Plastic Sections Research Articles

Inducible RPE-specific GPX4 knockout causes oxidative stress and retinal degeneration with features of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of vision loss in the elderly. This disease involves oxidative stress burden in the retina leading to death of retinal pigment epithelial (RPE) cells and photoreceptors. The retina is susceptible to oxidative stress, in part due to high metabolic activity and high concentration of polyunsaturated fatty acids that undergo lipid peroxidation chain reactions. Antioxidant enzymes exist in the retina to combat this stress, including glutathione peroxidase 4 (GPX4). GPX4 specifically reduces oxidized lipids, protecting against lipid peroxidation-induced oxidative stress, which is noted in dry AMD. We hypothesize that Gpx4 knockout within the RPE will result in an environment of chronic oxidative stress yielding degeneration akin to AMD. C57BL/6J mice with a floxed Gpx4 gene were mated with Rpe65Cre/ER mice. Offspring containing Rpe65Cre ± alleles and either Gpx4 WT or Gpx4 fl/fl alleles were administered tamoxifen to induce Gpx4 knockout in Gpx4 fl/fl mice. At sequential timepoints, retinal phenotypes were assessed via in vivo imaging utilizing confocal scanning laser ophthalmoscopy and optical coherence tomography (OCT), and visual function was probed by electroretinography. Retinas were studied post-mortem by immunohistochemical analyses, electron microscopy, plastic sectioning, and quantitative polymerase chain reaction and Western analyses. The RPE-specific Gpx4 knockout model was validated via Western analysis indicating diminished GPX4 protein only within the RPE and not the neural retina. Following Gpx4 knockout, RPE cells became dysfunctional and died, with significant cell loss occurring 2 weeks post-knockout. Progressive thinning of the photoreceptor layer followed RPE degeneration and was accompanied by loss of visual function. OCT and light microscopy showed hyperreflective foci and enlarged, pigmented cells in and above the RPE layer. Electron microscopy revealed decreased mitochondrial cristae and loss of basal and apical RPE ultrastructure. Finally, there was increased carboxyethylpyrrole staining, indicating oxidation of docosahexaenoic acid, and increased levels of mRNAs encoding oxidative stress-associated genes in the RPE and photoreceptors. Overall, we show that RPE-localized GPX4 is necessary for the health of the RPE and outer retina, and that knockout recapitulates phenotypes of dry AMD.

Behaviour of rectangular concrete-filled steel tube beams under monotonic and cyclic loadings

Concrete filled steel tube (CFST) has been extensively explored for columns but limitedly explored for beams. This current study investigates the behaviour of rectangular CFST beams under monotonic and cyclic loadings. Experiments were conducted for 12 CFST beams with depth-to-thickness (D/t) ratios of 66.7–111.1, followed by theoretical analyses. The experimental results indicated that tensile yielding and compressive local buckling of steel tubes governed the plastic behaviour of the tested CFST beams. The buckling significantly degraded the strength of CFST beams. When the D/t ratio decreased from 111.1 to 66.7, the stiffness, yield load, and ultimate load increased by 33.2%, 49.4%, and 40.0%, respectively, but the ultimate deflection was reduced by ∼19.5%. The effect of cyclic loading induced a degradation of stiffness of 0.85–2.85%/cycle, depending on the increment of the peak cycle deflection. The buckling negatively affected the ultimate state, significantly reducing the ductility. Investigations into solutions to delay the buckling of steel tubes should be encouraged. Three approaches based on concepts of composite sections, fully plastic sections of steel tubes, and the proposed decoupling were applied to compute the ultimate strengths of the tested beams. The calculation results indicated that the model of fully plastic sections of steel tubes exhibited the best agreement with the test results. The fully plastic and proposed decoupling models provided reasonable results, while the composite model slightly overestimated the ultimate load of CFST beams. The results provide some technical information for structural engineers in designing rectangular CFST beams.

Improved Visualization of Oral Microbial Consortia.

