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Purpose: This study aims to determine the percentage depth dose (PDD) of a phantom material made from soy-lignin bonded Rhizophora spp. particleboard coated with a gloss finish by using Monte Carlo Geant4 Application for Tomographic Emission (GATE) simulation. Materials and Methods: The particleboard was fabricated using a hot pressing technique at target density of 1.0 g·cm−3 and the elemental fraction was recorded for the simulation. The PDD was simulated in the GATE simulation using the linear accelerator Elekta Synergy model for the water phantom and Rhizophora phantom, and the results were compared with the experimental PDD performed by several studies. Beam flatness and beam symmetry were also measured in this study. Results: The simulated PDD for Rhizophora and water was in agreement with the experimental PDD of water with overall discrepancies of 0% to 8.7% at depth ranging from 1.0 to 15.0 cm. In the GATE simulation, all the points passed the clinical 3%/3 mm criterion in comparison with water, with the final percentage of 2.34% for Rhizophora phantom and 2.49% for the water phantom simulated in GATE. Both the symmetries are all within the range of an acceptable value of 2.0% according to the recommendation, with the beam symmetry of the water phantom and Rhizophora phantom at 0.58% and 0.28%, respectively. Conclusions: The findings of this study provide the necessary foundation to confidently use the phantom for radiotherapy purposes, especially in treatment planning.

Over the last 50 years, the use of wood adhesives in the manufacturing of wood-based panel goods has increased the efficiency of wood resources. Wood adhesives are becoming more popular as the need for wood-based panels grows. By 2028, the global market for wood adhesives is expected to reach 21.8 billion dollars. Even though urea-formaldehyde (UF), phenol-formaldehyde (PF), melamine-formaldehyde (MF), phenol-resorcinol-formaldehyde (PRF), and resorcinol-formaldehyde (RF) resins are excellent in terms of bonding performance, workability, quality, and economy, they consist of harmful or toxic chemical agents derived from fossil resources, which make their application severely limited. This review aims to go through the most significant ‘green’ wood adhesives for manufacturing high-performance wood-based panels, such as lignin, tannin, protein, natural rubber, emulsion polymer isocyanate (EPI), 1C PUR polyurethane (for glue-laminated wood and cross-laminated timber), PMDI (for particleboards, medium-density and low-density fiberboards), carboxylic acid, and vegetable oil. The physical and mechanical characteristics of bio-based wood adhesives, as well as the development of sustainable, greener, and high-performance bio-based wood adhesives, are discussed in this work. Original research papers and review articles are among the most important sources since they provide complete information on the most recent developments in sustainable, eco-friendly, and high-performance bio-based wood adhesives.

Biodegradable adhesives prepared using three different forms of soy protein-based products (defatted soy flour/soy protein concentrate/soy protein isolate), sodium hydroxide, and itaconic acid polyamidoamine-epichlorohydrin (IA-PAE) with 0 wt%–20 wt% substitution rates were utilized to enhance the production of mangrove wood composites. 1H nuclear magnetic resonance, differential scanning calorimetry, and ultra-high-resolution field emission scanning electron microscopy were employed to characterize the composite samples. Other measurements involved the determination of viscosity, pH, physical, mechanical, dimensional stability, CT numbers, and relative electron density parameters. The ideal curing conditions for the composite bio-adhesives were found to be 15 wt% IA-PAE, 602.50 ± 172.21–391.11 ± 105.82 mPa s, pH 11.0, 180 °C, and 18 min, respectively. The improved physiochemical characteristics of DSF, SPC, and SPI confirmed that NaOH/IA-PAE was integrated into the adhesive system and ameliorated the overall performance of the resulting composites. The results showed that all composite samples, except for those bonded with 0 wt% and 5 wt% IA-PAE, matched up with the quality specification stated in the JIS A-5908 and ASTM D1037. Samples D1, D2, and D3 exhibited optimum characteristics, demonstrating their uses in the development of low-toxicity and sustainable reference tissue substitute phantom in radiological areas.

Background: Different compositions of DSF/NaOH/IA-PAE/R. spp. composite particleboard phantoms were constructed. Methods: Photon attenuation characteristics were ascertained using gamma rays from 137Cs and 60Co. Absorbed doses at the location of an ionization chamber and Gafchromic EBT3 radiochromic films were calculated for high-energy photons (6 and 10 MV) and electrons (6, 9, 12, and 15 MeV). Results: The calculated TPR20,10 values indicate that the percentage discrepancy for 6 and 10 MV was in the range of 0.29–0.72% and 0.26–0.65%. It was also found that the relative difference in the dmax to water and solid water phantoms was between 1.08–1.28% and 5.42–6.70%. The discrepancies in the determination of PDD curves with 6, 9, 12, and 15 MeV, and those of water and solid water phantoms, ranged from 2.40–4.84%. Comparable results were found using the EBT3 films with variations of 2.0–7.0% for 6 and 10 MV photons. Likewise, the discrepancies for 6, 9, 12, and 15 MeV electrons were within an acceptable range of 2.0–4.5%. Conclusions: On the basis of these findings, the DSF/NaOH/IA-PAE/R. spp. particleboard phantoms with 15 wt% IA-PAE addition level can be effectively used as alternative tissue-equivalent phantom material for radiation therapy applications.

