Tensile Strength Measurements Research Articles

In Vitro Investigation of Vocal Fold Cellular Response to Variations in Hydrogel Porosity and Elasticity.

Tissue regeneration is intricately influenced by the dynamic interplay between the physical attributes of tissue engineering scaffolds and the resulting biological responses. A tunable microporous hydrogel system was engineered using gelatin methacryloyl (GelMA) and polyethylene glycol diacrylate (PEGDA), with polyethylene glycol (PEG) serving as a porogen. Through systematic variation of PEGDA molecular weights, hydrogels with varying mechanical and architectural properties were obtained. The objective of the present study was to elucidate the impact of substrate mechanics and architecture on the immunological and reparative activities of vocal fold tissues. Mechanical characterization of the hydrogels was performed using tensile strength measurements and rheometry. Their morphological properties were investigated using scanning electron microscopy (SEM) and confocal microscopy. A series of biological assays were conducted. Cellular morphology, differentiation, and collagen synthesis of human vocal fold fibroblasts (hVFFs) were evaluated using immunostaining. Fibroblast proliferation was studied using the WST-1 assay, and cell migration was investigated via the Boyden chamber assay. Macrophage polarization and secretions were also examined using immunostaining and ELISA. The results revealed that increasing the molecular weight of PEGDA from 700 Da to 10,000 Da resulted in decreased hydrogel stiffness, from 62.6 to 8.8 kPa, and increased pore dimensions from approximately 64.9 to 137.4 μm. Biological evaluations revealed that hydrogels with a higher stiffness promoted fibroblast proliferation and spreading, albeit with an increased propensity for fibrosis, as indicated by a surge in myofibroblast differentiation and collagen synthesis. In contrast, hydrogels with greater molecular weights had a softer matrix with expanded pores, enhancing cellular migration and promoting an M2 macrophage phenotype conducive to tissue healing. The findings show that the hydrogels formulated with a PEGDA molecular weight of 6000 Da are best among the hydrogels considered for vocal fold repair. The microporous hydrogels could be tuned to serve in other tissue engineering applications.

Measurement of true tensile strength from Brazilian tensile strength laboratory tests

Brazilian tensile strength (BTS) testing in standard practice is a practical method to approximate tensile strength for rock core using the conversion of axial compressive vertical and diametral loading to horizontal tensile stress in the centre of the core disk. The method, however, routinely inflates tensile strength, using peak tensile stress calculated from the BTS, versus true tensile stress (TTS) from direct tensile strength (DTS) tests. This study presents a novel technique to measure TTS directly from the BTS test via the onset of nonlinearity in horizontal strain response. TTS is equivalent to the peak strength of a DTS test. While not yet standardized, the modification to achieve TTS measurements is to instrument the BTS specimen with a horizontal strain gauge on each flat side. Over 100 BTS specimens of varying lithologies were instrumented, tested, and analyzed to measure their TTS and compare to peak BTS. Results demonstrate the average measured TTS is 0.81BTS, 0.75BTS, 0.85BTS for granitoid, carbonate, and metamorphic rocks, respectively. This concurs with previous studies, validating the proposed novel TTS measurement method. We recommend measurement of TTS be adopted into standard practice for BTS laboratory testing to improve accuracy of tensile strength data in rock engineering design.

Sintesis dan Karakterisasi Polivinil Alkohol (PVA) Terlapis Polieugenol

A study has been conducted on materials containing polyvinyl alcohol (PVA) coated with poly eugenol. This research aims to explore the synthesis process and properties of PVA coated with poly eugenol. Characterization of PVA includes tensile strength measurement and surface observation using SEM. Additionally, the antioxidant activity of PVA was also tested using the DPPH method. In this study, PVA films were obtained by dissolving PVA in a water solvent. The characterization results indicate that the tensile strength ranges from 25.56 to 271.10 Mpa, elongation reaches 315.20 to 320%, and the young modulus ranges from 4.05 to 6.27 Mpa. Surface observation with SEM shows a smooth surface without pores. The antioxidant activity test shows IC50 values ranging from 84.11 to 175.37 ppm.

