Fiber Shape Research Articles

Vibroscope method for determination of cross-sectional area of glass and carbon fibres – Theory and further development

Accurate determination of cross-sectional area of glass and carbon fibres by the vibroscope method is examined. Complete derivations of the central frequency solutions are presented, to make these derivations accessible in modern scientific literature. The effect of non-zero bending stiffness is included. The influence of shape of fibre cross-sectional area is analysed. Only small deviations in cross-sectional areas are found due to fibre shape, allowing for the use of the vibroscope method for fibres with non-circular cross-sectional areas. Two correction factors are introduced for the effect of volume change and area change of a tensioned fibre, allowing determination of the cross-sectional area of the non-tensioned fibre. A model plot of the vibroscope equation is presented, showing the numerical effect of the corrections on the fibre cross-sectional area depending on the applied tension force. The relations shown by the model plot have implications for the experimental settings of the vibroscope method.

Study on impact resistance performance of MSWIFA-based low-carbon fiber-reinforced concrete

The accumulation of carbide slag (CS), red mud (RM), and municipal solid waste incineration fly ash (MSWIFA) has led to significant environmental pollution issues, necessitating urgent resource utilization. Building upon the previously developed CS-MSWIFA synergistic activation RM-slag cementitious system, this study aims to further incorporate iron tailings sand and polypropylene fibers to prepare fiber-reinforced concrete. The systematic investigation focuses on the influence of cementitious material types, aggregate types, fiber shapes, lengths, and dosages on the impact resistance of concrete. Furthermore, an impact damage evolution equation and life prediction model were developed based on the two-parameter Weibull distribution. Results indicate that the type of cementitious material and aggregate has minimal influence on the impact resistance of concrete, while the addition of fibers significantly enhances its impact resistance, shifting the failure mode from brittle to ductile. Mesh polypropylene fibers with a length of 12 mm and a volume dosage of 1.0 % demonstrate excellent impact resistance, with initial and final crack numbers reaching 78 and 105, respectively. This represents an increase of 136.4 % and 200.0 % compared to the control concrete without fibers. The findings of this study offer new avenues for the resource utilization of solid waste and provide theoretical foundations and technical support for the potential application of solid waste based fiber-reinforced concrete in structural engineering.

Invisible threat to mesopelagic fish: Microplastics and artificial cellulose particles in bigfin lanternfish Symbolophorus californiensis from the Northwest Pacific Ocean

Lanternfishes play an important role in connecting epipelagic and mesopelagic ecosystems. Due to their global distribution, diel vertical migration, and low trophic position, they may be highly susceptible to the ingestion of microplastics (MPs) and artificial cellulose particles (ACs). However, the role of lanternfishes in these emergent pollution research remains underestimated. In this study, we compared the abundance and characteristics of MPs and ACs in the stomach and intestine of bigfin lanternfish (Symbolophorus californiensis) from the Northwest Pacific Ocean. The results showed no difference in the abundance and size of MPs between the stomach (0.28 ± 0.63 items/individual, 103.72–2946.58 μm) and intestine (0.32 ± 0.56 items/individual, 122.03–4398.17 μm). The majority of MPs were fibrous in shape, with blue and transparent being the predominant colors. Polyester (28.2 %) and polyethylene terephthalate (20.5 %) were the most common polymer types. ACs were also primary in the shape of fiber (93.2 %), with transparent being the predominant color. The abundance of ACs in the intestine (0.49 ± 0.83 items/individual) was significantly higher than that in the stomach (0.18 ± 0.43 items/individual), while similar particle sizes were observed. This study provides an important baseline on lanternfishes contamination by MPs and ACs. Understanding this impact of mesopelagic fish is crucial for enhancing our comprehension of the vertical transfer mechanism of these pollutants between epipelagic and mesopelagic ecosystems.

