Short Fiber Research Articles

Investigation of Impact Behaviour of Sisal Fiber Reinforced Phenol Formaldehyde Composites

Short Sisal fiber reinforced Phenol Formaldehyde resin composites are prepared with varied fiber lengths (5 mm and 10 mm) and for varied weight fraction (20%, 25% and 30%) of the fibers. Here in this work, Sisal fiber is used as reinforcement. Since it is abundantly available in nature and majority of it is getting wasted without being used as reinforcement in engineering applications. Over the last thirty years composite materials, plastics and ceramics have been the dominant emerging materials. The 10 mm fiber length reinforced composite shown improved mechanical properties than 5 mm fiber length reinforced composite. Increase in impact strength is seen when the fiber content in the composite is increased from 20% to 25% and 25% to 30%. The fiber strength, for different fiber lengths and fiber volume fraction, the work of fracture is proportional to the fiber length and fiber volume fraction. Although results show increment in impact strength with fiber volume fraction, proportionality is not demonstrated. This suggests that there are other mechanisms that affect the impact strength of the composites. Crack propagation is the predominant toughening mechanism in notched impact test. Improvement in impact strength characterizes that fibers as stress transferring medium are able to absorb impact energy effectively. Good interaction with crack increases the energy needed for further crack formation and propagation. The exceptional case could be due to low fiber content and relatively short fiber length so that the energy is not dissipated effectively. Weak interfacial bonding of natural fibers is mainly due to incompatibility of hydrophobic matrix and hydrophilic fiber. High moisture absorption causes dimensional changes of natural fibers as well.

Fabrication of dense Cf/SiC ceramic matrix composites using 3D printing and PIP with short carbon fibre as a toughening material

ABSTRACT To achieve weight reduction, toughness enhancement, and the fabrication of complex structures in SiC composites, a combination of SLS and PIP processes was used. Silicon carbide powder served as the matrix material, while short carbon fibres were used for toughening, resulting in dense Cf/SiC ceramic matrix composites. The effects of varying carbon fibre sizes and contents on the microstructure and mechanical properties of Cf/SiC composites were examined. Results indicated that adding 8% carbon fibre increased the fracture toughness of Cf/SiC composites by 33.33%. Further increases in carbon fibre content showed minimal effects on fracture toughness. Based on experimental results and finite element simulations, toughening mechanisms, including fibre pull-out, fibre debonding, and crack deflection, were further elucidated. Consequently, Cf/SiC composites with complex structures, such as turbine specimens and lattice structures, were successfully fabricated.

Single-mode chirped high-contrast metastructure VCSEL for 106 Gbps PAM4 transmission

Short-reach optical interconnects, employing an 850 nm wavelength multimode vertical cavity surface emitting laser (VCSEL) and multimode fiber (MMF), are confronted with transmission distance limitation as the transmission speed increases. Achieving higher speeds over the same transmission distance necessitates a significant enhancement in the fiber’s effective bandwidth, resulting in substantial costs. Employing single-mode VCSEL with single-mode fiber transmission presents as a more economically viable solution. Here we report, to our knowledge, the first demonstration of an 850 nm single-mode VCSEL using a chirped high-contrast metastructure (HCM) as the top mirror with spatially graded reflectivity to suppress higher-order modes. The chirped HCM top reflector is designed to favor lasing of the fundamental mode. We show stable single-mode lasing with a >40dB side mode suppression ratio (SMSR) up to 15 times threshold current and an open eye through a short single-mode fiber SM800 transmission at 106 Gbps PAM4 modulation. This study highlights the potential for scalable single-mode VCSEL in advanced optical interconnects, providing a cost-effective pathway for high-speed applications.

Realizing 0.7 dB/m gain in O + E band by promoting BACs-P formation in bismuth-doped phosphosilicate fiber with double-pass configuration.