Measurement of tensile and shear strength of interfacial bonding in fiber reinforced soft composites combining experiments and simulation

Interfacial bonding strength plays a key role in the mechanical performance of fiber reinforced polymers. However, measurement of interfacial bonding strength in fiber reinforced soft composites (FRSCs) becomes a challenging issue, because the large deformation capability of soft matrix invalidates most of current testing methods. This paper demonstrates an advanced method combining experiments and simulation, which provides a convenient and reliable means to measure both tensile strength and shear strength of interfacial bonding for FRSCs. The specimen is made by embedding a fiber bundle in a soft plate for transverse tensile test. Various stress states along the fiber–matrix interface can be realized by controlling the inclination angle of fiber bundle to the stretching direction. Tensile strength and shear strength of interfacial bonding in FRSCs can be estimated based on the analysis of critical stress states. The comparison with the widely adopted fiber pull-out test indicates that the nominal shear strength obtained in pull-out test is severely underestimated.

Green synthesis of CdS/flaxseed mucilage nanocomposite films using gamma irradiation for packaging applications

Abstract The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that all of the films exhibited more antibacterial activity against S. aureus than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.

PH-regulated Tannic acid and soybean protein isolate adhesive for enhanced performance in plant-based meat analogues

A food adhesive comprising tannic acid (TA) and soybean protein isolate (SPI) was developed to establish a cohesive bond between soy protein gel and simulated fat. The impact of varying TA concentrations and pH levels on the adhesive’s rheology, thermal stability, chemical structure, and tensile strength were investigated. Rheological results revealed a gradual decrease in adhesive viscosity with increasing TA content. Differential scanning calorimetry (DSC) and thermal gravimetric (TG) results indicated that the stability of the adhesive improved with higher TA concentrations, reaching its peak at 0.50% TA addition. The incorporation of TA resulted in the cross-linking of amino group in unfolded SPI molecules, forming a mesh structure. However, under alkaline conditions (pH 9), adhesive viscosity and stability increased compared to the original pH. This shift was due to the disruption of the SPI colloidal charge structure, an increase in the stretching of functional groups, further unfolding of the structure, and an enhanced binding of SPI to TA. Under the initial pH conditions, SPI reacted with TA's active site to form covalent crosslinked networks and hydrogen bonds. In alkaline condition, beyond hydrogen and ionic bonding, the catechol structure was oxidized, forming an ortho-quinone that crosslinked SPI and created a denser structure. Tensile strength measurements and freeze–thaw experiments revealed that the adhesive exhibited maximum tensile strength and optimal adhesion with 0.75% TA at pH 9, providing the best overall performance. This study provides a new formulation and approach for developing plant-based meat analogues adhesives.

Three-Dimensional Graphene Sheet-Carbon Veil Thermoelectric Composite with Microinterfaces for Energy Applications.

Over the years, various processing techniques have been explored to synthesize three-dimensional graphene (3DG) composites with tunable properties for advanced applications. In this work, we have demonstrated a new procedure to join a 3D graphene sheet (3DGS) synthesized by chemical vapor deposition (CVD) with a commercially available carbon veil (CV) via cold rolling to create 3DGS-CV composites. Characterization techniques such as scanning electron microscopy (SEM), Raman mapping, X-ray diffraction (XRD), electrical resistance, tensile strength, and Seebeck coefficient measurements were performed to understand various properties of the 3DGS-CV composite. Extrusion of 3DGS into the pores of CV with multiple microinterfaces between 3DGS and the graphitic fibers of CV was observed, which was facilitated by cold rolling. The extruded 3D graphene revealed pristine-like behavior with no change in the shape of the Raman 2D peak and Seebeck coefficient. Thermoelectric (TE) power generation and photothermoelectric responses have been demonstrated with in-plane TE devices of various designs made of p-type 3DGS and n-type CV couples yielding a Seebeck coefficient of 32.5 μV K-1. Unlike various TE materials, 3DGS, CV, and the 3DGS-CV composite were very stable at high relative humidity. The 3DGS-CV composite revealed a thin, flexible profile, good moisture and thermal stability, and scalability for fabrication. These qualities allowed it to be successfully tested for temperature monitoring of a Li-ion battery during charging cycles and for large-area temperature mapping.

