Search Results (300)

TC4DT (ELI) is a damage-tolerant titanium alloy characterized by high fracture toughness and slow crack propagation rates, and is, therefore, considered one of the standard materials for model fasteners in modern equipment. However, its high yield strength leads to excessive tool wear and forming defects. This paper presents a complete FE simulation framework to investigate the thread-rolling process of TC4DT(ELI) bolts M16 × 1.5. Using the actual geometries of the workpiece and rollers, an elasto-plastic three-dimensional finite element model was built in ABAQUS/Explicit to perform verification simulations, with the theoretical blank diameter and forming force as the reference benchmarks. The simulation results agreed well with the actual industrial data. This study carried out single-factor analyses of the effect of three important process parameters—the roll speed, friction coefficient, and initial temperature—on the resulting stress–strain distribution, forming force, and thread formation depth. A modal analysis was performed in ANSYS Workbench to check the structural integrity and avoid resonance while operating. According to the results, the optimized parameters decreased the maximum forming force by 14.8% and improved thread filling. Compared with experimental data, the simulation error in the blank diameter was controlled within 1.2%. The present work, a reliable numerical underpinning for replacing expensive and time-consuming trial-and-error processes, forms a basis for high-performance titanium alloy fasteners and assists in the wider application of such fasteners in modern equipment and any advanced manufacturing industries. Full article

Surface defects in high-temperature continuous cast billets are critical factors affecting the quality of steel products. Owing to high-temperature radiation, heavy dust contamination, varying billet specifications, and background interference from oxide scales and water stains, existing online surface defect detection technologies for high-temperature continuous cast billets still suffer from limitations including high false-positive rates, inefficient identification of pseudo-defects, and the inability to simultaneously detect three-dimensional (3D) depth information alongside two-dimensional (2D) features. To solve these problems, this paper proposes a multi-dimensional online detection technology for surface defects in high-temperature continuous cast billets based on multi-information fusion. A four-channel multispectral image sensor and a corresponding three-light-source imaging system were developed. Furthermore, a defect sample augmentation method, a deep learning-based 2D recognition method, and a photometric stereo-based 3D reconstruction method were designed to mitigate problems of low detection accuracy and poor robustness caused by sample imbalance among different defect types. Finally, industrial applications were conducted on large-section continuous cast billets, beam blanks, and billets during the grinding process. According to the surface defect detection requirements of different continuous cast billets, multispectral multi-information fusion and traditional 2D defect imaging methods were adopted respectively. The results demonstrate high-precision online detection of surface defects in continuous cast billets, with favorable practical application effects. Full article

Electrical imaging logging images play a crucial role in petroleum exploration; however, in practical applications, blank strips frequently appear due to instrument malfunctions or data transmission failures, severely compromising geological interpretation and hydrocarbon evaluation. Existing image inpainting methods have limited adaptability to blank strips at different depth scales and exhibit blurred high-resolution geological textures. To address these issues, this paper proposes a blank strip filling method that integrates Arbitrary Kernel Convolution (AKConv) with the Aggregated Contextual-Transformations Generative Adversarial Network (AOT-GAN). Specifically, the adaptive sampling mechanism of AKConv is incorporated into the generator network of AOT-GAN, enabling the model—to effectively capture long-range contextual information and adaptively handle blank strips of varying scales and shapes through multi-scale feature fusion. Experimental results on real oilfield datasets demonstrate that the proposed method achieves significant improvements in PSNR, SSIM, and MAE, exhibiting superior structural preservation and texture sharpness—especially in restoring deep and large-scale blank strips. Furthermore, visual comparisons confirm the method’s superior performance in recovering key geological features, such as bedding continuity and fracture structures, thus providing an effective approach for electrical imaging logging image restoration. Full article

