Material Composition Research Articles

Literature Review: Guava Leaves (Psidium Guajava) for Treating Diarrhea

Diarrhea is a significant health problem, especially in developing countries. Guava leaves (Psidium guajava) have long been used in traditional medicine to treat diarrhea. This study aims to review the literature on the effectiveness of guava leaves in treating diarrhea by focusing on ten aspects: raw material name, raw material content, raw material composition, active substance content, efficacy claims, empirical data, raw material standardization, preclinical test, toxicity test, and clinical trial. The results of several studies show that guava leaves contain tannins, flavonoids, saponins, and essential oils that play a role in the antidiarrheal effect. Preclinical research shows a reduction in the frequency of bowel movements and an increase in stool consistency in animal models. Although empirical claims and preclinical trials support the use of guava leaves as a treatment for diarrhea, more research is still needed regarding the standardization of raw materials, toxicity tests, and clinical trials to ensure its overall efficacy and safety.

Total body irradiation is associated with long-term deficits in femoral bone structure but not mechanical properties in male rhesus macaques.

Exposure to ionizing radiation for oncological therapy increases the risk for late-onset fractures in survivors. However, the effects of total body irradiation (TBI) on adult bone are not well-characterized. The primary aim of this study was to quantify the long-term effects of TBI on bone microstructure, material composition, and mechanical behavior in skeletally mature rhesus macaque (Macaca mulatta) non-human primates. Femora were obtained post-mortem from animals exposed to an acute dose of TBI (6.0-6.75Gy) nearly a decade earlier, age-matched non-irradiated controls, and non-irradiated young animals. The microstructure of femoral trabecular and cortical bone was assessed via micro-computed tomography. Material composition was evaluated by measuring total fluorescent advanced glycation end products (fAGEs). Cortical bone mechanical behavior was quantified via four-point bending and cyclic reference point indentation (cRPI). Animals exposed to TBI had slightly worse cortical microstructure, including lower cortical thickness (-11%, p = 0.037) and cortical area (-24%, p = 0.049), but similar fAGE content and mechanical properties as age-matched controls. Aging did not influence cortical microstructure, fAGE content, or cRPI measures but diminished femoral cortical post-yield properties, including toughness to fracture (-32%, p = 0.032). Because TBI was administered after the acquisition of peak bone mass, these results suggest that the skeletons of long-term survivors of adulthood TBI may be resilient, retaining or recovering their mechanical integrity during the post-treatment period, despite radiation-induced architectural deficits. Further investigation is necessary to better understand radiation-induced skeletal fragility in mature and immature bone to improve care for radiation patients of all ages.

Discovery and Reconstruction of the Remains of the Beacon-Equipped Hollow Enemy Towers along the Ming Great Wall

Hollow Enemy Towers, as iconic structures of the Ming Great Wall, are renowned for their roles in defense surveillance, weapon storage, and firearm operation. Recent studies have indicated that certain Hollow Enemy Towers along the Ji Town section of the Ming Great Wall also serve the function of Beacon Towers for beacon signaling. However, previous studies have not definitively determined if these towers were distinctively marked, nor have they provided a comprehensive account of their current distribution and original historical appearance. This paper initially examined the historical documentation of white lime markings employed on the outer walls of certain Hollow Enemy Towers, which served as Beacon Towers during the middle and late Ming periods. Utilizing multidisciplinary methodologies, this research identified remains of lime markings of the Beacon-Equipped Hollow Enemy Towers along the Ji Town section of the Ming Great Wall, illustrating their extensive distribution. We analyzed the material composition and construction techniques of the lime mortar. This analysis clarifies the scope of lime plastering on the exterior walls of these towers and offers a point of reference for restoring their original historical appearance. The results make a significant supplement to the types of signaling structures on the Great Wall, enriching existing understanding of the original appearance of the Great Wall’s historical landscape.

