employing both gas metal arc welding (GMAW) and cold metal transfer (CMT) processes. This study explores the correlation between WAAM techniques and their effects on the bead geometry, microstructure and mechanical properties. The microstructure of the cylinders consisted of vertically growing austenite dendrites with residual ferrite (δ) within the austenite (γ) matrix. Compared to the bottom region (region ①), the top region (region ②) contained more residual ferrite. Although the microstructural characteristics from region ① to region ② are similar, they exhibit different ferrite morphologies. The rapid cooling rate in the CMT-AM process resulted in finer structures and a greater presence of ferrite phases in both regions compared to the GMAW-AM method. Cylinders produced by the CMT process displayed nearly uniform properties across both regions and demonstrated superior tensile properties, hardness, and impact toughness relative to those made using the GMAW technique. The WAAM 304L ASS cylinders also showed enhanced performance compared to stainless steel manufactured using traditional industrial forging standards, indicating that WAAM-processed 304L ASS cylinders are suitable for industrial applications.

Investigation of melt flow index and tensile properties of dual metal reinforced polymer composites for 3D printing using machine learning approach: Biomedical and engineering applications

This study investigates the enhancement of mechanical properties of metal/polymer composites produced through fused deposition modeling and the prediction of the ultimate tensile strength (UTS) by machine learning using a Classification and Regression Tree (CART). The composites, comprising 80% acrylonitrile butadiene styrene matrix and 10% each of aluminum (Al) and copper (Cu) fillers, were subjected to a comprehensive exploration of printing parameters, including printing temperature, infill pattern, and infill density using the Taguchi method. The CART unveiled a hierarchical tree structure with four terminal nodes, each representing distinct subgroups of materials characterized by similar UTS properties. The predictors’ importance was assessed, highlighting their role in determining material strength. The model exhibited a high predictive power with an R-squared value of 0.9154 on the training data and 0.8922 on the test data, demonstrating its efficacy in capturing variability. The optimal combination of parameters for maximizing UTS was a zigzag infill pattern, a printing temperature of 245 °C, and an infill density of 10%, which is associated with the highest UTS of 680 N. The model’s reliability was confirmed through a paired t-test and test and confidence interval for two variances, revealing no significant difference between the observed and predicted UTS values. This research contributes to advancing additive manufacturing processes by leveraging CART analysis to optimize printing parameters and predict material strength. The identified optimal conditions and subgroup characteristics pave the way for developing robust and predictable metal/polymer composites, offering valuable insights for material design in the era of advanced manufacturing technologies.

Supporting decision-making of collaborative robot (cobot) adoption: The development of a framework

Collaborative robots (cobots) are emerging in manufacturing as a response to the current mass customization production paradigm and the fifth industrial revolution. Before adopting this technology in production processes and benefiting from its advantages, manufacturers need to analyze the investment. Therefore, this study aims to develop a decision-making framework for cobot adoption, incorporating a comprehensive set of quantitative and qualitative criteria, to be used by decision-makers in manufacturing companies. To achieve that objective, a qualitative study was conducted by collecting data through interviews with key actors in the cobot (or advanced manufacturing technologies) adoption decision process in manufacturing companies. The main findings of this study include, firstly, an extensive list of decision criteria, as well as some indicators to be used by decision-makers, some of which are new to the literature. Secondly, a decision-making framework for cobot adoption is proposed, as well as a set of guidelines to use it. The framework is based on a weighted scoring method and can be customizable by the manufacturing company depending on its specific context, needs, and resources. The main contribution of this study consists in assisting decision-makers of manufacturing companies in performing more complete and sustained decision analyses regarding cobots adoption.

