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Abaca fiber degradation in concrete owing to its alkaline nature decreases the strength of concrete. This research focuses on overcoming the degradation by alkaline treatment with sodium hydroxide (NaOH) to improve fiber performance. This study was completed with the extraction process of fiber, mechanical properties, micro-structural analysis of composite fiber concrete for both M30 and M40 grades, and durability performance if the fiber content, aspect ratio of fiber and molarities of Sodium Hydroxide were optimized using splitting tensile strength of the concrete matrix and it was found that the optimum percentage of fiber content was 1% at 12% alkali treatment. The composite concrete has achieved an increase of 2700 to 3100 kg m −2 in split tensile strength with treated abaca fibers compared to untreated fiber concrete. In addition, treated abaca fiber concrete provides better performance in mechanical and durability studies. The binding nature of fiber concrete is better than that of conventional concrete, which is evidenced in microstructural analysis. This study ultimately concluded that the treated abaca fiber composite concrete is a better alternative to commercially available untreated abaca fibers and other natural fibers.

As the boundary between the Indochina and the South China blocks, the Ailao Shan-Red River (ASRR) shear zone underwent a sinistral strike-slip shearing which is characterized by ductile deformation structures along the Ailao Shan range. The timing issue of left-lateral shearing along the ASRR shear zone is of first-order importance in constraining the nature and regional significance of the shear zone. It has been, therefore, focused on by many previous studies, but debates still exist on the age of initiation and termination of shearing along the shear zone. In this paper, we dated 5 samples of granitic plutons (dykes) along the Ailao Shan shear zone. Zircon U–Pb ages of four sheared or partly sheared granitic rocks give ages of 30.9 ± 0.7, 36.6 ± 0.1, 25.9 ± 1.0 and 27.2 ± 0.2 Ma, respectively. An undeformed granitic dyke intruding mylonitic foliation gives crystallization age of 21.8 ± 1 Ma. The Th/U ratios of zircon grains from these rocks fall into two populations (0.17–1.01 and 0.07–0.08), reflecting magmatic and metamorphic origins of the zircons. Detailed structural and microstructural analysis reveals that the granitic intrusions are ascribed to pre-, syn- and post-shearing magmatisms. The zircon U–Pb ages of these granites provide constraints on timing of the initiation (later than 31 Ma from pre-shearing granitic plutons, but earlier than 27 Ma from syn-shearing granitic dykes) and termination (ca. 21 Ma from the post-shearing granitic dykes) of strong ductile left-lateral shearing, which is consistent with previous results on the Diancang Shan and Day Nui Con Voi massifs in the literature. We also conclude that the left-lateral shearing along the ASRR shear zone is the result of southeastward extrusion of the Indochina block during the Indian–Eurasian plate collision. Furthermore, the left-lateral shearing was accompanied by the ridge jump, postdating the opening, of the South China Sea.

Microstructural characterization and analysis is the foundation of microstructural science, connecting materials structure to composition, process history, and properties. Microstructural quantification traditionally involves a human deciding what to measure and then devising a method for doing so. However, recent advances in computer vision (CV) and machine learning (ML) offer new approaches for extracting information from microstructural images. This overview surveys CV methods for numerically encoding the visual information contained in a microstructural image using either feature-based representations or convolutional neural network (CNN) layers, which then provides input to supervised or unsupervised ML algorithms that find associations and trends in the high-dimensional image representation. CV/ML systems for microstructural characterization and analysis span the taxonomy of image analysis tasks, including image classification, semantic segmentation, object detection, and instance segmentation. These tools enable new approaches to microstructural analysis, including the development of new, rich visual metrics and the discovery of processing-microstructure-property relationships.

The Microstructural Hierarchy Descriptor (μSHD) is a systematic and extensible method for quantitative microstructural analysis. In this study, the μSHD method is used to investigate the microstructural evolution of solder joints in various external fields. The results show that the orientation in SAC305 joints is significantly larger on scales from J = 3 to 7 before aging, indicating pronounced network-like structures. However, this phenomenon disappears after isothermal aging, leading to a more uniform distribution of orientation across all scales. In SnAgInBi joints, both the scale and orientation features decrease on scales J < 7 but increase on scale J = 8 after thermal cycling, corresponding to grain coarsening. In Sn37Pb joints, features on orientations L = 1 and 8, which align with the direction of electron flow, show a significant increase after electromigration. Furthermore, features on scales J ≥ 5 increase, while changes on smaller scales are minimal. These findings demonstrate the usefulness of the μSHD method in capturing the nuanced microstructural changes of solder joints subjected to external fields, providing valuable and quantitative microstructural descriptors to establish linkages with the reliability of electronic assemblies.

Additive manufacturing (AM) has gained great importance in the recent development to produce metallic structural elements for civil engineering applications. However, research effort has been focused mainly on powder-based processes, while there is still limited knowledge concerning the structural response of wire-and-arc additive manufactured (WAAM) metallic elements, and very few experimental data concerning their mechanical properties. This paper presents the first results of a wide experimental campaign aimed at assessing the mechanical properties of WAAM plates produced using a commercial ER308LSi stainless steel welding wire. The aim is to evaluate the effect of the orientation in the tensile behavior of planar elements considering specimens extracted along three different directions with respect to the deposition layer: transversal direction (T), longitudinal direction (L), and diagonal direction (D). Compositional, microstructural, and fractographic analyses were carried out to relate the specific microstructural features induced by WAAM to the mechanical properties. The results show that the chemical composition of the plates meets the requirements of UNS-S-30403 for an AISI 304L austenitic stainless steel. The as-built samples were substantially defect-free and characterized by a very fine microstructure of γ and δ phases The fineness of the microstructure and the negligible defect content led to values of tensile strength and elongation to failure in line with the traditionally manufactured stainless steel elements. Anisotropy in the tensile properties between T, L, and D specimens was observed, and the highest elastic and plastic properties were measured in D specimens. This result is related to the crystallographic and mechanical fibering induced by the additive process, that led also, in case of D samples, to the highest density of cell boundaries, obstacles to the dislocation slip, located at 45° with respect to the loading direction, where plastic deformation preferentially occurs.

