DSpace Angular :: Browsing by Author "Kareem, M.W."

Browsing by Author "Kareem, M.W."

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A review of solar air heater for drying of agricultural products
(Advanced Materials Research, 2014-02-27) Kareem, M.W.
Bulk of farm products need to be preserved because of their perishable nature. The cheapest and environmental friendly means is indirect usage of solar irradiance to reduce the moisture content of these products to a level that cannot sustain the activities of micro-organisms. The research on solar collector has gained its popularity over the years due to man’s quest for green energy which has led to increase in demand for the utilization of solar energy. Harnessing of solar energy by man for drying purposes was predominantly by direct method which reduces the quality and quantity of the dried products. This work presents the most recent contributions on solar air heater of flat plate absorber category. Various models, material of component parts and performance efficiency of these air heaters were discussed and there is need for collector optimization. The study was concluded with a focus on multiple pass approach of solar harvesting.
Bioconvection analysis for convectively heated radiative flow of Sutterby fluid involving efficacy of ferromagnetic nanoparticles
(Elsevier, 2024-08-16) Muhammad Tabrez; Amjad Ali Pasha; Waqar Azeem Khan; Iftikhar Hussain; Salem Algarni; Talal Alqahtani; Kareem, M.W.; Mehboob Ali
In this article explained about the study 2-D Sutterby fluid model with suspension of microorganisms in ferrofluid, while radiation aspect is also considered here. Basic purpose of using microorganism is to obtain more stability in suspension. Here the important characteristics of thermophoresis parameter, viscous dissipation, magnetic interaction parameter and Brownian motion parameter are examined. Now, the system of non-linear P. D.Es is changed into set of O.D.Es then we solved these equations by using famous mathematical scheme bvp4c. Graphical results showed that temperature of Sutterby ferrofluid intensifies with increase in the estimations of thermal Biot number as well as radiation effects whereas results in reduction of Prandtl number. The density of microorganism reduces for greater values of Peclet number.
Biphenyl monolayer construction with single transition metal doping as electrocatalysts for conversion CO2 to fuel
(Elsevier, 2024-08-14) Rahadian Zainul; Ali B.M. Ali; Dheyaa J. Jasim; Alaa Dhari Jawad Al- Bayati; Irwanjot Kaur; Abhishek Kumar; Ibrahim Mahariq; Mohd Abul Hasan; Saiful Islam; Kareem, M.W.
Developing sophisticated electrocatalysts is crucial in capturing chemically unreactive CO2 and transforming it into valuable products like fuel. This is essential for effectively tackling the issues of energy crisis and greenhouse gas emissions while maintaining considerable sustainability standards. Nevertheless, effectively managing the selectivity of products while maintaining a small overpotential remains a challenging task. Present work utilized density functional theory (DFT) for studying electrocatalytic potential of various single transition metals (TMs), such as cobalt, iron, and manganese, in process of carbon dioxide reduction reaction (CO2RR). Effectiveness of CO2RR was evaluated for each TM by analyzing their interaction with reaction intermediates (CHO, CO, and COOH) when incorporated into biphenyl monolayer (BPM) systems. Based on the analysis of ΔE values and barriers, it was determined that incorporating Fe into the biphenyl monolayer system is the most efficacious approach for the CO2RR to generate methane. This configuration achieves an exceptionally low overpotential potential (UL) of 􀀀 0.36 V. In hydrogen evolution reaction (HER), it was observed that CO2 exhibits a higher affinity for occupying the activation site on Fe-BPM compared to H2. This difference in adsorption energy (Ead) (􀀀 0.94 eV for CO2 vs. 􀀀 0.43 eV for H2) highlights their distinct behaviors. Additionally, Fe-BPM effectively suppresses the HER during the CO2RR process, as indicated by the HER’s UL of 􀀀 0.43 V. Findings of present study are anticipated to provide a novel direction in the advancement of electrocatalysts with low potential, while simultaneously exhibiting remarkable selectivity and activity for CO2RR.
Comparative study of single pass collector and double pass solar collector filled with porous media
(Asian Journal of Scientific Research, 2013-01-15) Kareem, M.W.
This research reports a comparative study of the convectional single pass flat plate collector and the double pass solar collector filled with porous media such as gravel and metal chips at the lower channel of the absorbing unit. The component materials, design, performance efficiencies, capabilities and the application of the solar collectors are presented to show various disparities that exist between the collectors. Emphasis was laid on the multi-pass approach as a gate way to future development on solar collectors.