The long fiber length required for the amplification of bismuth-doped fiber (BDF) has hindered its practical application. In this paper, we propose and demonstrate a feasible method to improve the active absorption of bismuth active centers (BACs) by optimizing the drawing conditions, achieving a high gain with a short fiber length. The bismuth-doped phosphosilicate fiber (BPSF) preform was fabricated by the modified chemical vapor deposition (MCVD) process and drawn into fiber under nine different conditions. The results indicate that the active absorption of BACs increases as the drawing temperature increases and the drawing speed decreases within these drawing parameters. Meanwhile, the corresponding gain per unit length is improved. Furthermore, a maximum gain of 31.6 dB at 1350 nm with the >20 dB gain wavelength range of 1311-1401 nm was achieved in a double-pass double-pump configuration, using only 45 m BPSF. Meanwhile, the -3 dB bandwidth was 1328-1370 nm. The gain per unit length is 0.7 dB/m, which, to the best of our knowledge, is the highest gain per unit length reported for the BPSF.

Effects of Absorption on the Tribological Properties of Carbon Fiber Reinforced Polyamide-6 Composites Manufactured by Fused Deposition Modeling

Abstract The present work studied the water absorption behavior of polymeric composite materials fabricated using 3D printing technology, as well as its effect on their tribological properties. Polyamide-6 was selected as the base matrix material. Short and continuous carbon fibers are used as the reinforced material. The results showed that the moisture absorption would impair the mechanical properties of polymer matrix and interface bonding between the fiber and the matrix. As a result, the tensile strength of the fiber reinforced polymer composites (FRPCs) decreases with water absorption. Nevertheless, the effects of moisture absorption on the wear properties of FRPCs are more complicated, which are depending on the fiber length and sliding conditions. With the short fiber reinforcements, moisture absorption deteriorated the wear resistance under all the testing conditions. With the increase of moisture level, more severe fiber damage/removal was observed, associated with the higher wear loss. With a relative high volume fracture of continuous carbon fiber (∼35 vol%), however, the wear resistance of the FRPC increased with moisture level, especially under a relatively low load. Based on microscopic observations, it was proposed that water inside FRPC specimens is able to provide the lubricating and cleaning effects, which contribute to a lower friction and smooth worn surfaces. The work provides new insights into designing and selecting printed polymer materials, subjected to different loading conditions.

Investigation of particle size distribution and ultrafiltration of digestates from short-fibre residues in paper mills

ABSTRACT Industrial digestates from short-fibre residues, generated in paper recycling mills, are driving interest in resource recovery. This study aims to explore their potential for water recovery. Understanding particle dynamics aids in optimizing dewatering for digestate management. The particle size distribution in this study revealed significant fractions: <0.63 μm (6–20%), 0.63–20 μm (38–52%), and >20 μm (11–16%). Pre-treatment with Na4P2O7 and H2O2 enhances settling and lowers total dissolved solids (TDSs) but results in variation of size distribution. Additionally, this study investigates further water reuse in paper mills, focusing on the quality of ultrafiltration (UF) permeate obtained from the digestate of short fibres. UF permeate analysis reveals deviations from freshwater standards in paper mills. Despite effective TS removal, UF permeate falls short of paper mill water standards due to high TDSs, electrical conductivity, and nutrient concentrations, necessitating further downstream treatment with nanofiltration or reverse osmosis. A substantial reduction of permeate flux from 31 to 5 L/(m2·h) over the time indicated fouling and inefficient membrane wash. The silt density index of the UF membrane at 30 min registered 2.1, suggesting potential fouling. Further investigations on optimizing UF operations to enhance permeate flux and exploring alternative UF membranes are required.

