Fourier Transform Research Articles

Microplastics in the Atmospheric Deposited Dust Collected from Different Traffic Intersections in Dhaka City

Plastic particles less than 5 mm in size, known as microplastics, can infiltrate the environment from a variety of sources. This study aimed to assess the presence of microplastics (MPs) in the atmosphere at fifteen major traffic intersections in the greater Dhaka city from July to August 2022.The deposition rate (DP) of MPs was calculated and the observed DPs value ranged from 1.11×106 MPs/m2/day to 5.78×106 MPs/m2/day with a portion of microplastics exhibiting fluorescence activity. Fourier Transform Infrared (FTIR) spectroscopy was used to analyze the functional groups present in microplastics. The identified polymer compositions of MPs were polyethylene (PE), Nylon-6 and natural polymers (cellulose and rubber). The current study highlights the data and knowledge gaps on the atmospheric transport of microplastics and their impact to the deterioration of overall urban air quality. Dhaka Univ. J. Sci. 72(2): 07-14, 2024 (July)

The optical properties of nano-structural α-Fe2O3 dependence on the shape.

Three different crystal morphologies of α-Fe2O3, including uniform hexagonal, square, and rhombic shapes, were prepared according to the aqueous-thermal reaction. The hexagonal-shaped α-Fe2O3 was enclosed by the 104 plane, while the square and rhombic structures were enclosed by the 110 plane. Two absorption peaks at 455 and 532 cm-1 were found for the perpendicular (⊥) modes, and one absorption peak at 650 cm-1 appeared for the parallel (||) mode for hexagon-shaped α-Fe2O3 during analysis by Fourier-transform infrared spectroscopy. However, the peaks of square- and rhombic-shaped α-Fe2O3 for perpendicular (⊥) mode blueshifted, and the former two peaks merged together forming a broad band at approximately 480 cm-1. For Raman spectra determination, the peaks arose from the Brillouin zone center, and two additional peaks were observed at 660 and 1320 cm-1, belonging to 1 longitudinal optical (1LO) and 2 longitudinal optical (2LO) modes. All three materials exhibited higher intensities when excited at a wavelength of 633 cm-1. Furthermore, in the polarization state, the centers of all peak positions slightly shifted for hexagon-shaped α-Fe2O3, but all peak positions for square-shaped and rhombic-shaped α-Fe2O3 exhibited a significant blueshift. The structure of hexagon-shaped α-Fe2O3 was relatively tolerant regarding the polarization properties of vibration modes; however, the symmetry of crystal square-shaped and rhombic-shaped α-Fe2O3 changed, subsequently revealing different optical properties. RESEARCH HIGHLIGHTS: The hexagon-shaped, square-shaped, and rhombic-shaped α-Fe2O3 enclosed by different planes were synthesized. The Fourier Transform Infrared spectrometer peaks of α-Fe2O3 depended on their hexagon, square and rhombic shapes. Compared with hexagon-shaped α-Fe2O3, the Raman peaks for square and rhombi ones significantly shifted. The hexagon-shaped α-Fe2O3 is relatively tolerant regarding the polarization properties.

Dynamic Complexity of a Discrete-time Prey-Predator Model with Mixed Functional Responses

Plastic particles less than 5 mm in size, known as microplastics, can infiltrate the environment from a variety of sources. This study aimed to assess the presence of microplastics (MPs) in the atmosphere at fifteen major traffic intersections in the greater Dhaka city from July to August 2022.The deposition rate (DP) of MPs was calculated and the observed DPs value ranged from 1.11×106 MPs/m2/day to 5.78×106 MPs/m2/day with a portion of microplastics exhibiting fluorescence activity. Fourier Transform Infrared (FTIR) spectroscopy was used to analyze the functional groups present in microplastics. The identified polymer compositions of MPs were polyethylene (PE), Nylon-6 and natural polymers (cellulose and rubber). The current study highlights the data and knowledge gaps on the atmospheric transport of microplastics and their impact to the deterioration of overall urban air quality. Dhaka Univ. J. Sci. 72(2): 15-24, 2024 (July)

