Waste Fibers Research Articles

Polymer quantum dots doped in metal organic framework for sono-catalytic degradation of sulfamethazine

Sulfamethazine as one of sulfa drugs could be discharged in the surface, drinking and ground water, to be accumulated in the organs, migrating later to foodstuff and eventually raises the possibility of developing a variety of infectious diseases in human beings and animals. On the other hand, polymer quantum dots (PQDs) as a type of carbon-based nanostructures are exhibited with excellent photoluminescent properties, abundancy, easy of surface decoration and biocompatibility with low toxic effects. Herein, simple and environmentally benign technique was reported to reuse acrylate waste fibers (AWF) for nucleation of PQDs (size = 5.6 nm, zetapotential = -6 to -11). The so-nucleated PQDs were successively doped within metal organic framework (namely, MIL-125-NH2) to prepare PQDs@MIL-125-NH2 composite, to be applicable as sono-photocatalyst for degradation of sulfamethazine. Successive doping of PQDs within MIL-125-NH2 was approved via different instrumental analysis such as Electron Microscope, X-ray diffraction, and infrared spectroscopy. Kinetic parameters for sono-photocatalytic degradation of sulfamethazine were also estimated. The recyclability of PQDs@MIL-125-NH2 composite was also approved. PQDs@MIL-125-NH2 composite as sono-photocatalyst exhibited the highest affinity for full degradation (99.9%) within 90 min of rate constant of 28.79 ± 1.21± 1.5 × 10−3 min−1. For PQDs@MIL-125-NH2 composite, the percentage of sono-photocatalytic degradation for sulfamethazine was lowered from 99.9% to be 96% to be reduced with only 4% after recycling for 5 times. Reaction mechanisms for ingraining PQDs and the sono-photocatalytic action of the prepared of PQDs@MIL-125-NH2 composite for degradation of sulfamethazine were elucidated.

PARTICLE BOARD HEAT INSULATION PINEAPPLE LEAF FIBER WASTE AND HVS PAPER AS AN ALTERNATIVE TO IMPROVE INDOOR ENVIRONMENTAL QUALITY

The limited supply of wood as a raw material in various industries requires a better alternative material. Wasted-based composite engineering can be a solution to this problem. What's more, composite can be engineered according to needs, such as having the ability to reduce heat to maintain comfortable room temperature conditions. Therefore, in this research, a particle board reinforced by pineapple leaf fiber waste and HVS paper waste was developed to know the effect of the particle board reinforcement composition on reducing heat. In this research, a comparison of pineapple leaf fiber waste and HVS paper waste was used at 100%:0%; 70%:30%; 50%:50%; 30%:70%; and 0%:100% with resin adhesive. This particle board is made by mixing all the ingredients and then printing it into a mold and then carrying out the drying process. The test was carried out based on a temperature difference analysis. The most optimum particle board reinforcement composition to reduce heat is 100% pineapple leaf fiber waste : 0% HVS paper waste.

Properties of a Low-Carbon Binder-Based Mortar Made with Waste LCD Glass and Waste Rope (Nylon) Fibers

Carbon dioxide emissions are one of the problems that arouses the interest of scientists because of their harmful effects on the environment and climate. The construction sector, particularly the cement industry, is a significant source of CO2. On the other hand, solid waste constitutes a major problem facing governments due to the difficulty of decomposing it and the fact that it requires large areas for landfill. Among these wastes are LCD waste glass (WG) and used rope waste. Therefore, reusing these wastes, for example, in concrete technology, is a promising solution to reduce their environmental impact. Limited studies have dealt with the simultaneous utilization of glass waste as a substitute for cement and rope waste (nylon) fiber (WRF). Therefore, this study aimed to partially replace cement with WG with the addition of rope waste as fibers. Thirteen mixtures were poured: a reference mixture (without replacement or addition) and three other groups containing WG and WRF in proportions of 5, 15 and 25% by cement weight and 0.25, 0.5 and 0.75% by mortar weight, respectively. Flow rate, compression strength, flexural strength, dry density, water absorption, dynamic modulus of elasticity, ultrasonic pulse velocity and electrical resistivity were tested. The results indicate that the best ratio for replacing cement with WG without fibers was 5% of the weight of cement. However, using WRF increased the amount of glass replacement to 25%, with an improvement in strength and durability characteristics.

