AJET_Vol 08 N 02
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Item Effects of absorber layer thickness and doping density on the performance of perovskite solar cells: a simulation analysis using SCAPS-1D software(University of Eloued جامعة الوادي, 2023-06-14) Bouderbala Ibrahim Yaacoub -Hamdi Nor-El HoudaThe photovoltaic devices based on perovskite have witnessed a rapid increase in performance and are moving towards commercialization due to their low-cost electricity production. In this simulation work, we studied the photovoltaic performance of solar cells based on methylammonium tin iodide (MASnI3) perovskite materials using the numerical simulation tool SCAPS-1D. The main objective is to improve the performance of this solar cell by determining the optimum properties for its operation. The influence of different key parameters, such as the thickness of the absorber layer and the doping acceptor density in the same layer, is thoroughly analyzed through SCAPS-1D. The optimized absorber layer with a thickness of 700 nm shows the highest power conversion efficiency of 26.21%. An increase in the doping density in the perovskite layer roughly increases the efficiency performance of the device to 30.21%. Based on our simulation results, it can be concluded that the TiO2/MASnI3/Spiro-OMeTAD structure for PSC is a potential alternative to the third generation of solar cells. It has the potential to be efficient and inexpensive in future researchItem MHD natural convection in a cavity partially heated having a wavy wall and filled with Al2O3-water nanofluid(University of Eloued جامعة الوادي, 2023-04-24) Rahmoune Imene-Bougoul,SaadiThis study focuses on the coupling of MHD natural convection in a cavity filled with Al2O3- water nanofluid. The cavity consists of vertical walls maintained at the temperature Tc, while the horizontal ones are adiabatic. The source is fixed at a high temperature Th and one of vertical walls is corrugated. Ansys Fluent software based on finite volume method was used to solve different transport equations through the use of a monophasic model. Several pertinent parameters were considered in the present study, such as Rayleigh number ( 4 5 7.68.10 Ra 3.072.10 ), Hartmann number (0 Ha 75 ), and solid volume fractions ( 0 0.05 ). The influence of these parameters on heat transfer and flow structure was analyzed by examining streamlines, isotherms, velocity and temperature profiles, and Nusselt numbers. Based on the results obtained, we notice that heat transfer enhancement rises with both Rayleigh number and nanoparticle volume fraction, but it decreases when Hartmann number increases. Also, we note that the conduction heat transfer becomes significant and that by convection becomes limited and sometimes suppressed for high values of the HartmannItem Strength of glass powder based high performance concrete during the time(University of Eloued جامعة الوادي, 2023-06-29) ArabBahia Aissat -Mehaddene RachidRecycling waste glass and protection of the environment with decreasing of the cement use in building are the main context of this research work. The influence of waste Glass Powder very rich in silica SiO2 as partial replacement of Algerian cement without additions based High Performance Concretes with superplasticizers is evaluated, varying the percentage of Glass Powder by 0%, 10% and 20% (by weight of cement). Compression and the three-point bending tests carried out on High Performance Concretes by fixing the water binder ratio and after water cement ratio at 0.35, the results show that the addition of Glass Powder improves the behaviour of the concrete material compared to the handling and the ease of implementation in an appreciable way. The study shows also that compressive and flexural strengths are significantly influenced by the substitution rate of Glass Powder, a drop is noticed at a young age for concrete with Glass Powder (7 and 28days) and strength gains at 90 and 365 days compared to the control concrete with 0%, this admitted that poozolanic and alkali silica reactions occurred from 28 days.Item Sol-gel synthesis of ZnO nanoparticles for optmized photocatalytic degradation of Eriochrome Black T under UV irradiation(University of Eloued جامعة الوادي, 2023-04-27) Auwal Yusha-Muhammad Sulaiman Darmaa-Kamaluddeen Abubakar IsahbIn this work, zinc oxide (ZnO) nanoparticles was synthesized by sol-gel method and characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), energy dispersive