Green synthesis of reduced graphene oxide using Persea americana mill. extract: Characterization, oxygen reduction reaction and antibacterial application

Reduced graphene oxide (rGO) has garnered tremendous attention due to its salient properties that make it applicable in various electrochemical and environmental remediation fields. However, the commonly used chemical method to obtain rGO from graphene oxide (GO) involves toxic chemicals making both the process and product toxic and expensive. In the present work, the suitability of Avocado (Persea americana Mill) seed extract to reduce as-synthesized GO to rGO was investigated fully by optimising the reducing parameters such as the pH, temperature, amount of extract and reduction time. The formation of rGO from GO was confirmed with UV–Vis spectrophotometry (UV–Vis), Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and the thermogravimetric analysis (TGA). The optimal conditions for reducing GO with avocado seed extract are pH 8, 100 °C, and 12 h. The average thickness and width for the rGO was 5.55 nm and 11.39 nm accordingly. While GO exhibited a ζ of −29.9.3 mV, the reduced GO possessed a − 38.2 mV. Calculations from the Kotouckey-Levich's equation demonstrated that the obtained rGO can potentially be applied as an oxygen reduction reaction (ORR) catalyst for the generation of hydrogen peroxide since it follows a 2e− pathway mechanism where hydrogen peroxide is generated as an intermediate. Additionally, the avocado seed extract reduced GO demonstrated a slight growth inhibition of methicillin resistant S. aureus (MRSA).

Eco-benevolent synthesis of ZnO-NPs and ZnO-MFs from Inula oculus-christi L. (Asteraceae) with effective antioxidant, antimicrobial, DNA cleavage, and decolorization efficiencies.

As a result of the changes occurring globally in recent years, millions of people are facing challenging and even life-threatening diseases such as cancer and the COVID-19 pandemic, among others. This phenomenon has spurred researchers towards developing and implementing innovative and environmentally friendly scientific methods, merging disciplines with significant technological potential, such as nanotechnology with medicinal plants. Therefore, the focus of this research is to synthesize zinc nanoparticles (ZnO-NPs) and microflowers (ZnO-MFs) using extracts of the medicinal plant I. oculus christi prepared in n-hexane and methanol as new bioreduction and capping agents through a simple and environmentally friendly chemical approach. Optical, thermal, and morphological structural analyses of ZnO-NPs and ZnO-MFs were conducted using Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), and Field Emission Scanning Electron Microscopy (FE-SEM). Metabolic profiles of extracts from different plant parts were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) and supported by visualization of contents through Principal Component Analysis (PCA), hierarchical cluster analysis heatmaps, and Pearson correlation graphs. Interestingly, ZnO-NPs and ZnO-MFs exhibited strong antioxidant properties and demonstrated particularly potent antimicrobial activity against Micrococcus luteus NRRL B-4375, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 strains compared to standard antibiotics. Furthermore, ZnO-NPs and ZnO-MFs showed excellent plasmid DNA-cleavage activity of pBR322 with increasing doses. The photocatalytic performance of the synthesized ZnO-NPs and ZnO-MFs was evaluated for methylene blue (MB), congo red (CR), and safranin-O(SO) dyes, demonstrating remarkable color removal efficiency. Overall, the results provide a promising avenue for the green synthesis of ZnO-NPs and ZnO-MFs using I. oculus-christi L. inflorescence and pappus extracts, potentially revolutionizing biopharmaceutical and catalytic applications in these fields.