The deep integration of machine learning technology with geological prospecting has brought to the forefront a key challenge: how to construct geological-mineralization models by fusing multi-source data, select model features with guidance from metallogenic factors, build multi-source metallogenic prediction models with geological constraints, and ultimately achieve a thorough integration of domain knowledge and machine intelligence. The Eastern-Central Tianshan region is one of China’s most important copper–nickel mineral resource bases, predominantly hosting magmatic copper–nickel sulfide deposits with significant resource potential. In this context, this paper proposes a metallogenic prediction model based on multi-modal feature fusion technology. The model employs a Residual Neural Network (ResNet) incorporating a Squeeze-and-Excitation (SE) attention mechanism and a Multi-Layer Perceptron (MLP) to extract features from different modalities. It integrates multi-source data, including geochemical information, geological metallogenic factors, and aeromagnetic data. A cross-modal feature interaction module, constructed using attention weighting and a gating mechanism, enables deep fusion of the features. After training, the model achieved a prediction accuracy of 97% on the test set. Compared to a unimodal model constructed using Random Forest, the confidence and discriminative capability of the training results were significantly enhanced, validating the effectiveness of multi-modal feature fusion. Applying the trained model to the study area, a total of 11 prospective metallogenic zones were delineated. These include 4 zones in the peripheries of known deposits and 7 zones in previously unexplored (blank) areas. Notably, some known mineral occurrences fall within the predicted blank-area targets, validating the feasibility and significant value of multi-modal feature fusion in mineral prediction. This work provides a novel methodology for the subsequent integrated processing of multi-source data. Full article

This paper presents the design and evaluation of an interactive simulator for plaster turning in porcelain slip-casting. Whereas most virtual pottery systems model clay deformation, our tool simulates the subtractive shaping of rigid plaster blanks, an essential intermediate step in mould-master production. Co-designed with expert practitioners through a user-centred process, the simulator follows workshop practice from blank preparation to the geometric constraints of the turning wheel. We report five iterative prototypes and show how expert feedback replaced generic sculpting metaphors with task-faithful interactions, including correct hand positioning, rotation-dependent turning, and authentic preparatory routines. Our evaluation suggests that the system supports the acquisition of tacit procedural knowledge while also producing geometric data compatible with physically based rendering workflows. This research contributes to the digital preservation of intangible cultural heritage by making the material reasoning of porcelain manufacture accessible in a virtual environment. Full article

Pawnshop buildings are places where pawn transactions are conducted. They are usually composed of a front shop and a back building, and their shape resembles a fortress. As a typical gambling city, pawnshops in Macau appeared as early as the Qing Dynasty. By the late Qing Dynasty (1644–1912) and early Republic of China (1912–1949), they had become a common market. They reached their peak during the Anti-Japanese War and were an important financial institution for the people to solve their urgent needs. Today, many pawnshop buildings have become architectural heritage sites and are distributed around the buffer zone of the World Heritage Site. Their location is consistent with the evolution of urban space and the development of gambling and tourism industries. However, existing research lacks systematic research based on spatial quantification technology and it has yet to be determined whether there is a spatial alignment relationship between pawnshop location and urban spatial structure. This paper takes the whole of Macau as the research area and combines DepthmapX space syntax, GIS analysis, and historical data comparison of pawnshop buildings to explore the path dependence characteristics of pawnshop building location and the service radius law in urban space. The study found that the location of pawnshop buildings in Macau has evolved through three stages: initially relying on traditional market spaces, then gathering around casino areas during a stable phase, and finally becoming closely tied to the core areas of gambling venues in the prosperous stage. It shows a path dependence that is continuously strengthened on nodes with low traffic resistance. The service radius of pawnshop buildings exhibits an unbalanced characteristic, with a dense core area and a blank peripheral area, forming a multi-level system of a 200 m core service circle, a 400 m extended service circle, and an 800 m radiation service circle. This study proposes pathways for the adaptive reuse and activation of traditional pawnbroking architectural heritage. For instance, by drawing on the operational model of the Tak Seng On Pawnshop, the integration of cultural exhibition and livelihood services can be realized, thereby providing practical references for the adaptive reuse and conservation of heritage assets. This study offers dual theoretical and practical support for the conservation of pawnbroking architectural heritage in Macau, the site selection and planning of modern pawnbroking establishments, and the optimization of the city’s urban spatial structure. Meanwhile, it enriches the research system on the spatial alignment between the peripheral financial industry and urban space. Full article