PREPARATION, CHARACTERIZATION AND EVALUATION OF GELLAN GUM/GLYCOL CHITOSAN BASED BAICALEIN HYDROGEL FOR WOUND HEALING

Objective: The present work was emphasized on preparation, characterization and evaluation of baicalein loaded hydrogel to promote healing of wounds. Methods: Baicalein loaded hydrogel was developed using Gellan gum and Glycol chitosan polymers. Prepared hydrogels were characterized for various parameters like Field Emission Scanning Electron Microscopy (FE-SEM), swelling property, entrapment efficiency, rheology and drug release. Wound healing study was investigated by using incision dead space wound models. Healing effect was assessed by measurement of tensile strength, collagen content, hydroxyproline content, protein content and antioxidant status. Results: The percent entrapment efficiency of optimized hydrogel found to be 89.78±2.07 which resulted in controlled release of drug 85.03% in 12 h. The significant increased level of catalase and superoxide dismutase (SOD) was noticed in dead space wound model. The tensile strength study shows increase in collagen synthesis due to treatment with Baicalein loaded hydrogel. The higher collagen content, better granulation, increase in tensile strength was noticed. Histopathological examination also confirmed higher degree of re-epithelialization and enhanced cutaneous wound repair. Conclusion: In conclusion, biodegradable Baicalein loaded hydrogel might have high potential for wound healing with improved oxidative status and extended release of Baicalein.

QUALITY BY DESIGN SUPPORTED CONSTRUCTION OF ORAL FAST-DISSOLVING FILMS FOR TELMISARTAN: RECONNOITERING THE QUALITY ATTRIBUTES

Objective: The angiotensin II receptor antagonist telmisartan (TMS) is often used to treat hypertension. The BCS class II antihypertensive drug TMS has a low solubility, poorly absorbed when taken orally. The goal of this study was to formulate an oral fast-dissolving film (OFDF) of TMS. In recent years, the concept of a rapidly dissolving dosage form as an innovative delivery system has gained popularity. By decreasing dosing frequency, maximize therapeutic effectiveness, bioavailability, and stability. It will also prevent the drugs from being metabolized in the first place. This technique allows for faster drug absorption from the gastrointestinal tract (GIT), which might result in a more rapid onset of action. Methods: An experimental design known as Box-Behnken was employed to optimize a OFDF. Mango kernel (100-300 mg), maltodextrin (200-350 mg), and propylene glycol (PG) (15-30%) were chosen as independent variables with the highest preference. Included measurements of T5 tensile strength, disintegration time, folding endurance, elongation, and drug release efficiency as dependent variables. Results: The physical properties of the films were found to be satisfactory, and Fourier transform infrared (FTIR) analysis failed to detect any drug-polymer interaction. F4 was found to have the greatest bioadhesive strength of 49.82 gm and the longest ex-vivo mucoadhesion duration of 189 min. A higher concentration of mango kernel in the formulation resulted in a greater rate of drug release. More than 60% of the drug was discharged within 10 min. Conclusion: The oral mucosa of a rat was used for ex-vivo for irritation studies. Based on the pharmacokinetic plasma parameters, which is made into quick-dissolving films that are taken by mouth, is much better absorbed than aqueous suspensions. Studies of the enhanced formulation's stability showed that F4 may be stored for up to three months without deterioration.

Development of PU foam dressings loaded with extract of Plectranthus amboinicus for burn wound healing

Objective To develop Plectranthus amboinicus extract loaded Polyurethane foam dressing for burn wound healing. Significance Plectranthus amboinicus is traditionally used as an anti-inflammatory and wound-healing agent. Its incorporation in a PU foam dressing will offer the dual benefits of foam dressing as well as the healing potential of P. amboinicus. Methods PU foam dressings were prepared and loaded with P. ambionicus leaf extract (PAE). The dressings were prepared with varying concentrations (0.5–2%) of extract along with Toluene diisocyanate, polypropylene glycol (PPG), and liquid paraffin. The dressings were characterized by Scanning Electron Microscopy and evaluated for Moisture Vapor Transmission Rate, absorption rate, porosity, and mechanical strength followed by in vivo burn wound-healing studies in comparison to a marketed dressing. Results The MVTR was found to be optimum in formulations FD2-FD4 with values ranging from 2068.06 ± 0.99 to 2095.00 ± 0.25 g/m2/day. Absorption rate was found to be between 1.27 ± 0.01, 1.31 ± 0.00, and 1.30 ± 0.02 g/cm2 for formulations FD2-FD4. Formulations FD1, FD2, FD3, FD4 showed better porosity when compared to other formulations. Formulation FD4 was further characterized by micro-CT and a porosity of 46.32% was obtained. Tensile strength measurement indicated that the selected formulations were flexible enough to withstand regular handling during dressing changes. Acute dermal irritation performed on rabbits showed no irritation, erythema, eschar, and edema. In vivo wound-healing studies performed on albino wistar rats showed that the FD4 formulation has better wound healing property. Conclusion Plectranthus ambionicus-loaded PU foam dressing demonstrated promising burn wound-healing potential

Synergistic Effects of SDS and H2O2 Combinations on Tracheal Scaffold Development: An In Vitro Study Using Goat Trachea.

