bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INFLUENCE OF PYROLYSIS PROCESS CONDITIONS ON THE QUALITY OF COCONUT SHELLS CHARCOAL
Authors: Ahmad Rabi Kabir , Sulaiman Shaharin Anwar , Yusuf Suzana B , Dol Sharul Sham , Umar H.A , Inayat M.
Published: February 2024

The availability of biofuel from renewable raw material and its lower negative environmental impact, when compared to fossil fuels, are some of the properties that make a biofuel commendatory. In this study, the influence of residence time, temperature and particle size on the quality parameters such as ash content, moisture content and the calorific value of the coconut shell charcoal was studied. The charcoal was obtained by carbonising clean, thoroughly dried coconut shells in an oxygen-free environment at a temperature range of 250-450°C, the residence time of 15-75 minutes, and particle sizes of 5 mm and 25 mm. The charcoal was analysed in terms of the changes of these quality parameters as a result of thermal conversion of the coconut shells during the pyrolysis process. All the studied quality parameters were dependent on the pyrolysis process conditions. The calorific value and the ash content increased with an increase in the residence time from 25.99 MJ/kg to 29.54 MJ/kg and 1.02% to 1.13%, while the higher the residence time of the pyrolysis process, the lower the moisture content in the charcoal. An increase in pyrolysis temperature from 250°C to 450°C increased the ash content and the calorific value of the charcoal from 1.01% to 1.11% and 24.73 MJ/kg to 29.15 MJ/kg respectively. In the case of moisture content, it decreased with an increase in temperature from 2.43% to 1.21%.

Keywords: Pyrolysis, charcoal, calorific value, ash content, moisture content, temperature, residence time
ASSESSMENT OF MAGNESIUM OXIDE (MGO) AND SILICA DIOXIDE (SIO2) NANO-FLUIDS ADDITION WITH SURFACTANTS AS NEW TECHNIQUE TO CONTROL FINES MIGRATION
Authors: Ern Lim Wan , Zamir Asif , Irawan Sonny
Published: February 2024

Formation damage in oil reservoirs because of fines migration is among the main contributors to productivity decline. Conventionally, chemical methods such as complex organic polymers are used to prevent fines migration by stabilizing or maintain the fines particles in aggregated form. However, most of the chemical fines stabilizer is not robust, which functionalize based on the composition of exchangeable cations in clay minerals, temporary stabilization and are not environmentally friendly. In this research work, qualitative methods were developed to investigate the potential of Magnesium Oxide (MgO) and Silica Dioxide (SiO2) Nano-Fluids addition with surfactants (Triton X-100 and Tween 80) as a new technique to control fines migration. Silicon Dioxide nanoparticles used in this experiment are in the form of colloidal silica with spherically sized at 10-15 nm then stabilized electrostatically to allow the particles to stay suspended in the solution. To measure the Nano-Fluids and fines solution stability, the minerals (kaolinite, bentonite and illite-smectite) crushed and suspended in 100 mL distilled water with 0.20%, 0.50%, 1.50% and 3% concentration,respectively. The suspended fines solutions left for 24 hours. Solution stability measured using the Zetasizer Nano ZSP by recording their turbidity (NTU) and zeta potential (mV). The results from the assessment shown that bentonite and kaolinite fines are more susceptible to migration in sandstone reservoirs due to their high colloidal stability from their zeta potential measurements and their morphologies. It can also be concluded that Silicon Dioxide (SiO2) is more stable when these nanoparticles are suspended in de-ionized water only, which gives zeta potential values of -26.10 mV. The addition of surfactants (Triton X-100 and Tween 80) has also shown significant results on protected fines migration. Triton X-100 and Tween 80 increased Silicon Dioxide (SiO2) Nano-fluid zeta potential value at -30.6 mV, which is beneficial for the Nano-Fluid to travel deeper into the formation to treat problematic areas of fines migration.Keywords: MgO and SiO2 nano-fluid, zeta potential, fines migration, surfactant, nanoparticles
EXPERIMENTAL STUDY OF CHLORIDE-INDUCED STRESS CORROSION CRACKING (CISCC) FOR AUSTENITIC SUS 304L UNDER THERMAL INSULATION
Authors: Lee Jia Wei , Kok Eng Kee , Zakaria W.L.W.
Published: February 2024

Chloride-Induced Stress Corrosion Cracking (CISCC) has been frequently reported in the petrochemical industries where it usually causes failure to the austenitic stainless steel structures encased with thermal insulation in a chloride-containing environment. This study aims to analyze and evaluate the risk of chloride concentration and different types of insulation materials on CISCC of Austenitic SUS 304L. The experimental study was carried out for 14 days using U-bend specimens through the Drip Test apparatus, as per ASTM G30 and ASTM C692. U-Bend specimens were installed onto the test rig and shielded with different insulation materials. Sodium chloride (NaCl) salt solutions were periodically dripped onto the specimens, to simulate the wet and dry cycle. Insulation materials used were rockwool, calcium silicate and perlite, whereas the concentrations of NaCl solutions were set at 0.1, 1.0 and 3.5 wt.%. The specimens were inspected usingdye penetration tests (DPT), stereo microscope and optical microscope throughout the study to determine the CISCC susceptibility. Results showed that cracking was observed on the specimen with rockwool insulation at 3.5 wt% NaCl and 90°C. Rockwool has a high water absorption capacity at which saltwater will evaporate when in contact with a hot metal surface, resulting in the build-up of salt deposits of high concentration over time. SCC was not observed on other specimens with different conditions, but salt deposits, general corrosion and pitting corrosion were found. From the study, the thermal insulation of rockwool was found to have the highest tendency to cause SCC, followed by calcium silicate and perlite.Keywords: SUS304L, chloride-induced stress corrosion cracking, insulation materials, U-Bend specimen, drip test
RELIABILITY ASSESSMENT ON NETWORK EQUIVALENT USING MONTE-CARLO SIMULATION TECHNIQUE
Authors: Mohd Fauzi NoorFatin Farhanie , Roslan Nur Nabihah Rusyda , Muhammad Ridzuan Mohd Ikhwan
Published: February 2024