Dynamic Analysis and Vibration Control of Additively Manufactured Thin-Walled Polylactic Acid Polymer (PLAP) and PLAP Composite Beam Structures: Numerical Investigation and Experimental Validation

This study primarily presents a numerical investigation of the dynamic behavior and vibration control in thin-walled, additively manufactured (AM) beam structures, validated through experimental results. Vibration control in thin-walled structures has gained significant attention recently because vibrations can severely affect structural integrity. Therefore, it is necessary to minimize these vibrations or keep them within acceptable limits to ensure the structure’s integrity. In this study, the AM beam structures were made of polylactic acid polymer (PLAP), short carbon fiber reinforced in PLAP (SCFR|PLAP), and continuous carbon fiber reinforced in PLAP (CCFR|PLAP), with 0°|0° layer orientations. The finite element modeling (FEM) of the AM beam structures integrated with macro fiber composite (MFC) was carried out in Abaqus. The initial four modal frequencies of bending modes (BMs) and their respective modal shapes were acquired through numerical simulation. It is crucial to highlight the numerical findings that reveal discrepancies in the 1st modal frequencies of the beams, ranging up to 1.5% compared to their respective experimental values. For the 2nd, 3rd, and 4th modal frequencies, the discrepancies are within 10%. Subsequently, frequency response analysis (FRA) was carried out to observe the frequency-dependent vibration amplitude spectrum at the initial four BM frequencies. Despite discrepancy in the amplitude values between the numerical and experimental datasets, there was consistency in the overall amplitude behavior as frequency varied. THz spectroscopy was performed to identify voids or misalignment errors in the actual beam models. Finally, vibration amplitude control using MFC (M8507-P2) was examined in each kinematically excited numerical beam structure. After applying a counterforce with the MFC, the controlled vibration amplitudes for the PLAP, SCFR|PLAP, and CCFR|PLAP configurations were approximately ±19 µm, ±16 µm, and ±13 µm, respectively. The trend in the controlled amplitudes observed in the numerical findings was consistent with the experimental results. The numerical findings of the study reveal valuable insights for estimating trends related to vibration control in AM beam structures.

Bonding strength of short carbon fiber reinforced PA6 composites ultrasonic welding joints

AbstractShort carbon fiber composites have high specific modulus, high specific strength and excellent formability, which are suitable for short‐term and environmentally friendly ultrasonic welding. In this study, ultrasonic welding experiments were conducted on short carbon fiber reinforced PA6 composites using a servo‐driven non‐metallic ultrasonic welder. The weld specimens were analyzed for spot weld morphologies, interfacial bonding strength, failure modes and compressive shear fracture to establish the correlation between weld energy and weld quality. The results indicate that when the welding energy is 450 J, the short carbon fibers are interlaced at the interface, which has a pinning effect, thereby enhancing the joint strength reaching 2990 N, and the welding efficiency reaches 46%. Besides, the compressive shear section is divided into regions. The proportion of heat and area in different compressive shear regions are quantitatively analyzed, and the calculation model of joint strength is proposed. Meanwhile, the correlation between welding energy and its correlation, as well as three different shear failure modes, is obtained. This work is helpful for the optimization of carbon fiber reinforced thermoplastic (CFRTP) ultrasonic welding process parameters and the evaluation of joint strength.Highlights A special fixture for ultrasonic welding was designed to optimize the welding energy process of ultrasonic welding CFRTP, and the properties of ultrasonic welded joints were analyzed. When the welding energy is 450 J, a high shear strength welded joint of 2990 N was successfully prepared. The shear fracture of the welded joint was successfully obtained by designing a special clamp for compression shearing. The welding area was qualitatively divided according to the temperature measurement results of the interface center. In addition, the heat and area ratio of different zones in the compression‐shearing area under different welding energy were quantitatively analyzed, and the calculation model of joint strength was proposed. At the same time, the welding energy and its correlation, as well as three different shear failure modes were obtained. The short fiber distribution characterization and pores effect on the joint's strength were analyzed. The appearance of porosity defects has a significant weakening effect on the welded joint.