In this work, Rhizophora spp. particleboard phantoms were made using SPI-based adhesives, modified with sodium hydroxide and itaconic acid polyamidoamine-epichlorohydrin (0, 5, 10, and 15 wt%). An X-ray computed tomography (CT) imaging system was used to ascertain the CT numbers and density distribution profiles of the particleboards. The SPI-based/NaOH/IA-PAE/Rhizophora spp. particleboard phantoms with 15 wt% IA-PAE addition level had the highest solid content, flexural strength, flexural modulus, and internal bonding strength of 36.06 ± 1.08%, 18.61 ± 0.38 Nmm−2, 7605.76 ± 0.89 Nmm−2, and 0.463 ± 0.053 Nmm−2, respectively. The moisture content, mass density, water absorption, and dimensional stability were 6.93 ± 0.27%, 0.962 ± 0.037 gcm−3, 22.36 ± 2.47%, and 10.90 ± 0.86%, respectively. The results revealed that the mass attenuation coefficients and effective atomic number values within the 16.59–25.26 keV photon energy region, were close to the calculated XCOM values in water, with a p-value of 0.077. Moreover, the CT images showed that the dissimilarities in the discrepancy of the profile density decreased as the IA-PAE concentrations increased. Therefore, these results support the appropriateness of the SPI-based/NaOH/IA-PAE/Rhizophora spp. particleboard with 15 wt% IA-PAE adhesive as a suitable tissue-equivalent phantom material for medical health applications.

The selected functional properties of rice husk/wood blended particleboards which include thermal analysis, limiting oxygen index, morphological analysis, and mechanical properties have been investigated. Rice husk/wood particleboards were produced with one step hot press casting technique using citric acid to improve the compatibility in the particleboards with calcium oxide and aluminum oxide as flame retardants. The results showed improvement in the mechanical properties, flame retardancy, and thermal stability with the addition of flame retardants to the particleboards. The aluminum oxide synergy with citric acid in rice husk/wood particleboards gave the best flame retardancy.

Cassava is a type of crop popular in Asian countries. It can be easily cultivated and grows to a mature plant in 9 months. Considering its availability, this work studied activated carbon based on cassava stem. Ofloxacin was chosen as the adsorbate, simulating the wastewater from the pharmaceutical industry. Cassava stem was ground into particles and heated to the activated state, 787 °C. The cassava-stem-activated carbon was further treated with the surface modifier, namely sodium hydroxide and zinc chloride, to study the improvement in ofloxacin adsorption. Prepared adsorbents were characterised using the SEM, FT-IR, XRD, DSC and TGA methods before being evaluated through batch adsorption, thermodynamic, and kinetic studies. The surface area analysis indicates that treatment of the activated carbon with NaOH and ZnCl2 increases the surface area due to the removal of organic content by the chemicals. Better ofloxacin adsorption of all activated carbon samples can be obtained with solutions at pH 8. An endothermic reaction was predicted, shown by higher ofloxacin adsorption at a higher temperature, supported by a positive value of ΔH° in the thermodynamic studies. The negative values of ΔG° revealed that adsorptions were spontaneous. The higher R2 values indicate that the adsorption process follows the pseudo-second-order equation of kinetic study. The maximum adsorption capacities are 42.37, 62.11, 62.89 and 58.82 mg/g for raw cassava stem (RC), cassava-stem-activated carbon (AC), NaOH-modified cassava-stem-activated carbon (NAC), and ZnCl2 modified cassava-stem-activated carbon (ZAC). The adsorption capacity is good compared to previous works by other researchers, making it a possible alternative material for the pharmaceutical industry’s wastewater treatment.

The objective of this study was to explore the potential of particleboard made from a type of mangrove hardwood, i.e. Rhizophora spp., bonded with soy protein, and evaluate its suitability as a water-equivalent material. First, the bark of the raw hardwood was removed from its trunk prior to the grinding process. Next, three particleboards were fabricated with different percentages of soy protein (0 %, 8 %, and 16 %). The fabricated particleboards were each characterised for their density, mechanical properties, effective atomic number, morphological structure, elemental composition, and probability of photon interaction. The dimensional stability of each fabricated particleboard was evaluated according to the Japanese Industrial Standard (JIS) A 5908, Type-8, while the other properties were compared with that of the standard water phantom. There were improvements shown by the fabricated particleboards with 8 % and 16 % soy protein, in terms of dimensional stability. The morphological images also revealed that the particleboards bonded with 8 % and 16 % soy protein, have better contact between the particles, compared to the one bonded with 0 % soy protein. The elemental analysis, effective atomic number, and probability of photon interaction of the fabricated phantom showed identical results with that of the standard water phantom. Based on the findings of this study, the Rhizophora spp. particleboard bonded with soy protein has opened up possibilities for another potential alternative of solid phantom material as water-equivalent material.