Bacteria on the tongue dorsum (TD) form consortia tens to hundreds of microns in diameter organized around a core of epithelial cells. Whole-mount preparations have been instrumental in revealing their organization and specific microbial associations. However, their thickness and intricate 3-dimensional complexity present challenges for a comprehensive spatial analysis. To overcome these challenges, we employed a complementary approach: embedding in hydrophilic plastic followed by sectioning and postsectioning labeling. Samples were labeled by hybridization with multiplexed fluorescent oligonucleotide probes and visualized by spectral imaging and linear unmixing. Application of this strategy to TD biofilms improved the visualization of bacteria that were difficult to resolve in whole-mount imaging. Actinomyces, previously detected as patches, became resolved at the single-cell level. The filamentous taxa Leptotrichia and Lachnospiraceae, located at the core of the consortium, were regularly visualized whereas previously they were rarely detected when using whole mounts. Streptococcus salivarius, heterogeneously detected in whole mounts, were regularly and homogenously observed. Two-dimensional images provide valuable information about the organization of bacterial biofilms. However, they offer only a single plane of view for objects that can extend to hundreds of microns in thickness, and information obtained from such images may not always reflect the complexity of a 3-dimensional object. We combined serial physical sectioning with optical sectioning to facilitate the 3-dimensional reconstruction of consortia, spanning over 100 µm in thickness. Our work showcases the use of hydrophilic plastic embedding and sectioning for examining the structure of TD biofilms through spectral imaging fluorescence in situ hybridization. The result was improved visualization of important members of the human oral microbiome. This technique serves as a complementary method to the previously employed whole-mount analysis, offering its own set of advantages and limitations. Addressing the spatial complexity of bacterial consortia demands a multifaceted approach for a comprehensive and effective analysis.

Study on Seismic Mechanical Properties of Reinforced Concrete Energy Dissipation Wall and Seismic Response Analysis of Structure

Utilizing the nonlinear finite element analysis software, ABAQUS, an examination is undertaken to evaluate the ductility characteristics and seismic design methodologies pertinent to a representative reinforced concrete hollow high pier. The research encompasses several focal areas: elucidation of seismic design strategies related to ductility categories, exploration of plastic energy dissipation mechanisms, determination of ductility indices, and delineation of structural measures to enhance ductility. Employing the nonlinear FEA software, ABAQUS, it is recommended that the longitudinal reinforcement ratio for ductile piers fall within the range of 0.6% to 4%. Furthermore, for flexible bridge piers, the maximum spacing of confinement reinforcements should either exceed 100 mm, be sixfold the diameter of the longitudinal reinforcement, or equate to at least one-quarter of the pier column’s bending direction section width. Combined with the influence of high pier ductility seismic axial pressure ratio, reinforcement, concrete factors such as factor analysis results, put forward and checking a reinforced concrete hollow high pier ductility seismic optimization scheme, increase the strength of the plastic hinge area section, through the comparative analysis in different seismic strength of plastic hinge unit cloth, maximum ductility coefficient and pier top displacement to verify its influence on the ductile seismic.

Flexural behavior of high-strength RCFST column-to-column connections

This paper investigates the flexural behavior of high-strength rectangular concrete-filled steel tubular (RCFST) column-to-column connections with different configurations. Based on the tests, 35 additional finite element analysis (FEA) models were developed to perform the parametric analysis varying with the cross-sectional size effect of (D), the width-to-thickness ratio of steel tube (D/t), steel tube strength (fs,y), steel bars strength (fr,y), concrete strength (fc,r), length of steel bars (L), arrangement and quantity of steel bars, respectively. The current code underestimated the yield and plastic bending moment compared with the calculated results from GB 50010–2010, ACI 318–19, EN 1992–1-1:2004, and JSCE-SSCS-2007. Finally, the strain coordination method and the full plastic section method were proposed to calculate the yield and plastic bending moment of the connection.

Behaviour of glass fiber reinforced polymer (GFRP) structural profile columns under axial compression

Abstract Glass fiber-reinforced plastic (GFRP) structural profiles in the construction industry are a promising alternative to conventional building materials due to their high strength-to-weight ratio, high tensile strength, insulation properties, chemical resistance, fatigue properties, and lower maintenance cost. This study aims to evaluate the compression behaviour of semi-compact and slender glass fiber-reinforced plastic I-sections. Short, intermediate, and long columns of both slender and semi-compact I-sections were subjected to axial compression, and the experimental capacity was compared to available theoretical results. It was found that the experimental capacity of short, semi-compact, and long columns were 27 %, 49 %, and 40 % lower than the theoretical capacity of semi-compact I-sections. Short slender sections had an ultimate experimental capacity 55 % greater than the theoretical results. However, lower ultimate capacities were achieved for intermediate and long columns in the case of slender sections when compared to the theoretical capacity. Slender sections were prone to both global and local buckling, whereas semi-compact sections failed by global buckling alone. The study also concludes the need for proper section classification of glass fiber-reinforced plastic sections to consider buckling characteristics. The existing theoretical equations to estimate the load-carrying capacity was found to be overly conservative; hence it is necessary to conduct numerical and parametric studies to develop equations that are more in agreement with the experimental results.