Enhancing Health Data Assessment Performance: A Multi-Sensor Focused Study for Public Health

The term health data assessment performance described the process of assessing efficacy of acquiring and reporting health data. Multi sensor approach for predicting diabetes in public health scenarios, multi sensor for public health assimilates assorted data source and addresses community health challenges widely and efficiently. In this study, we proposed a Horse Herd Fused Discriminant Generative Adversarial Network (HHF-DGAN) algorithm for diabetes prediction. Sensor-based diabetes data is gathered from kaggle, and then data preprocessing using z-score normalization is inaccurate records from a dataset. To extract feature from the pre-processed data, Short-Time Fourier Transform (STFT) is used for dimensionality reduction. HHF-DGAN is a public health technique that addresses diabetes prevention and management while also including multi sensor assessment data. The proposed methods are to evaluate F1-score (86%), precision (92%), recall (93%), and accuracy (93%). The effectiveness of the suggested strategy in improving prediction reliability for diabetes detection in public health circumstances has been established by comparing it with existing methods. The study concludes field of healthcare assessments with a robust framework for leveraging multi sensor data and deep learning methods in disease prediction.

Development of a Suitable Method for the Synthesis of New Thiadiazoles Using Hydrazonoyl Halides

Background: Hydrazonoyl halides and methylhydrazinecarbodithioate have been generally utilized in the synthesis of heterocycles. Methods: This study describes a new and simple method to prepare new thiadiazoles from the reaction of N-(naphthalen-1-yl)-2-oxopropanehydrazonoyl chloride or ethyl 2-chloro-2-(2-(naphthalen-1-yl)hydrazono)acetate with methylhydrazinecarbodithioate in the presence of basic medium under reflux. In this study, the synthetic schemes are designed to show the chemical reactions. Elements analysis, Fourier Transform Infrared Spectroscopy (FT-IR), Mass Spectrom-etry (MS), and Nuclear Magnetic Resonance (NMR) are used to identify and characterize the final compounds. Results: There are two ways to synthesize the final thiadiazoles molecules. The first can be through nucleophile substitution of thiolate of methylhydrazonecarbodithioate to the chlorinated carbon of hydrazonoyl. Hydrochloric acid is then removed to provide an S-alkylated intermediate. Methanethiol is eliminated from this intermediate by an in situ intra-molecular cyclocondensation process to give the final products. The subsequent [3+2] cy-cloaddition involving 1,3-dipolar cycloadditions of nitrilimines to C=S is succeeded by the re-moval of methanethiol. Conclusion: This approach utilizes affordable, readily accessible reagents and simple reaction conditions to produce new thiadiazole derivatives with satisfactory yields.

Modelling and optimization of shea butter biodiesel engine performance evaluation using response surface methodology

In this study, the performance and emission parameters of compression ignition (CI) diesel engine powered by shea butter biodiesel blends with diesel via clay doped ionic liquid catalyst (CD-IL) were modelled, optimized and predicted using Response surface methodology (RSM) technique. Using the (American Society for Testing Materials) ASTM D 6751 criteria, the produced biodiesel's quality was successfully evaluated. The biodiesel blends (B0, B50, B100), load (100, 200, 300)kg and speeds (1400, 1800, 2200) rpm were considered as the factors while Brake thermal efficiency, Brake specific consumption, Brake power, Nitrogen oxide and carbon monoxide emission were considered as the responses of the shea butter biodiesel engine. Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Brunaeuer Emmet and Teller (BET) were used to analyze the catalyst before and after treatment to ascertain their suitability for the process. The capability of the models was evaluated using the correlation coefficient (R2) and mean square error (MSE). The second-order polynomial model is shown in the Analysis of Variance (ANOVA) with an (R2 -0.9948, Adjusted R2–0.9880, Predicted R2–0.9163) for brake thermal efficiency, (R2 -0.9908, Adjusted R2–0.9790, Predicted R2–0.8529) for brake specific consumption,(R2 -0.9988, Adjusted R2–0.9972, Predicted R2–0.9807) for brake power, (R2 -0.9995, Adjusted R2–0.9988, Predicted R2–0.9917) for Carbon monoxide emission and (R2 -0.9979, Adjusted R2–0.9951, Predicted R2–0.9659) Nitrogen dioxide emission demonstrating the model's acceptance. The optimal condition for shea butter biodiesel engine performance of brake thermal efficiency (16.3%), brake specific consumption(0.83),brake power (1.5), Carbon monoxide emission (175 ppm) and Nitrogen oxide (150 ppm) was obtained at a biodiesel blend (B50), load of 300 kg and speed of 2200 rpm. The 3D model graphs showed the process parameters impacted on the response significantly with better combustion, cleaner air.fuel ration blend, lesser friction loss and air consumption. Hence the proposed RSM modelling tool for shea butter biodiesel engine performance prediction had the best performance at (B50) (50% biodiesel and 50% diesel).