Influence of Equal Channel Angular Pressing Processing on the Microstructure, Hardness and Corrosion Resistance of Al-Si Alloy

In this study, the impact of heat treatment and Equal Channel Angular Pressing (ECAP) processing routes on refining the microstructure, hardness, and corrosion resistance of Al-7.5% S alloy in a 3.5% NaCl solution was examined. The alloy underwent T5 and T6 heat treatments, followed by ECAP processing via routes A and Bc in a mold with a channel angle of 120° at room temperature. The results indicate that dendritic α-Al grains transformed to globular and fiber shapes after processing routes Bc and A, respectively. Both processing routes fragmented coarse and brittle Si particles into smaller sizes in the eutectic phase. The use of a combination of heat treatment and the Equal Channel Angular Pressing (ECAP) process significantly improved the hardness and corrosion resistance of the samples. The hardness of the heat-treated samples increased considerably from 68 to 116 and 129 HV after three and four passes, respectively. Reducing the area ratio between the noble silicon particles and the less noble eutectic aluminum phase greatly enhances the resistance of alloy to pitting corrosion.

Optical fiber shape reconstruction algorithm based on 3D Euler spiral model

Abstract This paper presents a reconstruction algorithm that uses a 3D Euler spiral model to construct the microsegment of a 3D space curve to improve the reconstruction efficiency. Euler spiral is a curve whose shape information changes linearly with arc length, which improves the current assumption of the reconstruction algorithms that the shape information of the micro-segment is constant, and effectively reduces the number of interpolations required, and thus improves the efficiency of the shape algorithm. To verify the effectiveness of this algorithm, a method for constructing random space curves is proposed. Three random space curves of different lengths are reconstructed and the results are compared with the reconstruction algorithms based on the homogeneous transformation matrix and Bishop frame. The results show that this model can significantly improve the efficiency of the algorithm. Under the random space curves of 1 m, 10 m, and 100 m, the efficiency is enhanced by about 15, 27, and 30 times respectively. Prepare a shape sensor with a length of 1465mm to verify the highest reconstruction accuracy of 3D Euler spiral model, which is consistent with the simulation results. The results provide a solid foundation for further research in the field of shape sensing, and show potential for promoting the development of applications that rely on real-time shape measurements.

Facile and scalable synthesis of long-life porous MgO-nanofiber functionalized biochar adsorbent from magnesite for phosphate recycling

The recycling of phosphate from wastewater using regenerable and highly efficient MgO-modified biochar for Mg-P fertilizer application is of great interest. However, the practical application of MgO-modified biochar for the removal and recycling of phosphate is hindered by its short-recycled service-life. Herein, a facile yet scalable method is proposed to fabricate porous MgO nanofiber-functionalized biochar (PMgNF-BC) with enhanced phosphate adsorption and regeneration performances from wastewater using waste biomass and magnesite. The as-prepared PMgNF-BC exhibited the maximum phosphate adsorption capacities of 594.53, 661.57, and 725.43 mg/g at 298.15 K, 308.15 K and 318.15 K, respectively. More importantly, PMgNF-BC demonstrated excellent regeneration performance with the removal efficiency of 84.2 % after eight regeneration cycles. Furthermore, the regenerated PMgNF-BC exhibited the well-preserved fiber shape of MgO on BC, enabling splendid regeneration performance. This work validates PMgNF-BC as a sustainable adsorbent for recycling phosphorus from wastewater, addressing the urgent need for synthesizing biochar with high regeneration performance.

AI-based non-linear models for mechanical and toughness properties of sustainable fiber-reinforced geopolymer concrete (FRGPC)

The incorporation of fibers into geopolymer concrete (GPC) produces FRGPC which mitigates brittle failure and restrains macro crack propagation; however, research on predicting the mechanical and toughness properties of FRGPC remains limited. This study addresses this gap by developing prediction models for compressive strength (CS), flexural strength (FS), flexural toughness (FT), and fracture toughness (FR). A dataset of 600 data points was compiled from the published literature, encompassing various constituent proportions, fiber shapes, fiber dosages, aspect ratios, and curing conditions. Employing an artificial neural network (ANN) methodology, 10 independent variables (g1, g2, …., g10) were utilized to predict four dependent variables (CS, FS, FT, and FR), resulting in the development of eight non-linear ANN models for both straight fibers (SFs) and hooked fibers (HFs). Each model has shown a higher R 2 value and lower root mean square error (RMSE) for training (70%), testing (15%), and validation (15%) datasets. The prediction model for the CS of FRGPC with HFs (CS-HF) and SF (CS-SF) showed R 2 values of 0.983 and 0.973, and RMSE of 2.088 and 2.435 MPa highlighting the accuracy of the ANN models. Similarly, the comparative analysis for FR models exhibited R 2 values of 0.997 and 0.987, and RMSE values of 0.045 Mpa √m and 0.032 Mpa √m for FR-HF and FR-SF, highlighting that fiber addition strongly impacts improving toughness properties. To identify the most influential independent variable(s), sensitivity analysis revealed g10, g1, g8, and g9 as the most influential parameters for mechanical and toughness properties with SFs. For HFs, g1, g2, and g3 were most influential for mechanical properties, and g8, g9, and g10 for toughness. This study also presented the mathematical formulation of the developed models for better interpretability and to facilitate optimal and economical FRGPC mix design selection, highlighting the potential of AI-based models in advancing sustainable construction materials.

