Nonsmooth-Optimization-Based Bandwidth Optimal Control for Precision Motion Systems

Precision motion systems are at the core of various manufacturing equipment. The rapidly increasing demand for higher productivity necessitates higher control bandwidth in the motion systems to effectively reject disturbances while maintaining excellent positioning accuracy. However, most existing optimal control methods do not explicitly optimize for control bandwidth, and the classic loop-shaping method suffers from conservative designs and fails to address cross-couplings, which motivates the development of new control solutions for bandwidth optimization. This paper proposes a novel bandwidth optimal control formulation based on nonsmooth optimization for precision motion systems. Our proposed method explicitly optimizes the system's MIMO control bandwidth while constraining the H-infinity norm of the closed-loop sensitivity function for robustness. A nonsmooth optimization solver, GRANSO, is used to solve the proposed program, and an augmented quadratic programming (QP)--based descent direction search is proposed to facilitate convergence. Simulation evaluations show that the bandwidth optimal control method can achieve a 23% higher control bandwidth than conventional loop-shaping design, and the QP-based descent direction search can reduce iteration number by 60%, which illustrates the effectiveness and efficiency of the proposed approach

Transcending the Acceleration-Bandwidth Trade-off: Lightweight Precision Stages with Active Control of Flexible Dynamics

Micro/Nano-positioning stages are of great importance in a wide range of manufacturing machines and instruments. In recent years, the drastically growing demand for higher throughput and reduced power consumption in various IC manufacturing equipment calls for the development of next-generation precision positioning systems with unprecedented acceleration capability while maintaining exceptional positioning accuracy and high control bandwidth. Reducing the stage's weight is an effective approach to achieving this goal. However, the reduction of stages' weight tends to decrease its structural resonance frequency, which limits the closed-loop control bandwidth and can even cause stability issues. Aiming to overcome the aforementioned challenge and thus create new lightweight precision stages with substantially improved acceleration capability without sacrificing stage control performance, this research presents a novel sequential structure and control design framework for lightweight stages with low-frequency flexible modes of the stage being actively controlled. Additional actuators and sensors are placed to actively control the flexible structural dynamics of the lightweight stage to attain high control bandwidth. A case study is simulated to evaluate the effectiveness of the proposed approach, where a stage weight reduction of 24% is demonstrated compared to a baseline case, which demonstrates the potential of the proposed design framework. Experimental evaluation of the designed stage's motion performance will be performed on a magnetically levitated linear motor platform for performance demonstration.Comment: arXiv admin note: substantial text overlap with arXiv:2301.04208; text overlap with arXiv:2309.1173

A Multimodal Learning Framework for Comprehensive 3D Mineral Prospectivity Modeling with Jointly Learned Structure-Fluid Relationships

This study presents a novel multimodal fusion model for three-dimensional mineral prospectivity mapping (3D MPM), effectively integrating structural and fluid information through a deep network architecture. Leveraging Convolutional Neural Networks (CNN) and Multilayer Perceptrons (MLP), the model employs canonical correlation analysis (CCA) to align and fuse multimodal features. Rigorous evaluation on the Jiaojia gold deposit dataset demonstrates the model's superior performance in distinguishing ore-bearing instances and predicting mineral prospectivity, outperforming other models in result analyses. Ablation studies further reveal the benefits of joint feature utilization and CCA incorporation. This research not only advances mineral prospectivity modeling but also highlights the pivotal role of data integration and feature alignment for enhanced exploration decision-making

Synergistic Effect of HEDP.4Na and Different Induced Pouring Angles on Mechanical Properties of Fiber-Reinforced Alkali-Activated Slag Composites