From in-situ experimentation to in-line metrology: Advanced imaging characterization for battery research and manufacturing

The continuous advancement of battery technology necessitates innovative approaches in both research and manufacturing to ensure improved performance, reliability, and safety. This article explores the critical role of advanced imaging characterization techniques, spanning from in-situ experimentation to in-line metrology, in the development and production of lithium-ion batteries. By integrating real-time imaging and diagnostic tools, researchers and manufacturers can gain unprecedented insights into the electrochemical processes, material behaviors, structural defects and their evolutions in commercial-grade batteries. This comprehensive characterization enables the optimization of material compositions, electrode designs, and manufacturing processes, ultimately enhancing the efficiency and longevity of batteries. The synergy between in-situ experimentation and in-line metrology provides a robust framework for addressing the complex challenges in battery research and manufacturing, paving the way for innovations that will meet the growing demands of energy storage systems.

Physico‐chemical characterisation and light stability of dyes and pigments found in cultural heritage objects: Insights from microfading testing for assessing light fastness

AbstractUnderstanding the chemistry of dyes and pigments found in cultural heritage objects and their permanence is central for their preservation. Heritage science research has generally focused on either identification of materials present on actual objects or accelerated and natural ageing of mock‐up samples prepared using historically accurate methods to simulate the materiality of cultural heritage objects. A more recent strategy is the integration of these two research areas, which provides a holistic approach to assess both the chemical composition and stability of materials. Over the last 30 years, microfading testing (MFT) has notably contributed to understanding materials' responsiveness to light, minimising damage to objects from museum lighting and revealing insights into molecular structures of dyes and pigments, when employed in conjunction with other techniques. By combining MFT with diverse analytical methods, including imaging, spectroscopy, microscopy and chromatography, a more comprehensive approach is achieved. This joined‐up strategy contributes to improved decision‐making processes in the conservation and preservation of cultural heritage objects.

Optimization of microbial consortia and materials composition enhances gluconic acid content in kombucha.

The objective of this study was to optimize the microbial and ingredient composition of kombucha for enhanced production of gluconic acid (GA). Fourteen strains of Komagataeibacter spp. and one yeast strain of Dekkera sp. were isolated from kombucha. Among them, Komagataeibacter swingsii SS1 (SS1) and Komagataeibacter saccharivorans SS11 (SS11) were selected for their high GA production. A rapid reduction of pH, high GA content relative to acetic acid, and high cellulose production were observed in the tea infusion fermented by the microbial consortium (SS1 + SS11 + Dekkera bruxellensis Y24). From the correlation between the materials composition and quality indicators of kombucha, the decrease in pH was the most critical quality indicator of kombucha and the most closely related to GA content. Maximal GA production (11.7mg/mL) was obtained under the conditions of 1% (w/v) tea extract, 8.5% (w/v) glucose, and 1.5% (v/v) ethanol through the optimization of materials composition by response surface methodology. The GA content of kombucha was enhanced threefold in comparison to general kombucha by fermentation with Komagataeibacter spp. and optimization of the composition of the ingredients. Overall, this study showed that a specific microbial consortium and materials composition could be established by correlation analysis among the ingredients, which results in increased GA levels in kombucha. These findings offer valuable foundational data for both commercial production and quality control of kombucha.

Structure and properties of powders obtained by electrodispersion of pure Nickel metal waste in distilled water

Purpose. Investigation of the composition, structure and properties of powder materials obtained by electrodispersion of nickel waste of the PNK-0T1 brand in an oxygen-containing medium – distilled water.Methods. To determine the composition, structure and properties of powder materials, samples of powders obtained from waste nickel grade PNK-0T1 were studied. The powder material was obtained by electroerosive dispersion in distilled water. Microanalysis of powder particles was carried out using a scanning electron microscope, an analysis of the size distribution of powder particles was obtained using a particle size analyzer, an X-ray spectral microanalysis of powder particles was carried out using an energy-dispersive X-ray analyzer embedded in a scanning electron microscope, an analysis of the phase composition of powder particles was carried out using X-ray diffraction on the diffractometer.Results. During the study, it was revealed that the shape of the particles obtained from nickel powders is spherical and elliptical, and agglomerates of smaller particles are also noted on the increase. Oxygen and nickel are present in the composition of powder materials. The phases of pure nickel and nickel oxide NiO are marked in the phase composition. From the analysis of the granulometric histogram, it follows that the particle size spread varies in the range of 0.26...18.62 microns, the average volume diameter of the particles was 5.2 microns.Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste from expensive raw materials by the method of electroerosive dispersion, followed by improvement and optimization of the composition and structure of the alloy.