Review on the influencing factors towards improving properties of composite insulation panel made of natural waste fibers for building application

The low performance of insulation panels has received great attention from many researchers and engineers to improve their properties as it has become a limiting factor that minimize their usage specifically as insulation building material. Recently, there has been an increase in interest in the development of composite insulation panels made from natural waste fiber. Due to the abundance of natural waste fiber generated by the agricultural industry, it has made them suitable to be utilized as raw material for composite insulation panels. Having improper waste disposal management might result in these massive quantities of valuable natural waste fiber having a detrimental effect on our ecosystem and contributing to various environmental pollution. A composite insulation panel made from natural waste fibers has unique and versatile features in terms of thermal, physical, and mechanical properties. Seeing such potential, this paper presents a review on the influencing factors towards improving comprehensive properties of composite insulation panels. Factors that influence the properties of the panel, such as the physico-chemical properties of fiber, fiber geometrical structure, and fiber treatment were discussed. Previous and recent research efforts related to factors influencing the properties of composite insulation panels were also compiled. Last but not least, the suitable criteria, limiting factors, and condition of the fiber used in composite insulation panels were also all highlighted.

Testing the Properties of Cement and Gypsum Boards Reinforced with Nonwoven Fabrics Made of Waste and Recycled Fibres

Abstract The article attempts to assess the possibility of using non-woven fabrics made of waste fibers in cladding panels. For this purpose, woolen and polypropylene nonwovens were tested for mass per unit area, characteristic opening size, and lengthwise and crosswise elongation at maximum strength. Non-woven fabrics were placed in the middle of the thickness of cement and gypsum boards and subjected to tests of density, thermal conductivity coefficient λ, and bending strength. The influence of individual nonwoven fabrics with different properties on the properties of the finished composite was determined. It was found that wool nonwoven fabrics had the best effect on the thermal conductivity coefficient. A better affinity for nonwoven fabrics was shown by gypsum mortar. The best influence on the bending strength of the panels had polyester non-woven fabrics with the lowest mass per unit area and the largest characteristic opening size.

Poly(3-hydroxybuyrate) production from industrial hemp waste pretreated with a chemical-free hydrothermal process

In this study, a mild two-stage hydrothermal pretreatment was employed to optimally valorize industrial hemp (Cannabis sativa sp.) fibrous waste into sugars for Poly(3-hydroxybuyrate) (PHB) production using recombinant Escherichia coli LSBJ. Biomass was pretreated using hot water at 160, 180, and 200 °C for 5 and 10 min (15% solids), followed by disk refining. The sugar yields during enzymatic hydrolysis were found to improve with increasing temperature and the yields for hot water-disk refining pretreatment (HWDM) were higher compared to only hot water pretreatment at all conditions. The maximum glucose (56 g/L) and cellulose conversion (92%) were achieved for HWDM at 200 °C for 10 min. The hydrolysate obtained was fermented at a sugar concentration of 20 g/L. The PHB inclusion and concentration of 48% and 1.8 g/L, respectively, were similar to those from pure sugars. A pH-controlled fermentation resulted in a near bi-fold increase in PHB yield (3.46 g/L).

Cracking Behavior and Deflections in Recycled-Aggregate Beams Reinforced with Waste Fibers Subjected to Long-Term Constant Loading.

This report presents the results of long-term tests on concrete beams reinforced with steel cord. In this study, natural aggregate was wholly replaced with waste sand or with wastes from the production of ceramic products and ceramic hollow bricks. The amounts of individual fractions used were determined in accordance with guidelines for reference concrete. A total of eight mixtures were tested; these differed in terms of the type of waste aggregate used. Elements with various fiber-reinforcement ratios were made for each mixture. Steel fibers and waste fibers were used in amounts of 0.0%, 0.5%, and 1.0%. Compressive strength and modulus of elasticity were determined experimentally for each mixture. The main test was a four-point beam bending test. Beams with dimensions of 100 mm × 200 mm × 2900 mm were tested on a stand, which was specially prepared so that three beams could be tested simultaneously. Fiber-reinforcement ratios were 0.5% and 1.0%. Long-term studies were conducted for 1000 days. During the testing period, beam deflections and cracks were measured. The obtained results were compared with values calculated using several methods, considering the influence of dispersed reinforcement. The results enabled the best methods for calculating individual values for mixtures with different types of waste materials to be determined.

