Rheological properties are pivotal determinants across the materials range, spanning solids, liquids, and gases, elucidating their nuanced deformation responses under applied stresses. This knowledge assumes paramount significance in biocomposite material development, guiding the strategic formulation of these advanced materials. The intricate landscape of rheology unfolds through the exploration of diverse properties, including viscosity, yield stress, and relaxation times, employing multifaceted testing procedures such as dynamic and time–temperature assessments. In biocomposite material research, the seamless integration of matrix and reinforcement materials is a critical focal point. Rheological testing is an indispensable tool, proficiently gauging these distinct materials' complex interactions and binding nature. This paper intricately compiles the literature, explaining diverse testing methodologies and providing a nuanced explanation and guide for method selection, thereby contributing substantively to the ongoing advancements in biocomposite material science.

The treatment of palm oil mill effluent (POME) via adsorption was investigated using a novel nanocomposite powder with the addition of titanium (IV) dioxide (TiO2) and montmorillonite clay (MMT). Reduced heavy metal content, turbidity, pH, chemical oxygen demand (COD), and total suspended solids (TSS) in POME supported this result. The adsorption processes were carried out in POME with pH 4.4, 658 FAU turbidity, 1256 mg/l COD, and 563 mg/l TSS at a constant mixing speed of 180 rpm for 48 h, with different dosages of adsorbent. The atomic adsorption spectrometry (AAS) analysis revealed that MMT clay was effective in removing lead (Pb) and zinc (Zn) by 86.7 and 97.3

Luffa reinforced polylactic acid (PLA) bio-composites were prepared and examined. The luffa surface was treated using three chemicals, i.e., sodium hydroxide, 3-aminopropyltriethoxysilane, and acetic anhydride, which enhanced luffa compatibility with PLA. Mechanical testing was done on the chemically modified luffa reinforced PLA bio-composites, i.e., tensile, flexural, hardness, and thermal. Infrared spectral functional group and morphological analyses were performed on each sample. The results showed increases in tensile and flexural strength of 7.1% and 6.9% for sodium hydroxide, 5.7% and 1.4% for silane, and 4.3% and 0.4% for acetylation, respectively, especially to the surface-treated samples at 15 wt.% fiber volume, and a decrease in water uptake (%). Fourier transform infrared spectroscopy confirmed that the chemical surface treatments were successful with the removal of lignin and hemicellulose structures, which cause the surface structure of the modified fiber to be rough. Smooth surfaces were observed through SEM images. Thermal stability was enhanced due to improved interfacial bonding between luffa and PLA, eliminating other constituents and impurities. Moreover, the morphological analysis showed improved bonding compatibility between the luffa and PLA matrix.

Since its invention in 1907, plastic has been widely utilized worldwide. As plastics were thrown away after a single use, a severe problem arose, resulting in substantial pollution and contamination of the environment. Plastic bottles accounted for a significant portion of the plastic trash disposal. Plastic bottles are frequently made from waste polyethylene terephthalate (WPET). As a result, PET plastic bottles were employed as a by-product in this experiment since they are light in weight and, more significantly, help decrease trash pollution. The purpose of this study is to investigate the properties of concrete by partially replacing sand with plastic waste as fine aggregates, with the goal of this experiment being to determine the optimum percentage of sand replacement with plastic while maintaining compressive strength or achieving similar strength within the grade used when compared to reference concrete. 7 batches of 6 cubes each have been cast. One batch served as a control, three batches were cast without the addition of superplasticizer, and three more batches were cast with the optimal percentage of PET plastic replacement after the addition of superplasticizer. The subject of this investigation was the compressive strength test using 0%, 5%, 10%, and 15% PET plastic substituted with sand in concrete. After 7 days and 28 days of curing, a compressive strength test was performed. The plastic concrete’s maximum compressive strength was 27.6 MPa, which appears to be somewhat lower than the control sample. When a slight variation in strength is detected, the results are acceptable. The slightly lower strength obtained might be because of plastic's hydrophobic material. Therefore, a superplasticizer was added to improve the workability and compressive strength of the optimal plastic concrete. Naphthalene sulfonate formaldehyde was employed as a superplasticizer. Further research was carried out to understand better the characteristics of partial sand replaced with plastic, with or without a superplasticizer.