Influence of randomly placed resonant aggregates on the attenuation properties of metaconcrete: A numerical study

Concrete is a key material for many structural components in engineering, but its acoustic performance remains under discussion. Hence, the potential of the so-called metaconcrete has gained attention in research, mainly due to its capability to control vibrations and sound transmission when resonant aggregates are embedded in the concrete. These resonant aggregates are designed to have resonant frequencies regarding frequency bands of interest, so the interaction with the incident sound waves is attenuated within those frequencies. While available research has focused on the characterization of metaconcrete with a periodic arrangement of resonant aggregates, there is a gap regarding how their random allocation affects the characterization of metaconcrete. This study focuses on the numerical analysis of metaconcrete and the influence of randomly placed resonant aggregates on its attenuation properties. The numerical approach concentrates on the aggregate's material composition, location and volume fraction within the concrete to identify configurations that exhibit great wave attenuation. The results have shown that the attenuation effect is substantially advantageous when using a multi-frequency configuration for aggregates within the metaconcrete. Additionally, the random embedding of resonant aggregates offers a practical solution for their application in concrete structures.

Longitudinal dispersivity estimation according to heat and mass groundwater transport model calibration for Baikalsk paper and mill site

The paper presents the results of the numerical three-dimensional model of groundwater heat and mass transfer in the territory of Baikalsk paper and mill site calibration based on the materials of groundwater composition and properties twenty-year monitoring, which showed that the longitudinal dispersion at heat transfer is an order of magnitude greater than at mass transfer.

Characterization of Historical and Modern Leathers Using FTIR, XRD, SEM-EDX, and Thermal Techniques

Abstract A comprehensive study was conducted on four aged leather pieces of British origin that were utilized in book binding, dating back to the period between 1832 and 1860. The objective of this study was to characterize the thermal, structural, and deterioration properties of these historical leather fragments. Additionally, this study included two newly acquired leather samples of Indian provenance, proposed as potential replacements for this historical leather. The investigative process employed Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX). Through the FTIR analysis, distinct spectral shifts were identified in the amide A band, indicating a disruption of hydrogen bonding within the aged leather. XRD diffractograms revealed the presence of amorphous phases in the aged leather specimens, signifying the deterioration of their triple helical structure. Notably, DSC analysis provided insight into the denaturation of the collagen-tannin matrix inherent to the historical leather, underlining the transformative effects of time on this intricate material composition. Under SEM analysis, cracks, fibre deterioration, and a general weakening in structural integrity were observed in the aged leather fragments. The EDX data identified one of the new leather samples as chrome-tanned, while the remaining samples exhibited characteristics consistent with vegetable-tanned leather.

From Small Data Modeling to Large Language Model Screening: A Dual-Strategy Framework for Materials Intelligent Design.

Small data in materials present significant challenges to constructing highly accurate machine learning models, severely hindering the widespread implementation of data-driven materials intelligent design. In this study, the Dual-Strategy Materials Intelligent Design Framework (DSMID) is introduced, which integrates two innovative methods. The Adversarial domain Adaptive Embedding Generative network (AAEG) transfers data between related property datasets, even with only 90 data points, enhancing material composition characterization and improving property prediction. Additionally, to address the challenge of screening and evaluating numerous alloy designs, the Automated Material Screening and Evaluation Pipeline (AMSEP) is implemented. This pipeline utilizes large language models with extensive domain knowledge to efficiently identify promising experimental candidates through self-retrieval and self-summarization. Experimental findings demonstrate that this approach effectively identifies and prepares new eutectic High Entropy Alloy (EHEA), notably Al14(CoCrFe)19Ni28, achieving an ultimate tensile strength of 1085 MPa and 24% elongation without heat treatment or extra processing. This demonstrates significantly greater plasticity and equivalent strength compared to the typical as-cast eutectic HEA AlCoCrFeNi2.1. The DSMID framework, combining AAEG and AMSEP, addresses the challenges of small data modeling and extensive candidate screening, contributing to cost reduction and enhanced efficiency of material design. This framework offers a promising avenue for intelligent material design, particularly in scenarios constrained by limited data availability.