Effect of mixed metal oxide‐based catalysts for the removal of hydrophobic phthalates from water

AbstractContaminants of emerging concern (CECs) such as phthalic acid esters (PAEs) are ubiquitous, toxic and persistent in aquatic environments. Current study explored mixed metal oxide catalysts derived from magnesium aluminium (MAH), magnesium aluminium ruthenium (MAR‐H), magnesium aluminium nickel (MANH) hydroxides and copper aluminium hydroxides of ammonium (CAM‐Am) and sodium molybdate (CAM‐Na) to remove dibutyl phthalate (DBP) and di‐2‐ethyl hexyl phthalate (DEHP) from water. Powder X‐ray diffraction (XRD) studies of the catalysts before and after the treatment showed that their structures were stable and robust. During Fourier Transform Infrared (FTIR) studies, vibrational bands or peaks of ester and alkane functional groups of DBP and DEHP were observed at all the catalysts after treatment. Thermogravimetric analysis (TGA) confirmed phthalate adsorption at the five catalysts. Hydrolysis of DBP and DEHP was observed during treatment using CAM‐Am and CAM‐Na that was analysed and quantified using total organic carbon (TOC), high performance liquid chromatography (HPLC) and high‐resolution mass spectrometry (HRMS). From TOC analyses, optimal conditions of 500 mg L−1 catalyst dosage and 30 h treatment time were deduced for catalytic hydrolysis of DBP and DEHP. Present study illustrated that the catalysts MAH and MANH can adsorb PAEs while CAM‐Na can adsorb and hydrolyse them.

Selective signal enhancement in Fourier space as a tool for discovering ultrastructural organization of macromolecules from in situ TEM

We present a Fourier transform (FT) based analytical method that allows to obtain of ultrastructural details from TEM images at sub-nanometer scale applying a selective filtering for singular macromolecule electron microscopy density information. It can be applied to high-pressure frozen, frozen hydrated and epoxy freeze substituted and embedded biological species. Both 2D projections and orthoslices from reconstructed tomograms can be used as a source of structural information. The key to the method is to select the macromolecule or organelle of interest with an accuracy of ≥ 7 – 3 nm (depending on pixel size of initial tilt series or singular image acquisition) and explore both the central low frequency FT intensity and diffraction regions to obtain the spatial structural organization and its dimensional characteristics, respectively. We also introduce a structure-specific selective mask FT filtering approach that can significantly improve image information even in poorly contrasted TEM of resin sections without heavy-metal been used. The described method elucidates chromatin architecture without the need of averaging. A zigzag symmetry of 30 nm diameter chromatin fibers which in general is a controversial topic of research has been identified for C. elegans cells in vivo with sub-nanometer details being preserved in the images.

Engineering fully quaternized (Dimethylamino)ethyl methacrylate-based photoresins for 3D printing of biodegradable antimicrobial polymers

Nowadays, medical devices or implants are widely used in the medical field to treat different diseases. However, bacterial infections are one of the significant problems associated with medical devices and are recognized as a concern in healthcare worldwide. Addressing this problem has driven the exploration of new materials with potent antibacterial properties. In this regard, quaternary ammonium compounds (QACs), which are organic salts with an alkane chain and a charged part of quaternary ammonium groups, came up with a potent antibacterial activity. Herein, we report for the first-time dimethylamino ethyl methacrylate (DMAEM) derived quaternary ammonium monomer and crosslinker to prepare photoresins for DLP (Digital light processing) 3D printing. The structure of the synthesized monomer and crosslinker was confirmed via FTIR (Fourrier Transform Infrared) and 1H NMR (Hydrogen Nuclear Magnetic Resonance) while the physicochemical properties of the 3D printed polymer were investigated using TGA (Thermogravimetric Analysis), DSC (Differential Scanning Calorimeter) and UTM (Universal testing machine). By optimizing the printing conditions and monomer to crosslinker ratio, we can print high-resolution 3D-printed objects. Additionally, in vitro biodegradation, cytocompatibility, and hemocompatibility tests revealed that the printed polymers are biodegradable, cytocompatible, and hemocompatible in nature. More importantly, the printed polymers exhibited strong antibacterial activity against both gram-negative and gram-positive bacteria, suggesting their potential utility in personalized antibacterial medical devices.