Reliability in an electrical power system is the ability of the system to deliver electrical energy without any interruption. In the literature review, the analysis of the power system in low voltage (LV) network is less focused compared to the medium voltage (MV) and high voltage (HV) due to the absence of general exact data and sizing of the LV network. The LV network becomes complex when the sizing of the network increases. Thus, in this research, the performance of reliability in the LV network will be evaluated using an equivalent network by simplifying the network. This simplified network will reduce the simulation time. The performance in a complex network should first be evaluated before reliability assessments are carried out. The assessment of reliability is carried out using Monte-Carlo Simulation. The reliability indices, SAIFI, SAIDI and CAIDI between these two networks (detailed and equivalents network) are compared. The expected output in the detailed network will have the same or close readings of reliability indices as in an equivalent network.Keywords: low voltage, medium voltage, reliability. failure rate, repair time, interruptions
A COMPARATIVE STUDY OF ELECTRICITY GENERATION FROM INDUSTRIAL WASTEWATER THROUGH MICROBIAL FUEL CELL
Authors: Ma’arof M. I. N. , Chala Girma T. , Chaudhry M.B. , Premakumar B.K.
Published: February 2024

The present study presents a comparison of the electricity generation from industrial wastewater via Microbial Fuel Cell (MFC). Four experimental setups with four types of MFC were developed for this study. For MFC 1, 75% of wastewater from Factory A added to a fixed concentration of cow manure to obtain a solution of 600ml in the anodic chamber while adding distilled water into the cathodic chamber. Contrastingly, for MFC 2, 75% of wastewater from Factory A was added to a fixed concentration of cow manure to obtain a solution of 600ml in the anodic chamber, whereas distilled water mixed with 15g of potassium ferricyanide was added to the cathodic chamber. For MFC 3, a similar setup was made as in MFC 1 though it utilizes wastewater from Factory B. MFC 4 in return replicated the setup of MFC 2, yet the wastewater was collected from Factory B. Two (2) tests were conducted where Test 1 was to compare the voltage readings from MFC 1 and MFC 3, while Test 2 was for MFC 2 and MFC 4. It was observed that the voltage produced by the wastewater from Factory A was higher than that of voltage produced from Factory B by 41% in test 1 and 82.4% in test 2. Interestingly, the addition of potassium ferricyanide further increased the voltage by 63.17% when comparing between MFCs 4 and 3, while 111% for MFCs 2 and 1, respectively. Hence, it can be deduced that the addition of an external electron acceptor such as the potassium ferricyanide greatly increases the voltage produced. For future studies, other types of external electron acceptors could be tested in identifying its potential in improving the capability of the MFC.Keywords: microbial fuel cell, natural mixes, isoelectronic microbes, ecological concern
ANALYSIS OF LAND USE / LAND COVER AND CLIMATE IMPACTS ON KANGIMI STREAMFLOW AND SEDIMENT YIELD: KANGIMI CATCHMENT, KADUNA NIGERIA
Authors: Bello Umar Shamsuddeen , Shuaibu A.
Published: February 2024

The Kangimi reservoir is an important dam augmenting water supply and recreational activities in and around the Kangimi Watershed in Kaduna, Nigeria. However, the impending hydrological effect of land use / land cover (LULC) dynamics in relation to agricultural expansion has not been established. This study determines the LULC dynamics on hydrological parameters (streamflow and sediment yield) using the ArcGIS 10.2 interfaced with ArcSWAT 2009 and detailed LULC maps (1975, 2000 and 2013). The catchment was delineated into ten subbasins, and 39 hydrological response units (HRUs) were created according to multiple HRU development. Kangimi hydrology was simulated for three different LULC types. The model was verified through calibration and validation to determine its performance; the values were determined to be (R2=0.92, NS=0.93) for calibration and (R2=0.82, NS=0.86) for validation, respectively. The hydrological response was considered based on three conditions (climate of 1979-2014 & 1975 LULC, the climate of 1979-2014 & 2000 LULC, and climate of 1979-2014 & 2013 LULC). Model results for the Kangimi catchment confirm that agricultural growth and bare surface increase led to an increase in annual streamflow and sediment yield. Thehydrology streamflow increased 28.23% (from 345.2 m3/s to 387.37 m3/s) as well as 33.31% (from 60.03 to 90.02 t/ha) of sediment yield due to LULC and climate dynamics. The results confirm the prominence of incorporating physical hydrologic models through the use of GIS for estimating catchment characteristics and the relative effect of LULC dynamics on hydrologic response. A well-parameterized model can be equally used to estimate the impact of LULC dynamics on water quality, pesticide loading, nutrients and land management practice.Keywords: Hydrological parameters, Climate changes, SWAT, GIS
FSI SIMULATION OF A FLEXIBLE VORTEX GENERATOR AND THE EFFECTS OF VORTICES TO THE HEAT TRANSFER PROCESS
Authors: Dol Sharul Sham , Chan Hiang Bin , Wee Siaw Khur
Published: February 2024