The Effect of Biocomposite Material Composition with Natural Fiber Reinforced Polyester Matrix on Mechanical and Physical Strength

This study was conducted with the aim of determining the effect of natural fiber composition in polymer composites on the flexural strength and density of bio-composites with polyester matrix reinforced with ramie fiber, giant false agave (GFA), bamboo, and sugar cane fibers. Mechanical testing was carried out in the form of flexural strength testing and calculating density as a physical test. The composition of the matrix with fiber reinforcement was set at 70% polyester and 30% natural fiber. The variables used in this study were to create a dominant composition of fiber types in the form of a measured weight amount so as to produce a comparison of which type of natural fiber has a better test value. From the results of the flexural strength test, it was found that the bio-composite dominated by sugar cane fiber had the largest flexural strength value of 261.66 kg/cm2 while the bio-composite dominated by ramie and GFA sequentially produced flexural strengths of 101.465 kg/cm2 and 185.89 kg/cm2. The results of the density calculation show that the highest density was achieved by the bio-composite material with a dominant composition of hemp fiber (70% Polyester: 20% hemp fiber, 5% GFA fiber: 5% sugar cane fiber) of 1.049 g/cm3.

Reversibly Compressible Silanated Cellulose Nanofibril Aerogel for Triboelectric Taekwondo Scoring Sensors.

The integration of bio-based materials into triboelectric nanogenerators (TENGs) for energy harvesting from human body motions has sparked considerable research attention. Here, a silanated cellulose nanofibril (SCNF) aerogel is reported for structurally reliable TENGs and reversely compressible Taekwondo scoring sensors under repeated impacts. The preparation of the aerogel involves silanizing cellulose nanofibers (CNFs) with vinyltrimethoxysilane (VTMS), following by freeze-drying and post-heating treatment. The SCNF aerogel with crosslinked physico-chemical bonding and highly porous network is found to exhibit superior mechanical strength and reversible compressibility as well as enhanced water repellency and electron-donating ability. The TENG having a tribo-positive SCNF layer exhibits exceptional triboelectric performances, generating a voltage of 270V, current of 11µA, and power density of 401.1mWm-2 under an applied force of 8N at a frequency of 5Hz. With its inherent merits in material composition, structural configuration, and device sensitivity, the SCNF TENG demonstrates the capability to seamlessly integrate into a Taekwondo protection gear, serving as an efficient self-powered sensor for monitoring hitting scores. This study highlights the significant potential of a facilely fabricated SCNF aerogel for the development of high-performance, bio-friendly, and cost-effective Bio-TENGs, enabling their application as self-powered wearable devices and sports engineering sensors.

Corrosion mechanism of alkali-activated slag/metakaolin materials under carbonic acid solution

For promoting the application of alkali-activated slag/metakaolin (AASM) materials in karst areas, it is crucial to understand the corrosion properties of AASM materials in carbonic acid solutions. This paper systematically investigates the evolution of mechanical properties, phase composition, and microstructure of AASM materials in carbonic acid solution environments. The research results indicate that the corrosion mechanism of AASM in carbonic acid solution environments can be summarized as four stages: the dissolution stage, the C-(N)-A-S-H gel decalcification and calcium carbonate formation stage, the further corrosion of calcium carbonate stage, and the slow corrosion stage. Depending on the degree of Ca2+ leaching, the corrosion layers can be divided from the outermost to the innermost layers into the gel layer, the carbonation layer, and the un-corrosion layer. In carbonic acid solution environments, significant leaching of Na+ and OH− occurs in pore solution, which hinders the development of strength. Additionally, the diffusion of CO32− and HCO3− ions dissolved in water into the C-(N)-A-S-H gel, which react with the gel to form calcium carbonate, leads to gel decomposition. Moreover, the generated calcium carbonate is further corrosion into soluble calcium bicarbonate, resulting in substantial leaching of Ca2+, deterioration of pore structure, and increased aggregation degree of C-(N)-A-S-H gel structure. As the MK content increases, the calcium content in the system decreases, leading to a higher crosslinking degree and enhanced resistance of the C-(N)-A-S-H gel to carbonic acid solution corrosion, thereby reducing the corrosion rate of AASM materials. The research results provide new insights into the application of AASM materials in karst areas.