Currently, a tissue-engineered trachea has been popularly used as a biological graft for tracheal replacement in severe respiratory diseases. In the development of tissue-engineered tracheal scaffolds, in vitro studies play a crucial role in allowing researchers to evaluate the efficacy and safety of scaffold designs and fabrication techniques before progressing to in vivo or clinical trials. This research involved the decellularization of goat trachea using SDS, H2O2, and their combinations. Various quantitative and qualitative assessments were performed, including histological analysis, immunohistochemistry, and biomechanical testing. Hematoxylin and eosin staining evaluated the cellular content, while safranin O-fast green and Masson's trichrome staining assessed glycosaminoglycan content and collagen distribution, respectively. The immunohistochemical analysis focused on detecting MHC-1 antigen presence. Tensile strength measurements were conducted to evaluate the biomechanical properties of the decellularized scaffolds. The results demonstrated that the combination of SDS and H2O2 for goat tracheal decellularization yielded scaffolds with minimal cellular remnants, low toxicity, preserved ECM, and high tensile strength and elasticity. This method holds promise for developing functional tracheal scaffolds to address severe respiratory diseases effectively.

Agricultural resources in focus: Eco-friendly bioplastic synthesis from corn starch

The current research focuses on the development of bioplastics from agricultural resources like banana peels, potato peels and corn starch. The specific focus here is the utilization of agricultural resources into bioplastics as an eco-friendly alternative to conventional plastics. The main objective of this research is to explore the manufacturing of biodegradable plastics by utilizing these materials. The formation of bioplastics from banana and potato peels is not as successful, while notably consistent formation for bioplastics derived from corn starch. The additional research has been conducted on corn starch based bioplastic films. The impact of various glycerol amounts (0.2 g to 0.8 g) was studied concerning the measurement of tensile strength (1.52 MPa to 5.08 MPa) in corn starch-derived bioplastics. The physico-chemical properties, availability of FT-IR functional groups (C-O-H, O-H, C-H, C = O, CONH, C-O, and C-O-C) and SEM analysis are confirming bioplastic films surface derived from corn starch and compared to existing literature. Furthermore, the research includes solubility and biodegradability tests were determined the most suitable and preferred agricultural resources for biodegradable plastic production.

The Impact of Chitosan Incorporation on the Mechanical Characteristics of Biodegradable Packaging based on PLA/PCL Blend

The development of environmentally sustainable plastics has gained prominence due to their eco-friendliness and renewable nature. In this research, eco-friendly plastic was formulated by blending Polylactic Acid (PLA) and Polycaprolactone (PCL) with the incorporation of chitosan as a filler. The primary objective of this study is to scrutinize and delineate the influence of varying compositions of PLA/PCL/chitosan on the mechanical attributes of eco-friendly plastics. This was achieved through hot pressing methods at a temperature of 200°C for a duration of 1 hour. The composition ratios for PLA/PCL were set at 2/8 g, 3/7 g, 5/5 g, 7/3 g, and 8/2 g, while chitosan compositions ranged from 0.2 g to 0.6 g. Comprehensive assessment of the eco-friendly plastics involved biodegradability tests, tensile strength measurements, elongation evaluations, functional group analyses, and examination of plastic film morphology. Optimal performance, ascertained through characterization, was achieved with a composition of PLA/PCL/Chitosan at 8/2/0.6 g, yielding a 38.8% degradation rate, a tensile strength of 42.53 MPa with a composition of PLA/PCL/Chitosan at 8/2/0.4 g, and an elongation of 6.96% with a composition of PLA/PCL/Chitosan at 8/2/0.2 g. The functional groups identified included N-H, C-H, C=O, and C-O groups, indicating a blending process without the formation of new functional groups. Morphology testing revealed a smooth surface, although some undissolved chitosan particles were evident, likely due to non-uniform blending.