The effect of chemical treatment on silicon manganese slag and the effect of curing time on the compressive strength of completely replacement coarse aggregate silicon manganese concrete (SMC) relative to normal weight concrete (NWC) with gravel as coarse aggregate is the subject of this paper. Alkali and acidic base chemicals are used to alter the neat silicon manganese slag during chemical preparation. The mixture pattern proportions for Grade 30 and Grade 50, respectively, were used to create the concrete. Before the compressive strength tests, the samples were cast and cured for 7-, 14-, and 28-days. The properties of the silicon manganese slag and its concrete were studied using a scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The compressive strength of SMC30 and SMC50 obtained were 37.3 MPa and 51.1 MPa, respectively, on the 28-day. The alkaline treatment smoothest the matrix, while the acid treatment roughens the composition of the silicon manganese slag, according to SEM. The functional group demonstrated a major improvement in FTIR, while EDS revealed a high content of both silicon (Si) and manganese (Mn) elements. As a result, it can be observed that the power of SMC increases as the curing time increases for samples with complete replacement of normal aggregates using silicon slag.

The nanocarbon-based mixture was shown to be an effective adsorbent for removing dyes and heavy metals from wastewater via adsorption. The goal of this research was to prepare and investigate the properties of a bio-carbon mixture made from Dabai (Canarium odontophyllum) nutshell with the addition of titanium dioxide (TiO2) and montmorillonite (MMT) clay. Fourier transform infrared (FTIR) spectroscopy was used to determine the functional groups of raw carbon and potassium hydroxide (KOH)-activated carbon (AC). The FTIR analysis of the active carbon revealed that the active carbon had more surface chemistry than the non-AC. Scanning electron microscopy (SEM) analysis was used to compare the raw and AC morphologies and the developed nanocarbon. The results were confirmed using energy dispersive X-ray (EDX) analysis to verify the elements in the studied sample. The SEM analysis revealed that the structure of both the carbon samples was irregular, granular, and porous. BET analysis showed that nano-activated carbon had higher surface area compared to activated carbon itself. Response surface methodology (RSM) was used in DesignExpert 13.0 software for the sample composition development to achieve the best performance of the developed nanocarbon as an adsorbent.

Significant effects of organoclay and poly(melamine-co-formaldehyde)-methylated (PMFM) impregnation on the mechanical, morphological, and thermal characteristics of raw pulai wood were investigated in this work. The material's modulus of elasticity (MOE) as well as the maximum compression force (MCF) of the impregnated organoclay/PMFM pulai wood samples were optimized using a designed experiment. The MOE and MCF models had R-2 values of 0.9228 and 0.8340, respectively. After the impregnation of organoclay/PMFM pulai wood samples, the MOE and MCF increased considerably, indicating that the pulai wood's mechanical characteristics had improved. The compositional analysis verified the polymerization and dispersion of organoclay and PMFM. Using Fourier transform infrared spectroscopy, reduction in the hydroxyl groups was detected. The impregnated organoclay/PMFM pulai wood samples had successfully filled the pores and cell cavities, as seen by scanning electron microscopy. The thermal stability of the impregnated organoclay/PMFM pulai wood samples was better than that of the raw pulai wood, with a higher glass transition temperature as determined by differential scanning calorimetry. The thermogravimetric study revealed that the impregnated organoclay/PMFM pulai wood samples had higher decomposition temperatures than the raw pulai wood sample.

Biodegradable plastics are among the most promising materials to replace conventional petroleum-based plastics that have caused many adverse impacts on the environment, such as pollution (land, water, etc.) and global warming. Among a range of biodegradable plastics, poly lactic acid (PLA) is not only widely available but also safe to be decomposed after its usage without polluting the environment. PLA is also in parity with other conventional plastics such as PP, PET in terms of various properties suitable for industrial usage such as mechanical, physical, biocompatibility and processability. Thus, PLA has become the most used biopolymers in many industries such as agriculture, automotive and packaging by having these characteristics. Its higher demand has contributed to a stable increment in the global PLA market. In fact, over the years, the market for PLA has grown up and will keep on expanding in the future. Overall, the PLA-based bioplastic would be an excellent substitute for the existing conventional plastics in various applications, hence will serve to protect the environment not only from pollution but also work as a sustainable and economical product. This paper will review all the recent related works and literature on PLA as the biodegradable material regarding its properties, usability, productivity and substitute.