Preparation and the influence of twist factor on cut resistance performance of Kevlar short fiber covered yarn fabric

This research utilized Kevlar short fibre yarn to cover Kevlar and UHMWPE filaments, resulting in six different types of covered yarns and their associated fabrics. The aim of the research was to examine the impact of the twist factor of Kevlar short fibre yarn and the type of covered yarn on the mechanical properties of the yarns and their corresponding fabrics. The results indicated that the KPf covered yarn with a twist factor of 305 exhibited the highest breaking strength at 13.06cN/dtex, approximately 24% higher than the KKf covered yarn. The 225-KPf covered yarn fabric demonstrated peak breaking strength at 1772.01 N. Under similar conditions, KPf coated yarn outperformed KKf coated yarn in terms of tensile strength. However, KKf covered fabrics exhibited superior cutting resistance compared to KPf covered fabrics, with the 385-KKf fabric having the highest resistance at 1117.29 N. The study concluded that increased twist factor factors lead to varied outcomes in tensile performance and cutting resistance due to changes in inter-fiber spacing and cohesion pressure on the short fiber yarn, as well as the influence of material molecular structure.

An investigation on workability and strength on compression of GPC with addition of different aspect ratio glass fibers

The heating of limestone and other materials to high temperatures to produce Ordinary Portland cement (OPC), a key component in concrete releases of carbon dioxide CO2 which makes the construction industry a notable contributor to greenhouse gas emissions. The search for more sustainable alternatives has led to the exploration of alkali-activated materials as a replacement for OPC. Alkali-activated materials are a class of binders that can be used in concrete production without the need for traditional cement. These materials often include industrial by-products such as fly ash, GGBFS (sometimes also called GGBS) (Ground Granulated Blast Furnace Slag), and other waste materials. The development and adoption of alkali-activated materials represent a promising avenue for reducing the environmental impact of the construction industry. On-going research and collaboration are crucial to addressing technical challenges and promoting the widespread use of these alternative binders. The exploration and utilization of alternative materials such as GGBFS, fly ash, and geopolymer concrete play a crucial role in mitigating the environmental impact of the construction industry, particularly in terms of reducing CO2 emissions and utilizing industrial by-products effectively. A good concrete mix is obtained from combination of different size of aggregates. Addition of fibers plays a crucial role in enhancing the tensile strength of concrete. Similar synergy of addition of different aspect ratio of optimum dosages fibers as of different size of aggregates may improve strength and ductility of concrete. Short fibres can stop the propagation of micro-cracks with enhancement of toughness, and long fibres can stop the propagation of macro-cracks. From the aforementioned perspective, it is preferable to add the same volume of fibre with a different aspect ratio to improve the pre- and post-cracking performance of concrete. It also aids in boosting maximal strength.This study aims in preparing geopolymer concrete with graded glass fibres in order to investigate improvement the strength in compression and workability.

Development of cleaner production composite rebar using sugarcane bagasse biochar and areca short fibre for eco-friendly construction

Development of cleaner production composite rebar using sugarcane bagasse biochar and areca short fibre for eco-friendly construction

Preparation of Cf/Si3N4 composites based on vat photopolymerization combined with precursor infiltration and pyrolysis

AbstractThe development of vat photopolymerization (VPP) 3D printing technology has created the conditions for the fabrication of complex structured Si3N4 ceramics. However, Si3N4 ceramics produced through VPP often lack sufficient mechanical properties, which limiting their applications. This study introduces short carbon fibers (Cf) into the VPP‐Si3N4 ceramics, combined with the polymer infiltration and pyrolysis (PIP) process, to prepare Cf/Si3N4 composites. The effect of Cf content on slurry preparation, green part printing, and mechanical properties of the Cf/Si3N4 composites was systematically investigated. The results indicate that Cf significantly enhances the mechanical properties of Cf/Si3N4 composites. At 6 wt.% Cf content, the samples exhibit the highest strength and fracture toughness, reaching 183.2 MPa and 6.2 MPa·m1/2, respectively, representing increases of 29.7% and 92.3% compared to samples without Cf. The improvement in mechanical properties is partly due to the ‘pinning effect’ of Cf, which enhances interlayer bonding strength in the printed green parts, positively impacting the overall mechanical properties of the composites. Additionally, inherent toughening mechanisms of Cf, such as fiber pull‐out, crack deflection, and crack bridging, further enhance the composite's mechanical properties. This study confirms the feasibility of using Cf to enhance the mechanical properties of VPP‐Si3N4 ceramic.