Performance Simulation of Muon Detectors Based on Structural Design and Array Layout of Plastic Scintillators

The performances of muon detectors have prominent effects on the accuracy and application scenario of muon imaging. Previous studies have paid more attention to the performance improvements of muon detectors in the assembly of imaging systems and optimization of imaging algorithms, while, the structural design and array layout of plastic scintillators in muon detectors have received less attention. In this work, the simulation models of plastic scintillator, wavelength-shifting (WLS) fibers, and muon source are constructed in the Geant4 software. On this basis, different factors affecting light collection efficiency (LCE) have been investigated, including muon hitting position, plastic scintillator cross-sectional shape and size, and WLS fiber size and position. Meanwhile, the influences of scintillator array layout, average width, and muon energy on the position resolution performance of the detector are investigated. The constructive results have been listed as follows: (a) the longitudinal length of the plastic scintillator unit, the shape and size of the WLS fiber, and the position of the WLS fiber have a large impact on the LCE. (b) The Right-angled triangle staggered layout is suitable for small-sized scintillators with single-energy muon hitting, and the Rhombus staggered layout is suitable for large-sized scintillators with multiple-energy muon hitting. This work provides theoretical support for the structural design and array layout of plastic Scintillators, and it has an important significance as a guide for the design of the subsequent muography system.

Omnidirectional optic fiber shape sensor for submarine landslide monitoring

In-situ submarine landslide monitoring is imperative for ensuring the safety of ocean infrastructures, although it poses greater challenges compared to conventional landslide monitoring methods. In response to this need, we developed an omnidirectional optic fiber shape sensor (OFSS) and a self-contained submarine landslide monitoring system. Wavelength division multiplexing (WDM) and space division multiplexing (SDM) are used to build 10 omnidirectional curvature sensors with 3 fiber Bragg gating (FBG) arrays. Difference curvature demodulation algorithm is introduced to eliminate bending-irrelative effects. The omnidirectional curvature transmission matrix (OCTM) is obtained through calibration process with standard curvature molds. Frenet algorithm is used to recovery the shape. Laboratory experiments demonstrate OFSS’s ability to monitor 3D shape in real time, achieving the deflection error of 0.23 % and the bending direction error of 0.06 rad in the simple bending shape recovery experiment. In the S-shape recovery experiment, the OFSS’s deflection error is 0.77 % and the bending direction error is 0.04 rad. Subsequently, the system underwent testing in shallow water within a ship dock. In this experiment, the OFSS is successfully penetrated into the seabed and remained embedded in the soil for 90 min. The maximal shift observed at the end of the OFSS is 4.61×10-3m with the standard deviation of 9.95×10-4m, while the bending direction exhibited a maximal shift of 3×10-3 rad with the standard deviation of 7.51×10-4rad over the course of the 90-minute duration. These results validate the system’s effectiveness in providing accurate and reliable in-situ monitoring of submarine landslide.