Evolutionary mechanism of permeability of coal-rock combination considering interface effect: Model development and analysis

The existing permeability model for the coal-rock combinations treats coal and rock as parallel entities, neglecting the interface effect arising from their distinct mechanical responses. In this study, the differential deformation of coal and rock is investigated through triaxial compression-acoustic emission (AE)-seepage synchronous tests. By deriving the additional stress caused by the differential deformation at the interface, a permeability model that accounts for this interface effect is established and validated. The influencing mechanisms of permeability are quantitatively observed using the proposed model. The results show that the permeability of the coal-rock combination increases with the increase of kc0, kr0, ξc, and Lrt, and decreases with the increase of vc and Lct. Comparing kc0 and kr0, Lct and Lrt respectively, kr0 and Lct have a greater impact on the permeability of the coal-rock combination. ξc only affects the plastic section. Finally, for the low-permeability coal seam with poor permeability improvement, permeability improvement measures can be taken on the roof and floor are proposed to enhance the gas flow. This research holds significance for gas extraction and the prevention of compound dynamic disasters.

An evaluation of slenderness limitations of H-beams for special moment connections

This paper presents the results of seismic connection testing and finite element analyses (FEA) on the slenderness limitations of steel H-beams in special moment-frame (SMF) connections. The effectiveness of FEA models was first validated by the full-scale testing of a reduced-web-section (RWS) connection, and a post-earthquake bolted-web-welded-flange (BWWF) connection. FEA simulations were then performed to study the beam section properties and seismic connection performance. The result shows that if a H-beam has a compact section, the adopted connection will develop strength and ductility meeting the AISC seismic requirements, even though the plastic section modulus ratio between the beam flanges and whole section is less than 70%. The result also suggests the effectiveness of adding a web opening to a BWWF connection. These findings call for a re-examination of the requirements of highly ductile members in SMF connections.

Steps of spermiogenesis in the ostrich (Struthio camelus).

Few studies describe the sequence of morphological events that characterize spermiogenesis in birds. In this paper, the clearly observable steps of spermiogenesis are described and illustrated for the first time in a commercially important ratite, the ostrich, based on light microscopy of toluidine blue-stained plastic sections. Findings were supplemented and supported by ultrastructural observations, PNA labeling of acrosome development, and immunocytochemical labeling of isolated spermatogenic cells. Spermiogenesis in the ostrich followed the general pattern described in non-passerine birds. Eight steps were identified based on changes in nuclear shape and contents, positioning of the centriolar complex, and acrosome development. Only two steps could be recognized with certainty during development of the round spermatid which contributed to the fewer steps recorded for the ostrich compared to that described in some other bird species. The only lectin that displayed acrosome reactivity was PNA and only for the first three steps of spermiogenesis. This suggests that organizational and/or compositional changes may occur in the acrosome during development and merits further investigation. Immunological labeling provided additional evidence to support the finding of previous studies that the tip of the nucleus in the ostrich is shaped by the forming acrosome and not by the microtubular manchette. To our knowledge, this is the first complete description of spermiogenesis in ostrich and one of few in any avian species. In addition to comparative reproduction and animal science, this work has implications for evolutionary biology as the reported germ cell features provide a bridge between reptile and ratite-avian spermatogenesis.

Müller's Muscle as a Sensory Proprioceptive Organ: Histological and Histochemical Analysis.