This work numerically investigated the strength of vortices behind a flexible vortex generator (FVG) by calculating the circulation using Fluid-Structural Interaction (FSI) simulation of RANS (SST) k-ω model. The total circulation showed the vortices formed by the FVG was more significant than those originated by the rigid vortex generator (RVG). From the analyses, the case with more significant structural velocity results in a larger shear or circulation. The structural velocity computation proves an excellent consistency with the model predicted values. This has suggested the reliability of the proposed model. Therefore, the performance of FVG in turbulence augmentation has been identified, suggesting enhanced turbulent transport for the greater heat transfer process. Next, the numerical model was extended to examine the heat transfer performance of the FVG. In general, the findings show that the employment of the FVG has a significant positive impact on the heat transfer process in the heat exchanger.Keywords: CFD, circulation, flexible vortex generator, FSI, heat transfer, turbulence, wakes
ANALYSIS OF HIGH-RESOLUTION AEROMAGNETIC DATA OVER PARTS OF SOKOTO BASIN, NORTH-WEST NIGERIA
Authors: Olokoba Saheed Oluwakemi , Magaji Yusuf
Published: February 2024

Sokoto Basin is one of the sedimentary basins suspected to have high hydrocarbon potential. Hence, due to the possible deposit of this economic mineral, it is worthy of being preliminarily investigated. This paper uses high-resolution aeromagnetic data over parts of Sokoto Basin covering longitude 4.00°E-5.00°E and longitude 12.00°N-13.00°N, to assess the sedimentary thickness beneath the subsurface while also establishing the basement topography. The studied area covered four adjacent one-degree sheets, namely, sheet 27 (Lema), sheet 28 (Argungu), sheet 49 (BirninKebbi) and sheet 50 (Tambuwal). Enhancement of the total magnetic intensity map was carried out to improve the anomaly characteristic of source bodies, and two-dimensional Spectral analysis was carried out using GEOSOFT software (Oasis montaj6.24 version) in order to estimate magnetic source depths in the area. The shallower sources occur at a depth range of 0.23 km - 0.79 km with an average depth of 0.47 km, while the deeper sources occur at a depth range of 0.83 km -1.95 km with an average depth of 1.40 km. The maximum depth to the top of the magnetic source body gets deeper around Lema and IllelaKwandu while the minimum depth is around Tambuwal, Danjema and Birnin-kebbi. Thedepth estimated from the spectral analysis compares reasonably well with the results from the Euler deconvolution. The areas with higher sedimentary thickness toward the northern part of the study area are feasible for hydrocarbon generation and are thus recommended for other geophysical surveys.Keywords: Sokoto Basin, sedimentary thickness, hydrocarbon exploration, high-resolution, aeromagnetic data,geophysical surveys
EVALUATING THE MECHANISMS OF WAX DEPOSITION IN CRUDE OIL PIPELINES
Authors: Sulaimon Aliyu Adebayo , Gunasekaran Kavinraj , Vatsa Suyash
Published: February 2024

Flow assurance standstill as a massive issue as it involves ensuring fluid flows in well, flowline and trunk line. One of the major decisive for flow assurance crude oil is its constitution and solid deposits successful management. Wax deposition challenges and its control can be determined with the right prediction from wax deposition modelling. Certain factors like pipeline inclination that influences the rate of wax deposition need to be taken into consideration. For inclined wells, the model is tuned to account for low concentration slurries under inclined angles. Regarding this, a complete wax deposition model is developed to predict the rate of wax deposition by investigating all the possible wax deposition mechanisms which contribute actively for better wax deposition management in the oil fields. A thorough analysis has been carried out to show the significance of each deposition mechanisms and parameters in wax deposition model like rate of wax deposition, deposit thickness, the temperature in the pipeline, pressure drop in the pipeline. Based on the results achieved, it can be deduced that the shear stripping and rate enhancement effect due to oil trap has the highest contribution towards the wax deposition in the pipeline but the gravity settling velocity cannot be neglected without valid assumptions.Keywords: flow assurance, wax deposition, wax deposition mechanisms, wax deposition modelling, shear stripping, gravity settling velocity
PREDICTIVE ANALYTIC MODEL FOR ELECTRICAL CHILLER SYSTEM (ECC)
Authors: Mok Hat Muhammad Nazmi , Muhammad Masdi
Published: February 2024

District cooling plant is a very complex system consisting of various equipment. One of them is an electric centrifugal chiller that is widely used in the industry to supply chilled water to thermal energy storage (TES). This paper investigates the predictive analytics model of the electric chiller system using real operation data. Data pre-processing was performed to remove the outliers. Further to that, the machine learning model was used to develop an artificial neural network (ANN), whereby the best model with the lowest RMSE was obtained. Then, the ANN was used to correlate between the input and output variables to find the critical parameters which contributed to the Coefficient of Performance (COP). This model could also predict the output from the actual data of the COP. Lastly, the Shewhart control chart was utilised in the root cause analysis model (RCA) to detect the anomalies based on five critical parameters at the early stage before its failure. The supervised learning algorithms using the feedforward ANN model demonstrates the most accurate predictions compare to all models.Keywords: chiller, MATLAB, RMSE, Artificial Neural Network, Root Cause Analysis Model, Shewhart Control Chart
EFFECT OF ANNEALING ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF RESISTANCE SPOT WELDED -SUS316L
Authors: Bin sazali Akmal Syafiq , Mustapha Mazli
Published: February 2024

