Mohd Fairuz Dimin

Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

Efficient use of urea fertilizer (UF) as important nitrogen (N) source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs) grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and use efficiency (NUE). The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt%) and functionalization reflux time (12–24 hrs) with the corresponding responses (NUE, NU) were structured via the Response Surface Methodology (RSM) based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms ( value < 0.05) for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

Effect of Functionalised and Non-Functionalised Carbon Nanotubes-Urea Fertilizer on the Growth of Paddy

The roles of multi-walled carbon nanotubes (MWNTs) and functionalised multiwalled carbon nanotubes (fMWNTs) in enhancing the efficacy of urea fertilizer (UF) as plant nutrition for local MR219 paddy variety was investigated. The MWNTs and fMWNTs were grafted onto UF to produce UF-MWNTs fertilizer with three different conditions, coded as FMU1 (0.6 wt. % fMWNTs), FMU2 (0.1 wt. % fMWNTs) and MU (0.6 wt. % MWNTs. The batches of MR219 paddy were systematically grown in accordance to the general practice performed by the Malaysian Agricultural Research and Development Institute (MARDI). The procedure was conducted using a pot under exposure to natural light at three different fertilization times; after a certain number of days of sowing (DAS) at 14, 35 and 55 days. Interestingly, it was found that the crop growth of plants treated with FMU1 and FMU2 significantly increased by 22.6% and 38.5% compared to plants with MU addition. Also, paddy treated with FMU1 produced 21.4% higher number of panicles and 35% more grain yield than MU while paddy treated with FMU2 gave 28.6% more number of panicles and 36% higher grain yield than MU, which implies the advantage of fMWNTs over MWNTs to be combined with UF as plant nutrition. The chemical composition and morphology of UF-MWNTs fertilizers which is further characterised by FTiR and FESEM confirmed the successful and homogeneous grafting of UF onto the fMWNTs.

Optimization of Fluidised Bed Granulation Process Parameters for Urea Granule Manufacturing Using the Response Surface Method

Fluidised bed technology is commonly applied in the pharmaceutical, agricultural and food production technology. The aim of this work is to identify the optimum process parameters in order to gain the best hardness and density values for the urea granules from the fluidised bed granulation. The layout of the experiments are based on Central Composite Design of Response Surface Method. The analyzed data shown that the optimize value for each of these parameter are 0.10MPa, 32.11Hz, 50% w/w, 42.250C for spray pressure, fan speed, urea solution concentration and inlet air temperature with 1.71 kgf/granule hardness and 1.85 g/cm3 density were predicted. Experimentally, using the predicted optimize input parameter, the hardness and density observed were 0.20 kgf/granule and 1.30 g/cm3 respectively.

Microstructural Analysis On Biochar Obtained From Rubber Wood Sawdust Via Slow Pyrolysis

Biochar was derived from the crop residue as multifunction materials for agriculture purposes and a soil amendment to improve soil fertility. Rubber wood sawdust (RWSD) was heated slowly inside the vertical furnace for an hour at temperatures ranging from 300 °C to 700 °C. The aim of this study is to investigate the influence of pyrolysis temperatures on the physiochemical properties of the biochar. The properties of biochar were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM) attached with Energy Dispersive X-ray for elemental analysis. It was found that pore size distribution was more uniform on samples heated at higher temperature (700 °C). The SEM-EDX analysis confirmed the O:C ratio was directly proportional to the heating temperature. These means that slow pyrolysis of RWSD at 700 °C could produce biochar of greater cation exchange capacity (CEC) that important for soil fertility improvement.

Potential of Epoxidized Natural Rubber (ENR) as Hydrophobicity Contributor in Chitosan-Urea Fertilizer

This study is to investigate the potential of ENR to be incorporated with chitosan for slow release urea fertilizer. In this research, mixture of chitosan and epoxidized natural rubber (ENR) was used as binder to take advantage of their biodegradable and polar characteristics, respectively. The effect of mixing formulation to the properties of fertilizer was studied. Firstly, the chitosan and ENR were diluted in toluene with the presence of bentonite as filler. Then, urea powder was mixed and stirred for 20 minutes before left to dry overnight in an oven at 60°C. Water absorption and water retention analysis were carried out on compressed pellets. The increase of ENR loading was observed to contribute to the increase of hydrophobic properties of the fertilizer. The findings were supported by compositional analysis using Fourier Transform Infrared spectroscopy (FTIR).

