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Material characterization and inter/intra-particle validation for DEM simulation of urea coating process

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Particuology 2024年第5期88卷 32-48页

作者： Salma A.Nouh KuZilati KuShaari Lau Kok Keong shafirah samsuri Chemical Engineering Department Universiti Teknologi PETRONAS32610 Seri IskandarPerak Darul RidzuanMalaysia

Particle coating is a common operation in the controlled-release fertilizer (CRF) industry,where a coating layer is appliedto the urea cores.A discrete element method (DEM) computer simulation was applied to model the coating process for the urea granules using measured model *** accuracy of DEM input parameters for the coating material properties and the physical and mechanical characterizations of urea granules are crucial to the study of particle coating ***,to enhance the simulation accuracy,information on the material properties (urea granules) is *** this study,the elasticity parameters,shear modulus ,coefficient of restitution (CoR),and coefficient of rolling and static friction (CoRF) and (CoSF) of urea granules are estimated experimentally in addition to the physical *** sensitivity of the angle of repose of the urea bed was investigated at different coefficients of *** to the obtained experimental value of the angle of repose,values of 0.2 and 0.3 for CoRF and CoSF,respectively,were adjusted to obtain consistent urea granules’ motion for simulation and the ***,the spray droplet sizes and velocity distributions were estimated using the video-imaging process *** on this experimental characterization,elasticity parameters and spray properties were integrated into DEM simulation software as input data to perform numerical analysis of the coating process to compare simulation and experimental results,which show uniformity at three different pan speeds with a maximum deviation of 0.033 at 5 ***,consistency between DEM and experiment results was achieved in terms of average coating thickness (μm) of the selected samples and average intra-particle thickness variation ( CoV intra ).These results revealed that the coating film thickness is proportional to the rotation speed for the experiment and *** enhance the inter-particle coating uniformity,the effects of the

关键词： Contact model Discrete element method Urea fertilizer Coating process

CFD Simulation of Particles Mixing and Segregation in a Rotary Coating Disk: Influence of Drag Models and Restitution Coefficient

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Open Journal of Applied Sciences 2022年第3期12卷 267-283页

作者： Salma Awad Nouh Ku Zilati Bt Ku Shaari Lau Kok Keong shafirah Bt samsuri Tigabwa Yosef Ahmed Department of Chemical Engineering Universiti Teknologi PETRONAS Seri Iskandar Malaysia

In this paper, the dynamics of a transverse plane of a rotary coating disk of a binary mixture system comprising sand and urea particles were simulated using the two-fluid model along with the kinetic theory of granular flow in Fluent 19.1. Although some parameters relating to the material properties and size of the rotary coating disk have been researched, the effects of both drag force and restitution coefficient on the flow characteristics have yet to be examined. Thus, this paper numerically examines the effect of the inclusion of drag models and particle-particle restitution coefficients on particle dynamics in a rotary disk operating in the rolling regime of the granular bed. Three particle-particle drag models were considered: the Schiller-Naumann, Syamlal-O’Brien, and Gidaspow. The Syamlal-O’Brien and Gidaspow models were both able to successfully simulate particle segregation in a perfect rolling regime, whereas the Schiller-Naumann drag model appeared to be unable to predict the segregation of the particles and the rolling flow regime under the assumed conditions. Four different values of the restitution coefficient were also investigated: 0.7, 0.8, 0.9, and 0.95. The higher restitution values of 0.9 and 0.95 were found to substantially affect flow characteristics, ensuring suitable rolling regime behaviour for the bed during the rotational movement. The lower restitution coefficients of 0.7 and 0.8, on the other hand, indicated that irregular velocity vectors could be obtained in the active region of the granular bed.