COMPARATIVE BETWEEN WATER LEVEL AND SOIL COVER MATERIAL ON GROWTH, PRODUCTIVITY AND WATER USE EFFICIENCY OF HOT PEPPER PLANT

Two field experiments were conducted during the two successive winter seasons of 2020-2021 and 2021-2022 on the experimental farm belonging to the Central Laboratory for Agricultural Climate, Agricultural Research Center, Giza Governorate, and Egypt. The study comprised three irrigation levels (50, 75, and 100% of estimated water requirement based on climatic data) and four soil cover treatments namely transparent polyethylene mulch (PE), rice straw (RS), date palm fiber wastes (DPf) and control (bare soil). Hot pepper seeds (Capsicum annuum L.), Super Noura F1 hybrid. Hot pepper transplants were cultivated in the field in the first week of September for both seasons. The main results show that using 100% water level led to increased vegetative and yield of hot pepper during both seasons followed by using 75% while deficit irrigation gave the lowest hot pepper growth and yield. Using 75% water level gave the highest water use efficiency. Using PE mulch led to increasing the soil temperature during the growth season followed by rice straw mulch whereas the date palm fiber wastes mulch decrease soil temperature during both seasons. Moreover, PE treatment led to an increase in the growth and yield of hot pepper during both seasons. Control treatment combined with a 50% water level decreased the growth and productivity of hot pepper during the two seasons.

Insights into the Applications of Natural Fibers to Metal Separation from Aqueous Solutions.

There is a wide range of renewable materials with attractive prospects for the development of green technologies for the removal and recovery of metals from aqueous streams. A special category among them are natural fibers of biological origin, which combine remarkable biosorption properties with the adaptability of useful forms for cleanup and recycling purposes. To support the efficient exploitation of these advantages, this article reviews the current state of research on the potential and real applications of natural cellulosic and protein fibers as biosorbents for the sequestration of metals from aqueous solutions. The discussion on the scientific literature reports is made in sections that consider the classification and characterization of natural fibers and the analysis of performances of lignocellulosic biofibers and wool, silk, and human hair waste fibers to the metal uptake from diluted aqueous solutions. Finally, future research directions are recommended. Compared to other reviews, this work debates, systematizes, and correlates the available data on the metal biosorption on plant and protein biofibers, under non-competitive and competitive conditions, from synthetic, simulated, and real solutions, providing a deep insight into the biosorbents based on both types of eco-friendly fibers.

Pengaruh Serat Ban Bekas dan Abu Batu Bara Terhadap Kuat Tarik Beton

In today's modern era, technological developments are needed to increase development in all fields. The manufacture of concrete can use partial cement substitution materials through the use of industrial by-products such as fly ash and fiber waste from used tires. The benefit of this research is to develop knowledge about concrete technology. The method used in this research is the ACI 211.1-91 (American Concrete Institute) and ASTM (American Society for Testing and Materials) methods with variations in the addition of used tire fiber by 0%, 5%, 10%, 15%, and 5% addition of fly ash from the weight of cement in each variation. The test object used is a cylinder with dimensions of 15 cm x 30 cm with a total of 20 test objects, the planned concrete quality is 17.00 MPa. The tensile strength of concrete test was carried out at the age of 28 days. The results of this study are that concrete with a variation of 0% produces a tensile strength of 2.32 MPa; while the tensile strength with variations of 5%, 10% and 15% were 2.71 MPa, 2.50 MPa and 2.41 MPa. The tensile strength of concrete using tire fiber waste and fly ash increases compared to normal concrete.

Thermal and mechanical characterization of composite materials from industrial plastic wastes and recycled nylon fibers for floor paving tiles application