Application of Sound Waves During the Curing of an Acrylic Resin and Its Composites Based on Short Carbon Fibers and Carbon Nanofibers.

Research into particulate polymer composites is of significant interest due to their potential for enhancing material properties, such as strength, thermal stability, and conductivity while maintaining low weight and cost. Among the various techniques for preparing particle-based composites, ultrasonic wave stimulation is one of the principal laboratory-scale methods for enhancing the dispersion of the discontinuous phase. Nevertheless, there is a scarcity of empirical evidence to substantiate the impact of stimulating materials with natural sound frequencies within the acoustic spectrum, ranging from 20 Hz to 20 kHz, during their formation process. The present work investigates the effect of acoustic stimuli with frequencies of 56, 111, and 180 Hz on the properties of an acrylic-based polymer and its discontinuous carbon-based composites. The results indicated that the stimulus frequency affects the cure time of the studied systems, with a notable reduction of 31% and 21% in the cure times of the neat polymer and carbon-nanofiber-based composites, respectively, after applying a frequency of 180 Hz. Additionally, the higher stimulation frequencies reduced porosity in the samples, increased the degree of dispersion of the discontinuous phase, and altered the composite materials' thermal, optical, and electrical behavior.

A novel Taguchi-based approach for optimizing neural network architectures: application to elastic short fiber composites

This study presents an innovative application of the Taguchi design of experiment method to optimize the structure of an Artificial Neural Network (ANN) model for the prediction of elastic properties of short fiber reinforced composites. The main goal is to minimize the computational effort required for hyperparameter optimization while enhancing the prediction accuracy. By utilizing a robust experimental design framework, the structure of an ANN model is optimized. This approach involves identifying a combination of hyperparameters that provides optimal predictive accuracy with the fewest algorithmic runs, thereby significantly reducing the required computational effort. The results suggested that the Taguchi-based developed ANN model with three hidden layers, 20 neurons in each hidden layer, elu activation function, Adam optimizer, and a learning rate of 0.001 can predict the anisotropic elastic properties of short fiber reinforced composites with a prediction accuracy of 97.71%. Then, external validation of the proposed ANN model was done using experimental data, and differences of less than 10% were obtained, indicating an appropriate predictive performance of the proposed ANN algorithm. Our findings demonstrate that the Taguchi method not only streamlines the hyperparameter tuning process but also substantially improves the algorithm's performance. These results highlight the potential of the Taguchi method as a powerful tool for optimizing machine learning algorithms, especially in scenarios where computational resources are limited. The implications of this study are far-reaching, offering insights for future research in the optimization of different algorithms for improved accuracies and computational efficiencies.

Regulating Astrocytes via Short Fibers for Spinal Cord Repair (Adv. Sci. 41/2024)

Regulating Astrocytes via Short Fibers for Spinal Cord Repair (Adv. Sci. 41/2024)

Extrusion Parameters Optimization and Mechanical Properties of Bio-Polyamide 11-Based Biocomposites Reinforced with Short Basalt Fibers.

The increasing demand for sustainable materials in high-value applications, particularly in the automotive industry, has prompted the development of biocomposites based on renewable or recyclable matrices and natural fibers as reinforcements. In this context, this paper aimed to produce composites with improved mechanical and thermal properties (tensile, flexural, and heat deflection temperature) through an optimized process pathway using a biobased polyamide reinforced with short basalt fibers. This study emphasizes the critical impact of fiber length, matrix adhesion, and the variation in matrix properties with increasing fiber content. These factors influence the properties of short-fiber composites produced via primary processing using extrusion and shaped through injection molding. The aim of this work was to optimize extrusion conditions using a 1D simulation software to minimize excessive fiber fragmentation during the extrusion process. The predictive model's capacity to forecast fiber degradation and the extent of additional fiber breakage during extrusion was evaluated. Furthermore, the impact of injection molding on these conditions was investigated. Moreover, a comprehensive thermomechanical characterization of the composites, comprising 10%, 20%, and 30% fiber content, was carried out, focusing on the correlation with morphology and processing using SEM and micro-CT analyses. In particular, how the extrusion process parameters adopted can influence fiber breakage and how injection molding can influence the fiber orientation were investigated, highlighting their influence in determining the final mechanical properties of short fiber composites. By optimizing the process parameters, an increment with respect to bio-PA11 in the tensile strength of 38%, stiffness of 140%, and HDT of 77% compared to the matrix were obtained.