In this study, we aimed to prepare and characterise hydrogel formulations using cellulose nanocrystals (CNCs), alginate (Alg), and polyethylene glycol diacrylate (PEGDA). The CNC/Alg/PEGDA formulations were formed using a double network crosslinking approach. Firstly, CNC was extracted from oil palm trunk, and the size and morphology of the CNCs were characterised using TEM analysis. Secondly, different formulations were prepared using CNCs, Alg, and PEGDA. The mixtures were crosslinked with Ca2+ ions and manually extruded using a syringe before being subjected to UV irradiation at 365 nm. The shear-thinning properties of the formulations were tested prior to any crosslinking, while the determination of storage and loss modulus was conducted post extrusion after the Ca2+ ion crosslink using a rheometer. For the analysis of swelling behaviour, the constructs treated with UV were immersed in PBS solution (pH 7.4) for 48 h. The morphology of the UV crosslinked construct was analysed using SEM imaging. The extracted CNC exhibited rod-like structures with an average diameter and length of around 7 ± 2.4 and 113 ± 20.7 nm, respectively. Almost all CNC/Alg/PEGDA formulations (pre-gel formulation) displayed shear-thinning behaviour with the power-law index η < 1, and the behaviour was more prominent in the 1% [w/v] Alg formulations. The CNC/Alg/PEGDA with 2.5% and 4% [w/v] Alg displayed a storage modulus dominance over loss modulus (G′ > G″) which suggests good shape fidelity. After the hydrogel constructs were subjected to UV treatment at 365 nm, only the F8 construct [4% CNC: 4% Alg: 40% PEGDA] demonstrated tough and flexible characteristics that possibly mimic the native articular cartilage property due to a similar water content percentage (79.5%). In addition, the small swelling ratio of 4.877 might contribute to a minimal change of the 3D construct’s geometry. The hydrogel revealed a rough and wavy surface, and the pore size ranged from 3 to 20 µm. Overall, the presence of CNCs in the double network hydrogel demonstrated importance and showed positive effects towards the fabrication of a potentially ideal 3D bioprinted scaffold.

Water treatment using activated carbon is widely accepted, despite its high production cost. Therefore, this study was aimed to investigate the potential of cassava stem in activated carbon form for methylene blue (MB) dye uptake from water. Raw cassava stem (RCS) was also utilized to evaluate the difference between cassava stem in its raw form and after being converted to the activated carbon (ACS). The MB adsorption from water using the RCS and ACS was done in this study. The batch adsorption study showed fast MB uptake by ACS at 60 min contact time, while higher adsorbent dosage and higher pH contributed to higher adsorption percentage. The thermodynamic study showed positive values of ∆H° of ACS, indicating that the adsorption process of MB was endothermic. Meanwhile, the negative value of ∆G° showed that the adsorption processes of MB were spontaneous. The thermodynamic study showed higher fitting to Langmuir isotherm, with data from the kinetic study showing better pseudo-second-order equation fitting, which suggests the chemisorption process had happened. The highest adsorption recorded by ACS was 384.61 mg/g, indicating the possibility of cassava stem as the lower cost raw material for activated carbon production with excellent adsorption characteristics.

Here, we report the extracellular biosynthesis of silver nanoparticles (AgNPs) and determination of their antibacterial and anticancer properties. We also explore the efficacy of bioAgNPs incorporated in cellulose nanocrystals (CNCs) and alginate (Alg) for the formation of an antibacterial hydrogel film. Streptomyces sp. PBD-311B was used for the biosynthesis of AgNPs. The synthesized bioAgNPs were characterized using UV-Vis spectroscopy, TEM, XRD, and FTIR analysis. Then, the bioAgNPs’ antibacterial and anticancer properties were determined using TEMA and cytotoxicity analysis. To form the antibacterial hydrogel film, bioAgNPs were mixed with a CNC and Alg solution and further characterized using FTIR analysis and a disc diffusion test. The average size of the synthesized bioAgNPs is around 69 ± 2 nm with a spherical shape. XRD analysis confirmed the formation of silver nanocrystals. FTIR analysis showed the presence of protein capping at the bioAgNP surface and could be attributed to the extracellular protein binding to bioAgNPs. The MIC value of bioAgNPs against P. aeruginosa USM-AR2 and MRSA was 6.25 mg/mL and 3.13 mg/mL, respectively. In addition, the bioAgNPs displayed cytotoxicity effects against cancer cells (DBTRG-0.5MG and MCF-7) and showed minimal effects against normal cells (SVG-p12 and MCF-10A), conferring selective toxicity. Interestingly, the bioAgNPs still exhibited inhibition activity when incorporated into CNC/Alg, which implies that the hydrogel film has antibacterial properties. It was also found that bioAgNP-CNC/Alg displayed a minimal or slow release of bioAgNPs owing to the intermolecular interaction and the hydrogel’s properties. Overall, bioAgNP-CNC/Alg is a promising antibacterial hydrogel film that showed inhibition against the pathogenic bacteria P. aeruginosa and MRSA and its application can be further evaluated for the inhibition of cancer cells. It showed benefits for surgical resection of a tumor to avoid post-operative wound infection and tumor recurrence at the surgical site.