Industrial plastic waste is growing globally at an alarming rate and environmental pollution from traditional landfill disposal and incineration treatments are of great concern. As a strategy to reduce plastic pollution, value-added composite materials from industrial plastic wastes reinforced with recycled nylon fibers for use in floor paving tile applications were developed. This is to address the disadvantages of existing ceramic tiles which are relatively heavy, brittle, and expensive.The plastic waste composite structures were produced via compression molding technique at an optimized randomly oriented constant fiber volume fraction of 50 wt% after the initial sorting, cleaning, drying, pulverizing, and melt-mixing. The molding temperature, pressure, and time for the composite’s structures were 220 ℃, 65 kg.cm−3, and 5 min respectively. The composites' thermal, mechanical, and microstructural properties were characterized in accordance with appropriate ASTM standards. From the results obtained, the differential scanning calorimetry (DSC) of mixed plastic wastes and nylon fiber wastes showed a processing temperature range of 130–180 ℃, and 250 ℃ respectively. Thermal degradation temperature (TGA) of the plastic and nylon fiber waste composites were stable above 400 ℃ with maximum bending strength, however, the reinforced plastic waste sandwiched composite structures had outstanding mechanical properties indicating unique characteristics suitable for floor paving tiles. Hence, the current research has developed tough and lightweight tiles composites that are economically viable, and their application will contribute to the development of the building and construction sectors thereby reducing about 10–15% of annual plastic waste generation and a sustainable environment.

Partial replacement of cement and fine aggregates with marble dust powder and polypropylene fiber

Normally sand, cement, gravel is used as a raw material of conventional concrete. Thus, the usage of these raw materials has been increased in a large amount for that reason in future the demand of these constructive materials will get less a chance to be fulfilled and so the cost of these materials will be drastically increased. This research emphasizes on the possibilities of using waste material from different engineering activities to prepare innovative concrete. Marble dust powder as a waste and polypropylene fiber was suggested in partial replacement of cement and fine aggregates. Different papers were studied on the replacement of these waste materials in concrete. The highest strength achieved by the concrete on replacing certain percentages of these waste materials. was found According to that we first replaced the cement with marble dust then when the highest strength was achieved at a particular percentage then at that percentage of replacement it was combined with different percentages of replacement of fine aggregates with polypropylene fibre. To determine the compressive strength, split tensile strength and flexural strength different tests were conducted. The use of marble dust powder was proposed in different percentages as an addition to cement. The replaced percentages are 9%, 11%, 13%, and 15%. Though the replacement percentage of polypropylene fiber with fine aggregates are 0.9%, 1.1%, 1.3% and 1.5%. The compressive strength test, split tensile strength test and the flexural strength test were performed after 7, 14 and 28 days after casting them. It was seen that for 13% replacement of cement with marble dust powder the compressive strength was enhanced by 11.9% after 28 days of casting when analyzed with the blend which has 0% replacement of MDP. Split tensile strength and flexural strength were enhanced by 12% and 12.75%. When 13% replacement of marble dust powder was combined with 1.1% of polypropylene fiber it resulted 15% improvement in compressive strength after 28 days of casting. Split tensile strength and flexural strength improved by 15% and 13.5% after 28 days. M25 concrete grade is designed as per is 456:2000.

Preparation and Evaluation of an Elastic Cushion with Waste Bamboo Fiber Based on Sitting Pressure Distribution of the Human Body

Waste bamboo fibers are mostly in a spiral coil state and exhibit a certain degree of elasticity, which has the potential to be used as elastic cushion filler. However, there are few studies on its application to elastic cushions. In order to efficiently use waste bamboo fibers, a bamboo-based elastic cushion (BEC) was prepared and evaluated. The BEC units were prepared by mixing bamboo waste fibers with ES fibers and dividing them into five grades according to elastic modulus. The BECs were arranged with BEC units based on the sitting pressure distribution of the human body and evaluated using objective and subjective methods. The appropriate process of BEC units was a heating temperature of 150 °C, heating time of 50 min, and bamboo proportion of 50~75%.The elastic modulus of units had a clear influence on the sitting pressure distribution of the BEC. With the increasing elastic modulus of BEC units, the maximum pressure and average pressure of the BEC first decreased and then increased, while the contact area showed an opposite trend. Additionally, the comfort rating of the BEC with higher elastic modulus units was higher, and the appropriate elastic modulus range was 0.25~0.40 MPa. The BECs made with units with different elastic moduli increased the comfort rating by 12.8% compared with that with the same units, and the sciatic node was the most sensitive part for humans when sitting on the BEC. The results could provide data support for the application of waste bamboo fibers in elastic cushions.