On the printability of high-density polyethylene (HDPE) reinforced with long glass and short carbon fibres

Purpose This research is about the possibilities of using high-density polyethylene (HDPE)-based composites consisting of long glass and short carbon fibres because HDPE is one of the more preferred thermoplastics day by day due to its sustainability, cost-effectiveness and availability in the relevant markets. HDPE has become an increasingly preferred material in the marine industry in recent years due to its high resistance to marine environmental conditions (high resistance to UV, surface-fouling marine organisms and corrosive effects of salty and low-pH water). In the highly competitive boat building industry, additive manufacturing offers new opportunities such as rapid prototyping and design freedom. This study aims to investigate the possibilities of using a material suitable for the marine environment and an additive manufacturing (AM) method offering new possibilities, especially for small craft with complex forms. Design/methodology/approach A total of six new HDPE-based composites consisting of long glass and short carbon fibres at 10, 15 and 20% by weight have been proposed for the first time in this study for the use in boat building industry, proposing the application of these new composite materials with AM method, which the industry is not yet fully adopted, is also an innovative aspect of the study. The performances of the materials in AM’s material extrusion (MEX) method were evaluated using the results obtained from mechanical (tensile, compression, shear and impact) and thermal (melt flow index [MFI], thermogravimetric analysis [TGA] and thermomechanical analysis [TMA]) tests. In addition, the structure of the composites was examined with scanning electron microscopy and micro computed tomography visually, and the rheological properties of the composites were also determined by the related tests. As an industrial case study, a ship propeller was manufactured from the composites produced with CF15, which was thought to give the best performance in marine use, and this propeller was tested under water flow. Findings It is evaluated that the composites proposed in this study can be used in marine industry in line with the analyses and test results. The performance of the propeller produced as a case application also confirms this view. The printability of HDPE-based composites, reinforced by both glass and carbon fibre, is much better than that of pure HDPE, and the composites are suitable for use AM’s MEX method in boat building industry. As the fibre contents in the proposed composites increase, the strength values increase and the impact resistance and hardness decrease. The CF15 composite, which meets each of those mechanical and physical values at an average level, is a recommended option for marine applications. Originality/value This study has two basic originalities: (1) On the basis of HDPE, which is widely used in the marine industry, to produce composites that will overcome the deficiencies of this material in practice and to present them to relevant industry by improving their properties; (2) at the same time, to discuss for the first time the use of new HDPE-based materials in AM, whose printability has also been improved through composite, to help dissemination of AM technologies in marine industry in general and in the boat building industry in particular.