spectroscopy (EDS) and ultraviolet-visible (UV-Vis) spectrophotometry. The XRD analysis of the as synthesized catalyst revealed a hexagonal wurtzite structure. The average particle size and band gap values were 24.67nm and 3.28eV respectively. The peak observed at 452cm-1 corresponds to Zn-O stretching vibrational band. The effect of operating paramers such as initial concentration of eriochrome black-T (EBT), concentration of catalyst and pH of the solution was optimized using box-benhken design (BBD) and response surface methodology (RSM). The optimum photodegradation efficiency of 96.59% was obtained at 15.00mg of EBT concentration, 0.40g catalyst concentration and initial pH of 9.00. The degradation model was statistically remarkable with p < 0.0001% in which the EBT initial concentration and catalyst concentration were the most significant variables influencing the degradation of EBT over ZnO photocatalyst under UV irradiationItem Arhaliassb,Abdellah . Dynamic simulation of preformed aqueous foam stability for enhanced oil recovery application(University of Eloued جامعة الوادي, 2023-08-31) Sakhi Tayeb -CheminiaRachida-SalhiaYacine -ArhaliassbAbdellahAqueous foam is a two-phase system consisting of a continuous liquid phase and a dispersed gas phase. Foams are widely used in a variety of industrial operations, such as the enhanced recovery of hydrocarbons. Because of their unique properties, they can solve a variety of reservoir heterogeneity problems, including early gas breakthrough, channeling, and even viscous fingering. A variety of phenomena affect the stability of foams during flow, for example, the drainage process, gas diffusion, and bubble coalescence. In this research, we used the level-set method to simulate foam stability in various aspects, such as factors affecting foam drainage and coalescence phenomena. According to the simulation results, the foam's lifetime is greatly impacted by the phenomena of drainage and coalescence. Moreover, its stability is strongly influenced by salt as well as the type of gas used to generate itItem Power quality improvement using series APF based on multi-level (NPC) inverter topologies with intelligent control approaches(University of Eloued جامعة الوادي, 2023-04-23) Chennai SalimThis paper presents the performance of novel configuration of series active power filter (Series APF) based on five-level neutral point clamped (NPC) using modified instantaneous reactive power theory control strategy with fuzzy control scheme. The series filter is adopted to decrease voltage harmonics, compensate all voltage disturbances and regulate the terminal voltage of the load. The series APF injects a voltage component in series with supply voltage which is added or subtracted from the source voltage thus maintaining the load side waveforms as pure sinusoidal. Multi-level inverters are currently being investigated and used in various industrial applications. Five-level (NPC) inverter topology is one of the most converters employed in medium and high power applications, their advantages include the capability to reduce the harmonic content and decrease the voltage or current ratings of the semiconductors. On the other hand intelligent techniques know today a great use, due to the advantages that offers compared to conventional techniques. To benefit of these advantages efficient control scheme for series APF using this techniques is proposed in this work. The fuzzy voltage controller is designed to improve compensation capability of series active power filter by adjusting the voltage error using a fuzzy rule. The simulation is performed using MATLAB-Simulink and SimPowerSystem Toolbox. The performance in steady and transient states show the efficiency and the simplicity of the proposed control scheme based on modified p-q control strategy. Before compensation the source voltage is much distorted with high THDv value equal to 46.93%. After compensation using proposed Series APF the THDv is reduced to 3.57% in conformity with 519-IEEE standard norms.Item Development of a two-row manually operated rice transplanter for smallholder farmers in Nigeria(University of Eloued جامعة الوادي, 2023-01-21) Muhammed Lawal Attand-Aliyu Idris Muhammad-Ismail Shuaibu NuhuA two-row rice transplanting machine was developed for smallholder farmers in Nigeria using standard-approved methods and locally available materials. The transplanter was designed in such a way that one operator can operate the machine. The machine