The Poor Flexural and Damping Properties of Building Materials Damages Concrete Structures and Affects their Service Life When Concrete Structures Are Subjected to Dynamic Loads. Three Different Dosages (I.e., 0%, 0.3%, and 0.6%) of Organic Phosphonates (HEDP.4Na) and Different Pouring Methods (I.e., Conventional Pouring Method, 90°-Induced Pouring Method, and 150°-Induced Pouring Method) Were Designed to Improve the Flexural and Damping Performance of Fiber-Reinforced Alkali-Activated Slag Composites (FR-AASC). the Enhanced Mechanism of HEDP.4Na Was Revealed by Phase Analysis (X-Ray Diffraction, XRD), Pore Structure Analysis (Mercury Intrusion Porosimetry, MIP), the Heat of Hydration, and Scanning Electron Microscopy (SEM) Analysis. the Results Showed that 0.3% HEDP.4Na Combined with the 150°-Induced Pouring Angle Can Significantly Improve the Mechanical Properties of the FR-AASC Sample Compared with the Reference Group. the Sample with 0.3% HEDP.4Na Cast by the 150°-Induced Pouring Angle Increased Compressive and Flexural Strength, Damping Energy Consumption and Storage Modulus by 20%, 60%, 78%, and 30%, Respectively, Compared with the Reference Sample Cast by the Conventional Pouring Methodology. HEDP.4Na Reduced the Early Hydration Heat and Total Porosity of the FR-AASC Matrix, Modified the Fiber–matrix Interface Transition Zone, and Increased the Frictional Energy Consumption of Steel Fibers. overall, the Synergistic Effect of HEDP.4Na and the Induced Pouring Methodology Significantly Improved the Flexural and Damping Properties of FR-AASC. This Study Can Provide a Guidance for Improving the Flexural and Damping Capacity of FR-AASC and Promote the Application of FR-AASC in Construction Engineering

Neuroprotective effects of electro-acupuncture in spinal cord injury rats via up-regulation of DUSP14

Purpose: To study the effect and mechanism of action of electro-acupuncture (EA) on nerve regeneration by analyzing the behavior, inflammation and cell death in spinal cord injury (SCI) rat model. Methods: SCI model was established according to Allen’s falling strike method. Electroacupuncture was performed on Jiaji (EX-B2)/Mingmen (GV4) acupoint with a 1 mA current intermittent wave at a frequency of 2Hz for 20 min daily. Interleukin (IL-6) and tumor necrosis factor-α (TNF-α) levels were measured using ELISA kits. Apoptosis-induced DNA strand breaks were evaluated by TUNEL assay while relative mRNA expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels were measured by western blot. Results: Relative mRNA and protein expressions of DUSP14 decreased in SCI rats with time but increased by EA treatment. Further, partial locomotor functional recovery was presented in SCI rats by EA treatment. Moreover, intraspinal injection of DUSP14 over-expression viral supernatants/EA treatment ameliorated inflammation and apoptosis in SCI rats. Meanwhile, the protein levels of NF-κB p65 (nucleus) and phosphorylated TGF-activated kinase 1 (p-TAK1) increased in SCI rats following EA treatment but were decreased by EA treatment and intraspinal injection of DUSP14 over-expression viral supernatants. Conclusion: EA acupoint treatment exerts neuroprotective effects in SCI rats via the reduction of inflammation and apoptosis, and induction of DUSP14

Prediction of Dynamic Mechanical Behaviors of Coral Concrete under Different Corrosive Environments and its Enhancement Mechanism

The marine structures are usually exposed to dynamic loadings within short periods and chemical attacks, resulting in severe dynamical damage or failure to concrete structures. The study of the time-dependent changes in the dynamic mechanical behavior of coral concrete under different corrosive environments and low-frequency waves is limited. For the safety and reliable use of coral concrete in the marine environment, different corrosion environments (chloride ions, sulfate ions, and mixed chloride-sulfate ions) and low-frequency waves (0.5–2.0 Hz) were designed to evaluate the dynamic properties of concrete. A model considering the effect of corroded age is formulated to predict the damping capacity of coral concrete. Testing results indicate that sulfate attack shows the most significant effect to influence the dynamic behaviors of coral concrete, while the effect of chloride ion penetration is negligible. The loss factor of coral concrete under corroded environments increases by 59.5% compared with ordinary concrete, even though the loss modulus and storage modulus of coral concrete reduce by 38.5% and 51.8%. It was attributed to coral concrete showing a low ability to resist sulfate attack, resulting in more cracks and pores in the matrix. Coral aggregate with high porosity and interconnected pores in coral concrete works like a cushion to dissipate more external energy. The proposed prediction model (R2 = 0.89) can accurately describe the relationship between erosion age and damping capacity in different corrosion environments, which can guide the application of coral concrete in marine and vibration environments

Effect of Amorphization Methods on the Properties and Structures of Potato Starch-Monoglyceride Complex