The purpose of this study was to determine whether proprioceptive nerves are present in Müller's muscle. This was a prospective cohort study in which histologic and immunofluorescence analyses of excised Müller's muscle specimens were performed. Twenty fresh Müller's muscle's specimens from patients undergoing posterior approach ptosis surgery in one center between 2017 and 2018 were evaluated by histologic and immunofluorescent analysis. Axonal types were determined by measuring axon diameter in methylene blue stained plastic sections and by immunofluorescence of frozen sections. We identified large (greater than 10 microns) and small myelinated fibers in the Müller's muscle, with 6.4% of these fibers being large. Immunofluorescent labeling with choline acetyltransferase showed no evidence of skeletal motor axons in the samples, indicating large axons are likely to be sensory and proprioceptive. In addition, we identified C-fibers using double labeling with peripherin and neural cell adhesion molecules. Overall, large myelinated sensory fibers are present in the Müller's muscle, likely serving proprioceptive innervation. This suggests that proprioception signals from Müller's muscle may have a role in eyelid spatial positioning and retracting, in addition to visual deprivation. This finding sheds new light on our understanding of this complex mechanism.

Cytotoxic and genotoxic effects of leaking chemicals from serum infusion sets: an in-vitro study.

Safety concerns about medical devices playing important role in health sciences and bioengineering research are rising day by day. Although there are specific standards regarding disposable medical materials, the information is updating with the toxicological studies. In this study, cytotoxic/genotoxic effects of chemicals leaking from serum infusion sets that have an important place in the clinic were investigated. Media containing leakage chemicals were prepared from equal samples taken from the plastic line sections of 13 different brands of serum infusion sets containing phthalates and the effects on the cultured cells were compared with the untreated control groups. To obtain leaking chemicals, extracting period was selected as 72h, a routine set-change time in the clinic as indicated in various publications. Neutral red uptake and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests were performed in L929 cells to determine cytotoxicity, and cytokinesis blocked micronucleus technique was performed in lymphocytes to determine genotoxicity. Cytotoxic and genotoxic damage levels were compared by evaluating cell-viability rates relative to control, micronucleus frequency, and nuclear division index values. The results showed that all sets caused a decrease in cell viability revealing the effects both on lysosomal and mitochondrial activity and increase in micronucleus frequencies in general. The number of similar studies is extremely limited, and in this study in addition to the short-term effects of using the serum infusion sets, the information about the sample tests to determine the biosecurity of disposable medical materials is given.

Fatigue analysis of metallic-plastic-metallic pipeline systems: A numerical study

Metallic (e.g., copper, steel and iron) and plastic (e.g., Polyethylene and Polyvinyl chloride) pipelines are often used in combination in water distribution networks (WDSs). The interface between a metallic pipe section and a plastic pipe section is typically associated with a significant change in hydraulic impedance (i.e., impedance mismatch). This impedance mismatch can result in significant pressure wave reflections during transient events, and multiple interfaces may induce repeated pressure waves bouncing in between. Limited studies have been conducted on the impact of these multiple wave reflections due to impedance mismatch, especially with respect to the risk of accelerated fatigue damage to the plastic pipe. The research presented in this paper investigates the pressure response of a metallic-plastic-metallic (M-P-M) pipeline system under repeated hydraulic transient events using analytical and numerical methods. The presence of additional cyclic hoop-stress loadings in the M-P-M configuration, both in frequency due to reflections and in loading magnitude due to superposition, has been demonstrated in comparison to a fully plastic pipe system under the same hydraulic transient event. The study investigates the impact of these additional loadings on the relative fatigue lifetime of the plastic section by adopting a fatigue analysis model based on the stress-life method. The results show that the plastic section in the M-P-M configuration can have a significant reduction in fatigue lifetime compared to the corresponding fully plastic configuration.

Organization of the body wall in lampreys informs the evolution of the vertebrate paired appendages.

Vertebrate paired appendages are one of the most important evolutionary novelties in vertebrates. During embryogenesis, the skeletal elements of paired appendages differentiate from the somatic mesoderm, which is a layer of lateral plate mesoderm. However, the presence of the somatic mesoderm in the common ancestor of vertebrates has been controversial. To address this problem, it is necessary but insufficient to understand the developmental process of lateral plate mesoderm formation in lamprey (jawless vertebrates) embryos. Here, I show the presence of the somatic mesoderm in lamprey (Lethenteron camtschaticum) embryos using plastic sectioning and transmission electron microscopy analysis. During the early pharyngeal stages, the somatic mesoderm transforms from the lateral plate mesoderm in the trunk region. Soon after, when the cardiac structures were morphologically distinct, the somatic mesoderm was recognized through the cardiac to more caudal regions. These findings indicated that the somatic mesoderm evolved before the emergence of paired appendages. I also discuss the developmental changes in the body wall organization in the common ancestor of vertebrates, which is likely related to the evolution of the paired appendages.