An optimization study focused on lattice structured custom arm casts for fractured bones inspiring additive manufacturing

In case of fractures, cracks or damage to bone tissues, it is important to use casts, fixatives and protective equipment. Especially in cases where long-term use of casts is required, soft tissue wounds may occur in the human body due to their moisture and airtight structure. For this reason, the use of casts with custom designs, breathable materials, and high mechanical properties has become widespread in recent years. This study focuses on the design of custom arm casts using advanced additive manufacturing technologies and lightweight materials. By utilizing Voronoi lattice structures and hexagonal surface meshes, optimized designs adaptable to additive manufacturing were obtained from a standard arm cast. All cast geometries were investigated under 196 N and 380 N forces. Then, the impact of a 100 g and 1000 g concrete piece with a speed of 12.5 m/s on the arm cast was investigated. As a result of the analyzes, stress, impact plate velocities, deformation, strain and deformation energy were evaluated. The results showed that the designed arm casts have up to 60% better impact strength compared to conventional arm casts. Based on the findings of this study, the use of custom arm casts with optimized lattice structures designed for additive manufacturing will demonstrate high performance.

Additive manufacturing of ultrahigh-resolution Poly(ε-caprolactone) scaffolds using melt electrowriting

Melt electrowriting (MEW) is an advanced additive manufacturing technology that produces high-resolution scaffolds for medical applications. Although there are many valuable parameter groups for MEW, the corresponding principles need to be clarified to improve the success of printing high-fidelity scaffolds. To this end, we investigate the print limit of MEW with respect to the minimum interfiber distance and the maximum print period based on a medical-grade poly(ε-caprolactone) material. The results indicate that relatively large turning loops and low turning speeds improve the print accuracy of the scaffolds; however, excessively large turning loops and low turning speeds result in fiber accumulation on the edge of the scaffolds, resulting in print failure. The turning loops with 500 μm in diameter and turning speeds of 0.625 × CTS (critical translation speed) can achieve well-defined MEW scaffolds with an interfiber distance down to 25 μm. For printing such high-resolution scaffolds, the constant printing process can last one week. Fiber placement gets random when the fiber diameter is larger than 2.5 μm, caused by the melt polymer degradation and shear thinning in the printing process. Additionally, we verify that the method of charge neutralization is not beneficial for improving the fiber overlay. This is a fundamental study clarifying the principles of printing high-resolution MEW scaffolds, being capable of extending the application of the MEW products.

Fourth industrial (r)evolution? Investigating the use of technology bundles and performance implications

PurposeThe purpose of this paper is to investigate how different manufacturing technologies are bundled together and how these bundles influence operations performance and, indirectly, business performance. With the emergence of Industry 4.0 (I4.0) technologies, manufacturing companies can use a wide variety of advanced manufacturing technologies (AMT) to build an efficient and effective production system. Nevertheless, the literature offers little guidance on how these technologies, including novel I4.0 technologies, should be combined in practice and how these combinations might have a different impact on performance.Design/methodology/approachUsing a survey study of 165 manufacturing plants from 11 different countries, we use factor analysis to empirically derive three distinct manufacturing technology bundles and structural equation modeling to quantify their relationship with operations and business performance.FindingsOur findings support an evolutionary rather than a revolutionary perspective. I4.0 technologies build on traditional manufacturing technologies and do not constitute a separate direction that would point towards a fundamental digital transformation of companies within our sample. Performance effects are rather weak: out of the three technology bundles identified, only “automation and robotization” have a positive influence on cost efficiency, while “base technologies” and “data-enabled technologies” do not offer a competitive advantage, neither in terms of cost nor in terms of differentiation. Furthermore, while the business performance impact is positive, it is quite weak, suggesting that financial returns on technology investments might require longer time periods.Originality/valueRelying on a complementarity approach, our research offers a novel perspective on technology implementation in the I4.0 era by investigating novel and traditional manufacturing technologies together.