Composite papers based on natural polymers

In this study, cellulose was extracted from Heliánthus tuberósus (Jerusalem artichoke) stems, and its quality indicators were thoroughly investigated. The isolation process involved the removal of impurities and non-cellulosic components, resulting in a purified cellulose sample suitable for further analysis and application.To explore the potential of Heliánthus tuberósus cellulose, composite paper was produced by incorporating basalt fiber into the cellulose matrix. The resulting paper was subjected to comprehensive testing to evaluate its mechanical properties, with a particular focus on tensile strength and tensile length.The tensile strength of the composite paper was determined using standardized testing methods, providing quantitative data on the material's ability to withstand applied forces without breaking or deforming. Tensile length, on the other hand, refers to the maximum elongation the paper can undergo before rupture occurs. These properties were assessed to gauge the overall performance and suitability of the composite paper for various applications.The obtained results were presented in a clear and concise manner, utilizing tables and graphs to facilitate data interpretation and comparison. Tables allowed for the tabulation of the measured tensile strength and tensile length values, providing a comprehensive overview of the material's mechanical characteristics. Graphs were employed to visualize trends, patterns, and potential correlations between different variables, aiding in a deeper understanding of the composite paper's behavior under various loading conditions.

Mechanical Properties and High Temperature Performance of Sustainable Reactive Powder Concrete Containing Waste Glass

At present, it is a challenge to produce a high performance reactive powder concrete (RPC) from local available materials due to the least costly components of a conventional concrete are eliminated by more expensive elements such as the silica fume and steel fibers. In the other hand, million tons of glass is being dumped every year all over the world. More than 75% of glass composition is basically silica and reported to having a pozzolanic reaction. Thus, glass is potentially suitable material as replacement materials for the RPC mixture. In our work, waste glass powder (WGP) was used to completely replace silica fume. Compressive strength, splitting tensile strength, flexural strength and elastic modulus measurements were reported along with the density and colour of the RPC produced. The highlight of this study is on the assessment of the RPC at high temperature tested by direct burning at 600˚C. This had addressed to a very limited reported finding on the high temperature performance of RPC utilizing waste materials. It was found that, RPC containing waste glass powder changes the colour of RPC from darkish grey to light grey. Adding waste glass powder had reduced the density of RPC by (0.05) gm/cm3. Using waste glass powder instead of silica fume had also improves the mechanical properties of RPC. However, there is no effect of adding waste glass powder in solving the spalling problem of RPC at high temperature up to 600˚C. This paper reports finding on the mechanical properties and high temperature performance of sustainable RPC that utilize waste glass powder in total replacement for the silica fume. This is carried out as an effort to address the high cost of the material used in the ordinary RPC and to enhance the recycling of local waste glass.

Synthesis and Characterization of Bioplastic from Macroalgae Padina australis

Synthetic plastics are one of the more significant contributors to waste in the environment. Bioplastic is a type of plastic that is environmentally friendly because it is made from biomass. In this study. brown macroalgae. Padina australis. is one of the potential raw materials found in large quantities in Indonesian waters and used to produce bioplastics with filtration technique. The aim of this study was to synthesis bioplastics using P. australis alginate with glycerol plasticizer.The alginate macroalgae were mixed with glycerol as a plasticizer in the following proportions: 1:15. 1:25. 2:15. and 2:25. with the quality determined through tensile strength measurements. water solubility. and degradation time. On day 12. the tensile strength of P. australis bioplastic was 3.24-7.33 MPa. the water solubility was 61.79-65.19%. and the biodegradability rate was 0.1-20.0%. When the macroalgae alginate and glycerol formulation was 2:25. the best bioplastic film produced had a tensile strength of 7.33 MPa and a water solubility of 61.79%. which was lower than the Indonesia National Standard number 7818/2016 for bioplastic products. P. australis. however. has the potential to be a promising alternative bioplastic product that contributes to the reduction of petroleum-based plastic pollution in the environment. Furthermore. as a preliminary study. it will be improved to meet industrial standards or find the products that match these characteristics.

Theoretical Investigation on Indirect Tensile Strength of Concrete with Rectangular Cross-Section under Locally Distributed Load.