Enhancement of Wound Dressings Through Cerium Canadate and Hydroxyapatite-Infused Hyaluronic acide and PVA Membranes: A Comprehensive Characterization and Biocompatibility Study

This study explores the development of advanced wound dressings by enhancing traditional bandages with suitable biomedical materials. We utilized Hyaluronic Acid (HA) and Polyvinyl Alcohol (PVA) as a polymeric matrix to create a novel membrane. Employing a film casting technique, we incorporated varying ratios of biological nanoparticles—Hydroxyapatite (HAP) and Cerium Vanadate (Ce₃(VO₄)₄)—to improve the wound dressing's properties. The resulting films were characterized using several techniques, including X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, Raman spectroscopy, and Thermogravimetric Analysis (TGA). Wettability assessments provided insights into the surface characteristics of the scaffolds, revealing a diverse range of contact angles that reflect varying hydrophilic properties. Notably, the pure PVA/HA sample exhibited a contact angle of approximately 31.2° ± 12.1°, indicating excellent hydrophilicity and a strong capacity for drug absorption. However, the incorporation of nanoparticles resulted in an increase in contact angles, suggesting a slight reduction in hydrophilicity. Specifically, the addition of HAP produced a contact angle of about 36.5° ± 6.7°, while the addition of Ce₃(VO₄)₄ resulted in a contact angle of approximately 38.6° ± 6.4°. A significant increase in contact angle to 42.23° ± 4.8° was observed when mixing the nanoparticles, though the introduction of Graphene Oxide (GO) reduced the angle to 37.4° ± 0.35°, enhancing the hydrophilic properties of the composite. Furthermore, in vitro cell viability testing was conducted to confirm the biocompatibility and bioactivity of the fabricated scaffolds. The results demonstrated the ability of the scaffolds to promote cell growth, with an increase of 88.4% in cell growth ratio observed at a suitable drug concentration of approximately 0.68 μg/ml. These findings highlight the potential of the developed scaffolds to enhance the wound healing process.

Kinetics and soft computing evaluation of Linseed oil transesterification via CD-BaCl-IL catalyst

A novel clay-doped ionic liquid and BaCl (CD-BaCl-IL) heterogeneous catalyst for biodiesel synthesis from linseed oil (LSO) was generated after 4 h of calcination at 600°C using Scanning Electron Micrograph (SEM), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray fluorescence (XRF) was used to evaluate the catalyst's processability. After optimization using response surface methodology (RSM), the second-order polynomial model was shown in the Analysis of variance (ANOVA) with R2 values of 0.9947, Adj R2 (0.9850), and Pred R2 (0.8594), demonstrating model acceptability. The maximum biodiesel yield (97.097 %) was obtained with 2.6 wt% catalyst, 6 mol/mol methanol/molar ratio, 1.5 h, 50 °C, and 400 rpm agitation. ANFIS predicted biodiesel yield more accurately than ANN (R2 = 0.999, MSE = 0.27594), with the lowest MSE (R2 = 0.99, MSE = 0.00038). Under optimal conditions, this study employed a kinetic model based on two elementary chemical processes: Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW). The LHHW model accurately described CD-BaCl-IL catalyst experimental data at 50 °C, with favourable parameters, an R2 value of 0.9348, and a variance of 2.61E-8. The surface reaction between adsorbed triglyceride and alcohol dictated the rate-determining step. Temperature increased the rate, indicating an endothermic process. The reaction's activation energy and frequency factor were 10.22 kJ/mol and 6.41 h-1, respectively. Linseed biodiesel met the D6751 criterion.