An acoustic imaging recognition based cutting tools wear state prediction method

Online monitoring of cutting tools wear is an important component of advanced manufacturing technology, which can greatly improve the processing efficiency and reduce the production cost. In this paper, a cutting tools wear state prediction method based on acoustic imaging recognition is developed. By applying the advantages of the functional generalized inverse beamforming method in the sound field reconstruction, the acoustic signal is used as the carrier to reconstruct the three-dimensional space radiated sound field. And then, slice the reconstructed sound field image and input it into the convolutional neural network model as a sample, to process and classify the image and mines the feature information related to state from the sound field image. By incorporating amplitude and phase information of the sound field, the presented method utilizes spatial domain mapping to accurately identify the noise source and address challenges such as low recognition rate and difficult diagnosis under weak fault conditions. Furthermore, the paper also demonstrates the recognition of sound field states through a fault experiment in sound box simulation, based on these theories. And the recognition of sound field states is achieved through a simulation fault experiment conducted on the sound box, thereby validating the feasibility of the state monitoring method based on pattern recognition of sound and image. Finally, the experimental object is selected as the four-edge carbide milling cutter, and the cutting tools wear state is monitored by integrating sound field reconstruction techniques with convolution feature extraction methods to validate the robustness of the proposed approach.

Induced alterations driven compromised structural properties in additively manufactured products

PurposeAdditive manufacturing also known as 3D printing is an evolving advanced manufacturing technology critical for the new era of complex machinery and operating systems. Manufacturing systems are increasingly faced with risk of attacks not only by traditional malicious actors such as hackers and cyber-criminals but also by some competitors and organizations engaged in corporate espionage. This paper aims to elaborate a plausible risk practice of designing and demonstrate a case study for the compromised-based malicious for polymer 3D printing system.Design/methodology/approachThis study assumes conditions when a machine was compromised and evaluates the effect of post compromised attack by studying its effects on tensile dog bone specimens as the printed object. The designed algorithm removed predetermined specific number of layers from the tensile samples. The samples were visually identical in terms of external physical dimensions even after removal of the layers. Samples were examined nondestructively for density. Additionally, destructive uniaxial tensile tests were carried out on the modified samples and compared to the unmodified sample as a control for various mechanical properties. It is worth noting that the current approach was adapted for illustrating the impact of cyber altercations on properties of additively produced parts in a quantitative manner. It concurrently pointed towards the vulnerabilities of advanced manufacturing systems and a need for designing robust mitigation/defense mechanism against the cyber altercations.FindingsDensity, Young’s modulus and maximum strength steadily decreased with an increase in the number of missing layers, whereas a no clear trend was observed in the case of % elongation. Post tensile test observations of the sample cross-sections confirmed the successful removal of the layers from the samples by the designed method. As a result, the current work presented a cyber-attack model and its quantitative implications on the mechanical properties of 3D printed objects.Originality/valueTo the best of the authors’ knowledge, this is the original work from the team. It is currently not under consideration for publication in any other avenue. The paper provides quantitative approach of realizing impact of cyber intrusions on deteriorated performance of additively manufactured products. It also enlists important intrusion mechanisms relevant to additive manufacturing.

