Algerian Journal of Engineering and Technology (AJET)
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Evaluation of rice milling quality and energy requirement via a developed vibratory rice grader
Get PDFIn the modern way of processing rice, rice is usually parboiled before milling operation and grading is one of the milling operations required to classify rice into different grades of importance viz. the head and broken rice. In this study, a vibratory rice grader was developed. The effect of processing conditions on the milling quality (milling recovery, head milled rice and broken rice), grading time, energy requirement and energy intensity were evaluated. The soaking time (4 – 6 h), steaming time (30 – 40 mins) and rice variety (FARO 15, FARO 60 and FARO 62) were interacted using Taguchi experimental design (L933). Standard equations were used to evaluate the effect of processing conditions on the milling quality, energy requirement and energy intensity of the rice grader. Milling recovery ranged from 53% to 70%, head milled rice (41% - 67%), broken milled rice (3% - 12%), grading time (4.4 – 5.8 mins), energy requirement (2.632 MJ to 2.649 MJ) and energy intensity (1.20 – 1.58 MJ/kg). An increase in soaking time and steaming time increased the grading time, milling recovery, head milled rice, energy requirement and energy intensity but reduced the broken milled rice. The estimated cost of the developed vibratory rice grader was $152. This study provides valuable information on a simple way of designing and developing a rice grader that could be adopted for grading rice into whole rice or head rice and broken rice
Modeling and optimization of processing parameters of strips produced from blends of cassava and cowpea flour
Get PDFMost Nigerian traditional foods have a low nutritional value, inconsistent sensory attributes, and short shelf life. Thus, upgrading becomes necessary for the technologies used in the processing, distributing, and storing of indigenous snack foods to improve the products' nutritional, sensory, and storage properties. A Box-Behnken (three-factor) response surface methodology was used to optimize the process. The effect of frying temperature (160 - 180°C), frying time (8 - 12 min) and percent cowpea flour (10 - 30%) on some attributes (moisture, fat, protein contents, texture, and color change) of cassava-cowpea strips fried snack. Data were analyzed by ANOVA and regression analysis. The moisture content ranged between 1.00% and 4.26%, fat content (8.41–11.94%), protein content (30.83–36.42%), texture (5.06–13.14 N) and color change (26.967–40.479). Frying temperature, frying time and % cowpea flour had a significant (P < 0.05) effect on moisture, fat, protein contents, texture and color change of cassava-cowpea strips. The processing conditions affected moisture, fat, protein, texture, and color change. Coefficients of determination, R2 were 0.87, 0.86, 0.79, 0.88 and 0.71, respectively. The best conditions for processing cassava-cowpea strips were 12 min frying time, 166.65 °C frying temperature, and 24.36% cowpea flour content. The desirability of optimization was 0.65. Therefore, composite flour from cassava and cowpea can be adopted or used to produce strips to prevent protein-energy malnutrition in the community
Design, construction and performance evaluation of a cucumber slicing machine
Get PDFThe cucumber slicing machine was designed, constructed and it is performance was evaluated. The major components of the slicing machine are the power unit, slicing compartment, knife compartment, collecting vessel were all fabricated and mounted on the machine. The performance parameters of the machine such as slicing efficiency, percentage loss, and output capacity were evaluated. T-test was used to compare the mean values of these parameters for manual and mechanical slicing. The average efficiency of the manual and mechanical slicing was found to be 71.84 % and 90.0 % respectively. The average percentage loss of the manual and mechanical slicing was found to be 5.5 % and 14.08 % respectively. The average output capacity of the manual and mechanical slicing was found to be 30 kg/hr and 165.60 kg/hr respectively. The efficiency of manual slicing is significantly higher than mechanical slicing. However, the mean value for mechanical percentage losses and output capacity is significant than manual slicing
Experimental investigation and numerical simulation of electrical tree growth in polyethylene under AC voltage
Get PDFThis paper reported the growth of electrical tree in low density polyethylene under AC voltage. Specimens of double needle geometry were achieved by compression molding. The evolutions of electrical tree length and discharge magnitude versus aging time were studied. The tests were carried out until dielectric breakdown of the polymer happens. Firstly, ionization of the cavities occurs inducing a rapid propagation of electrical tree. Secondly, the growth slows down resulting to the rise of gas pressure in the tree channels. The decrease in growth rate is also attributed to the increase of the electric conductivity of channel walls. This process is highlighted by the inception and the extinction of partial discharges. The presence of space charge affects the growth of tree. For the modelling of electrical tree, we have considered a model with two concentric spheres. The simulation results were validated by the experimental tests
Graphitization of lignin-modified phenolic resins: role of lignin pretreatments
Get PDFAiming at the generation of graphitic carbon from low-cost phenolic resins, this study investigated the role of lignin pretreatments on the amount of crystalline carbon generated from lignin-phenol-formaldehyde resins containing boron oxide, boric acid and ferrocene as graphitizing additives. Kraft lignin used to synthesize the resins was initially subjected to thermal and thermomechanical treatments to improve processability and promote greater mobility for ease of graphitization during carbonization. The results showed that the characteristics of lignin used to prepare the thermosetting resins affect the quantity of graphitic carbon that was generated during pyrolysis. The lignin-modified resin prepared using Kraft lignin, which has the lowest molecular weight and polydispersivity values produced the highest amount of graphitic carbon. This formulation containing 10 wt.% boric acid presents a graphitization level value of 73%. In addition, limited amounts of crystalline carbon were generated when boron oxide and ferrocene were used as graphitizing additives