The article presents studies of transpedicular screws made of titanium alloy BT6. A metallographic and microstructural analysis of screw blanks, prototypes of transpedicular screws made of BT6 alloy and commercially produced screws made of Ti-6Al-4V was performed. Specimens of transpedicular screws were manufactured using the vortex thread cutting method on a CITIZEN Cincom K16E-VII automatic lathe. The microgeometry of the screw surface was created by sandblasting using quartz sand as an abrasive material. Studies have shown that experimental and foreign samples of transpedicular screws have a similar microstructure, consisting of globular crystals of the β-phase located in a light matrix of the α-phase. The microhardness of the rod part of the screw made of Ti-6Al-4V alloy was 312...338 HV, the microhardness of the material of the prototypes was from 264 to 394 HV. Conclusions have been drawn that determine the feasibility of choosing rods made of titanium alloy BT6 as a blank for the manufacture of transpedicular screws.

HighlightsThe working principles and limitations of current anode materials at low temperatures are elucidated.Advantages and emphases of various modification strategies, including structural design, morphology control, surface & interface modifications, and multiphase materials of low-temperature anode materials, are reviewed.Perspectives and challenges in developing novel low-temperature anode materials are discussed.The severe degradation of electrochemical performance for lithium-ion batteries (LIBs) at low temperatures poses a significant challenge to their practical applications. Consequently, extensive efforts have been contributed to explore novel anode materials with high electronic conductivity and rapid Li+ diffusion kinetics for achieving favorable low-temperature performance of LIBs. Herein, we try to review the recent reports on the synthesis and characterizations of low-temperature anode materials. First, we summarize the underlying mechanisms responsible for the performance degradation of anode materials at subzero temperatures. Second, detailed discussions concerning the key pathways (boosting electronic conductivity, enhancing Li+ diffusion kinetics, and inhibiting lithium dendrite) for improving the low-temperature performance of anode materials are presented. Third, several commonly used low-temperature anode materials are briefly introduced. Fourth, recent progress in the engineering of these low-temperature anode materials is summarized in terms of structural design, morphology control, surface & interface modifications, and multiphase materials. Finally, the challenges that remain to be solved in the field of low-temperature anode materials are discussed. This review was organized to offer valuable insights and guidance for next-generation LIBs with excellent low-temperature electrochemical performance.

The work is motivated by the growing use of paperboard in eco-friendly packaging solutions, driven by its recyclability, mechanical properties, and compliance with European Union environmental regulations. This study presents a comparative analysis of the microstructure of two commercially used paperboard packaging materials: solid bleached sulfate and folding box board, using scanning electron microscopy. The investigation examines both unprocessed samples and those subjected to the creasing process, with a focus on surface morphology, fiber orientation and internal structural behavior. Cross-sectional scanning electron Microscopy imaging reveals significant differences in surface morphology. Solid bleached sulfate maintains its structural integrity more effectively, while folding box board shows higher effect of delamination, particularly at interfaces between its layers. Images of the surfaces of the folded box board showed the structure of the fibers, so a directionality analysis was performed using FIJI software. Photos of These findings highlight how material composition influences key packaging properties such as mechanical performance, printability, and recyclability. The study also reinforces the utility of scanning electron microscopy in assessing the suitability of fiber-based packaging materials, especially in the development of sustainable alternatives to plastic.

In order to enhance dielectric properties of polymer-derived SiC ceramics, a novel single-source-precursor was synthesized by the reaction of an allylhydrido polycarbosilane (AHPCS) and divinyl benzene (DVB) to form carbon-rich SiC. As expected, the free carbon contents of resultant SiC ceramics annealed at 1600 °C are significantly enhanced from 6.62 wt% to 44.67 wt%. After annealing at 900–1600 °C, the obtained carbon-rich SiC ceramics undergo phase separation from amorphous to crystalline feature where superfine SiC nanocrystals and turbostratic carbon networks are dispersed in an amorphous SiC(O) matrix. The dielectric properties and electromagnetic (EM) absorption performance of as-synthesized carbon-rich SiC ceramics are significantly improved by increasing the structural order and content of free carbon. For the 1600 °C ceramics mixed with paraffin wax, the minimum reflection coefficient ( RC min ) reaches –56.8 dB at 15.2 GHz with the thickness of 1.51 mm and a relatively broad effective bandwidth (the bandwidth of RC values lower than –10 dB) of 4.43 GHz, indicating the excellent EM absorption performance. The carbon-rich SiC ceramics have to be considered as harsh environmental EM absorbers with excellent chemical stability, high temperature, and oxidation and corrosion resistance.

This paper presents a software environment for processing, segmenting, quantifying, representing and manipulating digital microstructure data. The paper discusses the approach to building a generalized representation strategy for digital microstructures and the barriers encountered when trying to integrate a set of existing software tools to create an expandable codebase.