The rapid development of the lithium battery industry resulted in a large accumulation of spodumene mining residue (SMR). This paper explored the feasibility of using SMR as mineral admixtures in cement mortar. The properties of cement mortar, including flexural strength, compressive strength, fluidity, hydration characteristics, and durability, were studied. The interaction mechanism between SMR and cement mortar had been explored using the Dinger–Funk model, isothermal calorimetry, X-Ray Diffraction (XRD), fourier Transform Infrared Spectroscopy (FTIR), and thermogravimetry (TG) methods. Additionally, the environmental impact of cement mortar was quantitatively evaluated by the life cycle assessment method. The results showed that, while the dosage of SMR was no more than 20 wt.% replaced cement, the flexural strength, compressive strength, and anti-carbonation and sulfate corrosion resistance properties of S2 and S3 cement mortar were similar to that of the blank group. After curing for 28 d, the compressive strength of S1, S2, and S3 were 44.2 MPa, 43.15 MPa, and 40.32 MPa, respectively. SMR powder could improve the workability and reduce the cumulative hydration heat of cement mortar, which confirmed its application potential in large-volume concrete projects. The appropriate content of SMR incorporation into cement mortar could improve the structure and properties of cement-based materials through particle filling, the induced nucleation effect, and the pozzolanic effect. In addition, the utilization of SMR reduced the environmental emissions and resource consumption of cement-based materials. Using 1 m³ cement mortar as an example, for every 10 wt.% increase in SMR powder replacing cement, the energy consumption, the emissions of CO₂, CO, C_xH_y, NO_x, SO₂, dust, and resource consumption of cement mortar were decreased by approximately 342 MJ, 40 kg, 8.1 g, 5.55 g, 88.3 g, 5.24 g, 1.80 kg, and 74.3 kg, respectively. The research findings of this paper are expected to promote the resource utilization of SMR and reduce the carbon emissions of the building materials industry. Full article

A multifunctional diagnosis and treatment carrier, ZIF-8@CDs, based on carbon quantum dots (CDs) and the zeolitic imidazolate framework-8 (ZIF-8) metal–organic framework which serves as a core structure for constructing the responsive delivery platform, is developed in this paper. The anticancer drug doxorubicin (DOX) and Survivin oligo (siRNA) are loaded to form a ZIF-8@CDs/DOX@siRNA dual loading platform. CDs of 5–10 nm are synthesized by the solvent method and combined with ZIF-8. Electron microscopy shows that the composites are nearly spherical particles of approximately 200 nm, and the surface potential decreases from +36 mV before loading CDs to +25.7 mV after loading. The composite system shows unique advantages: (1) It has Fenton-like catalytic activity, catalyzes H₂O₂ to generate hydroxyl radicals, and consumes glutathione in the tumor microenvironment. The level of reactive oxygen species (ROS) in the ZIF-8@CDs group is significantly higher than that in the control group. (2) To achieve visual diagnosis and treatment, its fluorescence intensity is superior to that of the traditional Fluorescein isothiocyanate (FITC)-labeled vector; (3) It has a high loading capacity, with the loading amount of small nucleic acids reaching 36.25 μg/mg, and the uptake rate of siRNA by liver cancer cells is relatively ideal. The ZIF-8@CDs/DOX@siRNA dual-loading system is further constructed. Flow cytometry shows that the apoptosis rate of HepG2 cells induced by the ZIF-8@CDs/DOX@siRNA dual-loading system is 49%, which is significantly higher than that of the single-loading system (ZIF-8@CDs/DOX: 34.3%, ZIF-8@CDs@siRNA: 24.2%) and the blank vector (ZIF-8@CDs: 12.6%). The platform provides a new strategy for the integration of tumor diagnosis and treatment through the multi-mechanism synergy of chemical kinetic therapy, gene silencing and chemotherapy. Full article

The modern coinage industry ensures dimensional and weight precision, as well as improved surface quality, for its products. The speed of coin mass production requires increased performance for used machines and tools. Despite these, error incidence cannot be excluded. Some of these errors are recorded inside the punching machine and generate clipped blank disks; on their turn, those malformed disks lead to the clipped coins. In the first part, the paper presents the premises underlying the appearance of clipped blanks. There are some exemplified coins having different types of clips: curved, straight, and ragged. The literature review in the coinage field covers the following subjects: coin and die behavior under the striking load, viewpoints on 3D modeling, and finite element method (FEM) analysis, insights on various striking errors, with most of them more or less valued as collection metal pieces. The paper’s main purpose is outlined as follows: to study, using the available modern techniques, the particularities of different clipped coin types. In the second part of the paper, we introduced the adequate tridimensional (3D) model, for parts such as the die, collar, and the coin. It follows the assembled model corresponding to each studied case, which consists of the obverse and reverse striking dies and the collar, having inside them the coin. For each of the models, based on the initial conditions, the finite element analysis was performed. The paper’s last part presents the analysis’ results, the discussions, and the conclusions. Full article