SCATTERING OF ELECTROMAGNETIC WAVES ON FLAT GRID TWO-PERIODIC STRUCTURES

Context. One of the scientific hypotheses for the creation of nonreciprocal optical metasurfaces is based on the use of a wave channel in which rays of the direct and reverse diffraction scenarios are realized on two-periodic flat structures with nonlinear elements. Such processes in the nanometer wavelength range of electronic devices require precise calculations of the interaction of waves and microstructures of devices. It is also important to describe the behavior of antenna devices in mobile communications. Expanding the wavelength range of stable communication is achieved by using prefractal structures in antenna devices in combination with periodic structuring. Similar modeling problems arise when electromagnetic waves penetrate materials with a crystalline structure (radio transparency).
 Objective. To test this hypothesis, it is necessary to carry out mathematical modeling of the process of scattering of electromagnetic waves by metasurfaces under conditions of excitation of several diffraction orders. It is known that among two-periodic flat lattices of different structures there are five types that fill the plane. These are the Bravais grilles. The problem of scattering of an incident monochromatic TE polarized wave on a metal screen with recesses in two-periodic structures filled with silicon was considered.
 Method. The paper builds mathematical models for the study of spatial-amplitude spectra of metasurfaces on Brave lattices and gives some results of their numerical study. The condition for determining the diffraction orders propagating over the grating is proposed. Scattered field amplitudes are from the solution of the boundary value problem for the Helmholtz equation in the COMSOL Multiphysics 5.4 package. Similar problem formulations are possible when studying the penetration of an electromagnetic field into a crystalline substance.
 Results. Obtained relations for diffraction orders of electromagnetic waves scattered by a diffraction grating. The existence of wavelengths incident on a two-periodic lattice for which there is no reflected wave is shown for different shapes (rectangular, square, hexagonal) of periodic elements in the center of which a depression filled with silicon was made. Distributions of reflection coefficients for different geometric sizes of colored elements and recesses are given. The characteristics of the electric field at resonant modes in the form of modulus isolines show the nature of the interaction of the field over the periodic lattice and the scatterersdepressions. At the resonant wavelengths of the incident waves, standing waves appear in the scatterers.
 Conclusions. A mathematical model of the set of diffraction orders propagating from a square and hexagonal lattice into halfspace is proposed z >= 0. It has been shown that flat periodic lattice with square or hexagonal periodicity elements and resonant scatterers in the form of cylindrical recesses filled with silicon can produce a non-mirrored scattered field in metal. The response of the lattices to changes in the wavelength of the incident field by the structure of diffraction orders of the scattered field and high sensitivity to the rotation of the incident plane were revealed. The two-periodic lattices have prospects for creating anti-reflective surfaces of various devices. Two-periodic lattices have prospects for creating anti-reflective surfaces for various devices, laser or sensor electronic devices, antennas in mobile communication elements, and radio transparency elements. They have more advanced manufacturing technologies in relation to spatial crystal structures.

Global buckling and resistances of austenitic stainless steel semi-oval hollow section beam-columns

As advanced manufacturing technologies become increasingly mature in civil engineering, novel tubular sections, characterised by appealing architectural appearance and prominent structural efficiency, can be fabricated, with an example being semi-oval hollow section. The present paper reports an experimental and numerical investigation into the global buckling behaviour and resistances of austenitic stainless steel semi-oval hollow section beam-columns under combined compression and bending. An experimental programme was firstly performed on ten austenitic stainless steel semi-oval hollow section beam-column specimens and included initial geometric imperfection measurements and eccentric compression tests. The obtained test failure loads, load–mid-height lateral deflection curves and failure modes were fully reported. Following the experimental programme, a numerical modelling programme was conducted, including validation studies to validate developed finite element models against the test results and parametric studies to generate additional numerical data. Given that the existing European code and American specification do not cover the design of stainless steel semi-oval hollow section components, the applicability of the codified design interaction curves for austenitic stainless steel circular hollow section beam-columns to their semi-oval hollow section counterparts was evaluated based on the obtained test and numerical data. The European code was found to result in relatively accurate and consistent resistance predictions for austenitic stainless steel semi-oval hollow section beam-columns with Class 1 and 2 cross-sections, but the resistance predictions for those with Class 3 cross-sections were conservative and scattered. The American specification was shown to offer overall accurate and consistent resistance predictions, but some resistance predictions were marginally unsafe.

Efficiency and factors influencing China’s outward direct investment in ASEAN and the European Union: a comparative analysis

ABSTRACT This research examines China’s outward direct investment efficiency in ASEAN and the European Union (EU) using a stochastic frontier investment gravity model. We find that China’s investment efficiency in EU15 remained stable from 2003 to 2020, while efficiency in ASEAN and EU13 declined. China benefits from EU15’s advanced manufacturing and management technologies due to its high economic development. However, with an investment efficiency of 0.259, there is untapped potential. In ASEAN, factors like higher economic freedom positively impact China’s investment efficiency, and infrastructure opportunities negatively impact China’s investment efficiency. Economic distance positively affects China’s investment in EU countries, especially in EU15. But higher economic freedom intensifies global competition, limiting China’s direct investment, particularly in EU13. The EU’s infrastructure and updated investment agreements facilitate China’s investment, while the ‘Belt and Road’ initiative has limited impact.