Microplastics in the commercially available branded milk in Bangladesh: An emerging threat for human health

Microplastics (MPs) are polymer-based particles commonly found in diverse foods that pose serious human health impacts throughout the food chain. Assessment of MPs in different food products is a prime measure to combat MP-related food contamination. Therefore, this study first investigated the identification, characterization, and potential risks of MPs in the commercially available milk brands (19 dry powders and 06 liquid brands) in Bangladesh. The presence of MPs in milk samples was 279.47 ± 134.26 particles/kg and 182.27 ± 55.13 particles/L for powder and liquid milk, respectively, with a significant variety. Study findings displayed miscellaneous colors, fiber shapes (powder=78 %; liquid=81 %), > 0.1 mm sizes (powder=69 %; liquid=65 %), and polyethylene (powder=48 %; liquid=44 %) dominating MPs categories. The pollution load index indicated significant pollution due to the high abundance of MPs. Further, other risk-evaluating indices including contamination factor and Nemerow pollution index represent moderate to high MP-induced pollution for both milk samples. Low to moderate polymeric risks are exhibited by powder and liquid milk samples. Children could be exposed to 3.43 times higher MPs than adults through daily oral ingestion, which has significant health effects. This study found that powder milk was the most severely MPs induced risk than liquid milk. Consequently, this study finding established a reference point for MP contamination in milk, so special attention must be taken during production, storage, and packaging stages to reduce MP contamination.

More than just sweet: current insights into microplastics in honey products and a case study of Melipona quadrifasciata honey.

Honey, traditionally known as a pure and natural substance, has become an unexpected reservoir for microplastic contamination. This study consisted of an experimental investigation to assess the occurrence of microplastics in honey produced by Melipona quadrifasciata, a native bee species in Brazil. Our investigation covers eight areas (one sample per area), including built and vegetated areas located in São Paulo city, Brazil, to understand the distribution of microplastics in these environments. Honey samples (10 mL) were collected using a syringe and sent to the laboratory for further analysis. Microplastics extracted from honey samples were characterized under a stereomicroscope to determine their size, color, and morphology. Also, the polymer type was determined by FTIR analysis. All honey samples (100%) showed microplastics. The predominant particles displayed a fiber shape with a size below 299 μm and a transparent color and were primarily composed of polypropylene. Their concentrations ranged from 0.1 to 2.6 particles per mL of honey, raising concerns about their potential impact on bee populations and human consumers. This study underscores the need for further research on the sources and implications of microplastic contamination in Melipona quadrifasciata honey, shedding light on the broader issue of environmental plastic pollution and its impact on pollinators.

Appraisal of microplastic pollution and its related risks for urban indoor environment in Bangladesh using machine learning and diverse risk evolution indices

The widespread presence of Microplastics (MPs) is increasing in the indoor environment due to increasing annual plastic usage, which is becoming a global threat to human health. Therefore, this is the first research in Bangladesh to identify, and characterize, MP pollution and its allied threats to human health in the indoor urban environment, where 80 household dust samples were collected from the whole study area. The presence of MPs in household dust of the urban indoor environment was 25.8 ± 6.43 particles/g with a significant variety, whereas the fiber shape (73%), 0.5–1.00 mm ranged MPs size (58%), blue color (21%), and polystyrene polymer (34%) was the most ubiquitous MPs category. The pollution load index (1.61–2.96) indicated significant pollution due to the high abundance of MPs. Besides, other risks evaluating indices including contamination factor (1.00–3.51), and Nemerow pollution index (1.60–3.51) represent moderate to high MP-induced pollution. The polymer hazard index (119.54 ± 70.34) indicated significant risks for the selected polymers to the indoor environment living inhabitants. Machine learning approaches, especially random forest and support random vector machine were effective in predicting the number of MPs, where EC, salinity, pH, OC, and texture classes acted as controlling factors. Children and adults might be ingesting 4.12 ± 1.01 and 2.27 ± 0.57 particles/day through the ingestion exposure route, which has significant health effects. Polymer-associated lifetime cancer risk assessment results show that there are moderate risks for both adults and children, but children tend to be more susceptible to MP risks. The overall study found that Dhaka was the most severely MPs induced risky division among the others. This study reveals that high quantities of MPs in indoor environments could pose a serious health hazard' to different exposure groups.