This article encompasses the method related to image segmentation of the Field Emission Scanning Electron Microscope (FESEM) images of Acacia Mangium Wood derived Activated Carbons under different conditions. Image segmentation using Hue-Saturation-Value (HSV) thresholding method was adapted to identify the different pattern composition in the grayscale images by varying the intensity Value (V) and keeping Hue (H) and Saturation (S) to zero, and each pattern was considered as one type of element that constituted the Activated Carbon. The algorithm was developed to compute the percentage of each pattern using non-zero pixels, and on the basis of different patterns, different elements having certain percentage of composition were recorded. Later, these results were compared with the Energy Dispersive X-ray Spectroscopy (EDS) to cross check the difference in percentage of each element present at the surface of the Activated Carbon. Part of this result is published in the article [1], “Comparison of surface properties of wood biomass Activated Carbons and their application against rhodamine B and methylene blue dye” Surfaces and Interfaces vol. 11 (2018) pp1–13. • The methods involved will be useful for characterization of Activated Carbon materials. • Image segmentation using HSV thresholding will inspire other researchers to apply similar concept on other materials. • Different patterns obtained for FESEM images using HSV thresholding was able to determine the presence of multiple elements present in the prepared Activated Carbon samples.

Rhizophora spp. particleboard with the incorporation of lignin and soy flour as binders were fabricated and the influence of different percentages of lignin and soy flour (0%, 6% and 12%) on the physico-mechanical properties of the particleboard were studied. The samples were characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray fluorescence (XRF) and internal bonding. The results stipulated that the addition of binders in the fabrication of the particleboard did not change the functional groups according to the FTIR spectrum. For XRD, addition of binders did not reveal any major transformation within the composites. SEM and EDX analyses for all percentages of binders added showed no apparent disparity; however, it is important to note that the incorporation of binders allows better bonding between the molecules. In XRF analysis, lower percentage of chlorine in the adhesive-bonded samples may be advantageous in maintaining the natural properties of the particleboard. In internal bonding, increased internal bond strength in samples with binders may indicate better structural integrity and physico-mechanical strength. In conclusion, the incorporation of lignin and soy flour as binders may potentially strengthen and fortify the particleboard, thus, can be a reliable phantom in radiation dosimetry applications.

Crystallinity of cellulosic fiber directly affects the physical and chemical behavior of the individual fiber and ultimately the product made from. In a controlled condition, if the natural fiber is exposed to enzymatic hydrolysis, its crystallinity improves without affecting the cellulose component of the fiber. In this work, four basic factors for enzymatic reaction, i.e., temperature, time, pH, and enzyme amount, were optimized using response surface methodology (RSM). The response was taken as the fiber crystallinity index, measured by X-ray diffraction method. The optimum treated fiber was further analyzed for the field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA) and results were compared with untreated fiber. Medium density fiberboards (MDF) were manufactured from optimum treated fiber and its tensile properties and water resistance properties were compared with MDF made from untreated fiber. The observation revealed a maximum of up to 14% increment in fiber crystallinity index (CrI) as compared to untreated fiber. The MDF prepared from optimum treated fiber exhibits improved tensile property and lower water absorption property as compared to MDF prepared from untreated fibers.

Oil palm trunk is a kind of biomass rich in starch content. Oil palm trunk waste was available throughout the year in Malaysia and Indonesia due to continuous felling of nonproductive, over 25-year-old trees. Even though some manufacturers were using it in plywood and veneer production, they are hard to handle which later becomes less favorable raw materials due to a high moisture content where combination with a high starch content quickly attracts fungus and wood-decaying agents. The objective of this work was to evaluate properties of experimental wood composite panels, manufactured using oil palm-extracted starch modified with glutardialdehyde (OPSMG) as a binder. Different analyses were employed to characterize the properties of the samples besides evaluation of bending, internal bonding strength, and dimensional stability of the panels. Characterization on the functional group using the FT-IR analysis showed presence of aldehyde groups and ketone stretching vibrations at 1736.05 cm−1 and 1596.25 cm−1, which proves the presence of glutardialdehyde besides formation of bonding between the OPSMG and the woody materials. The XRD analysis showed the starch modification had lowered the crystallinity index which in turn increased the strength of the manufactured wood composites. The OPSMG wood composites were also found to have lower thermal stability, as evaluated using the TGA analysis. It was recorded that the maximum modulus of rupture for OPSMG wood composites was achieved at the 0.80 g/cm3 density level with an average value of 15.446 N/mm2 which showed 38.00% increment in strength between those two types of wood composites. Thickness swelling after immersion in water can still be improved by incorporating the moisture-repellent material later. After analyzing the results, it was concluded that modified oil palm starch has the potential to be used as an environment friendly binder for wood composite making.