Evaluation of thermal comfort in a test room equipped with a photovoltaic assisted thermoelectric air duct cooling system
(Elsevier, 2017-08-26) Kashif Irshad; Khairul Habib; Kareem, M.W.; Firdaus Basrawi; Bidyut Baran Saha
This study investigates the comfort performance of a test room equipped with the southfacing photovoltaic wall (PV-W) and north-facing thermo-electric air duct (TE-AD) system for the tropical climate. Both subjective and objective measurements were used to analyze the TE-AD system cooling performance when operated at variable input current supply (2e7 A) from a PV system. Indoor radiant and air temperatures, relative humidity, and air velocity were measured based on ISO 7730 for objective measurement. For subjective measurement, forty respondents were required to fill up the questionnaire that developed based on UNI EN ISO 10551 and UNI EN ISO 7730 guidelines in order to access their thermal comfort opinion. The results show that the thermal response of respondents associated with indoor situation of the test room have changed from (þ1) slightly warm to cool ( 2) when the input current supply rises from 2 A to 6 A. The overall predicted mean vote, predicted percentage dissatisfied indices, and acceptability vote shows that more than 90% of the respondents were thermally satisfied. Integration of the PV-W system with the TE-AD system increases the thermal comfort and reduces the thermal load of the test room with other benefits includes less fuel and energy consumption, high reliability, and less maintenance operation.
Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage
(Elsevier, 2023-11-04) Lukmon Owolabi Afolabi; Christopher Chintua Enweremadu; Kareem, M.W.; Adiat I. Arogundade; Kashif Irshad; Saiful Islam; K.O. Oladosu; Abdulhafid M. Elfaghi; Djamal Hissein Didane
Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorber and TES cavity for the DSSS-TES attained are 65.2 ◦C, 77.5 ◦C, 82.4 ◦C, 79.5 ◦C and 68.4 ◦C, respectively. DSSSTES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards.
Lumped component modelling of double pass solar collector with porous matrices
(Applied Mechanics and Materials, 2014-02-10) Kareem, M.W.
In this report, the modeling and simulation of a double pass solar air absorber was carried out using combination of Simscape and Simulink modeling tools. The solar system air mass flow rate and the porous media were critically investigated by using local weather data of Seri Iskandar, Perak, Malaysia. Optimal inlet air flow rate of 0.034kgm-2s-1 was obtained and one of the packed beds, sandstone extended the thermal transfer period of solar collector system by 1150s which displayed good agreement with the reported model and experimental outcomes. The results obtained have shown that it is a promising alternative tool for solar thermal experimentation modeling.
Machine learning analysis for the dynamics of hydromagnetic bio-convected nanofluid containing gyrotactic microorganisms using Bayesian distributed neural networks
(Elsevier, 2024-09-15) Zahoor Shah; Amjad Ali Pasha; Muhammad Asif Zahoor Raja; Sajjad Khan; Salem Algarni; Talal Alqahtani; Waqar Azeem Khan; Kareem, M.W.
This study investigates the complex phenomenon of hydromagnetic bio-convected Nanofluid with Gyrotactic microorganisms (HMBNFGM), containing nanoparticles and mobile microorganisms. The nanofluid’s flow over a vertical penetrable surface triggers bio-convection, characterized by the intricate interplay of upthrust and electromagnetic fields, which significantly influence the dynamics of microorganisms and nanoparticles. To model this complex system, machine learning analysis is done by employing Bayesian distributed neural networks (MLA-BDNNs), integrating advanced computational techniques with fluid dynamics principles. The Adam numerical approach is utilized to create an accurate dataset for MLA-BDNNs for the analysis of the fluid velocity profile fʹ(η), temperature profile θ(η), concentration profiles ξ(η), and microorganism profile χ(η), adjusting twelve parameters each for three distinct cases involving Grashof number (Gr), Eckert number (Ec), Brownian motion parameter (Nb), Buoyancy ratio parameter (Nr), thermophoresis parameter (Nt), traditional Lewis number (Le), bioconvection Lewis number (Lb), bio-convection Rayleigh number (Rb), and P´eclet number (Pe). The attained dataset is then employed in numerical computation to quantify the parameters of HMBNFGM fluidic model. The knacks of artificial intelligence is utilized for developing the proposed algorithm MLA-BDNNs for solving the HMBNFGM fluidic model. The best performance in terms of MSE are attained at points 4.92E-13, 4.45E-13, 8.90E-13, 5.01E-13, 1.96E-08, 6.83E-13, 7.62E-13, 8.16E-13 , 9.92E-13 , 5.84E-13 , 2.18E-13 , and 6.591E-12 against 262, 98, 119, 71, 134, 221, 136, 173, 138, 125, 182, and 63 epochs. The accuracy and precision of the proposed algorithm MLA-BDNNs are efficiently established by low level of MSE, near-optimal regression metric indices as well as error distribution on histograms presenting negligible magnitudes. The results got through the AI based MLA-BDNNs technique satisfy the reliability of the contribution in offering fairly and accurate solution of the HMBNFGM.
