Open Access Original Research Article

Checking Correctness of a Symbolic Reliability Expression for a Capacitated Network

Omar Mutab Alsalami, Ali Muhammad Ali Rushdi

Journal of Engineering Research and Reports, Page 12-29
DOI: 10.9734/jerr/2020/v18i217203

Checking a symbolic reliability expression for a flow network is useful for detecting faults in hand derivations and for debugging computer programs. This checking can be achieved in a systematic way, though it may be a formidable task. Three exhaustive tests are given when a reliability system or network has a flow constraint. These tests apply to unreliability and reliability expressions for non-coherent as well as coherent systems, and to cases when both nodes and branches are unreliable. Further properties of reliability expressions derived through various methods are discussed. All the tests and other pertinent results are proved and illustrated by examples.

Open Access Original Research Article

Modeling the Drying of Soybean Curd Residue Based Fish Feed

T. T. Ayanlade, J. A. Adegboyega, A. P. Olalusi

Journal of Engineering Research and Reports, Page 38-49
DOI: 10.9734/jerr/2020/v18i217205

The drying characteristics of Soybean curd residue (SCR) based fish feed were investigated using an oven at temperatures of 40, 50, 60, 70 and 80°C, and at a constant air velocity of 1.5 m/s. The ingredients composition for the fish feed were mixed and extruded using a single screw extruder. Then, the extruded fish feeds were dried in an oven at the various temperatures. The coefficient of determination (R2), Root Mean Square Error (RSME) and reduced chi-square (χ2) between the observed and predicted moisture ratio for all conditions of drying were used to study and evaluate the performance of the nine models fitted to the data gotten from the experimentation. Page model was the best for SCR based fish feed samples dried at 60°C which is the best temperature for drying by the coefficient of determination r2, which was concluded based on the mathematical modelling of the drying characteristics. Drying at all temperatures produced the proximate composition within the desirable limit. Although, protein and fat content decreased and were highest after drying at 400C, while carbohydrate and fibre increased and were highest after drying at 80°C temperature content of the fish feed. At 60°C, proximate composition was at the medium within desirable limits which can be fed directly to Clarias Gariepinus.

Open Access Original Research Article

Flue Gas Emissions and Performance Evaluation of Small-scale Solid Waste Incinerators at Njokerio and Ng’ondu in Njoro, Kenya

Nyoti Stephen G. Mugo, D. M. Nyaanga, S. F. Owido, G. O. Owino

Journal of Engineering Research and Reports, Page 50-66
DOI: 10.9734/jerr/2020/v18i217206

Solid waste management is challenging and incineration technique is more preferred to other methods in reduction of mass and volume, removal of odour and energy recovery in both industrial and residential environments. The challenges facing residents at Njokerio, Ng’ondu and Green Valley estates in Njoro, Kenya included poorly designed open-wastes collection systems, exceeding incinerator loading rates and inappropriate operating temperatures. It also include inadequate design specifications, poorly mixed solid wastes with high moisture contents resulting to high emissions of noxious heavy dense smoke. The aim of this study was to evaluate factors influencing flue gas emissions and performance of small-scale incinerators. Data collected were statistically analysed to determine trends, means, F-values and Least Significant Different (LSD) at . Wastes incineration at varying moisture contents (MC) from 15 to 75% produced mean emission values for carbon monoxide (CO), carbon dioxide (CO2), and hydrocarbon (HC) ranging between 5 and 11 ppm, 5 and 14%, and from 508 to 1168 ppm, respectively. Varying the incinerator loading rates from 15 to 75 kg/h yielded means CO ranging between 5 and 12 ppm, CO2 from 5 to 14%, and HC between 252 and 1096 ppm. Waste incineration at varying operating temperature levels from 180 to 900°C contributed to mean emissions for CO, CO2 and HC ranging from 14 to 5 ppm, 15 to 6% and 1253 to 316 ppm, respectively. The Egerton University dispensary incinerator had the best incineration performance compared to the rest. High moisture contents, overloaded incinerators and low operating temperature levels contributed to high emission levels of flue gases leading to dark and dense smoke which resulted into incomplete wastes combustion indicating poor incineration performance. Wastes incineration at low loading rates, low moisture contents and high operating temperatures produced white and fine bottom ash, low levels of carbon, implying complete wastes combustion.

Open Access Review Article

Influence of Powdered Moringa oleifera Lam. Almonds Dried at Different Temperatures on the Physico-chemical Quality of the Pond Water

Yerima Bako Djibo Aboubacar, Guero Yadji

Journal of Engineering Research and Reports, Page 1-11
DOI: 10.9734/jerr/2020/v18i217202

The study focused on the physico-chemical characterization of raw water samples from the Kongou Gorou pond treated with almond powder from Moringa oleifera seeds. The powder which was used for the present study was dried in the oven for one month at the respective temperatures of 25, 40 and 50 ° C and then applied at a dose of 100 mg /L. The parameters studied are pH, iron, copper, electrical conductivity, rate of dissolved substances (TDS), hardness, organic matter; calcium, HCO3-, magnesium, the Complete Alkalimetric Title (TAC).

The physico-chemical analysis showed that the waters studied have concentrations below the standards recommended by WHO in 2009. For the dose of 100 mg/L and stored at the respective temperatures of 50, 40 and 25 ° C, it was recorded: a pH close to neutrality, a reduction in iron content of 93.46% at 50 ° C, 90.76% and 90.76%, a decrease in magnesium of 27.21; 27.89 and 39.96%, a decrease in hardness of 37.98; 39.94 and 36.03%; a decrease in the TAC from 1.3 to 1.18; 1.29 and 1.23 ° F and finally a reduction of 9.26; 0.81 and 5.42% bicarbonate. At these respective temperatures of 50, 40 and 25 ° C, the electrical conductivity has increased by 33.63, 33.05 and 32.8µ / L at 2 hours of settling and from 34, 64, 34, 28 and 36, 23 µs. cm / L at 24 hours of settling; an increase in the rate of Dissolved Substances from 15.21 to 16.32; 16.33 and 16.72 mg / L; an increase in the order of 34.48, 26.72 and 13.79% in calcium levels; an increase on the one hand of copper from 0.114 mg/L to 0.903 and 2.39 mg/L respectively at 50 and 40 ° C and on the other hand a total removal of the latter at 25 ° C.

The results showed that the use of Moringa oleifera seeds effectively improves the physicochemical quality of the treated water, which not only meets the WHO drinkability standards but also the characteristics of water suitable for drip irrigation.

Open Access Review Article

Effect of Deficit Irrigation under Different Crop on Crop Productivity and Water Use Efficiency- A Review

Dessie Gieta Amare, Zigijit Kassa Abebe

Journal of Engineering Research and Reports, Page 30-37
DOI: 10.9734/jerr/2020/v18i217204

Deficit irrigation is a strategy which could be applied to utilize water efficiently. The goal of the article was to review and examine different irrigation deficit to compare its crop morphological characters, yield, water productivity and water use efficiency under different crop type. The overall idea and results are very actual and useful over the world in the semi-arid and arid area interms of water managment and better economic return per applied water.The maximum production in dryland, tomato should be irrigated using drip irrigation system with 100%ETc watering amount [17]. On the other hand 85%, 75% and 30% are also effective in terms of water saving and yield. 85%ETc irrigation level water applied system appears to be a promising alternative for water conservation and labor saving with negligible trade-off in yield of maize [15]. The application of deficit irrigation (75%ETc) could be adopted in lettuce production [16]. Form the review I have seen that The WP increased as the irrigation level reduced.