The large availability and cheap price of oil palm (Elaeis guineensis) trunk makes it an attractive raw material for value-added applications, but its low density and high carbohydrate content are highly undesirable. In this work, oil palm trunk (OPT) was steam-pretreated and compressed at high temperature. The compressed OPT was laminated using polyvinyl acetate (PVAc) using either 250 or 500 g/m2 adhesive spread rate (ASR). Soil burial testing was performed for three months on two different samples to study the deterioration and weight loss by bio-organisms. The laminated, compressed OPT formed with high PVAc ASR was found to be more durable against bio-organisms. The thermal stability of the compressed OPT was studied by thermogravimetric analysis (TGA), and it was observed that the weight loss was lower for steam-pretreated samples compared to those without steam pretreatment. Moisture absorption-desorption testing of compressed OPT was performed, and a hysteresis curve was generated. It was found that laminated, compressed OPTs with 500 g/m2 ASR had lower moisture absorption than those with 250 g/m2 ASR.

In the last two decades, laccases have received much attention from researchers because of their specific ability to oxidize lignin. This function of laccase is very useful for applications in several biotechnological processes, including delignification in the pulp and paper industry and the detoxification of industrial effluents from the textile and petrochemical industries. This review focuses on laccase-mediated fiberboard synthesis. Growing concerns regarding the emission of formaldehyde from wood composites has prompted industrialists to consider the fabrication of green composites. Laccase-mediated fiber treatments oxidize the lignin component without affecting the cellulose structure. As a result, free radicals are generated on the fiber surface, and these can act as potential reactive sites for further cross-linking reactions in board manufacturing. Binderless fiberboards prepared using such methods can be considered as green composites because the manufacturing process involves no additional resin.

Palm sap extracted from old oil palm trunks was previously found to contain sugar and nutrients (amino acids and vitamins). Some palm saps contain a low content of sugar due to differences in species or in plant physiology. Here we condensed palm sap with a low content of sugar using flat membrane filtration, then fermented the condensed palm sap at high temperature using the thermotolerant, high ethanol-producing yeast, Kluyveromyces marxianus. Ethanol production under non-optimum conditions was evaluated. Furthermore, the energy required to concentrate the palm sap, and the amount of energy that could be generated from the ethanol, was calculated. The condensation of sugar in sap from palm trunk required for economically viable ethanol production was evaluated.

Juvenile Neolamarckia cadamba or kelempayan tree has been harvested from forest plantation and converted into sawn timber. Some basic properties of timber such as physical and mechanical were determined from different parts of the tree namely lower, center and upper. The physical properties were evaluated. The mechanical properties were conducted using small test clear specimens. The results indicated that the physical and mechanical properties of the lower portion of the trunk were significantly superior compared to the upper portion of the trunk. The investigation revealed that the wood be able to use as a substitute material of the furniture components after some modification undertaken on its properties.

Formaldehyde emissions from conventional particleboards raise issues of health and safety. One of the potential solutions is binderless particleboards made without using synthetic adhesives. However, the physical and mechanical properties of untreated binderless particleboards are relatively poor compared to conventional particleboards. This research aims to reveal the potential of using steam pretreatment to improve binderless particleboard properties made from oil palm trunk. The oil palm trunk particles were treated with steam pretreatment for different durations of time (20, 40, 60 min). The chemical constituents of the treated and untreated particles were evaluated. The binderless particleboards were made from treated and untreated particles. In addition, panels using untreated oil palm trunk particles with 10% urea−formaldehyde resin were made and used as a comparison. The boards were evaluated according to European Standards. The results indicated that the hemicellulose and starch content gradually reduced with the progression of steam pretreatment. The physical and mechanical properties were improved by increasing steam pretreatment duration. The steam pretreatment was able to improve the properties of binderless particleboards made from oil palm trunk. However, the performance of steam-pretreated binderless particleboard in this study is not compatible with the particleboards made using 10% urea−formaldehyde.