Multi-scale RWKV with 2-dimensional temporal convolutional network for short-term photovoltaic power forecasting

Improving the accuracy of Photovoltaic (PV) power forecasting is crucial for optimizing the schedule of power stations and maintaining the grid stability. However, PV power generation exhibits complex periodicity and is significantly influenced by weather conditions, introducing instability, intermittency, and randomness, making accurate PV power forecasting a challenging task. Therefore, this study proposes a multi-scale Receptance Weighted Key Value with 2-Dimensional Temporal Convolutional Network (MSRWKV-2DTCN) for PV power forecasting, which can learn periodicity and interdependencies of data and improve forecasting accuracy. Firstly, the proposed model identifies multi-periodicity of PV power data with the Fast Fourier Transform (FFT). Subsequently, we combine these identified periods with the canonical time mixing block of Receptance Weighted Key Value (RWKV) and introduce a multi-scale time mixing block to learn periodicity of data. Finally, to explore complex interdependencies of historical data, we replace the channel-mixing block of RWKV with a multi-scale 2-Dimensional Temporal Convolutional Network (2D TCN). Experiments were conducted on real-world datasets collected from Yulara solar system in Australia to validate the performance of the proposed model. Comparisons with other PV power forecasting models and ablation studies confirm that the MSRWKV-2DTCN achieves higher accuracy in short-term PV power forecasting.

Synthesis and application of biodegradable seed coatings to assess the infestation of chickpea (Cicer arietinum L.) seeds by pests

Pulses such as chickpeas face significant damage caused by pests during their growth and storage. The overuse of synthetic pesticides on seeds requiring several cycles of active ingredient applications results in increased expenses and environmental risks by contaminating soil, water, and air. These risks of seed damage without use of harmful pesticides can be reduced by coating the seeds with biodegradable seed coatings. The objective of the study was assessing the effectiveness of biodegradable seed coating in managing stored grain pests and to examine its effects on the germination of chickpeas. For this study chickpea (Cicer arietinum L.) seeds were coated with biodegradable coatings like polyvinyl alcohol with multinutrients, neem oil, chitosan and mucilage-starch nanocrystals. The characterization of coatings was carried out using Fourier Transform Infrared Spectroscopy, X-ray Diffraction and Scanning Electron Microscope. Germination of coated and uncoated chickpea seeds was observed by paper-towel method after 5 and 10 days. Chitosan coated seeds had greatest root length (3.10 ± 0.05 cm), shoot length (3.93 ± 0.08 cm), dry weight (0.24 ± 0.05 g), fresh weight (0.43 ± 0.05 g), germination rate (98.87 %) and vigour index (639.09 ± 0.05) followed by polyvinyl alcohol with multinutrients coated seeds, mucilage-starch nano crystals coated seeds and control group after ten days. The lowest root length (0.97 ± 0.14 cm), shoot length (1.53 ± 0.12 cm), dry weight (0.1 ± 0.005 g), fresh weight (0.21 ± 0.14 g), germination rate (65 %) and vigour index (163.75 ± 4.72) were displayed by neem oil-coated seeds. The impact of stored grain pests was evaluated and it was shown that neem oil had the highest efficacy in controlling pulse beetle infestations followed by chitosan, polyvinyl alcohol with multinutrients and mucilage-starch nano crystals. Neem oil coating enhanced pest mortality by 95 % after 15 days, reduced seed damage by 16.3 % and minimized seed weight loss by 10.6 % after 30 and 45 days. Biodegradable seed coating is a cost-effective and environment friendly way to improve seed performance and protect crops sustainably.