Aromatics production from segmented co-pyrolysis of poplar sawdust and high-density polyethylene: Enhancing the synergistic effects

Catalytic co-pyrolysis of biomass and plastic waste is a promising approach for producing renewable biofuels and value-added chemicals. However, because of their different pyrolysis behaviors, the synergy between biomass and plastic is limited, and low-yield aromatics are produced. Herein, a modified segmented catalytic co-pyrolysis technology was proposed, and the effects of pyrolysis parameters were studied in detail to enhance the synergistic effect between feedstocks. For the biomass section (segment 1), catalytic fast pyrolysis (CFP) of poplar sawdust was conducted, and results showed that employing 15 wt% MgCl2 at 500 °C facilitated the production of furans. For the plastic section (segment 2), CFP of high-density polyethylene (HDPE) were performed. It was showed that instead of Y and beta zeolites, the utilization of ZSM-5 as a pyrolysis catalyst with a loading of ZSM-5/HDPE = 1.0, and a temperature of 600 °C was beneficial for the production of short-chain olefins. For the segmented co-pyrolysis of poplar sawdust and HDPE (segment 1 + segment 2), the biomass-to-plastic ratio was crucial in aromatics production. A ratio of 1:1 was found to be most effective in producing MAHs (54.8 area%), which was ∼3.9 or 1.6 times that for the separate CFP of biomass or HDPE. This was also consistent with its higher enhancement factor, confirming that the synergy between poplar sawdust and HDPE was dramatically enhanced. Finally, a segmented catalytic co-pyrolysis reaction pathway was proposed.

Plastic Section Moduli for I.S. Rolled Steel Beam Sections Zpy about Y-Y Axis

Abstract: There are many situations in which the I-Sections used in construction are subjected to moments about their weaker axis, i.e. the y-y axis. For such purposes the Plastic Section Modulus about y-y axis becomes necessary. In the present paper an attempt has been made to calculate and present the values of Zpy, for I.S. Rolled Steel Beam Sections (with tapered flanges). Since IS 800 : 2007[2] has not given the values of Zpy, of any section, one tapered flange I-Section, viz., 125 TFB @ 13.1 kg/m, from “Onesteel” (Australia),[4] has been used to ascertain the correctness of calculations. The results are presented in table form in descending order.

Calculation and Verification of ZPZ Values in IS 800:2007

Abstract: Plastic Section Modulus of a section is the first moment of the cross sectional area about an axis which divides the sectional area into two equal halves. In this paper an attempt has been made to calculate and verify the Zpz values of tapered flange I and C Sections. I-Section has been divided into a total of 13 component areas and C-Section into 7 component areas. The area of each component is calculated and the position of centroid of each component area is identified and used in the calculation of the Plastic Section Modulus of the cross section about Z-Z axis. Eleven I-sections and One C-section Zpz values are found to differ from the values given in the IS 800 : 2007[2] by more than 100 mm3 , i.e., 0.1 cm3 and are reported here. These verifications gain significance due to the fact that, in case of four I-sections, the difference is found to be more than 10000 mm3 , i.e., 10cm3

Strength and Deflection Reliability Estimation of Girder Steel Portal Frames Using the Bayesian Updating Method

Uncertainty is ubiquitous in any engineering system at any stage of product development and throughout a product's life cycle. As information and sensor technology develops, more and more data about engineering systems are gathered. A strong technique for calibrating models using new information and observations is Bayesian updating. The applied loads, yield strength, plastic section modulus, span, cross-section dimensions, and modulus of elasticity from the international literature have been updated through the local literature and a data survey for the interior girder portal frames to investigate the reliability index and the probability of failure of the system. First Order Reliability Method (FORM) and Monte Carlo (MC) simulations have been used to estimate the reliability and probability of failure of strength and serviceability limit state function. The results reveal that for shear force, the reliability index increased significantly from 9.03 to 16.01. At the same time, the reliability index of the bending moment and deflection increased from 4.34 to 5.30 and from 6.90 to 7.66 respectively.