The aim of the study is to improvise mechanical properties-tensile strength and microstructure behaviour of the material when the Resistance Spot Welding (RSW) is used to combine two metal-stainless steel (SUS316L). Constant nugget diameter needs to be maintained; thus, the constant parameter is needed by setting up 2.5 kN load with 5 kA 25 cycle as an optimum parameter. However, RSW the material absorbs high volumes of energy; hence it causes the material properties retarded. Therefore, post heat treatment (annealing) is used to treat the heat-affected zone of the welded diameter by manipulating the temperature of heat-treated, holding time and the heat rate. Tensile and microstructure tests are conducted to investigate the effectiveness of treatment analysis. It is found that annealing heat treatment improves the ductility of the material.Keywords: Resistance Spot Welded (RSW), stainless steel (SUS316L), heat affected zone, annealing, tensile load, Design of Experiments (DOE), Respond Surface Method (RSM)
SIMULATION STUDY ON VORTEX-INDUCED VIBRATION AIR WAKE ENERGY FOR AIRPORT RUNAWAY APPLICATION: A PRELIMINARY ANALYSIS
Authors: Abdullah Abdul Qader , Abdul Azeez Abid , Dol Sharul Sham , Khan Mohammad , Meor Said Mior Azman
Published: February 2024

The objective of this research paper is to conduct a preliminary analysis of the effects of various cylindrical cross-sectional shapes on vortex-induced vibration for airport runaway air wake energy generation. In the case of the airport runway, vortices are generated from the aeroplane bodies that exit and enter the runway during take-off and landing operations. These oscillations can be utilized to generate power due to the large fluctuations produced by the vortices. Vortexinduced vibration works on the principle of Kármán vortices where a cylindrical or bluff-body shaped object oscillates due to the alternate vortex formation on the boundary layers by adverse fluid pressure. The oscillation depends on the unsteady lift force generated. This mechanical oscillation is later converted to electrical energy. Five cylindrical crosssection cases are investigated by computational fluid dynamics (CFD) k-ω turbulence model to identify the best case that will provide the largest lift force; hence the maximum power output generation. These cases are simulated using typical take-off air speeds for jetliners in order to finalize the overall performance. The observed results show that the elliptical cross-section with 3” height and 2” length provides the best cross-section in producing the greatest amount of energy. The total power generated from a single-cylinder was 707.1 Watts. The system can be optimized for larger aeroplanes and operation frequencies as well as could be expanded for larger energy output.Keywords: airport runaway, lift force, oscillation, renewable, turbulence, vortex-induced vibration
EVALUATION OF SHEAR STRENGTH OF COMPACTED IRON ORE TAILINGS TREATED LATERITIC SOIL
Authors: Ishola Kazeem , Ijimdiya T. S. , Yohanna P. , Osinubi K. J.
Published: February 2024

This paper presents the results of a laboratory study on the evaluation of the shear strength of compacted iron ore tailings (IOT) treated lateritic soil. Lateritic soil used was treated with 0 up to 16% IOT by weight of dry soil. Test performed include index test, compaction (using British Standard Light, BSL and West Africa Standard, WAS energies) and shear strength test. One-way analysis of variance was carried out using Microsoft Excel to determine the level of significance of IOT on the treated soil. The results of the triaxial test show that there is an improvement in the shear strength of soil with the improvement of its shear strength parameters (cohesion and angle of internal friction). Cohesion values decreased from 0 up to 8% IOT content and then increased while the angle of internal friction risen from 0 up to 8% IOT content and then decreased. Also, from the triaxial test carried out with varying cell pressures from 100 to 300 kN/m2, an increase in shear strength parameters and shear strength were recorded. The shear strength increased in value by 49.79% and 18.15% for BSL and WAS compaction at 8% IOT content, respectively. Statistical analysis carried out on the results using analysis of variance (ANOVA) shows that IOT has a significant effect on the lateritic soil. An optimal blend of 8% IOT improved the shear strength of the soil and can be used for geotechnical engineering applications such as roads and embankments.Keywords: angle of internal friction, cohesion, iron ore tailing contents (IOT), Lateritic soil and Shear strength.
GEOLOGICAL CHALLENGES IN HYDRAULIC FRACTURING OPERATION: A CASE STUDY IN UNDISCLOSED PETROLEUM FIELD IN OMAN
Authors: Al Jabri Amer S.A. , Chala Girma T.
Published: February 2024