Physiological response of Bidens pilosa to cadmium stress monitored by Fourier Transform Infrared Spectroscopy

The cadmium (Cd) pollution of soil causes serious environmental problems. The present paper deals with the physiological response of the changes in chemical components in the root, stem and leaf of Bidens pilosa seedlings stressed by excess cadmium ions (Cd2+) using Fourier transform infrared spectroscopy technique (FTIR). Cadmium accumulation in plant and distribution in subcellular by atomic absorption spectroscopy were tested under different concentrations cadmium stress. Results indicated that at a Cd concentration of 7 mg·L-1, B. pilosa maintained normal growth without visible Cd toxicity symptoms, though biomass was reduced compared to controls. FTIR analysis revealed that the overall peak shapes of roots, stems, and leaves remained largely unchanged before and after heavy metal treatment, suggesting that the structural integrity of plant organs was not compromised. However, shifts in specific functional group absorption peaks, including hydroxy (3387-3417 cm-1), carboxyl (1411-1419 cm-1), and amide groups (1635 cm-1), were observed, indicating their involvement in the heavy metal absorption process. The characteristic peak intensity of leaves was higher at high Cd concentration than at medium-low Cd concentration, while peaks in stems and roots remained consistent with or exceeded those of the control group. Cd predominantly accumulated in cell walls (46.21%-55.32%) and was minimally distributed in chloroplasts and mitochondria (4.11%-8.43%). These findings suggest that B. pilosa exhibits strong tolerance to Cd-contaminated soil and has significant potential for phytoremediation. The FTIR method offers strong evidence supporting the development of phytoremediation technology.

Tropical peat soil changes across successive oil palm generations in Sarawak, Malaysia

Oil palm is commonly replanted once reaching the end of its productive lifespan. This cyclical planting practice in oil palm plantations could have long-term implications for the humification and properties of tropical peat soil. This study aimed to investigate the changes observed across successive generations of oil palm plantations in Sarawak, Malaysia. Fourier Transform Infrared Spectroscopy (FTIR) was applied to examine the quality of the Soil Organic Matter (SOM), specifically the functional groups, humification index, Hydrophobicity Index (HI), and Degree of Degradation (DDI). Overall, the peat humification trend was in the order of 2nd Gen > Forest >1st Gen. The higher presence of recalcitrant compounds of lignin in the soil was attributed to the higher HI and lower DDI in the 2nd Gen. The relationship between the Pyrophosphate Solubility Index (PSI) and the humification index further revealed a significant increase in the relative abundance of humic substances with the maturity of degraded organic matter. These findings suggest a notable transition, implicating a shift towards a more stable form of SOM over the long-term utilization of tropical peatland for oil palm plantations. This is characterised by a significant increase in the relative abundance of aromatic, phenolic, and carboxylic functional groups. The study also highlights the need for further research on the linkage between these changes and greenhouse gas emissions to enhance our understanding of the long-term biogeochemical cycle of oil palm on tropical peatlands.

Preparation and Performance Characterization of Waterborne Epoxy Resin Modified Asphalt Emulsion for Tack Coat

In order to eliminate the possible drawbacks of waterborne epoxy resin (WER) generated by the phase inversion method and the chemical modification method, this study prepared WER using a novel method, i.e., epoxy resin was introduced into the molecular structure of aqueous acrylic resin; after the combination of epoxy resin and the aqueous dispersion process, the aqueous epoxy acrylic resin can be prepared. Waterborne epoxy resin modified emulsified asphalt (WEREA) was then prepared for the application of a tack coat material. Fourier Transform Infrared Spectroscopy (FTIR) test was conducted to explore the possible reactions between the compositions. A rheology test, direct tension test, pull-off bonding test, and oblique shear test were also conducted. Results indicated that in the FTIR test, a new peak around 1732 cm-1 was formed due to the reaction between the carboxyl functional group in WER and the amino group in curing agent to form an ester bond. The incorporation of WER led to an elevation in the complex modulus and a simultaneous reduction in the phase angle of WEREA. When the temperature was larger than 60°C, the phase angle showed a decreased trend, indicating the material became less viscous due to the increased temperature, illustrating thermosetting characteristics of epoxy resin. As the content of waterborne epoxy resin (WER) increased, there was an observed decrease in the direct tensile rate, coupled with a concurrent increase in direct tensile strength. When the ratio of emulsified asphalt and WER was 1:0.6, the tensile strength of WEREA increased by 811% in contrast to the specimen without the inclusion of WER. There existed different optimal WER contents for the pull-off strength tests conducted on different substrates. For asphalt concrete substrate and steel slab substrate, the optimum ratio of emulsified asphalt to WER+curing agent was 1:0.4, and 1:0.8 was the optimum ratio for the cement concrete substrate. When the ratio between emulsified asphalt and the combination of WER along with the curing agent was 1:0.4 (WEREA-4), the oblique shear strength obtained the maximum value, which was increased by 18.7% in contrast to WEREA-0.