MnO2/rGO bifunctional catalyst and support materials for gel polymer electrolyte based Zn-air batteries

A high-performance and long-lasting, rechargeable Zn-air battery requires a reliable and effective bifunctional catalyst material to facilitate the oxygen reduction and oxygen evolution reactions during the battery operation. Manganese oxide (MnO2) is a promising non-precious perspective due to its multivalency and various polymorphic structures that effectively catalyze oxygen evolution and reduction. In the present work, MnO2 nanowires (NWs) have been integrated with over-reduced graphene oxide (rGO) in various concentrations via a facile hydrothermal route. The synthesized materials, tested in lab-made zinc-air battery devices fabricated using gel polymer electrolyte, exhibit a significant enhancement in the performance and 2–3 times the cycle life compared to the bare MnO2. The ZAB device was tested for galvanostatic charge-discharge technique, and results exhibit a cycle life of 165 h (495 cycles@20 min per cycle) when discharged up to 1.0 V at a current density of 5.2 mA/cm2 and displayed a capacity of 731 mAh/gZn. Reduced graphene oxide acts as a support material that enhances the conductivity and surface area of the active material and also provides active sites for catalysis. This work signifies the importance of the engineering of the catalyst, support material, and additives, as slight changes may result in a significant enhancement in the cycle life.The appropriate composition of catalyst and support material and a compatible gel polymer electrolyte facilitates the fabrication of flexible zinc-air batteries for various applications.

A 40-Year Time Series of Land Surface Emissivity Derived from AVHRR Sensors: A Fennoscandian Perspective

Accurate land surface temperature (LST) retrieval depends on precise knowledge of the land surface emissivity (LSE). Neglecting or inaccurately estimating the emissivity introduces substantial errors and uncertainty in LST measurements. The emissivity, which varies across different surfaces and land uses, reflects material composition and surface roughness. Satellite data offer a robust means to determine LSE at large scales. This study utilises the Normalised Difference Vegetation Index Threshold Method (NDVITHM) to produce a novel emissivity dataset spanning the last 40 years, specifically tailored for the Fennoscandian region, including Norway, Sweden, and Finland. Leveraging the long and continuous data series from the Advanced Very High Resolution Radiometer (AVHRR) sensors aboard the NOAA and MetOp satellites, an emissivity dataset is generated for 1981–2022. This dataset incorporates snow-cover information, enabling the creation of annual emissivity time series that account for winter conditions. LSE time series were extracted for six 15 × 15 km study sites and compared against the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD11A2 LSE product. The intercomparison reveals that, while both datasets generally align, significant seasonal differences exist. These disparities are attributable to differences in spectral response functions and temporal resolutions, as well as the method considering fixed values employed to calculate the emissivity. This study presents, for the first time, a 40-year time series of the emissivity for AVHRR channels 4 and 5 in Fennoscandia, highlighting the seasonal variability, land-cover influences, and wavelength-dependent emissivity differences. This dataset provides a valuable resource for future research on long-term land surface temperature and emissivity (LST&E) trends, as well as land-cover changes in the region, particularly with the use of Sentinel-3 data and upcoming missions such as EUMETSAT’s MetOp Second Generation, scheduled for launch in 2025.

Consumer Perception of Palm Sugar Products in Rokan Hulu District, Indonesia: A Prospective Analysis Approach

The demand for palm sugar has been consistently increasing each year, particularly due to the growing public awareness of health benefits. Palm sugar is considered a safer sweetener option due to its low glycemic index and absence of side effects. The primary objective of this research is to analyze consumer perceptions regarding the attributes of palm sugar. This analysis is crucial in assessing consumer satisfaction and loyalty toward palm sugar consumption. Consequently, the findings will contribute to enhancing the marketing mix strategies for palm sugar. The survey method was employed to conduct this research, with a sample size of 30 consumer respondents selected through random sampling. Additionally, an opinion poll was conducted with key individuals to gather insights on the development of palm sugar products. The collected data were then analyzed using a prospective analysis approach. The research results indicate that specific attributes significantly influence consumer perceptions when purchasing palm sugar. Consumer perceptions in purchasing palm sugar are based on details of the marketing mix attributes which are the determining attributes, namely: taste, quality, palm sugar color, texture, popularity of craftsmen, and price. The marketing development implications of this research are improvements to three attribute components, namely raw material composition information, product standards, hygiene, partnerships, and technology. This serves as a consideration for craftsmen to improve consumer perceptions of palm sugar. Keywords: marketing of palm sugar, perception, prospective