Production of hydrocarbons is hampered by obstacles known as formation damage. This damage needs to be removed or bypassed to retain well productivity. Hydraulic fracturing stimulation is one of the techniques used to overcome formation damage and enhance the productivity of the formation by maximizing the ultimate recovery. It was highlighted that there are some challenges associated with this technique and the most difficult challenges in hydraulic fracturing design and implementation are those related to geology of the reservoir. This study was, therefore, aimed at addressing the main geological challenges and providing the best low-cost solution and practice that leads to easy and successful stimulation operation. As an engineering solution in this study, fracturing geometry design was addressed to overcome geological challenges using advance simulator tool. Multiple fracking design by using computer simulation for a set of geological parameters aid on predicting the result out and avoid any complication in future production. Other challenges addressed by intelligent numerical evaluation used as a best practice in well stimulation to maximize the benefits of well production recovery. Optimizing fracturing fluid is also an important element covered in this study. An investigation was conducted on formation permeability variation for heterogeneous rock formation as one of the geological challenges faced by hydraulic fracturing operation for further understanding the geometry of fracturing for the success of stimulation operation. By fixing all other formation and pumping variables it was observed that formation permeability influences the length of fracture geometry, which could lead to stimulate out of pay zone.Keywords: hydraulic fracturing, geology, fracking, treatment fluid, geological challenges, frac treatment
CFD ANALYSIS ON THE SINGLE-PHASE FLOW ELECTRICAL SUBMERSIBLE PUMP PERFORMANCE CURVE
Authors: Kassem Omar Mostafa , Abdullah Abdul Qader , Dol Sharul Sham , Gadala Mohamed S. , Aris Mohd Shiraz
Published: February 2024

Most of the industrial fields, especially oil and gas, involve the application of electrical submersible pump (ESP) for flow transport. The pump performance will deteriorate depending on conditions of usage. The main parameters that affect or influence the pump performance curve are pump types, fluid flow rates, gas fractions, the impellers’ geometry, rotational speeds and fluid properties. In this work, the pump performance curve was studied as the governing parameters such as flow rates, meshing elements and turbulence models were varied. A computational fluid dynamics simulation (CFD) was applied and the findings were compared with the manufacturer’s data for single-phase flows. The main purpose was focused on getting the right technique to investigate this problem. The various turbulence CFD models were analysed and sources of errors were explained. The corresponding pump head losses were discussed and the main improvement or the criteria to obtain the highest efficiency were suggested. The results show that the k-epsilon with enhanced wall treatment is the best CFD technique since it produces the most accurate results and the least errors by allowing flexibility in large pressure gradient and rapid changes in flow properties.Keywords: ESP, CFD simulation, head loss, performance curve, turbulence models
PRELIMINARY EVALUATION TOOLS FOR WIND-PUMPED STORAGE ENERGY GENERATION SYSTEM
Authors: Jun Chang Chung , Rasid Mohd Azri Hizami , Daing Idris Daing Mohamad Nafiz
Published: February 2024

Energy demand never ceases to increase with larger cities, urbanization and migration to the cities. However, supplying the remaining and important rural areas with electricity remains costly. Exploring the off-grid energy generation is therefore a promising solution. After an exhaustive qualitative evaluation on different energy generation system, this study has chosen the Wind-Pumped Storage Hybrid (WPSH) system to be evaluated. A simulation tool was built to take the wind energy and convert it into pumping power to store water in a reservoir that will supply a hydro-turbine, generating electricity to a domestic area. A preliminary evaluation was done in Kajang for a selected day of July 20 2020. The result shows that the wind fluctuations and energy demand fluctuations affect the WPSH system’s capability to deliver sufficient energy through 24 hours. During the day, the amount of water accumulated in the reservoir is insufficient to meet the energy demand. It is only after 7.00 p.m that the system will be able to meet the demand and reserve a surplus of water in the reservoir.Keywords: renewable energy, wind-pumped storage, hybrid energy generation, wind power, evaluation tools
STIFFNESS BEHAVIOUR OF POLYCAL WIRE ROPE ISOLATOR VIA FINITE ELEMENT ANALYSIS
Authors: Gill Ashvinder Singh , Lemma ‪Tamiru Alemu
Published: February 2024

Vibration causes detrimental effects in daily applications such as camera mounting systems in drones i.e. jello-effects, distorted image and sensor accuracy deterioration. Hence, polycal Wire Rope Isolator (pWRI) is a passive isolation method proposed to overcome the vibration effects. However, the research being performed for pWRI is limited for vertical compressive static and monotonic loading case due to its complicated geometry and contact issues. In this research, the displacement loading-restoring force method was applied to investigate the stiffness behaviour of pWRI which studied the effects of thickness of joining plates, radius of curvature/bending radii, width to height ratio, and diameter of wire rope using ANSYS Static Structural Analysis and data source from ANSYS and literatures. The 3D CAD pWRI models were designed by CATIA v5 for the convenience of modelling in ANSYS. The results of the compression load-displacement behaviour followed a nonlinear pattern under compressive static loading and double linear retarding model under compressive monotonic loading. It was also found that, the stress and deformation distributions were similar for all the wire ropes in the isolator models. The deformation was more densely distributed near where the load was applied and subsided as it was away from load concentration. The effective stiffnesses were also ranked for each factors investigated based on respective isolator models. This research is unique in terms of the method used which is restoring force-displacement loading, proposed procedure of CAD modelling of polycal Wire Rope Isolator as there is no detailed research outlined which addresses the contact issue among wire ropes and extends the proposed data source for simulation in ANSYS.Keywords: displacement loading-restoring force, nonlinear, static, monotonic, double linear retarding model,deformation
INVESTIGATION OF COOLING CONDITION OF A ROOM WITH AIR-CONDITIONING WORKING CONCURRENTLY WITH AIR SUPPLY AND DISCHARGE SYSTEMS – A CASE STUDY
Authors: Chala Girma Tadesse , Joe Lee S. , Ma’arof Muhammad Izzat Nor
Published: February 2024