Active vibration control effect of 3D printed cruciform honeycomb laminates based on fiber-reinforced shape memory polymer

Honeycomb structures offer the benefits of being lightweight and having high out-of-face compressive stiffness, making them a popular choice for aerostructures. The present study delineates the design and active vibration control effect for fiber-reinforced cruciform honeycomb laminates (CHLs) characterized by variable parameters. Employing a continuous fiber 3D printer, carbon fiber filament and shape memory polymers (SMPs) were utilized in the fabrication of the specimens. Differential equations of motion for CHLs were deduced from Kirchhoff plate theory. To ascertain their frequency response, these laminates were subjected to a sinusoidal swept frequency excitation. Subsequently, the classical proportional integral derivative (PID) program was employed to scrutinize the efficacy of closed-loop active vibration control on CHLs. The investigation extended to analyzing the impact of active vibration control across laminates with disparate parameters, including an examination of the convergence speed during vibration control procedures. A comparative analysis of simulated versus experimental data revealed a substantial consonance between the two, thereby corroborating the accuracy of the experimental findings. This study offers crucial insights and reference value for the utilization of CHLs in the aerospace industry.

Experimental study and analytical modeling of tensile performance of ultra-high-performance concrete incorporating modified recycled aggregates

Incorporating recycled aggregates (RA) into Ultra-High-Performance Concrete (UHPC) is pivotal for the sustainable development of high-performance construction materials. This study investigates the enhancement of RA through two methods: low-concentration acid treatment and sodium silicate treatment, focusing on improving physical properties and microstructural integrity. Experimental designs encompassed varying types of modified RA (URA, T1RA, T2RA), RA replacement rates (0%, 25%, 50%, 100%), and two steel fiber shapes (SSF and HSF), resulting in twenty-one distinct axial tensile specimen formulations. The study reveals substantial improvements in modified RA's physical properties, effectively mitigating internal microcracks and pores. Modified RA significantly bolstered UHPC-RA's tensile strength, notably when chemically strengthened, underscoring its efficacy in enhancing RA quality. However, escalating RA content correlated with diminished mechanical indices like tensile strength and toughness, attributed to reduced specimen quality. Digital Image Correlation (DIC) accurately forecasted crack locations, highlighting the minimal influence of modified RA and fiber bridging on specimen failure modes. A comprehensive theoretical model incorporating RA deterioration and hooked steel fiber anchorage predicted tensile behaviour, offering vital insights for designing UHPC-RA systems.

Investigation of axial buckling behavior in composite laminates reinforced with S-glass fiber and epoxy featuring double cutouts

This research examines the impact of double cutouts on the critical buckling load of woven S-Glass/epoxy composite laminates. The study is divided into two parts: the first part involves comparisons, while the second part introduces numerical analyses. Initially, critical buckling loads of composite laminates without cutouts are determined using numerical and experimental methods. Subsequently, the results are compared to ensure consistency of critical load values obtained from the different methods. In the second part, the study investigates the effects of fiber angle, shape (square and circular), size, and position of cutouts in the composite plate using finite element analysis. The findings suggest that the shape and position of the cutout on the plate primarily influence the critical buckling load of the composite plates with circular cutouts, resulting in a relatively lower change in buckling load compared to square ones.

Polypropylene waste plastic fiber morphology as an influencing factor on the performance and durability of concrete: Experimental investigation, soft-computing modeling, and economic analysis

The increasing waste of plastic masses raises the danger alarm due to its adverse impacts on people and the natural environment. Hence, serious attempts should be made to manage this non-biodegradable waste for practical, sustainable, and sufficient uses, such as in construction. This research discusses experimentally the possibility of improving the behavior of concrete reinforced with waste plastic fibers (WPFs) from food trays by examining the effect of fibers morphology on concrete's mechanical properties and durability. This concept was intensively studied for steel fibers but rarely for WPFs. A 0.6 percentage of 30 mm long straight, spiral, and channel fibers were tested and compared. Compressive, tensile, and flexural strengths, impact resistance, water absorption, rapid chloride penetration tests, and microstructural analysis were conducted. The results revealed that the fibers shape influences the mechanical behavior along with the water absorption considerably, and that the spiral fibers exhibited superior performance compared to the other shapes. The mechanical properties of spiral fibers specimens have improved considerably compared to specimens of other shapes. However, the ion chloride penetration resistance did not witness any substantial improvement, and the brittle fracture of concrete did not change by using WPFs, despite the considerable increase of more than 66 % of the impact resistance of specimens with spiral fibers. According to the findings, spiral WPFs enhance concrete's behavior, making WPF implementation in concrete more efficient from an environmental and structural standpoint. Moreover, machine learning modeling and cost/benefit analysis were conducted in this work to better understand the WPF effect on concrete.