Design and Control of a Flexure-Based Dual Stage Piezoelectric Micropositioner

In the field of advanced manufacturing technology, there is a growing need for high-precision micro/nano positioners. The traditional single stage actuated positioners have encountered performance limitation in achieving longer travel range and higher precision. This motivates us to develop a novel dual stage piezoelectric-actuated micropositioner presented in this paper. The micropositioner incorporates displacement amplification mechanisms to overcome the limited range of piezoelectric actuators. Design considerations such as flexure characteristics and material selection are discussed, and structural analysis is performed using finite element analysis (FEA). For precise positioning, the dual stage control strategy is investigated and compared with the conventional proportional-integral-derivative (PID) single stage control method. In the proposed positioner, a combination of parallelogram and bridge mechanisms is utilized. The bridge mechanism works to amplify the piezoelectric actuator displacement output. The parallelogram mechanism, integrated within the system, helps mitigate resonance modes and contributes to the achievement of linearized motion. The characteristics of the micropositioner were evaluated using analytical modelling and FEA. Multiple analysis was used to optimise the positioner’s design parameters. Furthermore, experimental studies were carried out to validate the characteristics of the micropositioner performance in terms of achievable output travel range and sustained positioning accuracy.

Preparation and properties of a bismaleimide resin modified with a propargyl compound for electron beam irradiation curing

N, N, N′, N′ -Tetrapropargyl- p, p′-diaminodiphenylmethane (TPDDM) is synthesized and used to blended with 4,4′-bismaleimide diphenylmethane (BDM) as propargyl compound in a molten state to obtain a TPDDM modified bismaleimide (BTP) resin. The BTP resins are cured under electron-beam (EB) irradiation as well as heat. The cure degree and reactions of BTP resins are studied. The thermal stability and mechanical properties of the cured BTP resins are further investigated. The results show that the BTP resins can be cured under EB irradiation and have over 82% degree of cure, which increases with the increase of EB irradiation dose. The cure reactions of EB-cured BTP resin are similar to that of heat-cured BTP resin. The temperature at 5% weight loss ( Td5) and mechanical properties of the cured BTP resins are close analogies between EB and heat cure processes although the cure degrees of EB-cured BTP resins are lower. The glass transition temperature ( Tg) and flexural modulus of the EB-cured BTP resin are higher than that of the heat-cured BTP resin. The Tg of the EB-cured BTP resin can reach over 385°C. The TPDDM-modified BDM is a candidate bismaleimide resin for the EB irradiation curing process in advanced manufacturing technology.

Bibliometric Analysis of Personalized 3D-Printed Concrete-Based Modules for Construction: Leveraging the Ordinatio Method

The research landscape of personalized 3D-printed concrete-based modules for construction and their impact on thermal performance through generative design methods is explored through a bibliometric analysis. Comprehensive analysis techniques, including bibliographic data and visualization with VoSviewer, are employed to unveil collaborative networks, influential articles, research trends, and emerging themes within this domain. Global contributions are showcased, with citations predominantly from the UK and USA, while Denmark and Australia demonstrate a significant impact relative to publication numbers. Prominent authors like Buswell, Mechtcherine, and Zhang are highlighted through co-authorship analysis, revealing evolving collaborative patterns over time. Seminal works and influential authors are identified through co-citation analysis, providing insights into intellectual networks. Source citation analysis emphasizes the importance of sustainability and advanced manufacturing methods through key journals in the field. Keyword co-occurrence analysis identifies the core themes, including 3D concrete printing, additive manufacturing, and sustainability. Emerging trends indicate a growing focus on sustainability and adopting advanced manufacturing technologies. These insights have implications for future research, guiding impactful contributions in this evolving field.