This paper investigates cooling condition in the air-conditioned room working concurrently with air supply anddischarge systems. Case studies were conducted for a kitchen located at INTI Subang, Malaysia. The study wasconducted by measuring temperature, humidity, pressure and air velocity, followed by simulation studies using ANSYS-Fluent workbench to predict indoor thermal condition and other useful parameters. Simulation results were validated with experimental results, after which four case studies were performed to analyze their effects on human comforts and observe an optimal condition of each case. The four cases considered were: both windows and doors open (additional window) (Case 1), closed doors and windows open (additional windows) (Case 2), additional ventilation system (Case 3), and exhaust with half closed valve (Case 4). It was observed that Case 1 provided best indoor condition with the room temperature only at 296.4 K, which was 8.3 K lower than that of the original kitchen. The peak temperature for this case was also found the smallest. The addition of electronic valve between the main ventilation pipe and the negative outlet reduced the room temperature less efficiently compared to Case 1.Keywords: Air-conditioning, indoor temperature, humidity, air discharge, air inlet
PREDICTION OF PERFORMANCE AND EMISSION OF COMPRESSED NATURAL GAS (CNG) IN A SUPERCHARGED DIRECT INJECTION SPARK IGNITION ENGINE USING ARTIFICIAL NEURAL NETWORK
Authors: Chala Girma Tadesse , Chan Choon K. , Fa Kee J.
Published: February 2024

Emissions of greenhouse gases such as carbon dioxide, nitrogen oxide and some hydrocarbons have been the main causes of global warming and have posed severe impacts on climate changes. Consequently, the focus on sustainable developments has swiftly grown in recent years. The utilisation of Compressed Natural Gas (CNG) in the spark ignition (SI) engine or using as dual fuel in compression ignition (CI) engine is getting remarkable attention nowadays. In this paper, performance and emission of CNG in supercharged direct injection spark ignition engine were predicted via Artificial Neural Network (ANN). The Levenberg Marquardt training algorithm was used due to its fast response, easy operation and high accuracy. The models’ results are compared with experimental results available from a previous study by the author. It was observed that R2 values for both performance and emission of CNG were higher than 98%, indicating good prediction. Following the training, high accuracy with value higher than 95% was observed for both analyses. Hence, it can be concluded that ANN is a promising technique for the prediction of performance and emission of CNG in direct injection spark ignition engine that consists of numerous inputs and output conditions.Keywords: Natural gas, CNG, supercharging, artificial neural network
THE BEST FIT PROBABILITY DISTRIBUTION MODEL FOR THE ESTIMATION OF EXTREME RAINFALL IN LIMBANG, SARAWAK
Authors: Tahir Taimoor , Hashim Ahmad Mustafa , Takaijudin Husna , Wan Yusof Khamaruzaman , Osman Manal
Published: February 2024

In Malaysia, the increment of annual rainfall patterns is causing frequent floods, mainly in Sabah and Sarawak.Limbang river basin was selected as a case study due to it was facing of high-risk flooding problem mainly during the transition of climate. This study was aimed to estimate the frequency of rainfall under various return periods and to identify the best fit model probability distribution of annual maximum rainfall based on twenty-four hours sample in Limbang. The three statistical models were used, which are Gumbel, Log-Pearson type III, and Log-Normal. Based on the goodness of fit tests, Chi-Square, Kolmogorov Smirnov test, and the Log-Normal was found to be the best fit model for the station of Panduran. The Log-Pearson type III was found to be the best-fit distribution model for the rest of the stations, which occupies almost more than 90%. The maximum values of expected rainfall were calculated using the best fit probability distributions and could be used by a design engineer in the future.Keywords: flood, return period, Gumbel distribution
EFFECTS OF GAS VOLUME FRACTIONS ON ELECTRICAL SUBMERSIBLE PUMP PERFORMANCE UNDER TWO-PHASE FLOW
Authors: Shahid Salman , Hassan Abdul Qader , Dol Sharul Sham , Gadala Mohamed S , Aris Mohd Shiraz
Published: February 2024

An Electrical Submersible Pump (ESP) is the most commonly used artificial lifting method in the oil and gas industry through conversion of kinetic energy to pump pressure head; however, issues like gas entrainment and shifting production rates tend to cause ESP pressure degradation. Flow behaviours inside the ESP, such as gas pockets or pressure surging tend to diminish the pump pressure head significantly. Observation of gas-liquid flow in the ESP is challenging due to the compact, sophisticated geometry and highly turbulent flow strucutres. This paper observes two-phase flow in the ESP through CFD simulation, and illustrates its pressure degradation through Air Volume Fraction contours showing formations of gas pockets and recirculation bubbles. This research utilized Mixture Flow as its main two-phase model with 1%, 6% and 10% Gas Volume Fraction (GVF) ratios inside the pump at a constant flow rate of 250 L/min. The results show a clear pump head degradation from 3.062 m to 2.251 m overall. The centrifugal pump under two-phase flow is not able to generate the same amount of pressure head as it normally does due to the bubble point pressure and this decrease in pump pressure head is a potentially unstable behaviour, which is acknowledged as pressure surging.
DEVELOPMENT OF RAINFALL INTENSITY DURATION FREQUENCY (IDF) CURVES FOR DESIGN OF HYDRAULIC STRUCTURES IN KANO STATE, NIGERIA
Authors: Mohammed Abdulrasheed , Dan’Azumi Salisu , Ahmed Modibbo Abubakar , Adamu Abubakar Abbas
Published: February 2024