关键词： Rolling Mode Drag Model Restitution Coefficient CFD

Characterization of Nitrogen Uptake Pattern in Malaysian Rice MR219 at Different Growth Stages Using ^(15)N Isotope

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Rice science 2015年第5期22卷 250-254页

作者： Mohammad Mu'az HASHIM Mohd Khanif YUSOP Radziah OTHMAN samsuri Abdul WAHID Department of Land Management Faculty of Agriculture University Putra Malaysia

Nitrogen （N） use efficiency is usually less than 50%, and it remains a major problem in rice cultivation. Controlled release fertilizer （CRF） technology is one of the well-known efforts to overcome this problem. The efficiency of CRF, however, is very much dependent on the timing of nutrient release. This study was conducted to determine the precise time of N uptake by rice as a guideline to develop efficient CRF. Fertilizer N uptake by rice at different growth stages was investigated by using 15N isotopic technique. Rice was planted in pots, with 15N urea as N source at the rate of 120 kg/hm2. Potassium and phosphorus were applied at the same rate of 50 kg/hm2. Standard agronomic practices were employed throughout the growing periods. Rice plants were harvested every two weeks until maturation at the 14th week and analyzed for total N and 15N content. Nitrogen derived from fertilizer was calculated. Total N uptake in plants consistently increased until the 11th week. After that, it started to plateau and finally declined. Moreover, N utilization by rice plants peaked at 50%, which occurred during the 11th week after transplanting. N derived from fertilizer in rice plants were in the range of 18.7% to 40.0% in all plant tissues. The remaining N was derived from soil. Based on this study, N release from CRF should complete by the 11th week after planting to ensure the maximum fertilizer N uptake by rice plants. Efficient CRF should contribute to higher N derived from fertilizer which also resulted in a higher total N uptake by rice plants, increasing the potential of rice to produce higher yield while at the same time of reducina loss.

关键词： nitrogen use efficienc rice controlled release fertilizer 15N isotope

Root cause of sand production and methodologies for prediction

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Petroleum 2021年第3期7卷 263-271页

作者： Surej Kumar Subbiah Arifin samsuri Assef Mohamad-Hussein Mohd Zaidi Jaafar Ying Ru Chen Rajeev Ranjan Kumar Department of Petroleum Engineering Faculty of EngineeringUniversiti Teknologi MalaysiaMalaysia Schlumberger GatwickUnited Kingdom Schlumberger DohaQatar Schlumberger MumbaiIndia

The consequences of sandstone reservoir rock failure may lead to sand *** phenomenon can have negative impact on lifting cost and economic of any field *** erosion due to sanding can lead to loss of integrity and hydrocarbon *** decision on the type of completion can risk the viability of the *** facilitate best sand management over the life of a field and to maintain economical productivity,accurate prediction of sand production volume/rates is needed to increase both productivity and the ultimate recovery of the hydrocarbon while keeping the operating cost *** paper summarizes the sand production modeling for onset and volume of sand namely technology that required to improve understanding on sand production and *** main questions will be answered,why industry needs to worry about sand production,what are the available technologies to predict sanding volume/rates finally,how the current technologies can be improved to estimate sand production volume/rates.

关键词： Sand production Sanding rates Geomechanics Sand control Constitutive model Failure criteria

Redefining biofuels:Investigating oil palm biomass as a promising cellulose feedstock for nitrocellulose-based propellant production

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Defence Technology（防务技术） 2024年第7期37卷 111-132页

作者： Khoirul Solehah binti Abdul Rahim Alinda binti samsuri Siti Hasnawati binti Jamal Siti Aminah binti Mohd Nor Siti Nor Ain binti Rusly Hafizah binti Ariff Nur Shazwani binti Abdul Latif Centre for Tropicalization(CENTROP) Defence Research InstituteUniversiti Pertahanan Nasional MalaysiaKem Sungai Besi57000 Kuala LumpurMalaysia Department of Chemistry and Biology Centre for Defence Foundation StudiesUniversiti Pertahanan Nasional MalaysiaKem Sungai Besi57000 Kuala LumpurMalaysia