Glucose oxidase (EC 1.1.3.4) sensors that have been developed and widely used for glucose monitoring have generally relied on electrochemical principle. In this study, the potential use of colorimetric method for glucose detection utilizing glucose oxidase-magnetic cellulose nanocrystals (CNCs) is explored. Magnetic cellulose nanocrystals (magnetic CNCs) were fabricated using iron oxide nanoparticles (IONPs) and cellulose nanocrystals (CNCs) via electrostatic self-assembly technique. Glucose oxidase was successfully immobilized on magnetic CNCs using carbodiimide-coupling reaction. About 33% of GOx was successfully attached on magnetic CNCs, and the affinity of GOx-magnetic CNCs to glucose molecules was slightly higher than free enzymes. Furthermore, immobilization does not affect the specificity of GOx-magnetic CNCs towards glucose and can detect glucose from 0.25 mM to 2.5 mM. Apart from that, GOx-magnetic CNCs stored at 4 °C for 4 weeks retained 70% of its initial activity and can be recycled for at least ten consecutive cycles.

The objective of this study was to investigate the physical properties, including density, moisture content, thickness swelling, and water absorption, in addition to the mechanical properties such as modulus of rupture, modulus of elasticity, and internal bond strength of experimental panels that were made from rubberwood particles using oil palm starch modified with epichlorohydrin as a binder. The samples were also examined using X-ray diffractometry, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The panel properties were compared with the properties of panels manufactured using native oil palm starch. The properties of starch and starch adhesives were also investigated. The panels were produced based on 0.60 g/cm3 and 0.80 g/cm3 target densities and two press times of 15 and 20 min. The results showed that the 0.80 g/cm3 panels manufactured using modified oil palm starch and with 15 min of press time had better properties than did the others. However, a lower thickness swelling value was found for panels with density 0.60 g/cm3 and with 15 min of press time. Based on the results in this study, it can be concluded that the use of oil palm starch modified with epichlorohydrin as a binder has the potential to be used as a green adhesive in commercial applications.

Compressed wood, which is formed by a process that increases the wood’s density, aims to improve its strength and dimensional stability. Compressed wood can be used in building and construction, especially for construction of walls and flooring. Currently, supplies of wood are becoming limited, and the oil palm tree has become one of the largest plantation species in Malaysia. Oil palm trunk could be an appropriate choice for an alternative source for compressed wood. This paper aims to review the current status of oil palm biomass, including the availability of this tree, in order to illustrate the potential of oil palm biomass as an alternative source for compressed wood. Up to the present there has been insufficient information regarding the manufacturing conditions and properties of compressed wood from oil palm trunk. This paper will cover the background of compressed wood and the possibilities of producing compressed wood using oil palm trunk as a raw material.

The study was done to investigate the antioxidant, total phenol content and antifungal characteristics of phenolics compounds of extracts from Cinnamomum iners (Reinw. ex Blume-Lauraceae) wood. Radical scavenging activity method of DPPH was used to determine antioxidant activity of the extracts. Four fungus, namely white fungi (Pycnoporus sanguineus, Trametes versicolor, Fomitopsis palustris) and brown fungi (Gleophyllum trabeum) were used to determine the antifungal activity of the Cinnamomum iners extracts. The results showed that ethanol extract had the highest antioxidant activity with EC50 value of 14.96 µg/mL followed by chloroform extract with EC50 >30 µg/mL while water extract did not show any significant antioxidant activity. For total phenolics content, ethanol extract resulted on the highest value of 56.23%, followed by chloroform extract and water extract having total phenolic values of 51.13% and 7% respectively. On the other hand for antifungal assay, ethanol extract produce the widest inhibition zone followed by chloroform extract and water extract respectively.

The objective of the study was to investigate physical and mechanical properties of experimental particleboard panels manufactured from oil palm (Elaeis guineensis) biomass without using any adhesives. Different parts of oil palm, including the core and mid sections of trunks, fronds, bark, and leaves, were used to make the panels with an average target density of 0.80g/cm3. Based on the test results, it seems that panels made from bark and leaves did not have satisfactory strength and dimensional stability. However, the panels having particles from the core portion of the trunks exhibited the highest modulus of rupture and internal bond strength but lowest in thickness swelling and water absorption values among the samples. The panels made with particles of mid-section of trunks and fronds followed the samples having core portion trunks material. Three types of raw material, namely fronds, mid-, and core-parts of the trunks appeared as though they could have potential to manufacture particleboard panels with acceptable properties based on requirements stated in Japanese Industrial Standard (JIS). Similar to the above findings, surface quality of the samples were also found acceptable for the panels made from three types of particles. Based on the results of this work, oil palm in the form of biomass could be considered as an environmentally friendly alternative raw material to manufacture binderless particleboard panels.

