Abstract
This experimental study evaluates the properties of concrete produced using natural coarse aggregate (NCA) and recycled coarse aggregate (RCA) obtained from demolished structures, with a particular focus on how RCA content influences compressive strength. The objective is to assess the feasibility of employing RCA as a sustainable alternative to natural aggregate in structural concrete. A series of mixes incorporating four RCA replacement ratios (0%, 50%, 75%, and 100%) was developed to produce an eco-friendly concrete that reduces construction related waste and environmental pollution. The results show that concrete compressive strength decreases as the RCA replacement ratio increases. At 28 days, the reductions in compressive strength were 7.80% for 50% RCA, 12.89% for 75% RCA, and 14.45% for 100% RCA compared with the natural aggregate control mix. However, the reduction up to 50% RCA was relatively small, indicating that partial replacement can meet structural performance requirements while supporting sustainability goals. The findings also confirm that compressive strength increases significantly with curing age, although higher RCA content leads to lower early age and long-term strength. Notably, the 0% and 50% RCA mixes retained more than 90% of their 28 days strength at 120 days. A parallel numerical analysis conducted using ABAQUS demonstrated a consistent increase in axial deformation with higher RCA replacement ratios, confirming the associated reduction in stiffness and aligning with the experimental mechanical trends. Overall, the results highlight the importance of considering both curing age and RCA content when evaluating the mechanical behavior of recycled aggregate concrete and demonstrate its potential for sustainable structural applications.
Abstract
In the present study, dynamic bihavior analysis of sandwich plate has been performed by employing refined shear deformation plate theory. Novel imperfections types are studied which may arise during fabrication and are named as even porosity, uneven porosity, logarithmic-uneven porosities, linear-uneven porosities. The material gradation along the direction of thickness is taken as per power law (P-FGM) and sigmoid law (S-FGM). The face layers are modeled as functionally graded (FG) across their thickness, while the core consists of a homogeneous ceramic layer. The governing equations are formulated using Hamilton's principle, and a closed-form solution for a simply supported rectangular plate is derived through the Navier method. Extensive parametric study to investigate the natural frequency have been performed for different side to thickness ratio (a/h), aspect ratio (a/b) and porosity parameters (Ζ). The accuracy of the proposed theory is verified by comparing selected results with data from existing literature.
Key Words
dynamic behavior; functionally graded materials; Navier's method; porosity; refined plate theory
Address
Ahmed Keddouri: Faculty of Natural and Life Sciences, Department of Earth and Universe Sciences, Ziane Achour University of Djelfa, Algeria
Nafissa Zouatnia: Department of Civil Engineering, University of Tiaret, 14000 Tiaret, Algeria
Lazreg Hadji: Department of Civil Engineering, University of Tiaret, 14000 Tiaret, Algeria/ Suleyman Demirel University, Isparta, 32260, Turkiye
Royal Madan: Department of Mechanical Engineering, Graphic Era (Deemed to be University), Dehradun, India
Hassen Ait Atmane: Laboratory of Structures, Geotechnics and Risks, Department of Civil Engineering, Hassiba Benbouali University of Chlef, Chlef, Algeria
Rohit Kumar Singh Gautam: Department of Mechanical Engineering, Teerthanker Mahaveer University, Moradabad, 244001, India
Atteshamuddin S. Sayyad: Department of Structural Engineering, Sanjivani College of Engineering Kopargaon, Savitribai Phule Pune University, Kopargaon, Maharashtra, India
Abstract
Lactose is a major sugar naturally present in milk. It is co-existing as α- and β-isomers. Unfortunately, due to lactose intolerance, which affects a significant portion of global populations, detection, quantification and separation of lactose composition is crucial. Hence highlighting the importance of accurate lactose detection and monitoring in food products to ensure consumer safety and health. Previously, molecularly imprinted polymer (MIP) has been applied for designing synthetic polymer for detecting specific target molecule with high selectivity. In this research, molecular docking was employed to create optimum selectively binding for both isomer form of Lactose-MIP. The objective is to virtually screen 38 functional monomers (FM), building block of Lactose-MIP, specifically common silane monomer, evaluating their binding energy (ΔE), binding site of Lactose-MIP and non-covalent molecular interactions. All 38 FM were docked with both α- and β-form of lactose using AutoDock 4.2. Performing the ligand-ligand docking, we found that all the FM were successfully bound non-covalently with lactose. Based on the ranking of lowest binding-energy (ΔE), 3-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS) was the favourable to bind with α-Lactose, while Ureidopropyltrimethoxysilane (UPTMS) is with β-Lactose. The study reveals multiple binding sites with different conformation of Lactose-FM complexes positions, indicating possibility of multiple ratio and monomer combination for developing Lactose-MIP.