Prediction of crystal structure, phase group, and stability of 2D materials through data science coupled with DFT

Two-dimensional materials offer unique mechanical strength, electrical conductivity, and tunable electronic properties, driving advancements in electronics, energy storage, and catalysis. The crystal structure of the materials is fundamental to several properties. In this study, we employ solely the elemental features to construct a random forest classification model achieving an 82.56% accuracy in predicting the crystal structure of the compounds. Additionally, one vs rest binary classifiers are developed for each crystal structure within our 2D materials dataset, with accuracies ranging from 86% to 99%, enhancing their practical utility. Features based on stoichiometric norms have been found to play a major role in the prediction because of the fact that certain crystal structures are associated with more balanced compositions, leading to lower norm values, while others with imbalances have higher norm values. It has also been observed that material compositions with an overall higher amount of p valence electrons tend to show monoclinic, orthorhombic and triclinic crystal structures. Moreover, in compounds with a lower total electronegativity of the constituent elements, the occurrence of trigonal and tetragonal systems has been found to be more probable. In a similar fashion, hexagonal crystal systems have been more often found in compounds where the sum of Van Der Waals radius of the constituent atoms is lower. To validate our model, Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method, and Density Functional Theory (DFT) are utilized to predict the crystal structure, phase group, and stability of a 2D material.

Analysis of the Influence of Variation in Medical Waste Heating Value on the Electrical Energy Output of Generator in Medical Waste Cogeneration Incinerator System using Gatecycle Solver

Abstract Medical waste incinerator is a technology capable of processing and exterminating hazardous medical waste through combustion at temperatures exceeding 800°C. Medical waste exhibits a range of heating values depending on its material composition. The heating value represents the potential heat energy released when a substance undergoes complete combustion. A cogeneration incinerator is designed to treat medical waste while also harnessing the heat of the flue gas that emanates from the combustion process. The flue gas acts as a hot fluid that transfers its heat, causing the water temperature inside the boiler to increase and transform into high-temperature steam. This steam drives a steam turbine connected to a generator to generate electrical energy. The amount of electrical energy generated is influenced by the steam quality produced through the boiler’s water-heating process. This study aims to investigate the influence of variation in the heating value in medical waste on the electrical energy output of the generator in a medical waste cogeneration incinerator system. The range of heating value variations used in the testing varies from 25 MJ/kg to 35 MJ/kg. The variation is tested through thorough simulations using GateCycle software to obtain data on the electrical energy generated. To achieve a maximum electrical energy output of 200 kW, fuel with a total heating value of 32.25 MJ/kg is required. This study is beneficial to be implemented as renewable energy sources based on biomass powerplant systems.

Investigation on Erosion Resistance in Polyester-Jute Composites with Red Mud Particulate: Impact of Fibre Treatment and Particulate Addition.

This research investigates the manufacturing and characterisation of polyester-based composites reinforced with jute fibres and red mud particulates. The motivation stems from the need for sustainable, high-performance materials for applications in industries, like aerospace and automotive, where resistance to erosion is critical. Jute, a renewable fibre, combined with red mud, an industrial byproduct, offers an eco-friendly alternative to conventional composites. The composites were fabricated using compression moulding with varying red mud contents (10, 20, and 30 wt.%) and a fixed 40 wt.% of jute fibre. Fibre treatments included sodium hydroxide (NaOH) and silane treatments to improve bonding and performance. Erosion tests were performed using an air-jet erosion tester, examining the effects of the red mud content, fibre treatment, and impact angles. Scanning Electron Microscope (SEM) analysis provided insights into the erosion mechanisms. A distinctive reduction in erosion rates at higher impact angles (30°-60°) was observed, attributed to the semi-ductile nature of the composites. The addition of red mud enhanced erosion resistance, although an excess of 30 wt.% reduced resistance due to poor surface bonding. Silane-treated composites showed the lowest erosion rates. This study provides new insights into the interplay among material composition, fibre treatment, and erosion dynamics, contributing to the development of optimised, eco-friendly composite materials.