consists of ground wheels, sprockets, chain, frame, float, transplanting mechanism, seedling tray, shaft and handle. The developed rice transplanter was evaluated based on a 2 x 2 x 3 factorial experimental design arranged in a strip plot design to ascertain its operational performance. The performance parameters of the rice transplanter revealed a field capacity and efficiency of 0.0146 ha/h and 55.66%, respectively. A variation in the distance between the hills was observed. The mean values were found to be 322.9 mm. The number of seedlings dispensed per hill varied in different plots. In most cases, 2-3 numbers of seedlings are dispensed per hill. The depth of the hill varies between 23 mm to 38 mm respectively. The mean depth was found to be 30.33 mm. The mean percentage of the missing and floating hills was 40% and 45%, respectively. The missing and floating hills were high in the transplanted plot. Results obtained from the analysis of variance show that the effects of treatment tillage operation and water depth have a significant effect on the machine. Based on the result obtained it can be concluded that more performance evaluation with machine and soil parameters needs to be conducted on the machine. This technology is recommended for use in rural areas to increase productivity by rice farmers.Item Sliding mode sensorless control of an asynchronous motor based on an MRAS-type observer(University of Eloued جامعة الوادي, 2023-01-26) Hichem Hamiani- Ali Abderrazak Tadjeddine- Iliace Arbaoui- Mohammed Sofiane Bendelhoum- Abdelkrim BenaliThis work deals with the problem of speed control of a sensorless asynchronous motor. Conventional control laws by PI or PID for example, although still widely used, may prove to be insufficient or unsuitable. We then develop control laws by state feedback, their use nevertheless requires the measurement of the state vector. However, in many cases, sensors for measuring all the physical quantities are not available, essentially for cost reasons. An observer, which is a mathematical object, makes it possible to reconstruct this state vector from the only physical measurements available. In this context, we will propose the use of the sliding mode technique, which is a recursive control method and represents a tool for the study of dynamic stability. We will then approach the observers and in particular those resulting from the theory of the reference model (MRAS). In this proposed work, we are interested in the study of the asynchronous motor by the application of the sliding mode which is a relatively recent technique for nonlinear systems. It is combined with the vector control principle with oriented rotor flux to design robust machine control laws. The motor state quantities are estimated by the MRAS algorithm. A comparison of the performances is established to come out with general conclusions and in particular with regard to the use of the observer to estimate the quantities of state of the engine to control it later by this technique.Item Theoretical properties of Thiazepine and its derivatives on inhibition of Aluminium Al (110) surface(University of Eloued جامعة الوادي, 2023-02-28) Iorhunaa,Fater. Thomasb,Nyime Aondofa .Lawalc, Saifullah MuhammadIn this work, corrosion inhibition of Aluminium was evaluated theoretically through quantum functions. The studied molecules thiazepine and its derivatives were optimized and simulated with local density function B3LYP using DFT-D under restricted spin polarization DNP basis to obtain the stable geometry of the thiazepine structures. the Fukui density functions were evaluated to determine the frontier molecular orbitals (FMO) of the compounds. The number of adsorption sites (physisorption) was the mode of interaction with the heteroatoms such as Chlorine, Nitrogen, Sulphur oxygen and methylene (-CH2-) functional groups serving as the focal point for the selectivity of the donation and acceptance of electrons between the metal and the pyrimidine molecules as (ω+) electron accepting power and (ω−) electron donating power complement each other. The adsorption efficiency of the molecules as obtained by the simulated molecules was in the order PTA>CTA>ATP>TZP. Selectivity of the molecules was observed as the thiazepine molecules donate electrons more to p-orbital of the Al (110) surfaceItem Postharvest shelf life extension of Cucumber (Cucumis sativus) and Irish potato (Solanum tuberosum) using X-rays in Benue State, Nigeria(University of Eloued