A comprehensive study of carbon nanoparticle shape and orientation effects on composite elastic properties using FEA

In this study, three critical parameters that influence the effective composite properties of Carbon nanoparticles were tested and modeled using finite elements through Digimat Finite Element Analysis (FEA) software, employing representative volume elements (RVE). The primary parameters under consideration are the fiber shape, fiber orientation, and fiber volume fraction. Four of the many different shapes of Carbon nanoparticles, namely Tubes, Disk, Sphere, and Cylinder, were investigated, coupled with four distinct orientations for tubes: horizontal, aligned at 45°, random, and vertical each varying in the carbon fiber volume fraction. The material of choice was pure epoxy resin because of the nature of the bonding between its two phases and its wide range of usage. Forces were applied along the X-axis, coupled with shear in the XY plane. This study revealed that the orientation of CNTs primarily influences the Elastic Young’s modulus, whereas the size of the CNTs has the main effect on the shear modulus, followed by orientation. The horizontal CNTs demonstrated superior Young’s modulus, but the random orientation had a more pronounced impact on the shear modulus variation. Regarding the analysis of the nanoparticles shapes, the disk shape with fixed orientation revealed the highest elastic modulus, after which the cylinder shape and the sphere recorded the minimum elastic modulus among the three studied shapes.

Stroke-induced excess in capillarization relative to oxidative capacity in rats is muscle specific.

Stroke is not only associated with muscle weakness, but also associated with reduced muscle fatigue resistance and reduced desaturation during exercise that may be caused by a reduced oxidative capacity and/or microvasculature. Therefore, the objective of the present study was to determine the effects of stroke on muscle mass, fiber size and shape, capillarization and oxidative capacity of the rat m. extensor carpi radialis (ECR) and m. flexor carpi ulnaris (FCU) after a photothrombotic stroke in the forelimb region of the primary sensorimotor cortex. The main observation of the present study was that 4 weeks after induction of stroke there were no significant changes in muscle fiber size and shape. Although there was no significant capillary rarefaction, there was some evidence for remodeling of the capillary bed as reflected by a reduced heterogeneity of capillary spacing (p = 0.006) that may result in improved muscle oxygenation. In the ECR, but not in the FCU, this was accompanied by reduction in muscle fiber oxidative capacity as reflected by reduced optical density of sections stained for succinate dehydrogenase (p = 0.013). The reduced oxidative capacity and absence of significant capillary rarefaction resulted in a capillary to fiber ratio per unit of oxidative capacity that was higher after stroke in the ECR (p = 0.01), but not in the FCU. This suggests that at least during the early stages, stroke is not necessarily accompanied by muscle fiber atrophy, and that stroke-induced reductions in oxidative capacity resulting in relative excess of capillarization are muscle specific.

Study on the effect of polypropylene fiber shape and admixture on the mechanical properties of concrete

Study on the effect of polypropylene fiber shape and admixture on the mechanical properties of concrete

Statistical modeling of 3D fiber geometry in pultruded GFRP composite: A multi-scale approach

The fiber geometry is a crucial determinant of the fiber reinforced polymer composites’ mechanical properties. Specifically, the manufacturing process of stretching and gradual curving in pultruded composites invariably results in complex 3D fiber geometries. Despite its significance, there is still lacking a statistical method to accurately describe these spatially curved fiber shapes. This paper presents a novel multi-scale mathematical approach for modeling the complex 3D fiber geometry in pultruded glass fiber reinforced polymer (GFRP) composites, which includes the analysis of fiber misalignment and waviness at two scales. At the mesoscopic level, a modified elliptical symmetry angular Gaussian (ESAG) model effectively characterizes the fiber misalignment. Simultaneously, at the micro scale, a cosine series representation is employed for capturing local fiber waviness. The approach is verified with XCT scanning results of pultruded GFRP specimens. The current statistical modeling method provides a multi-scale approach for geometry analysis and further simulation of pultruded composite materials.