The feasibility of the production of cellulose acetate (CA) from recycled paper dust from carton boxes was examined. Two pre-treatments were carried out on the carton box’s paper dust (CPD) to improve the pulp properties for better effect of synthesis. The results showed that the acid and oxygen-alkaline pretreatments were capable of increasing the alpha-cellulose content from 80.5 percent to 87.3 percent and 85.3 percent, respectively. Both pre-treatments also decreased the hemicellulose and ash contents by more than 50 percent. The degree of substitution (DS) of the resultant CA from pre-treated paper dust was improved from 1.94 to 2.13-2.16. The CA that was synthesized from the recycled paper dust showed comparable DS and had a similar trend of Fourier Transform Infrared (FTIR) spectra. Both pretreated pulps also showed an increment in the degree of crystallinity and had maximum degradation effect of temperature when compared to CPD CA. However, all the cellulose acetates produced showed a lower DS and thermal stability compared to commercial cellulose acetate (C CA). The degree of crystallinity of all the cellulose acetate was decreased in comparison to the original material.

The aim of this study was to observe the effects of alkaline activating agents on the characteristics, composition, and surface morphology of the designed activated carbons. Activated carbons were prepared by pyrolysis of Acacia mangium wood in the presence of two basic activating agents (calcium oxide and potassium hydroxide). The extent of impregnation ratio of precursor to activating agents was fixed at 2:1(w/w). Prior to pyrolysis, 24 hours soaking was conducted at 348 K. Activation was carried out in a stainless steel capped graphite crucible at 773 K for 2 hours in the absence of purge gas. The burn-off percentage was found to be 70.27±0.93% for CaO activated carbon (COAC) and 73.30±0.20% for KOH activated carbon (PHAC). The activating agents had a strong influence on the surface functional groups as well as elemental composition of these activated carbons. Characterization of the activated carbon obtained was performed with field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and nitrogen adsorption as Brunauer, Emmett and Teller (BET) and Dubinin-Radushkevich (DR) isotherms.

The new 1, 2, 3, selenadiazole derivative (3) was prepared from friedelin (1) via the corresponding semicarbazone (2) using Lalezari cyclization. The compounds were prepared, separated and characterized on the basis of microanalysis and spectral studies. The isolated friedelin and its selenadiazole were screened in vitro for their antimicrobial activities against various pathogenic bacterial were found to be highly active against all the selected pathogens. Compound 3 showed an inhibition zone of 14 mm and 12 mm respectively against highly resistant S. albus and C. albicans. A general mechanistic scheme for these reactions is also suggested based on current and previous results. Keywords: Friedelin, semicarbazone, ketomethylene, cyclization, selenadiazole

In the title isoquinoline-1,3,4-trione derivative, C18H9NO5, the five-membered ring of the indane fragment adopts an envelope conformation with the nitrogen-substituted C atom being the flap. The planes of the indane benzene ring and the isoquinoline-1,3,4-trione ring make a dihedral angle of 82.06 (6)°. In the crystal, molecules are linked into chains extending along the bc plane via C—H...O hydrogen-bonding interactions, enclosing R22(8) and R22(10) loops. The chains are further connected by π–π stacking interations, with centroid-to-centroid distances of 3.9050 (7) Å, forming layers parallel to the b axis.

In the indane ring system of the title molecule, C13H12O4, the hydroxy-bearing C atom is 0.134 (1) Å out of the plane of the remaining essentially planar atoms (r.m.s. deviation = 0.010 Å). In the crystal, molecules are linked into chains along the b axis by intermolecular O—H...O hydrogen bonds. Additional stabilization is provided by weak intermolecular C—H...O hydrogen bonds.

In the title molecule, C10H8N2O4, the imidazolidine ring adopts a twisted conformation. In the crystal, the molecules are linked via a pair of bifurcated intermolecular O—H...O hydrogen bonds, forming an inversion dimer. The dimers are further linked via N—H...O hydrogen bonds into a tape along the b axis.

In the title compound, C8H7N3O2·H2O, the 2-methyl-5-nitro-1H-benzimidazole molecule, excluding the methyl H atoms, is approximately planar, with a maximum deviation of 0.137 (1) Å. The crystal structure is stabilized by water molecules via N—H...O(water), O(water)—H...O and O(water)—H...N hydrogen bonds, forming sheets parallel to the (100) plane. A short intermolecular contact between the benzene and imidazole rings, with a centroid–centroid distance of 3.6419 (10) Å, indicates a π–π interaction.

The asymmetric unit of the title compound, C27H46, contains two crytallographically independent cholest-5-ene molecules (A and B). In each molecule, the three six-membered rings are all in chair conformations, while the five-membered ring is in a twist conformation. The terminal isopropyl group of molecule A has a (−)-gauche conformation, whereas that of molecule B has a (+)-gauche conformation. No significant intermolecular interactions are observed in the crystal structure.

In the title compound, C21H22O5, the mean planes of the pyran and dimethoxyphenyl rings are nearly perpendicular to one another, with the dihedral angle between them being 88.21 (8)°. The pyran ring adopts a boat conformation whereas the two fused cyclohexane rings adopt envelope conformations. In the crystal, molecules are linked into a three-dimensional network by intermolecular C—H...O hydrogen bonds.