Advancements in Biofiller-Reinforced PLA Composites for 3D Printing: A Review

Additive manufacturing is key in realizing highly complex and high-performance composite materials. Among all the various kinds of functionality that could be added to a composite component, continuous fiber-reinforced composites have been drawing much attention because of their attractive combination of properties. The comprehensive spectrum of knowledge that ranges from the basics concerned with structure, morphology, synthesis, physical, and chemical properties finally reaches to this analytical study of advanced composites. Most generally, such a composite is structured on a thermoplastic or thermoset polymer matrix that embeds the load-carrying reinforcing fibers; probably best known are carbon, glass, and aramid fibers. These composites, which involve fibers continuously reinforcing, have high strength relative to their weight. They are also anisotropic, meaning they have qualities that vary from one direction to another – something which might be customisable for specific load cases. They warp and shrink less during their life in an outside environment than conventionally made bioplastics due to a fact that short fibers can provide reinforcement to them. This 3-D printing object is manufactured by special additive manufacture technology during the manufacturing process after compounding and extruding the fiber-reinforced composite filament. The final properties of 3D printed parts could be tailorable through changing variables such a fiber type, fiber length, volume fraction, polymer matrix material, orientation of fibers, and printing process parameters. These continuous fiber-reinforced 3D printed composites could achieve tensile strengths up to one GPa, have stiffness values reaching even a rating of countless Gpa, and have ad thicknesses in the range from about 1.4–1.8 g/cm³. This finding could be applied in basically all major industries, from aerospace and the automotive industry to sports gear. Such conclusions from the analysis may be useful in the selection of appropriate materials and techniques while even guiding the development of new applications with respect to such advanced composite materials.

Cyclic Performance of Reinforced Concrete Columns Strengthened with Basalt-Fibre-Reinforced Cementitious Matrix (BFRCM)

The purpose of this experimental investigation was to confirm whether the Basalt-Fibre-Reinforced Cement Matrix (BFRCM) effectively enhances the cyclic performance of columns made of reinforced concrete (RC). The BFRCM system, which comprises basalt fabric mesh reinforced with a cementitious matrix containing polyvinyl alcohol (PVA) fibre, has significant practical implications. In the testing phase, concrete and steel reinforcement were used to create RC column specimens, which were then strengthened with three, four, and five layers of BFRCM. The horizontal cyclic and constant axial loads were applied and tested to evaluate the performance of RC columns with and without strengthening. By improving the energy dissipation by approximately 9 to 32% and increasing stiffness by roughly 24 to 44%, the column specimen with three, four, and five layers of BFRCM performed better than the control specimen. Furthermore, incorporating short fibre into the matrix effectively improved the tensile properties of the FRCM systems and decreased the shrinkage-induced cracks. The increased stiffness indicates that the column with BFRCM has better structural strength because it can sustain higher loads with less deflection. The thorough comparative analyses examined the RC column specimens’ failure modes, hysteretic responses, stiffness degradation, and energy dissipation, providing a reliable basis for the conclusions. The test results confirmed that the BFRCM effectively enhanced the seismic capabilities and has been promised a way to strengthen RC elements, providing valuable insights for civil engineering and materials science.

Genome-wide association studies of bundle and single fiber length traits reveal the genetic basis of within-sample variation in upland cotton fiber length

Within-sample variation in cotton fiber len,gth is a major factor influencing the production and quality of yarns. The textile industry has been searching for approaches of improving the long fiber fraction and minimizing the short fiber fraction within a cotton sample to produce superior fiber and yarn quality. USTER® High Volume Instrument (HVI) has been widely used for a rapid assessment of cotton fiber length traits from a fiber bundle. However, its effectiveness for genetic studies has been questioned due to the indirect estimations of the cotton fiber traits that cannot be measured from a fiber bundle. To overcome the limits of the HVI fiber length traits, we utilized the Advanced Fiber Information System (AFIS) measuring fiber length traits directly from individual fibers based on weight or number. Comparative fiber length analyses showed AFIS provided higher sensitivity in detecting the fiber length variations within and among cotton samples than HVI. The weight-based AFIS length traits were strongly correlated with the corresponding HVI lengths, whereas the number-based AFIS mean length showed a relatively weaker correlation with the HVI lengths. Integrations of the weight based-length traits with genome-wide association studies (GWAS) enabled classifying the QTLs specifically associated with long, mean, or short fiber length traits and identified a false positive associated with the indirectly estimated HVI short fiber trait. Unlike the weight based-AFIS length traits, the number-based AFIS length trait did not show a negative correlation with a weight related-HVI property, and identified a single QTL that was not detected by the corresponding HVI trait. These results suggested that integrating the AFIS method with GWAS helped discoveries of the genome loci involved in the within-sample variation in cotton fiber length and characterizations of the fiber length QTLs.