Journal of Engineering Research and Reports

Prognostics is a term that engineering borrowed from medicine to refer to the discipline concerned with the Remaining Useful Life (RUL) of an engineering device. This paper surveys the RUL prediction techniques and classifies them into four categories of model-based techniques,
knowledge-based techniques, experience-based techniques, and data-driven techniques. A comparative review is given for the main features, prominent advantages, potential shortcomings and main subcategories for each of these categories. The survey is supported by an extensive list
for up-to-date references.

Past two decades, the usage of ceramic tools has increased especially in milling and turning process. These advanced ceramic tools have good characteristics that are capable in maintaining high hardness in temperatures and also wears much slower when compared to carbide tools. With limited data available on the tool itself, research is to be done on these advance ceramic tools. The main purpose of this research project is to determine the cutting parameters affecting the cutting temperature and cutting force. The cutting parameters are cutting speed, depth of cut and feed rate. Silicon Nitride is chosen as the tool and Steel AISI4140 is chosen as the work piece. Analysis is conducted through Box-Behnken method with 3 levels, 3 factors and 2 responses. The regression model for cutting temperature and cutting force responses are identified. Analysis of Variance (ANOVA) is done to determine the effect of the cutting parameters and their contribution towards the cutting temperature and cutting force response. It is found that feed rate has the most influence on cutting temperature and force. The optimal cutting parameters that produce the lowest cutting temperature and lowest cutting force are also obtained.

In this paper, the reliability of axial compressors of gas turbines used in oil and gas installations was analyzed by the application of the two-parameter Weibull distribution method. Reliability analysis is an important tool to minimize the failures of equipment, shorten repair time and enhance maintenance effectiveness because when a system is well-maintained system, it minimizes operating costs and optimizes throughput. The study involves the analysis of the failure times of three identical gas turbine compressors. The two-parameter Weibull distribution method was found to best fit the failure data with a correlation coefficient of 0.9886 using the rank regression method. Based on the result obtained for the two-parameter Weibull estimates, it is deduced that the compressors under consideration are at the end of their operational life (wear-out period). From the Weibull estimates obtained, the reliability and mean time to failure of the compressors were determined. This result can be used to carry out timely and effective maintenance of the compressors so as to improve their operation and availability.

This study was undertaken to evaluate the effect of field practice on the tensile properties of pineapple leaf fibre (PAFL). The pineapple leaves were treated in the field with calcium nitrate (Ca(NO₃)₂) at four concentrations (0 mg/l, 100 mg/l, 200 mg/l and 300 mg/l). All the treatments were applied through foliar application, twice monthly, for duration of five months. The pineapple leaves were harvested after five months of the treatment application, and their fibre extracted through the retting method. In addition, the cellulose content of the PALF was determined according to approved method. The extracted fibre was subjected to tensile test, using ASTM International approved methods. Results obtained from the tensile test revealed that the pre-harvested treatment had significant (p ≤0.5) effect on the tensile properties of the PALF. The tensile strength increased from 583.67 MPa to 880.83 MPa; while the Young’s modulus increased from 23.77 GPa to 28.23 GPa, as the treatment concentration increased from 0 mg/l to 300 mg/l. Likewise, the tensile elongation decreased from 3.13 mm to 1.83 mm, as the treatment concentration increased from 0 mg/l to 300 mg/l. In terms of the cellulose content, the study revealed that the cellulose content of the fibre increased significantly (p ≤0.05) with increased in the treatment concentration. At the concentration of 0 mg/l, the PAFL had cellulose content of 63.6%, which increased linearly to 77% at the concentration of 300 mg/l. From these results, it can be seen that field practice greatly increased the potential of PALF in composites production and other industrial applications.

Surface waters are generally turbid because they contain suspended matter, organic matter, chemical and physical or even biological elements that make these waters unfit for drip irrigation. The almond powder of Moringa oleifera that was used in the study was dried in an oven for one month at temperatures of 25, 40 and 50°C and used to treat the water of Kongou Gorou Zarmagandey pond so it is suitable for localized irrigation. The purpose of this study was to evaluate the physico-bacteriological quality of the waters of this pond. The parameters studied are Escherichia. coli, faecal Streptococci, total germs and sulphito-reducers, organic matter, total residues and the color of treated water. After treatment of water with 100 mg/Lp Moringa oleifera seed powders dried at the respective temperatures of 25, 40 and 50°C, the supernatants were removed and analyzed. The results of this analysis show an increase in organic matter of 52.59, 55.84 and 57.14%; a slight reduction in total residues of 0.7%, 4.3% and 2.5% at the respective temperatures of 50, 40 and 25°C; an abatement of Escherichia. Coli is total (100% for all temperatures). For Streptococci, a reduction of 99.24% was observed for the dose at 25°C and 98.48% for those at 40 and 50°C. For Sulfo-reducing agents, the efficacy of the treatments is therefore total, 100% for doses of 100 mg. 1 to 25 and 40°C and about 99.99% for that at 50°C. Finally, in terms of color, there was a drop of 97.62%; 97.858% and 98.167% at the respective temperatures of 50°C, 25°C and 40°C. The analysis of the water in the study area shows that the latter is in line with the FAO guidelines on the physico-bacteriological aspects of irrigation water in general and that of drip irrigation in particular.