Multi-pass solar air heating collector system for drying of screw-pine leaf (Pandanus tectorius)
(Elsevier, 2017-01-27) Kareem, M.W.; Khairul Habib; Sopian K.; Ruslan M.H
An experimental investigation of solar drying of screw-pine leaf has been conducted in the open space of the solar research site, Universiti Teknologi PETRONAS Malaysia (4.385693 N, 100.979203 E). Screwpine leaf has been used for handcraft in many villages in Asia and Africa. A transient state lumped element analysis was developed to determine the thermal performance of the multi-pass solar collector system (MSCS) in accordance with ASHRAE standards. The facility was assessed under the average daily solar irradiance of 412.6 Wm 2 and ambient temperature of 30 C over an air mass flow rate range from 0.010 kgs 1 to 0.032 kgs 1. Drying kinetics profiles of screw-pine have been obtained and an improved range from 22% to 26% of instantaneous thermal collector efficiency has been recorded over the double pass collector system (DPCS) while thermal energy storage has contributed 5e8% to system performance. MSCS performance has been determined and achieved the thermal collector, pickup, drying and exergy efficiencies of 58.73%, 66.95%, 36.04% and 27.23e86.82%, respectively. The level of risk on the investment in MSCS has been measured using economic indices to obtain a payback period of 0.75 year. The thermal loss through conventional collector back plate has been prevented by integration of collector unit and the drying cabinet of the system. There is still need to further improve the system performance efficiency through enhanced energy saving innovation technique.
Numerical modelling of hot air multi-pass solar dryer
(International Solar Energy Society Conference Proceedings, 2014-07-06) Kareem, M.W.
This article presents the investigation of modeling solar drying system using partial differential equation module of MATLAB to predict the thermal conditions of a drying system with pebble beds as heat storage medium. A 2-dimensional geometry of the air heater was examined using both Dirichlet and Neumann boundary conditions to define the heat transfer and temperature gradient at the walls of the system. Appropriate thermal equations were used to define the multi-layer drying system with specific properties of materials which have significant effect on the performance efficiency of the solar collector. Finite element method of meshing the system component was employed to solve the heat transfer equation. The dynamic simulation of the air heater was tested for 5000 s at the average maximum daily temperature of 318 K with solar irradiation of 800 Wm-2. Despite five cabinet channels design, the temperature gradient of hot air distribution at various points was less than 1 K. The heat transfer simulation of the system has been achieved in good agreement with the reported studies. However, the mass transfer aspect of the model still needs to be improved upon for better and accurate collector characterization.
Optimization of fuel briquette made from bi-composite biomass for domestic heating applications
(Elsevier, 2023-08-21) K.O. Oladosu; S.A. Babalola; Kareem, M.W.; H.A. Ajimotokan; M. Y. Kolawole; W.A. Issa; A.S. Olawore; E.A. Ponle
This study aimed at optimizing the fuel briquettes produced from flamboyant pod (FBP), and corn cob (CC) mixed with cassava starch (SB) as a binder using custom design methodology (CDM). The compressive strength, ash yield, and emission analysis of the briquettes produced were determined. The combustion efficiency parameters as well as CO, NO2, PM2.5, and PM10 of the emissions were compared to optimal fuel briquettes and charcoal fuel. The optimal combination of compressive strength and ash yield was obtained for the briquette fuel blend formulated from 30 wt.% flamboyant pod, 51 wt.% corn cob and 17 wt.% starch. While the water boiling time of the fuel increased by about 35–48% compared to charcoal fuel, the ignition time and the specific fuel consumption rate decreased by ~34% and 16%, respectively. Furthermore, the major air pollutants were reduced from 222 to 196 ppm for CO, 3.63–2.34 ppm for NO2, and 0.21–0.09 ppm for PM 2.5. These properties of the briquette align with charcoal, thus supporting the use of flamboyant-corcob-starch (FBCS) briquettes as a supplementary source of energy to charcoal.