جامعة الوادي, 2023-01-18) Akaagergera,Nguvan Becky -Isidore Komofor Ngongiaha-Alexander A. Tyovendaa-Soweh Raymond Mbinkonga-b,c, Kenkwa Basil Songwee- Rousinne Komofor ChetghofThis paper investigates the postharvest shelf life extension of cucumber and irish potato using X-rays, in Benue State, Nigeria. The selection of samples for the research was done from the traditional markets in Gboko for similar properties as depicted in the literature. For both products, six samples each with one kept as the control sample were X-ray irradiated with and of X-rays. An ambient storage temperature range of 27 – 30oC was recorded. The measured density, moisture content M.C (%), and pH were in the intervals: , , and for cucumber, and , , and for irish potato respectively. The percentage mass shrinkage ( ( )) of the control and 100 X-ray irradiated samples were: 45.0% and 31.6% for cucumber, and 23.8% and 20.5% for irish potato respectively. The mass shrinkage ( ) was found to increase during preservation and higher values extended the shelf life of the products. The of X-rays was effective in preserving cucumber for an additional 7 – 8 days and irish potato for additional 10 – 15 days of storage. In essence, cucumber and irish potato can be stored by exposure to specific values of diagnostic X-rays.Item Effects of holder pasteurization operating parameters on pasteurized raw milk quality(University of Eloued جامعة الوادي, 2023-01-18) Sunmonu Musliu Olushola- Oyedunb Aliu OlamideA batch pasteurizer could be considered a closed system and it mostly makes use of heat, stirring, or agitation and speed variation as a process parameter for pasteurization. This study investigates if these parameters support the holder pasteurization method using White Fulani cow breed milk samples. The milk samples were pasteurized at 63°C for 30 minutes with slight but insignificant variations in pH values up to 7.55. The stirring speeds used in this study were 30 rpm, 36 rpm, and 42 rpm. The results showed a significant difference in the microbial loads and phytochemical values due to the study treatments. The microbial loads varied between 1.05* 104CFU/ml to 8.25*107 CFU/ml while the phytochemical values were between 0.12 mg/ml to 27.67 mg/ml. The milk samples were poor in phenol and flavonoid but their differences were significant at p≤0.05 after pasteurization. The speed of 30 rpm and 36 rpm did not show a significant difference at p≤0.05 in the fungi counts after the pasteurization. The blade shapes considered were anchor, helical, and vane. These blade shapes used contributed to the holder pasteurization processItem Comparative study of biogas yield from animal manure in barn and farm(University of Eloued جامعة الوادي, 2023-02-17) MohammedMuetaz - Boghandora Sulaiman- HassanRazena- JirhimanAbraheem- Ahmeedah AliThe need for energy crops and animal manures for the production of biogas is rising globally. Farmers that raise cattle may use manure as an alternative energy source. Manure is partially converted into energy in the form of biogas by an anaerobic digester. To improve the biogas yield from animal manure must be taken into consideration the quality of manure. It is clear that the difference in the method of pasture has an important impact on biogas production. The study aims to compare the amount of biogas produced from manure animals in barns (closed pastures) and animals in farms (open pastures). The study included different types of manure cows, sheep, and poultry. Experiments were performed in a 2 L plastic bottle digester in a water bath at a 37°C mesophilic range. During the 12-day hydraulic retention period, a mixture of animal dung and water was employed in a 1:1 ratio (HRT). The volumetric water replacement method was used to calculate the amount of gas produced. The results showed that the barn manure had higher biogas production than the farm manure approximately 3 times because their feed had concentrated nutritional supplementsItem Local sensitivity analysis of the AquaCrop model outputs for wheat under Semi-Arid water stress condition(University of Eloued جامعة الوادي, 2023-01-18) Harunaa , Muhammad Mansur . Ismailb,Habibu. Bashira,Ali Umar .Dibala, Jibril MusaThe FAO AquaCrop model has been extensively reported to simulate wheat growth and productivity in response to environmental conditions in many parts of the world. However, the calibration of the model could be tedious due to its large number of input parameters. The complexity in