Physical, thermal and functional groups’ characteristics of biofoam cup made from coconut fibre waste, soy flour and Rhizopus oligosporus

Biofoam is a replacement packaging for Styrofoam made from natural fibres that are naturally biodegradable and food-safe. Many studies use chemicals and starch as a matrix adhesive in the manufacture of biofoam. In previous studies, biofoam cups have been developed using the mold Rhizopus oligosporus which is found in coconut fibre. The objective of this study was to analyse the physical, thermal and functional groups’ characteristics in order to determine the most durable biofoam cup. The mixtures of fibre, tempeh mold, and soy flour were fermented for 3 days at 35°C in two stacked plastic cups and were dried for 46 hours at 50°C to stop the fermentation process. The biofoam cups were then analysed for the physical, thermal and functional groups’ characteristics. The most favourable characteristics of the biofoam cup is not easily destroyed and resistant to heat. The results showed that it had 0.08 g/cm3 ± 0.1 g/cm3 of density and 320.54°C of thermal gravimetry analysis. It also had a hydroxyl functional group (O-H) at wave number 3273.20 cm−1, an alkyl group (C-H) at wave number 2937.59 cm−1, a carbonyl group (C=O) at wave number 1654.92 cm−1, 1535.34 cm−1, and 1259.52 cm−1, and the C-O functional group at the wave number 1060.85 cm−1.

Pengolahan Limbah Serat Fiber sebagai Substitusi Material Pengisi Media Tanam Organik di Mitra WBS Fiberglass Poncokusumo

Micro-enterprises in the community still need a helping hand in the form of a service program from the campus. It is known that the micro-enterprise community belongs to the lower middle class, so there is still a lack of interest in seeking information/literacy and this results in the absence of business development in the future in a better direction. In Karanganyar Village, Poncokusumo, Malang, a fiber business was found in the manufacture of tools made of plastic, this business has been running for 3 years and there is still no high enough development. In addition, another problem is the problem of fiber waste that has not been utilized at all. There was no processing or conversion into useful and economically valuable materials. The solution offered is the manufacture of organic pots/growing media. The method of implementing this service used three stages, namely preparation, implementation, and reporting. The data collected in the form of documentation, observation, and the results of filling out the respondent's questionnaire which was then analyzed descriptively qualitatively. The results of the service showed that organic growing media from fiberglass can be applied and attract partners' interest. Knowledge of occupational health and safety has enthusiastically educated partners. The results of the partner satisfaction questionnaire showed that this service activity has a very satisfied response category of 65.7% and a satisfied response of 34.3%. So, WBS fiberglass partners have received, supported, appreciated, and followed this service well.

Testing The Compressive Strength Of Concrete With The Utilization Of Rice Husk Ash And Palm Fiber

Development in the field of structure is currently progressing very rapidly in various field so that concrete is one of the choices as a structural material in building construction, basically concrete is made by mixing portland cement, coarse aggregate, fine aggregate, and water as a binder for these materials. Due to the development of the issue of current resource limitations, the prevention is by innovating the manufacture of concrete using palm fiber waste as an added ingredient from sand and rice husk ash waste as an added ingredient from cement. The purpose of study was to (1) analyze the compressive strength of concrete with variations ini rice husk ash and palm fiber (2) analyze the addition of rice husk ash and palm fiber with different mixture variations that could affect the compressive strength of concrete. The result showed that normal concrete with an average compressive strength of 24.20 MPa and an increase in compressive strength with a mixture of 0.5% palm fiber and 5% rice husk ash with an average strength of 25.90 MPa without using superplasticizer, if the variation mixture exceeding the mixed variation of 0.5% palm fiber and 5% rice husk ash will deacrease

Reaction kinetics, pyrolytic behavior and product characterization of dewatered solids from spent fermentation coir wastes using a fixed batch reactor

Solid residues after pretreatment and hydrolysis of coir pith and Bit fiber waste was dewatered, dried and pyrolyzed at 300, 350, and 400 °C using a fixed bed batch pyrolyzer. The products were characterized using ultimate analysis, FTIR and GCMS. Bit fiber yielded more bio-oil (26.3 %), rich in 4-Methoxy phenol (60.94 %) and a Higher Heating Value of 27.06 MJ kg−1. Coir pith bio-oil with Higher Heating Value of 27.16 MJ kg−1, was rich in 2-Methoxy Phenol, which are principal lignin degradation products. Non condensable gases included mixture of methane, carbon dioxide and isomers of butene. Activation energy for thermal decomposition was studied using Coats and Redfern model from thermogravimetric data at heating rates of 10 and 15 k min−1, which showed two major phases of decomposition. Activation energy was higher for devolatilization phase of bit fiber waste (132 kJ/ mol) owing to higher percentage of lignin than in coir pith waste (Ea = 114 kJ/ mol).