The asymmetric unit of the title compound, C14H17N3O3·0.25H2O, comprises two independent organic molecules and a water molecule lying on a crystallographic twofold rotation axis with 50% site occupancy. In both independent molecules, the cyclohexene rings adopt envelope conformations but superposition of the two molecules shows that the flap atoms point in opposite directions. In the crystal, N—H...O and C—H...O hydrogen bonds interconnect adjacent molecules into a three-dimensional network. Weak intermolecular π–π aromatic stacking interactions [centroid–centroid distances = 3.4985 (9) and 3.6630 (9) Å] are also observed.

The asymmetric unit of the title quinoxaline compound, C10H9N3O2, contains two crystallographically independent molecules (A and B). The quinoxaline ring systems are essentially planar, with maximum deviations of 0.006 (1) and 0.017 (1) Å, respectively, for molecules A and B. In molecule A, the dihedral angle formed between the quinoxaline ring system and nitro group is 10.94 (3)° [6.31 (13)° for molecule B]. In the crystal, molecules are linked into chains propagating along [001]: one forms zigzag chains linked by C—H...O hydrogen bonds, whilst the other forms ladder-like chains by way of C—H...N and C—H...O hydrogen bonds. The packing is further consolidated by weak π–π interactions [range of centroid–centroid distances = 3.5895 (7)–3.6324 (7) Å].

In the title compound, C14H18N2O, the benzimidazole grouping is close to planar, with a maximum deviation of 0.042 Å; the six-membered non-aromatic ring adopts an envelope conformation. In the crystal structure, molecules are linked into infinite sheets lying parallel to the bc plane by O—H...N and C—H...O hydrogen bonds.

In the decahydrophenanthrenone ring system of the title compound, C27H44O, the two cyclohexane rings adopt chair conformations, whereas the cyclohexene ring adopts an envelope conformation. The cyclopentane ring is twisted. In the crystal structure, molecules are stacked along the a axis, but no significant intermolecular interactions are observed.

In the title compound, C15H8N2O, the fused ring system is approximately planar, with a maximum deviation of 0.039 (1) Å. In the crystal, weak intermolecular C—H...O interactions help to establish the packing.

The title compound, C27H43ClO, is a steroid derivative composed of a saturated carbon fused-ring framework with an alkyl side chain. The A and C rings have chair conformations and the B and D rings assume half-chair conformations. The cholesterol side chain is fully extended with a gauche, trans conformation of the terminal methyl groups. In the crystal structure, the molecules are aligned in an antiparallel fashion, forming alternate layers. These layers are then linked via C—H...O hydrogen bonds, forming a three-dimensional network.

In the title compound, C34H51NO2, the dihedral angle between the planes of the phenyl ring and the carbonyl group is 9.30 (2)°. No significant intermolecular interactions are observed in the crystal structure. The C5H11 fragment is disordered over two positions with site occupancies of 0.611 (6) and 0.389 (6).

The crystal structure of the title compound, C15H14O6·H2O, has been redetermined from single-crystal X-ray data. The structure was originally determined by Peet et al. [J. Heterocycl. Chem. (1995), 32, 33–41] but the atomic coordinates were not reported or deposited in the Cambridge Structural Database. The ethyl substituent is disordered over two sites with refined occupancies of 0.815 (6) and 0.185 (6). The indeno group is almost planar [maximum deviation 0.0922 (14) Å] and makes an angle of 68.81 (4)° with the furan ring. The fused ring molecules are assembled in pairs by intermolecular O—H...O hydrogen bonds. The resulting dimers are also hydrogen bonded to the water molecules, forming double-stranded chains running along the a axis.

In this study, some characteristics of Rhizophora spp. particleboards bonded with Serishoom (traditional animal–based adhesive) as a phantom material was investigated. The Rhizophora spp. particleboards were fabricated in two Serishoom adhesive treatment levels (6% and 12%) with three Rhizophora spp. particle sizes (≤ 149 µm, 149 µm – 500 µm, and 500 µm – 1000 µm) at 1 g.cm-3 of the target density. The internal bond strength and the dimensional stability of the Serishoom-bonded Rhizophora spp. particleboards were improved by using the smaller Rhizophora spp. particle size and the higher Serishoom adhesive treatment level. The effective atomic numbers of the Serishoom-bonded Rhizophora spp. particleboards were determineted to be 7,56 to 7,58 by an energy dispersive X-ray, which is in good agreement with those of water and breast tissue. In addition, the density distribution profiles of the fabricated Serishoom-bonded Rhizophora spp. particleboards were determined by the Kriging method with the use Surfer8 computer software, which indicated that there was good density homogeneity throughout the Serishoom-bonded Rhizophora spp. particleboards. The results showed a potential of the Serishoom-bonded Rhizophora spp. particleboard bonded with Serishoom to be used as a phantom material.