the model evaluation could be simplified by conducting a prior sensitivity analysis (SA), which information on it is hard to come-by in the North-eastern Nigeria. The SA of the model’s output variables to its input parameters was conducted using the local sensitivity analysis (LSA) technique. An early maturing REYNA-28 wheat variety was used under water deficit conditions in the semi-arid North-eastern Nigeria. The analysis revealed that the simulation of grain yield was highly influenced by days-to-flowering (DtF), normalized water productivity (WP*), reference harvest index (HIo), crop coefficient when the canopy is complete but prior to senescence (KcTrx) and maximum effective rooting depth (Zx) with sensitivity coefficients (SCs) of 1.23, 1.05, 0.83, 0.75 and 0.61, respectively. Biomass yield was highly sensitive to days-to-emergence (DtE), WP*, KcTrx, number of plants per hectare (den), soil surface covered by individual seedlings at 90 % emergence (ccs) and initial canopy cover (cco). The sensitivity of canopy cover was more to its related parameters such as DtE, maximum canopy cover (CCx), days-to-maximum canopy cover (DtCCx), canopy growth coefficient (CGC), ccs, cco, den and days-to-start of senescence (DtSS). Stress parameters were found to be either insensitive or with negligible sensitivity except lower soil water depletion threshold for canopy expansion (Pexlw). The analysis also revealed that the model outputs were insensitive to half of the model’s input parameters. These parameters could be fixed within their ranges in order to simplify the model and ease its calibration. The influential/sensitive parameters on the other hand require higher consideration during data collection, fine-tuning and calibration. This work can be validated using different SA techniques and wheat variety and under different environmental condition.Item Numerical simulation of time-fractional Navier-Stokes equation in cylindrical coordinates for an unsteady one-dimensional motion of a viscous fluid flow in a given tube(University of Eloued جامعة الوادي, 2023-01-18) Falade Kazeem Iyandaa-Adio Adesina Kamorudeenb-Taiwo Omotayo Adebayoc-Lawan Muhammad Auwala- Badamasi Sahura MuhammadaThis paper proposed and applied a three-step computational algorithm to solve the time-fractional Navier-Stokes equation (FNS) in a given cylindrical coordinates for one-way unstable flow motion. The Caputo definition of fraction order was obtained using the Riemann Liouville fractional integral operator, which was coded with the MAPLE18 software command and applied to simulate the different fractional values presented in 2D and 3D surface graphs for understanding better the operation of fractional Navier-Stokes equations over time in cylindrical coordinates. We considered different test cases to show the proposed algorithm's efficiency, robustness, and feasibility, which ultimately reduces the computational time and ease of implementation for the simulation of the fractional order of the fractional Navier-Stokes equation consideredItem Drought Analysis of Wheat in Humid (Wales) and Dry (Iraq) Conditions(University of Eloued جامعة الوادي, 2022-08-20) Çayan AlkanIt is necessity to examine the relationships between droughts and plant yields, which are affected by climate change. In this study, by choosing sample countries from the Middle East and Northern Europe, It was aimed to determine the relationship between wheat yields and drought. Considering that Wales represents the wet conditions and Iraq represents the dry conditions in the World, in this study, the drought conditions of these two countries were analyzed with standard precipitation index (SPI), standard runoff index (SRI) and palmer drought severity index (PDSI). In Cardiff, it was determined that the meteorological humidity increased and there is a normal climate in terms of hydrologic. This led to an increase in wheat yields. In terms of meteorologic drought, Iraq cities from arid to humid are Kirkuk, Mosul, Baghdad and Basra, respectively. Agriculturally, they are listed as Basra, Baghdad and Mosul, respectively. It was determined that wheat yield decreases in Iraq were caused by non-climatic factors. Generally, it was determined that drought periods spread homogenously throughout Iraq. Nevertheless, It is determined that drought is much more widespread and severe in Iraq in 2003, 2004 and 1964. In future dry years, production should be supported with irrigation and fertilization in Wales and Iraq