Recently, starch-based fat replacers (FRs) have emerged as unique ingredients, possessing few calories and high vascular scavenger function without adverse organoleptic changes. Here, a two-step modification method for the development of a starch-based FRs is reported. First, native potato starch is amorphized by grinding, alkali and ethanol treatment. Then, the amorphized starch is complexed with monoglyceride. The results show that alkaline amorphous potato starch (AAPS) has the best emulsifying activity; ethanol amorphous potato starch complex (EAPSC) has the highest content of resistant starch (RS) (21.49%), while grinding amorphous potato starch (GAPS) retains the granular structure of the original starch best. The amorphization reduces the amylose content of starch, leading to reduced swelling power and increased digestibility. Complexation, on the other hand, is more like attaching a layer of the hydrophobic membrane. Combined with DSC and XRD, amorphization reduces the value of enthalpy and crystallinity, while the complexation process does the opposite. Overall, EAPSC is the best candidate for novel FRs, due to its greater emulsion stability and enzyme resistance. The experimental results provide a theoretical basis for the application of a novel potato starch-monoglyceride complex in foods such as cakes and snack fillings

Dynamical Properties of Environmental High-Performance Composites with Calcined Clay

Concrete structures may be exposed to dynamic loadings within short periods such as earthquakes and vehicles load, resulting in substantial damage to human life and property because of the collapse of concrete structures. The research achievements on dynamic properties of high-performance composites with LC3 (HPC-LC3) are limited, although dynamic loadings are commonly encountered in infrastructure. The study aims to develop a new-green concrete product (HPC-LC3) with high dynamical properties and promote its mass use in a vibration service environment by investigating dynamical properties of HPC-LC3. Dynamical properties of structure can be promoted at material level by means of enhancing the inherent ability of cement-matrix materials to passively absorb the vibrational energy. Dynamic properties of traditional HPC may be improved by incorporated LC3 because of excellent mechanical properties. The fiber pull-out, thermogravimetric analysis (TGA), (nuclear magnetic resonance) NMR, and microstructure test were used to reveal the enhanced mechanism of dynamic properties in the HPC with LC3 (HPC-LC3), and the economic efficiency of HPC is also evaluated to promote its mass application. The results indicate that the dynamic properties of HPC-LC3 increased by 47% in damping capacity, 102% in storage modulus, 16% in energy dissipation, in comparison with the reference (HPC-OPC). Meanwhile, compared with the reference, the compressive and flexural strengths of LC3-50 increased by 14% and 27%. TGA and NMR results indicate that LC3-50 shows better hydration characteristics, longer alumina-silicate chain length (from 3.9 to 8) than HPC-OPC. The proposed composites reduced embodied energy, embedded CO2 emissions, and costs of HPC by up to 33%, 45%, and 7%, respectively. Thus, the green product (HPC-LC3) with 30%–40% calcined clay, high dynamic properties and more sustainable, will be recommended to mass use in a vibration service environment

Identification and characterization of a novel gene involved in glandular trichome development in Nepeta tenuifolia

Nepeta tenuifolia is a medicinal plant rich in terpenoids and flavonoids with antiviral, immunoregulatory, and anti-inflammatory activities. The peltate glandular trichome (PGT) is a multicellular structure considered to be the primary storage organ for monoterpenes; it may serve as an ideal model for studying cell differentiation and the development of glandular trichomes (GTs). The genes that regulate the development of GTs have not yet been well studied. In this study, we identified NtMIXTA1, a GT development-associated gene from the R2R3 MYB SBG9 family. NtMIXTA1 overexpression in tobacco resulted in the production of longer and denser GTs. Virus-induced gene silencing of NtMIXTA1 resulted in lower PGT density, a significant reduction in monoterpene concentration, and the decreased expression of genes related to monoterpene biosynthesis. Comparative transcriptome and widely targeted metabolic analyses revealed that silencing NtMIXTA1 significantly influenced the expression of genes, and the production of metabolites involved in the biosynthesis of terpenoids, flavonoids, and lipids. This study provides a solid foundation describing a mechanism underlying the regulation of GT development. In addition, this study further deepens our understanding of the regulatory networks involved in GT development and GT development-associated metabolite flux, as well as provides valuable reference data for studying plants with a high medicinal value without genetic transformation