Key Words
docking study; in-silico screening; lactose; molecularly imprinted polymer
Address
Rosfatihah Roslim, Azalina Mohamed Nasir, Noorhidayah Ishak: Faculty of Chemical Engineering & Technology, Kompleks Pusat Pengajian Jejawi 3, Universiti Malaysia Perlis (UniMAP) 02600 Arau, Perlis, Malaysia
Ang Lee Sin: Department of Physics, Faculty of Applied Sciences, Universiti Teknologi MARA (Perlis), 02600 Arau, Perlis
Abstract
Eutrophication happened due to excessive phosphate release from agricultural and industrial run off causing biodiversity deterioration and polluted the water. This research aims to develop a high-performance Graphene Oxide Ion Imprinted Polymer (GO-IIP) for the selective removal of phosphate in water solution. To overcome the high mass transfer resistance typical of conventional bulk polymerization, surface ion imprinted polymerization (SIIP) can offer significantly faster binding kinetics capacity and higher template accessibility which offering superior reusability. Meanwhile Graphene Oxide is added as supporting material in this SIIP to provide oxygen functional group allowing easy covalent modification and high surface area for imprinted to occur. Methodologies integrate a structured three-phase approach of computational screening, laboratory synthesis, and adsorption performance in aqueous solution. Initially, seven functional monomers allylthiourea (AT), acrylic acid (AA), acrylamide (AM), methacrylic acid (MAA), itaconic acid (ITA), 2-hydroxyethyl methacrylate (2-HEMA), and methyl methacrylate (MMA) were evaluated using HyperChem software to simulate energy interactions with the phosphate template. Results identified allylthiourea as the most effective monomer, exhibiting the strongest theoretical affinity with an interaction energy (ΔE) of -85.0508 kcal/mol and also in experimental test with highest value of imprinting factor 2.098. The synthesized GO-IIP are characterized using SEM, FTIR, and TGA to confirm successful grafting and thermal stability.
Key Words
allylthiourea; computational screening; graphene oxide; phosphate removal; surface ion imprinted polymer
Address
Siti Khadijah Mohamad Ya, Noorhidayah Ishak, Siti Khalijah Mahmad Rozi: Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, Malaysia
Adilah Anuar: Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, Malaysia/ Centre of Excellence for Frontier Material Research, Universiti Malaysia Perlis, No. 64-66, Blok B, Taman Pertiwi Indah, Jalan Kangar - Alor Setar, Kampung Seriab, 01000 Kangar, Perlis
Abdelmnim Altwaiq: Department of Chemistry, College of Arts and Sciences, University of Petra, P.O. Box 961343, Amman 11196, Jordan
Mohd Azrie Awang: Faculty of Food Science and Nutrition,Universiti Malaysia Sabah, Jalan UMS,88400 Kota Kinabalu, Sabah, Malaysia
Abstract
The escalating global production of synthetic petrochemical-based plastics poses severe environmental challenges, with their resistance to degradation causing widespread accumulation in landfills and oceans. Traditional recycling methods prove insufficient, necessitating innovative solutions. This study targets polypropylene (PP), a widely used but has lower recycling rates compared to other commodity plastics. Employing a bio-based strategy, the research explores the potential of Aspergillus terreus and Engyodontium album for PP degradation. Fungi, with their enzymatic capabilities, present a promising avenue for breaking down PP. The investigation pioneers the exploration of untested fungi for PP degradation, elucidating the degradation mechanism and end-product formation. Through targeted microorganism selection and pre-treatment strategies, UV and heat were identified as effective enhancers of enzymatic degradation, particularly for PP film. A. terreus and E. album fungi successfully degraded treated PP film, confirmed through chemical, thermal, and morphological analyses. These efforts hold potential for significantly improving PP degradation and offer insights into optimising processes, thereby contributing to a more sustainable approach to plastic waste management and holding broader implications for addressing the degradation of other synthetic polymers.
Address
Amira Farzana Samat, Adilah Anuar, Norhidayah Abd Aziz, Khairunissa Syairah Ahmad Sohaimi: Faculty of Chemical Engineering and Technology, Universiti Malaysia Perlis, 02100 Padang Besar, Perlis, Malaysia
Ali Abbas: School of Chemical and Biomolecular Engineering, Faculty of Engineering and IT, The University of Sydney, NSW 2006, Australia
Dee Carter: School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, NSW, 2006, Australia
Abstract
The conversion of biomass waste into adsorbents offers a sustainable approach for water treatment. This study aims to investigate the effect of pyrolysis temperature at 400, 600, and 800 °C on biochar derived from palm kernel shell for methylene blue (MB) adsorption. Biochar samples were characterized using yield determination, X-ray fluorescence (XRF), CHNS elemental analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Adsorption performance was evaluated at different MB concentrations (10, 30, and 50 ppm) and adsorbent dosages (0.05, 0.15, and 0.25 g). The biochar yield decreased from 76.2% at 400 °C to 72.8% at 600 °C and 57.2% at 800 °C, while conversion increased from 23.8% to 42.8%. CHNS analysis revealed carbon enrichment and increased aromaticity with increasing temperature, whereas SEM and XRD analyses confirmed significant morphological and structural transformations during carbonization. Adsorption results showed that MB removal efficiency (RE) decreased slightly with increasing MB concentration but improved with increasing adsorbent dosage. Biochar produced at 600 °C demonstrated the best adsorption performance, achieving a maximum RE of 68.09% at an adsorbent dosage of 0.25 g. These findings suggest that an optimum pyrolysis temperature is required to balance biochar yield, carbonization, and adsorption effectiveness.
Address
Adel Ali Azawqari: Faculty of Mechanical Engineering & Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia/ Faculty of Engineering and Information Technology, Taiz University, Taiz, Yemen
Sri Raj Rajeswari Munusamy, Nur Maizatul Shima Adzali: Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia/ Centre of Excellence for Frontier Materials Research (CFMR), Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
Nur Farhana Diyana M. Yunos: Faculty of Mechanical Engineering & Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia/ Centre of Excellence for Frontier Materials Research (CFMR), Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
Mohammad Nayazy Hairil Abd Wahab: Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
open access 📚 Virtual Special Issue