This study investigated sawdust waste as a partial replacement for sand as fine aggregates in producing lightweight sawdust concrete (SC). In Malaysia, sawmills create a considerable amount of wood waste, which has caused environmental issues as it is turned into burning materials. This investigation used sawdust to substitute river sand in the concrete mix proportions of 5%, 10%, 15%, and 20% by weight. The impact of compressive strength, workability, and density was investigated by changing the amount of sand replacement with sawdust. Concrete cubes of 100 mm × 100 mm × 100 mm were produced for compressive strength tests. The compressive strength was measured after 7, 14, and 28 days of cure. Furthermore, the strength and density of conventional concrete and sawdust concrete were examined. The study's findings demonstrated increased sawdust content in concrete decreased compressive strength and density. According to the findings of the experiments, the optimal sawdust content is found to be 5%, with the highest strength of 17.2 MPa after 28 days. As a consequence of the results and observations, sawdust concrete may be used for lightweight structural applications.KeywordsSawdust wasteFine aggregatesConcreteCompressive strengthDensity

Due to its non-toxicity and environmentally friendly nature, carbohydrate-based fatty acid (CFA) esters are encouragingly used as antimicrobials and synthetic intermediates. They also are notably applied in food, surfactant, and pharmaceutical industries. In this respect, methyl 2,6-di-O-isopentanoyl-α-D-glucopyranoside (2), synthesized in a single step from methyl α-D-glucopyranoside (1), was converted into four other 3,4-di-O-acyl esters (3 – 6). All the newly synthesized CFA esters (2 – 6) were applied for the first time to study decay resistances of aspen (Populus tremula) and pine (Pinus sibirica) wood from decay caused by white-rot (Polyporous versicolor L.ex. Fr.) and brown-rot (Postia placenta (Fr). Cke.) fungi. Most of these CFA esters protected these woods from fungal attack, reduced deterioration, and preserved the weight percentage of woods at a certain point. It is noted that the CFA esters compounds reduced the deterioration and suppressed the weight percentage loss of wood at a certain point and from low to moderate decay resistances against the selected fungi.

Generalised extreme value (GEV) distribution is traditionally applied to model extreme event and their return period. There are three parameters (location, scale and shape) in GEV distribution, which needs to be determined before its application. Different techniques have been developed to estimate the parameters of the GEV distribution. There is no specific guidance regarding the optimal method for estimating the parameters of the GEV distribution. This paper investigated the sensitivity of different parameters estimation techniques which are being commonly used in the application of the GEV distribution. Stationary GEV was adopted for the homogeneous data sets; whereas, non-stationarity GEV was implemented for the non-homogeneous data sets. Four methods were applied in the estimation of the GEV distribution parameters for four different timescales. The methods were applied in extreme rainfall modelling using extreme rainfall data in Tasmania, Australia as a case study. It was found that adoption of any GEV parameter estimation methods does not change the GEV type in Tasmanian extreme rainfall. The length of the data series has significant influence on the values of the GEV distribution parameters. The Fréchet type GEV distribution is suitable in most of the analysed rainfall stations in Tasmania.

A computer program has been developed to control the firing process of ZnO varistors. The binder burnout and shrinkage stages are controlled through a closed feedback loop using a i286 based personal computer. The effect of rate-controlled sintering (RCS) on the formation of microstructure and simultaneously on electrical characteristics of varistors has been studied in arrester block with Vnom=5 kV and a diameter of 42 mm. Leakage, watt loss and non-linear coefficient has been improved and microstructure with low porosity has been achieved by RCS.

The energy-absorption capability of zinc oxide varistors depends on both the binder burn-out and shrinkage rate of the disc. This paper presents a study of the development of a failure model of a varistor disc with a nominal voltage Vnom=5 kV and a diameter of 42 mm manufactured by rate-controlled sintering. The mathematical model has been developed in terms of the binder burn-out rate and the shrinkage rate for the electrical-energy capability during initial failure and 50% failure of the samples, to secure the optimum temperature profile for the sintering operation. The effect of the binder burn-out and the shrinkage rate has been investigated using design of experiments and response surface methodology (RSM). Response surface contours were constructed by computer, giving the response in terms of the binder burn-out rate and the shrinkage rate.

Metal matrix composites (MMCs) are a new range of advanced materials. Recently the strength of particulate reinforced MMCs have been analyzed theoretically by dislocation models which were developed originally to analyze the dispersion hardening mechanism of two-phase metals [1]. This paper presents the development of a compressive strength model for aluminium matrix composite (Al-6061/SiC) manufactured by powder metallurgy route. The mathematical prediction models for compressive strength have been developed in terms of sintering temperature, sintering time and volume fraction of reinforcement. These variables were investigated using design of experiments and response surface methodology. Response surface contours were constructed giving the response in terms of sintering temperature, time and volume fraction of reinforcement.