Warm deep drawing is an effective special deep drawing technique for improving the forming limits of difficult-to-form materials such as aluminum alloys, magnesium alloys, and stainless steels. This paper experimentally investigated the effect of a combined variable process path, which integrates a variable punch speed (VSPD) and a variable blank holder force (VBHF) path, on the warm deep drawing performance of an A5182 aluminum alloy sheet at 300 °C (where the strain rate sensitivity index m equals 0.11). Experiments demonstrated not only a reduction in the forming time and an improved wall thickness uniformity, but also an improvement in the forming limits. The significant improvement in the forming characteristics is discussed in terms of the theoretical three-dimensional process window (SPD-BHF-flange reduction ratio (ΔDR*) space) consisting of the fracture limit and flange wrinkling limit derived from deep drawing theory, and it was shown to be consistent with the experimental results. Finaly, the novel combined VSPD/VBHF process path successfully achieved deep drawing with a challenging drawing ratio (DR) of 3.3. Full article

Construction steel is responsible for considerable amounts of carbon emissions in building sectors, and promoting the low-carbon design of steel components is conducive to the sustainable development of the industry. As one of the most typical components, I/H-beams are widely used in steel structures. In this paper, a new comprehensive index named carbon-capacity ratio (CCR) was proposed considering both mechanical properties and carbon emissions of I/H-beams, based on which the geometry coefficient and material coefficient were derived. Quantitative investigation was then conducted on the geometry coefficient to figure out the effects of different geometry variables, and the geometry criteria for low-carbon design of steel beams were concluded considering different load conditions. Results show that for double-symmetric cross-sections bearing flexural loads, larger flange width and beam height are suggested, while for single-symmetric cross-sections bearing flexural loads, increasing beam height as well as flange width and thickness can all contribute to sustainable beam designs, but adopting large beam height is the most effective. For cross-sections bearing shear loads, increasing beam height and web thickness would be beneficial. The feasible design domain (FDD) for geometry variables was proposed to be predicted with either linear or hyperbolic criteria depending on different loads and cross-sections. Additionally, a qualitative discussion was also given on the material coefficient, and steel with higher strength or that produced from recycled scrap using energy-saving technologies, as well as new prototyping techniques with lower energy and material loss, are recommended for beam fabrication. This study is expected to serve as a preliminary supplement to the blank in current codes or standards for low-carbon design of construction steel. Full article

In the processes of deep hole drilling and boring, tool deflection and chatter are prevalent problems that significantly affect the quality and efficiency of deep hole part machining. This paper designs a Helical-Type Vibration-Damping and Deflection Correction Device for BTA (boring and trepanning association) deep hole drilling based on the principles of fluid dynamic pressure lubrication and squeeze film damping. By leveraging the flow field characteristics of cutting oil during machining, the device achieves vibration-damping, deflection correction, and enhanced support for the tool system throughout the drilling operation. Through theoretical analysis, this research examines the oil film pressure distribution and stability of the Designed Vibration-Damping and Deviation Correction Device. It also explores the influence patterns of factors such as cutting parameters, device structure, minimum film thickness, film thickness ratio, and length-to-diameter ratio on its vibration-damping, deviation correction, and stability performance. Taking a $\varphi 29.35$ deep hole as the research object, an experimental platform was designed and constructed to measure and verify the device’s vibration-damping and deviation correction effects under different operating conditions. Deep hole drilling tests were carried out on 10 conventional gun steel specimens ($\varphi 29.35$ × 3000 $\mathrm{m}\mathrm{m}$). The results indicate that, when the minimum oil film gap of the Vibration-Damping and Deflection Correction Device is 0.08$\mathrm{m}\mathrm{m}$, the axis deviation range is 0.27~0.45$\mathrm{m}\mathrm{m}$, with a surface roughness of 0.589 to 0.677$\mathsf{\mu }\mathrm{m}$. Compared to similar conditions without the device, these represent reductions of 55~73% and 47.07~53.95%, respectively. It allows for a reduction of over 10% in blank material allowance and an increase of 5–15% in tool feed rates. Full article