Rainfall intensity is an essential parameter in the design of any hydraulic structure. The IDF curves are used to design hydraulic structures such as culverts, bridges, roads, urban drainage systems, and many more. Colonial masters developed the first IDF curve for Kano State based on records of 1938 - 1944 (6 years) followed by Oyenbade (1982), and since then, it has not been reviewed or updated. As a result of changes in rainfall patterns that have taken place over time and the climate change, the Oyenbade IDF curves might no longer be suitable for hydraulics design in Kano State. Therefore, this research aims to develop the new IDF curves and establish empirical equations of rainfall intensity that can be used for safe and economic hydraulics design in Kano State. India Meteorological Department (IMD) reduction formula was used to disaggregate maximum daily rainfall of Kano gauge station into the rainfall of shorter durations. Lognormal probability distribution was found to fit best the data set of all the durations using Easyfit 5.0 software and estimate rainfall intensities for 2, 5, 10, 25, 50, and 100 years return periods. It was found out that rainfall intensities increase with the increase in return periods but decreases with an increase in duration. The coefficient of determination ‘R2’ for all return periods indicated a strong relationship in IDF models developed. Hence, the new IDF curves developed should estimate rainfall intensities for hydraulics design in Kano State. The derived IDF models could be used for better results and accuracy.

Keywords: Probability distributions, IMD reduction formula, return periods, rainfall duration, easy fit software 5.0
COMPARATIVE ANALYSIS OF THERMAL STRESS OF Si AND SiC MOSFETs
Authors: Devadas Shree Chakravarthy , Kannan Ramani
Published: February 2024

The performance of power MOSFET is affected by high thermal stress exposure. A high level of thermal stress is induced when the MOSFET experiences a temperature change. This finding is about the bonding wire lift-off on the solder pad. The MOSFET model is designed with the heatsink to ensure accurate results are obtained in this research work. The key intention of this research is to investigate the condition of silicon and silicon carbide power MOSFETs during thermal stress. The thermal properties of silicon and silicon carbide MOSFET were investigated by developing a 3D modal and thermal stress simulation in the COMSOL Multiphysics software. Thermal resistance was calculated by randomly selecting a power loss value of 100 Watts. Junction temperature for silicon and silicon carbide MOSFET was taken from several articles mentioned in the results and discussion.

Keywords: Thermal stress, bonding wire lift-off, temperature change, MOSFET
OVERFIT PREVENTION IN HUMAN MOTION DATA BY ARTIFICIAL NEURAL NETWORK
Authors: Chan Choon Kit , Chala Girma T.
Published: February 2024

Motion analysis has been an active research area for the past decade. Several approaches had been proposed to detect and recognize motion activity for different applications such as motion estimation, modeling, and reconstruction. However, a suitable classifier is required to be embedded with the surveillance system to ensure accurate motion recognition. During these processes, the recognition system compares the captured motion with the motion database in order to recognize the motion activity. However, the classifier can only recognize the motion activities that are closely fit with the database, and overfitting has been an issue in this process. Hence, this paper is aimed at resolving overfitting problem by using Artificial Neural Network (ANN) for motion classification. The motion data was transformed into numerical data with an aid of Kinovea. Data mining software called WEKA was used to perform motion classification. Multi-Layer Perceptron (MLP), which is known as ANN, was modified to recognize different motion activities in the classification process. It was observed that MLP is able to yield classification accuracy of 97.62%. Overfitting issues were also solved by manipulating learning rates in the ANN classifier. A reduced learning rate from 0.3 to 0.1 improved the classification accuracy of jumping motion by up to 12.04%.

Keywords: overfitting, data pre-processing, classification, multi-layer perceptron, recognition, WEKA
EFFECTS OF PARTICLES DISAGGREGATION UNDER ULTRASONIC-ASSISTED WATERFLOODING ON OIL RECOVERY
Authors: Abdellatif Abdelrahman Abuobeida Mahir , Aziz Nabilla Afzan Abdul
Published: February 2024

Ultrasonic waves have a wide variety of applications in a variety of fields. It is used in the oil and gas industry to remove near wellbore damage, and several studies have been conducted to examine its application with waterflooding. Additionally, ultrasonic waves are used in engineering to determine the stability of sediments through dispersion and disaggregation. This study aims to incorporate both the ultrasonic waterflooding aspect with the stability of the sediment by investigating the impact of sonication exposure duration on particle size and oil recovery under waterflooding. Six (6) coarse sand samples were used in the experiment to simulate the porous media found in a sand pack. A sieving test was conducted on each sand sample to obtain its Particle Size Distribution (PSD) curve prior and post sonication. Waterflooding was conducted using 3% NaCl brine as the wetting phase and decane (C10H22) as a non-wetting phase. Ultrasonic waves were applied continuously throughout the waterflooding durations (i.e., 15,30,45 minutes), and both temperature and decane recovery were recorded. The results show that ultrasonic results in minimal additional recovery less than 2%, and an increase in temperature of 2-8°C was observed. However, longer sonication results in higher particle disaggregation, which reduces permeability by15.50%-41.85% and can result in sand production. This study can be continued through investigation on the utilization of cyclic ultrasonic-assisted waterflooding as a technique that may aid in recovery without causing detrital effects to the reservoir sand layer.Keywords: permeability, stability, sonication, dispersion, size distribution
MULTIPHASE DRILLING KICK ANNULAR FLOW BEHAVIOUR IN VERTICAL AND INCLINED WELL PROFILES
Authors: Jamaludeen Muhammad Fadrul , Md Yusof Muhammad Aslam
Published: February 2024