An Experimental Study on Mechanical Properties and Fracture Characteristics of Saturated Concrete under Coupling Effect of Low Temperature and Dynamic Load

Concrete is widely used in bridge foundation, water supply, and drainage engineering. On the one hand, the saturated concrete is always in the saturated state. In the cold winter, northeast China and the alpine region suffer from freezing disaster. On the other hand, it has to continue to bear the dynamic load action of vehicles and running water, which makes the stress state of saturated concrete more complicated under the coupling action of low temperature and dynamic load. In order to study the mechanical properties and fracture characteristics of saturated concrete under the coupling effect of low temperature and dynamic load, the impact compression tests of concrete under normal temperature 20°C, -5°C, -10°C, and -15°C were carried out with a diameter of 74 mm split Hopkinson pressure bar (SHPB). The stress-strain characteristics, energy dissipation, and failure modes of specimens under different low temperatures were studied. From a detailed point of view, the failure mechanism of low-temperature water-saturated concrete is expounded. The results show that under the same dynamic load, the dynamic stress-strain curve of saturated concrete changes obviously with the change of low temperature. The dynamic compressive strength of the natural specimen at room temperature is high while that of the water-saturated specimen is low, and the dynamic compressive strength is opposite at low temperature. At the same temperature, the energy time-history curves of concrete in the saturated state are different from those in the natural state, mainly in the plastic section. The energy time-history curves of saturated concrete are different at different temperatures, and the energy dissipation rate of saturated concrete increases linearly with the decrease of temperature. Under the experimental conditions, the dynamic strength of saturated concrete increases linearly with the decrease of temperature, and the peak strain of saturated concrete decreases linearly with the increase of temperature. With the decrease of temperature, the fragmentation of saturated concrete under the impact of the same air pressure gradually increases, and the integrity of the specimen gradually improves. Low temperature can improve the impact resistance of saturated concrete, which is consistent with the failure law of natural state concrete. The water-saturated low-temperature state of the concrete void is filled with ice crystal particles; for low-temperature water-saturated concrete in the impact of the dynamic load, the microstructure is affected by the ice crystal structure which is not easy to change; the specimen along the axial force direction microdefect development produces a crack, the crack along the parallel to the pressure direction of cracking, through the two ends of the specimen, and finally produces axial splitting tensile damage. The research results have important theoretical significance for the safety design of low temperature saturated concrete structures.

Engineering Characterisation of Wearing Course Materials Modified with Waste Plastic

This review paper shows several sections of bitumen, asphalt mixtures, polymers, and waste plastic in pavement engineering. The paper reviews and evaluates the influence of using waste polymer in improving the rheological and engineering properties of the modified binder and mixtures. Evaluation of properties and design of stone mastic asphalt mixtures are reviewed. Reports and studies had investigated the advantages and importance of using polymer in bitumen modification; however, they yet show a gap in research in terms of the role of waste polymer in improving the durability, aging, and fatigue life in the long term of service.

Flexural strength of innovative thin-walled composite cold-formed steel/PE-ECC beams

A detailed experimental investigation on the flexural behaviour of an innovative precast composite element combining cold-formed steel (CFS) and engineered cementitious composites (ECC) is presented in this paper. Bonding ECC to the lightweight thin-walled CFS sections enhanced the buckling, bearing, and torsional properties of the composite sections. The proposed composite system will be used as precast flexural members in framed structures with large spans or as a rehabilitation approach for corroded cold-formed and hot-rolled steel flexural members. Simply supported beams with comparatively long spans with span-to-depth ratios of 6.83 and 13.48 were installed back-to-back and tested under a 4-point loading configuration. The behaviour of composite CFS/ECC beams under bending was investigated and compared with the bare CFS sections. Composite CFS/MOR beams incorporating high-strength mortar (MOR) as an ECC replacement were also investigated. The test specimens were divided into three series with sixteen tests in total. Series A (SC300) included six tests utilising 300-mm height SupaCee sections, Series B (C300) included four tests using 300-mm height lipped-Cee sections, and Series C (SC150) included six tests utilising 150-mm height SupaCee sections. The composite CFS/ECC beams exhibited high load-bearing capacities after reaching their plastic section capacities, while the bare CFS beams failed to reach their yield section capacities due to distortional buckling. Composite CFS/MOR beams could not reach their plastic moment capacities due to debonding between MOR and CFS after MOR crushing. The moment capacities of the composite CFS/ECC beams increased up to 140.0% over their duplicate bare CFS sections, while composite CFS/MOR beams showed only a 72.0% increase over CFS sections. Lastly, design equations to predict the moment capacity of composite CFS/ECC beams are presented, based on the experimental results.