The indirect tensile test plays a crucial role in experimental investigations of brittle material properties. In this study, a mechanical analysis model of the rectangular test block is established based on the theory of elastic mechanics for the characteristics of the indirect tensile test. The theoretical solution of the triangular series is derived for the rectangular test block under the locally distributed load. The finite element simulation results and splitting test results were compared with the theoretical results. The results of the study verify the accuracy of the theoretical solutions. Based on the proposed analytical solution, the effects of loading width and length-to-height ratio (h/l) of local loading on the measured tensile strength of test block are discussed. The results demonstrate that the tensile strength of the test block increases as the loading width expands, and the rate of growth in the recorded tensile strength gradually stabilizes. The variation in loading width affects the location of crack initiation points during the concrete test block splitting tests. When the loading width exceeds 6% of the side length of test block, the cracking point is positioned at the center of test block, ensuring the effectiveness of the splitting test. As the length-to-height ratio of the test block increases, there is a general upward trend in the measured tensile strength. When h/l < 0.6, the measured tensile strength initially increases before decreasing. However, when h/l > 0.6, the measured tensile strength consistently increases, with the rate of increase gradually diminishing until it stabilizes. The length-to-height ratio also significantly influences the location of the cracking point in the test block. As the length-to-height ratio increases, the cracking point initially shifts from around the center to the central point and then further from the center toward the edge. To ensure that the location of the crack initiation point is in the center of the specimen and that the tensile strength is close to the measured result, the length to height ratio can be chosen at around 0.85.

Specimen size effect on compressive and splitting tensile strengths of sustainable geopolymeric recycled aggregate concrete: Experimental and theoretical analysis

The use of industrial solid wastes (e.g., slag, fly ash) and recycled concrete aggregate (RA) to manufacture geopolymeric recycled aggregate concrete (GRAC) has been proved as a sustainable and environment-friendly approach for the concrete industry, and has received an extensive prospect. Understanding the specimen size effect of GRAC is fundamental and essential in the entire design and analysis of concrete components and structures. This paper presents an experimental study on the specimen size effect on compressive and splitting tensile strengths of GRAC, with the influence of RA replacement ratio and water-to-binder (w/b) ratio emphasized. A total of 168 GRAC cubes with four different specimen sizes (70.7, 100, 150 and 200 mm) are tested. The results show that the compressive and splitting tensile strengths of GRAC decrease with increasing RA contents due to the increased amount of defects, with the decreasing amplitudes of about 4%–30.4% for compressive strength and 2.96%–34.91% for splitting tensile strength, respectively, except that their size effect becomes more apparent. While the strengths and specimen size effect degrees of GRAC all decrease with the increase of w/b ratio. Based on Weibull's, Bazant's and Capinteri's size effect laws (SELs), analytical models for SELs of compressive and splitting tensile strengths of GRAC are respectively established. The comparison results indicate that the Bazant's SEL is more suitable for the cubic compressive strength of GRAC, while the splitting tensile strength using Weibull's statistical SEL achieves the most accurate prediction results. Moreover, conversion factors are suggested for the transformation of the compressive and splitting tensile strength measurements of GRAC. Finally, a life cycle assessment method is conducted to evaluate the carbon emission potential of GRAC, which is proven to be a green and low-carbon construction material with an over 60% carbon reduction compared to cement-based plain concrete.

Measurements of Tensile Strength and Elongation of 3D Printed Polylactide Solids Produced with Different Temperatures of Extruder Using Coordinate Measuring Technique and Finite Element Method

Measurements of Tensile Strength and Elongation of 3D Printed Polylactide Solids Produced with Different Temperatures of Extruder Using Coordinate Measuring Technique and Finite Element Method

Remediation of groundwater pollution using photocatalytic membrane reactors

Recalcitrant pollutants in groundwater and industrial wastewater streams are very dangerous for the environment and human health. The conventional water treatment processes are not capable to degrade/removing them due to their very high chemical stability. The photocatalytic membrane reactors represent a possible route for overcoming the limits present in the conventional ones. In this study, photocatalyst loaded mixed matrix membranes (PMMM) were prepared using non solvent induced phase inversion process and titanium dioxide as a photocatalyst. SEM and EDX analyses, contact angle, and tensile strength measurements were used for characterizing the membranes. Their catalytic activity was assessed using the methyl orange as a recalcitrant pollutant. The photoactivity of the PMM membranes increased with the TiO2 content. The membrane loaded with the 2.5 wt % of titanium dioxide achieved better degradation and retained high degradation efficiency after 4 cycles, indicating the stability of the membrane.