This paper presents the results of numerical modeling and vibration testing of a nanosatellite’s optical payload, aimed at assessing its mechanical stability under the mechanical impacts of launch. The purpose of the study is to compare finite element modeling (FEM) data with experimental testing to refine the computational model and improve the reliability of mechanical stability predictions. The methodology included an FEM analysis with an average damping coefficient, an adapter blank test, a resonance study with a low-level sinusoidal run, random vibration tests, and a sinusoidal pulse test. The FEM results showed an average yield margin of safety MoS = 2.5 with a minimum MoS = 1.8 in the primary mirror mount area. The adapter blank test confirmed the absence of natural resonances in the operating range. The resonance study revealed modes in the 300–1340 Hz range, with the most pronounced peaks in the secondary mirror bracket (520–600 Hz) and the electronics unit (1030–1100 Hz). A comparison of the root mean square (RMS) acceleration values between calculations and tests revealed discrepancies due to the heterogeneous nature of the damping. The values of ζ determined by the half-power method varied from 0.9% to 4.8%, which confirms the dependence of the damping properties on the frequency and localization of the modes. The obtained results confirmed the structural integrity of the payload, allowed for the localization of structural elements, and substantiated the need to consider actual damping coefficients in FEM models. The presented data can be used to optimize the design and improve mechanical stability during payload integration into the satellite platform. Full article

In this study, a slow-release fertilizer (SRF) was obtained by occluding NPK 10–10–10 into two matrices and compared with the uncoated mineral fertilizer (F). The first matrix, FOMI, used biosolids/paper sludge at 3:1 (w/w); the second, FOMII, used biosolids/clay at 1:1 (w/w). Materials and pellets were physiochemically and microbiologically characterized. Release kinetics were evaluated in water and in soil columns packed with acid-washed sand; matrix-only controls and sand blanks confirmed negligible background N, P, and K. The uncoated mineral fertilizer (F) showed a rapid burst, whereas occlusion slowed release. FOMII reduced release relative to F, and FOMI produced the slowest, controlled profiles: kinetic fits yielded lower k values for FOMI than for FOMII and F. FOMI also exhibited higher water-retention capacity (WRC) and cation-exchange capacity (CEC), consistent with its greater organic-matter content. In soil, FOMI released less than 15% at 48 h and no more than 75% at 30 d, meeting European Committee for Standardization (CEN) SRF criteria; FOMII released faster than FOMI but slower than F, which exceeded 90% within the test period. Therefore, FOMI is a biodegradable, low-cost SRF that improves fertilizer-use efficiency while returning organic matter to agricultural soils; FOMII shows intermediate yet beneficial performance. Full article

Nowadays, Flutter with the Dart programming language has become widely popular in mobile developments, allowing developers to build multi-platform applications using one codebase. An increasing number of companies are adopting these technologies to create scalable and maintainable mobile applications. Despite this increasing relevance, university curricula often lack structured resources for Flutter/Dart, limiting opportunities for students to learn it in academic environments. To address this gap, we previously developed the Flutter Programming Learning Assistance System (FPLAS), which supports self-learning through interactive problems focused on code comprehension through code-based exercises and visual interfaces. However, it was observed that many students completed the exercises without fully understanding even basic concepts, if they already had some knowledge of object-oriented programming (OOP). As a result, they may not be able to design and implement Flutter/Dart codes independently, highlighting a mismatch between the system’s outcomes and intended learning goals. In this paper, we propose a guided self-study approach of integrating documentation, code, visual output, and exercise in FPLAS. Two existing problem types, namely, Grammar Understanding Problems (GUP) and Element Fill-in-Blank Problems (EFP), are combined together with documentation, code, and output into a new format called Integrated Introductory Problems (INTs). For evaluations, we generated 16 INT instances and conducted two rounds of evaluations. The first round with 23 master students in Okayama University, Japan, showed high correct answer rates but low usability ratings. After revising the documentation and the system design, the second round with 25 fourth-year undergraduate students in the same university demonstrated high usability and consistent performances, which confirms the effectiveness of the proposal. Full article