Synthesis and physical characterization of novel Ag2S-CdS /Ag /GNP ternary nanocomposite

A new type of Ag2S-CdS/Ag/GNP nanocomposite material was successfully synthesized in the presented work. The structural and physical properties of compounds were studied separately and together. Ag2S-CdS/Ag/GNP nanocomposite materials were studied by Xray diffraction (XRD), Ultraviolet-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Raman spectroscopy and Scanning Electron Microscopy (SEM). Based on the results, Ag nanowires (NWs) were successfully synthesized, and then it was determined that during the hybridization process, two phases of acanthite Ag2S and the cubic crystal system of Ag2O were formed. Then, Ag2S-CdS NWs were formed from mixed monoclinic Ag2S and hexagonal CdS. In the absorption spectrum of Ag NWs, the main absorbance peaks were observed at 357.3 nm and 380.2 nm. The energy gap (Eg) values of the Ag sample are 3.8 eV. The band gap value of Ag2S (2.5, 3.8, 4.6 eV) and Ag2S-CdS (2.5, 3.8, 4.8 eV) have a triple value due to the formation of a hybrid structure. The Raman spectrum of Ag2S-CdS belongs to longitudinal-optical (LO) phonon modes of zinc-blende phase CdS and for the 1, 2, and 3 times spin-coated samples on the surface of GNP/PVA have observed all characteristic Raman peaks, which belong to NWs at 485.13 cm-1, and 960.22 cm-1.

THE ENCAPSULATION OF NOBLE METAL OVER METAL OXIDE SEMICONDUCTOR TiO2@Ag FOR THE DEGRADATION OF SULPHUR DYE IN EFFLUENT WATER BY PHOTOCATALYSIS AND ELECTROCHEMICAL WATER SPLITTING

Metal Oxide Semiconductor - Metal core-shell nanostructure with TiO2 as core and Ag nanoparticles as shell (TiO2@Ag) have been synthesized by a simple, environmentally friendly room temperature wet chemical method. The prepared TiO2@Ag core-shell nanoparticle was characterized by using various analytic techniques. X-ray diffraction analysis confirms the formation of tetragonal bcc structure anatase phase of TiO2 and Face-Centred Cubic structure (fcc) of silver in core-shell nanostructure. Fourier Transform Infrared Spectroscopy (FTIR) study proved the presence of characteristic peaks of both TiO2 and Ag. XPS study revealed the existence Ti4+ and metallic silver in core-shell nanostructure, High - Resolution Transmission Electron Microscopy (HR-TEM) and High - Resolution Scanning Electron Microscopy (HR – SEM) revealed the covering of Ag nanoparticles at the surface of TiO2 spheres. The TiO2@Ag core-shell nanoparticles exhibit a high residual mass of 95.9% and stability to withstand up to 1000⁰ C. The prepared TiO2@Ag core-shell nanoparticles as photocatalyst showed enhanced photocatalytic degradation (240 mins) of sulphur dye in effluent water with a degradation efficiency of 81% and capable of employing in wastewater treatment to eliminate toxic elements present in it. In the current study, we have used core-shell nanoparticles prepared using the wet chemical method at room temperature. The prepared core-shell nanoparticles were used to study the photocatalytic degradation of sulphur black dye directly collected from textile effluent water. They were also used for the production of oxygen and hydrogen through the electrolysis process. The synthesized TiO2@Ag core-shell nanoparticles act as effective electrocatalyst for the production of oxygen and hydrogen through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) using the electrolysis process.