Potential of waste woven polypropylene fiber and textile mesh for production of gypsum-based composite

The huge production of woven polypropylene bags has led to an increase generation of plastic waste. The recycling of waste woven polypropylene bags and textiles in construction applications can be a viable option. Therefore, an attempt has been made to utilize the woven polypropylene fibers and textiles in the production of gypsum-based composite false ceiling tile for an economical and sustainable construction product. In the current research work, different water-to-powder ratios (0.6 %, 0.7 %, 0.8 %, 0.9 %) and fiber contents (0.25 %, 0.35 %, 0.45 %, 0.55 %) in the gypsum-based composite were prepared. Flexural plates with different thicknesses (18, 15, 12, and 9 mm) incorporating different recycling fibers and reinforced with different types of meshes were manufactured to produce sustainable gypsum-based plates. The physical properties, compressive and flexural strength properties of the fiber-reinforced gypsum-based composite were also evaluated. The textile and woven polypropylene fiber mesh reinforced gypsum false ceiling plates were compared with the control specimen. The results revealed that the density of gypsum-based composite decreased up to 26 % with the increase in the proportion of waste fiber contents. The compressive and flexural strength of gypsum-based composites exhibited a decrease with an increase in fiber contents and water-to-powder ratio. However, all the specimens satisfied the acceptable limit of 1 MPa and 2 MPa, respectively, according to BS EN 14246. The bending strength of all the plates incorporating different fiber content and thicknesses satisfied the minimum specified flexural strength criteria according to BS EN 14246. Moreover, the plates with different thicknesses and fiber contents also satisfied the minimum specified flexural criteria except for the plate with a thickness of 9 mm. However, all the plates with varying thicknesses and reinforced mesh have also satisfied the minimum load criteria specified by BS EN 14246. Thus, it can be envisioned that the woven polypropylene fibers and textiles can be effectively utilized to produce sustainable gypsum-based composite leading to reduce waste generation.

Concrete with Coconut Fibre Treated with Sodium Hypochlorite – Compressive and Flexural Strength

Concrete needs to be reinforced to improve its engineering qualities. Coconut fibres were employed for this study since they are widely accessible and come in big numbers. The study compares the qualities of plain concrete and concrete reinforced with coconut fibre based on a laboratory experiment. Better management of these waste fibres will result from using coconut fibres. Two types of coconut fibre treatment were employed – treatment with tap water and treatment with sodium hypochlorite. It is found in this study that adding 1% of coconut fibre does not increase the concrete strength after 7 and 14 days of curing. However, it was discovered that using 1% coconut fibres treated using tap water increased the compressive and flexural strength of the concrete after 28 days of curing by roughly 4% and 3%, respectively. Compressive and flexural strength development agrees very well with each other. Hence, it is concluded that 1% was the ideal fibre concentration (by weight of cement) to obtain a better 28th day of compressive and flexural strength, although not for 7 and 14 days. However, concrete with the highest strengths demonstrated a very low slump value, only 20 mm. A smaller or bigger slump value showed smaller concrete strengths.

Fabrication and Utilization of High Loft Mats Based on Recycling Egyptian Pulled Wool and Flax Fibers Waste for Thermal Insulation Applications

Heating and cooling activities of buildings consume a considerable amount of energy used in building envelopes and are responsible for almost 16 % of CO2 emissions in the air. This problem has been confronted with a recent worldwide trend by introducing eco-friendly buildings with net zero emissions. Currently used thermal insulators in building envelopes are usually made from synthetic polymers which are difficult to recycle or dispose of. This paper presents a novel bio-composite mats using Egyptian pulled wool fiber waste and flax fibers waste as an alternative to commercial polystyrene foam. High loft nonwoven mats with different blends of wool and flax are fabricated and characterized to utilize a composite structure with satisfactory thermal and physical properties. Thermal conductivity test, ignition test, and compression and recovery test are applied to the developed specimens. The results proved the competitiveness and suitability of the proposed composites to be used as building interior insulators when compared to polystyrene and other similar composite materials from literature.