Performance analysis of a multi-pass solar thermal collector system under transient state assisted by porous media
(Elsevier, 2017-06-25) Kareem, M.W.; Gilani S.I; Khairul Habib; Kashif Irshad; Bidyut Baran Saha
An enhanced forced convective multi-pass solar air heating collector (MPSAHC) system aided with granite pebble bed has been investigated in this present article. The air heating collector system was tested in the outdoor solar research site of Universiti Teknologi PETRONAS, Malaysia (4.385693° N and 100.979203° E). Transport pipe for movement of heated air around the system was eliminated in the design of the MPSAHC facility to minimise the thermal losses, pressure drop and the pumping cost of the hot air in the control volume. The daily ambient temperature and relative humidity range recorded during the repeated tests are 21.09–36.64 °C and 48.04–87.9%, respectively. The collector unit achieved a peak temperature of 80.29 °C while the optimum system air mass flow rate of 0.016 kgs−1 was applied. Despite high relative humidity of the environment, the stream of ambient air was heated to 48.53 °C, 57.75 °C and 71.19 °C at different positions in the MPSAHC which correspond to single pass, double pass and multi-pass effects, respectively. The porous matrix exhibited slow energy discharge at night time with air temperature difference of 14.27 °C at 18:00 h to 4.54 °C at 24:00 h over environmental air temperature. MPSAHC system delivered specific energy demand (SED) of 11.51 kWh kg−1 while the maximum thermal collector and daily average transient collector efficiencies of 72.59% and 36.38% were achieved, respectively. A good agreement has been established between reported studies and the present investigation. Although continuity of system operation at night was achieved using porous matrix but improvement is still needed to optimise the system performance.
Random vortex element modelling of groundwater flow
(World Academy of Science, Engineering and Technology, 2012-06-01) Kareem, M.W.
Exploitation of groundwater for both domestic and industrial uses has continuously been undertaken in different parts of the world. The proper harnessing of available water required adequate analysis of the flow in the aquifer. Successful attempts have been made using finite difference and finite element methods. However, the possibility of vortex element method as an alternative technique was considered in this work. A model was developed using random vortex element method to simulate groundwater flow with constant head at the aquifer boundary. This was carried out by transforming the governing equation for groundwater flow into a typical vorticity equation for vortex method. The model was then used to determine groundwater head at varying time for Lagos basement complex with transmisivity and storativity of 5.5 X 10-5 m and 6.840796 X 10-2 respectively. The aquifer thickness varied from 4.0 m to 7.0 m. At the aquifer thickness of 4.0m the predicted groundwater heads varied from 0.0 m to 0.024833690 m, while at the aquifer thickness of 7.0m the predicted heads varied from 0.0m to 0.159134 m for varying time step at 0.1 s. The head differs only from literature value by 2.44%. Random vortex element method is therefore a viable numerical tool for predicting the groundwater flow parameters of the aquifer at any desired location.
Study of thermoelectric and photovoltaic facade system for energy efficient building development: A review
(Elsevier, 2019-05-17) Kashif Irshad; Khairul Habib; R. Saidur; Kareem, M.W.; Bidyut Baran Saha
Energy usage in buildings has become a critical issue due to increase in occupants’ time spent inside a building and use of energy intensive equipment for providing comfort. Utilization of an alternate source of energy can be considered one of the promising solutions to tackle this issue. In the present paper, a review of photovoltaic (PV) and thermoelectric (TE) technologies implemented for energy efficient building development is presented, discussed and critically analyzed. Then, the basics of the solar panel and its performance parameters are introduced. After that, the integration of the PV technology in the building particularly on the wall and its benefits with respect to the building energy consumption has been thoroughly studied. It was found that about half of building thermal load was reduced by installation of a PV panel over the wall. In addition, the thermoelectric module as a substitute to the air conditioning technology is reviewed and literature that focuses on the integration of both TE and PV for building applications has been studied. It can be seen that the PV integrated with the TE system increases the energy saving potential by 22% and reduces 5e10 C indoor temperature from the ambient conditions. At the end of this article, few challenges, environmental aspect and future research directions are also addressed in detail.
Thermal comfort analysis of building assisted with photo voltaic trombe wall
(EDP Sciences, 2016-07-15) Kashif Irishad; Khairul Habib; Nagarajan Thirumalaiswamy; Kareem, M.W.
Maintaining indoor climate condition of building compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW) on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results shows that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. The comfort indexes (PMV and PPD) lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover, PV-TW system significantly reduces energy consumption and CO2 emission of the building and also 2-4 oC of temperature differences between indoor and outdoor climate of building was examined.

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