Assessing the significance of rate and time pulse spraying in top spray granulation of urea fertilizer using Taguchi Method

Studies in urea granulation process using Top Spray Fluidized Bed Granulator (TSFBG) is still limited and requires in-depth research about the effectiveness and influence of droplets to the formation of urea granule (UG). Rate and time interval of spraying technique (Pulse) significantly influence the physical properties of urea granules. Cassava starch dissolves in water was selected as the binder released at various time interval to observe impact of spray droplet on UG size formation. Using Taguchi Method, the study had identified three leading factors contributed to the formation of droplet size namely volume of binder (VOB), time pulse of spraying (TPS) and spraying rate (SR). These factors were then evaluated in terms of the influence on response as signal-to-noise analysis (S/N ratios) from Taguchi to validate UG size in range 2 mm to 4 mm from screening process with respect to the actual experimental data. These results were useful for future experiment reference to determine pressure drop and surface contact during interaction between droplet and urea powder particles using TSFBG to obtain uniform UG size and smooth surface layer with reasonable hardness.

The Influence of Nitric Acid Treatment on the Crystallographic Structure of Multiwalled Carbon Nanotubes

Commercially available Multiwalled Carbon Nanotubes (MWCNTs) were refluxed with nitric acid in order to improve the density of the acidic surface functional groups. The formation of oxygen containing functional groups may lead to surface enhancement of MWCNTs for further modifications. The crude MWCNTs were refluxed in nitric acid at 100 °C for time ranging between 3 to 24 h. The influence of treatment time on crystalline structure was investigated using X-Ray Diffraction (XRD); the results confirmed that all treated MWCNTs are crystalline. The density of the surface functional groups on treated MWCNTs was examined by Fourier Transform Infrared (FTIR). The FTIR spectrums revealed a strong vibration band at 1739, 1219, 1369 cm-1 that indicates covalently bound acidic surface functional groups existed on the treated MWCNTs. The amount of acidic groups increased with the reflux time up to 15 h treatment as measured by an acid-base Boehm titration. The vibrational spectroscopy of these functional groups also increased with the increasing reflux time.

Analytical Hierarchy Process for Design Selection of Micro Hot-Marking Tool

Veracious concept selection process is crucial in design engineering where, a concept with concise description will fulfill customers’ requirements. Failure in concept selection can lead to inaccurate design which will result in unnecessary process repetition of the initial stage. One of the best tools that can be used in determining the best design concept is Analytical Hierarchy Process (AHP). Micro Hot-Marking Tool (HMT) is a super-finished tool with micro tip which is to be used for alphabetical marking process using CNC milling machine. In this research, AHP was successfully employed in selecting design concept for HMT. Four significant and robust concepts were analyzed, namely C1, C2, C3 & C4. Concept 2 (C2) has been chosen as the best concept with the highest score of 27% among all the evaluated concepts which will be taken into next design stage.

Influence of Surface Treatment on the Surface Energy of Tungsten Carbide Inserts

The effect of substrate cleaning using ultrasonic cleaner on tungsten carbide was investigated. The surface energy of the substrate was measured using two liquids with dominant polar and dominant dispersion components which were distilled water (DI) and methylene iodide. Owens-Wendt method was carried out to calculate the surface energy of the substrate. The result showed that the cleaning process using solvent B (alkaline, DI, acid, DI, DI, alcohol) for 20 minutes without the wiping process led to the highest surface energy of 126.3399 dyne/cm with the polar component of 80.538 dyne/cm. Findings from this research suggested that type of solvent, cleaning time, and interactions among solvent type, cleaning time, and wiping process significantly influenced surface energy of the substrate.