Application of polyvinylpyrrolidone-iodine complex as corrosion inhibitor for carbon steel using an experimental design method
Get PDFCorrosion processes are responsible for numerous losses, especially in the industrial sector. Inhibitors are commonly used to prevent corrosion in acidic medium. The aim of this study was to apply an experimental design to optimize the influencing parameters such as inhibitor concentration, temperature and immersion time on the corrosion inhibition of polyvinylpyrrolidone-iodine (PVP-I) complexes on carbon steel using the weight loss technique (WL). The parameters of the corrosion protection process were optimized and predictive mathematical models were developed using the Response Surface Methodology (RSM) using the Central Composite Design (CCD). It was also found that the data predicted by the regression analysis had a good agreement with the data obtained from the experiments, with the values R2 = 0.999 and Adj. R2 = 0.997 for the inhibitory effect. The best efficiencies for experiments that were not performed were determined by experimental design (DOE
Study and evaluation of electronic transport property for an InAlN based on Monte Carlo
Get PDFThe emergence of the semiconductors III-N with heterojunction structures has made it possible to study a wide range of two-dimensional phenomena. This paper devotes to simulate the characteristics of the InAlN material, taking into ac-count temperature and doping as dependencies of conduction properties and performance using MOCASIM of the Tcad-Silvaco software. For the electronic transport model analyzing, we adopted most of the predominant mechanisms using various scattering effects including: optical phonon scattering, acoustic phonon scattering through deformation potential and piezoelectric potential, ionized impurity scattering, and grain boundary scattering. As expected, the carrier transports in the GaN layer are affected by the spontaneous polarization of the InAlN layer. To interact that, the diffusion of grain boundaries has been switched from the diffusion of ionized impurities by the deposition of InAlN. In order to achieve the most improvement possible for the electron transferring in terms of thickness and alloy composition related to the improvement of super-deposited layers. The confinement of sub-bands in channel quantum well is also taken into account in the computation of electron mobility. In the end, the adopted electron model is improved by including the effects of deep electron traps
Effect of selected oven drying temperatures on the quality of Tiger Nut (Cyperus Esculentus) and Ginger Nut (Zingiber Officinale)
Get PDFThe present study was to evaluate the effect of selected drying temperatures on the quality of tiger nut (Cyperus Esculentus) and ginger (Zingiber Officinale). The temperatures used were 25, 50, and 75°C for 4 hours. The quality composition determined were moisture content, crude protein, crude fiber, crude fat, ash content, and carbohydrate. From the results, the tiger nut parameters that show significant difference at the three drying temperatures 25, 50, and 75°C with their mean values were moisture content 0.05, 0.20, and 1.05%, crude protein 8.75, 6.56, and 5.47%, and crude fat 10.28, 14.60 and 12.65%. For ginger nuts were moisture content was 1.25, 2.15, and 2.60%, and crude protein was 15.31, 14.22, and 17.50%. While the parameters that show no significant difference at the three drying temperatures 25, 50, and 75°C with their mean values were crude fiber 1.26, 1.27, and 1.28%, ash content 2.95, 3.95, and 4.90%, and carbohydrate 76.75, 74.62, and 75.72. For gingers were ash content 8.7, 6.50, and 7.35%, crude fat 8.72, 10.43 and 9.20%, crude fiber 1.42, 1.23 and 1.28%, and carbohydrate 65.84, 67.63, and 64.67. Drying temperatures are crucial in affecting food internal structure, composition and widely practiced as a method of preserving agricultural products because of its ease and affordability.
 
Enhancing Energy Efficiency for Optimal Multiple Photovoltaic DG and DSTATCOM Integration for Techno-Economic and Environmental Analysis: A Case Study of Adrar City Distribution System
Get PDFThe insertion of renewable energy resources in existing distribution systems has effectively improved its performance and operation. This paper presents the efficiency of the optimal integration of multiple Photovoltaic DG (PV-DG), and Distribution Static Compensator (DSTATCOM) simultaneously in a practical Power Distribution System (PDS), through the maximization of the Multi-objective function (MOF) based on the Real Power Loss Level (RPLL), the Short Circuit Level (SCL), the Voltage Deviation Level (VDL), the Net Saving Level (NSL), and Environmental Pollution Reduction Level (EPRL) by various Inertia Weight Particle Swarm Optimization (IW-PSO) algorithms. The proposed IW-PSO algorithms applied in the practical Adrar city 205-bus distribution system in Algeria. The obtained results prove the efficiency of the algorithms in terms of achieving the minimum power loss and improvement of the voltage profiles, the EIW-PSO exhibits the best results of MOF compared to other algorithms
Investigation of soundness and erosion rate of rocks used for strengths the bank river in southern Iraq
Get PDFRocks are the basic materials that are used to strengthen the banks of rivers. Their properties and characteristics play an important role in controlling erosion problems. This paper compares and studies the soundness and erosion rates of several types of rocks collected from four locations in Muthanna Province, southern Iraq. Soundness testing is performed using two experimental approaches (ASTM C88 method and EN 1367-2 (Annex B) approaches). To perform the erosion test, a rotating erosion testing apparatus (RETA) was built in the laboratory. Soundness tests indicated that the rock of South Muthanna sites (SRM2) had a lower resistance to degradation, whereas the rock of West Muthanna sites (WMA1) had a higher resistance. Both ASTM C88 and EN 1367-2 techniques yield similar results, but the EN 1367-2 method yields greater mass loss than ASTM C88. As well, it was discovered that the porosity of the rock and its capacity to absorb water directly affect the soundness test results. Tests conducted with the erosion function apparatus (EFA) indicated that the erosion rate value is higher than those obtained from the rotating erosion testing apparatus (RETA). High water salinity decreases erosion rates; whereas higher water velocity leads to increase it