This review paper explores the potential of oil palm biomass as a valuable cellulose source for the production of nitrocellulose-based propellants,contributing to the green revolution and sustainable energy *** highlights the availability of the corresponding biomass in Malaysia and in line with global studies,the chemical compositions,as well as a brief description of current technologies for converting biomass of oil palm into value added products specifically *** to achieve maximum utilization of biomass from oil palm industry for cellulose production and prospective source for nitrocellulose-based propellant are also *** methodology section outlines the pretreatment of lignocellulosic fibres,cellulose extraction,and nitrocellulose production ***,the review underscores the prospective of palm oil biomass as a sustainable cellulose source for propellant manufacturing,while acknowledging the need for further research and advancements in the field.

关键词： Biopolymer Cellulose nitrate Energetic materials Green technology Palm oil

Wavelet diagnosis of ECG signals with kaiser based noise diminution

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Journal of Biomedical Science and Engineering 2012年第12期5卷 705-714页

作者： Sridhathan Chandramouleeswaran Ahmed M. A. Haidar Fahmi samsuri Faculty of Electrical and Electronics Engineering University Malaysia Pahang Kuantan Malaysia School of Electrical Computer and Telecommunications Engineering University of Wollongong New South Wales Australia

The evaluation of distortion diagnosis using Wavelet function for Electrocardiogram (ECG), Electroencephalogram (EEG) and Phonocardiography (PCG) is not novel. However, some of the technological and economic issues remain challenging. The work in this paper is focusing on the reduction of the noise interferences and analyzes different kinds of ECG signals. Furthermore, a physiological monitoring system with a programming model for the filtration of ECG is presented. Kaiser based Finite Impulse Response (FIR) filter is used for noise reduction and identification of R peaks based on Peak Detection Algorithm (PDA). Two approaches are implemented for detecting the R peaks;Amplitude Threshold Value (ATV) and Peak Prediction Technique (PPT). Daubechies wavelet transform is applied to analyze the ECG of driver under stress, arrhythmia and sudden cardiac arrest signals. From the obtained results, it was found that the PPT is an effective and efficient technique in detecting the R peaks compared to ATV.

关键词： Diagnostic Distortion Wavelet Transforms ECG Noise Interferences FIR Filter Kaiser Window

Short-Term Field Decomposition and Physico-Chemical Transformation of Jatropha Pod Biochar in Acidic Mineral Soil

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Open Journal of Soil Science 2014年第7期4卷 226-234页

作者： Cheah Poh Meng Ahmad Husni Mohd Hanif samsuri Abd Wahid Luqman Chuah Abdullah Department of Chemical Engineering Faculty of Engineering Universiti Putra Malaysia Serdang Malaysia Department of Land Management Faculty of Agriculture Universiti Putra Malaysia Serdang Malaysia

Details regarding field decomposition and transformation of biochar in Malaysia are scarce. The objectives of this study were to investigate the physico-chemical changes experienced by Jatropha pod biochar (JPB) in acidic mineral soil under field condition. Elemental composition was determined using CHNS-O analyzer and surface area with Brunauer-Emmett-Teller (BET) method. The JPB surface chemistry and structure were studied using the Fourier Transform Infrared (FTIR) spectroscopy and 13C solid state Nuclear Magnetic Resonance (NMR) spectroscopy, respectively. The JPB short-term decomposition was investigated by using a litter bag study and decomposition data were best fitted by a hyperbolic decay model compared to an exponential decay model because no significant dry weight loss was detected after 4 months. Two phases (volatile and near stagnant) were detected for JPB field decomposition. The volatile phase was due to rapid loss of labile fraction such as carbohydrate during the initial 4 months. The near stagnant phase was probably due to adsorption of organic matter and soil minerals. The JPB was fragmented into smaller pieces, encouraging surface adsorption. Redox reaction was prominent as shown by the production of hydroxyl, carboxylic and phenolic functional groups. The JPB became more recalcitrant after 12 months of application to the soils.

关键词： Litter Bag Study Redox FTIR NMR Hyperbolic Decay Model