One of the exponentially important drilling parameter has many misconceptions, and prompt confusion is the drilling kick. The current conventional approach assume a single-phase bubble model and neglect the multiphase flow in the drilling kick calculations, which lead to diversified solutions and misconceptions in well design. Hence, this study presents a mathematical model to analyse the behaviour of gas-liquid flow in different well profiles, which are vertical and deviated wells up to 60 degree inclination. The model analysed the annular pressure and temperature profiles as the influx rise to the surface. The methodology constructed to achieve the objective involve an iterative mathematical model to calculate pressure drop across the wellbore and temperature gradient for single-phase and multiphase flow models, indicating the type of flow regimes at each depth. The results show the impact of the selected parameters on the pressure and temperature generated, which eventually influence the drilling kick calculations. The annulus pressure increases 44.37% from multiphase vertical well annulus pressure to single-phase annulus pressure, and the pressureincrement is higher in highly deviated well profile. It is important to precisely and accurately estimate the gas void fraction since it influences all two-phase flow parameters such as pressure drop, mixture density, and gas velocity in the annulus. The pressure and temperature profile then developed into a model which incorporates the drilling kick concept. Apart from that, the Z deviation factor which indicates the gas solubility was also studied and included in the simulation.Keywords: Annular flow, flow regime, multiphase drilling kick, vertical well, inclined well
SYNGAS PRODUCTION FROM GREENHOUSE GASES VIA DRM OVER Ni/Al2O3 CATALYST: EFFECT OF Ca ADDITION
Authors: Jamal Norhidayu , Yusuf Mohammad , Abdullah Bawadi
Published: February 2024

In view of the escalating global warming phenomenon, utilization of CO2 has become an important event in recent decades. Syngas production via Dry Reforming of Methane (DRM) is one of the promising methods to produce COX-free hydrogen as a renewable and sustainable energy source. DRM requires an active functioning catalyst since it is a highly endothermic process. The catalytic behaviour of 10 wt.% Ni supported on Al2O3 and doped with CaO is investigated for DRM. In the present study, the effect of alkaline earth metal oxide (CaO) loading (varying from 0.5-2.0 wt.%) on the structure, properties, stability, and performances of the Ni-CaO/Al2O3 catalyst for the DRM process is studied. The catalysts were prepared by wet impregnation method and characterized by Scanning Electron Microscopy (SEM) to study the morphology of the fresh and spent catalyst and Thermogravimetric Analyzer (TGA), which changes in physical and chemical properties of the catalysts are measured as a function of increasing temperature and time. DRM is carried out in a fixed-bed reactor at a temperature range from 600°C to 800°C. Further, the effect of CH4 partial pressure on the conversion of CH4, CO2 and syngas ratio were also investigated. The thermal stability of the catalyst increased on loading with CaO, and CAT-4 (1.5 wt.% CaO, 8.5 wt.% Ni on Al2O3) displayed the optimum activity, stability, and least coke formation.Keywords: Global warming, syngas, catalyst, wet impregnation
NUMERICAL STUDY TO PREDICT PROPERTIES OF WAXY CRUDE OIL UNDER DYNAMIC COOLING
Authors: Hwa Goh K , Chala Girma Tadesse
Published: February 2024

In this paper, a parametric study was conducted via ANSYS-Fluent workbench to predict the properties of waxy crude oil subjected to dynamic cooling. Different case studies were conducted to validate the numerical study, and prediction of temperature for pipelines of up to 100 m length was made. It was observed that the percentage difference between the experimental and simulation results was below 20%. The temperature drop was smaller with a higher flow rate, with the temperature dropping from 350K to 338K in an uninsulated pipe of 100 m length. The temperature drop for lower flow rate could be considered significant to reach wax appearance temperature during dynamic cooling. This study would be a supporting step to involve simulation in predicting the properties of waxy crude oil in different pipe sizes.Keywords: Waxy crude oil, dynamic cooling, ANSYS-Fluent, parametric study
OUTLIER AND HOMOGENEITY ANALYSIS OF EXTREME RAINFALL SERIES IN KANO, NIGERIA
Authors: Mohammed Abdulrasheed , Dan’Azumi Salisu , Ahmed Modibbo Abubakar
Published: February 2024

Data preparation is one of the most important steps in the field of hydrology since the results of any research depend on whether the input data were reliable and rightly collected or not. Reliability and quality of long-term rainfall data are required before carrying out any study in hydrology. For this reason, outlier identification techniques and homogeneity tests have proved helpful. This study aimed at carrying out outliers and homogeneity analysis of extreme rainfall data series for the Kano rainfall gauging station. XLSTAT, 2019 was used to identify outliers through Grubb’s test for outliers/two-tailed test and Dixon test for outliers/two-tailed statistic test and Standard Normal Homogeneity Test (SNHT), Buishand Range (BR) Test, Pettitt Test, and Von Neumann Ratio (VNR) Test were used for homogeneity analysis. Four outliers were identified and treated accordingly. The results of homogeneity tests showed that the maximum daily rainfall data of the Kano gauging station is homogenous and classified as useful. The maximum daily rainfall data of Kano station can be used for any study in water resources and environmental engineerings, such as in Development of Intensity Duration Frequency (IDF) Curves and Rainfall-Runoff Simulations.Keywords: Outliers test, homogeneity tests, rainfall data, XLSTAT 2019