14 research outputs found
Incidence of smut and red rot diseases of sugarcane in southern part of Niger State, North Central Nigeria
Sugarcane production is threatened globally by smut and red rot diseases, which farmers in the study area take for granted because they see the diseases as natural calamities associated with large-scale cultivation of sugarcane. Incidence of smut and red rot diseases of sugar-cane in the study area was assessed between October 2016 and June, 2017. Thirty-two sugarcanes (800 per farm) were assessed on forty farms randomly selected from 16 towns/villages in Southern part of Niger State. Each of the sugarcanes aged between 6 and 10 months were observed visually for symptoms of the diseases. Number of infected sugarcanes was used to determine the percentage incidence of the diseases on each farm. Percentage incidence of smut ranged from 25.0 to 35.0 (Bida LGA), 20.0 to 22.5 (Gbako LGA) and 20.0 to 30.4 (Lavun LGA), while percentage incidence of red rot ranged from 5 to 6.5 (Bida LGA), 6.1 to 12.0 (Gbako LGA) and 5.4 to 9.3 (Lavun LGA). Significant pairwise differences at pā¤0.05 existed in the means of percentage incidence of smut in Bida and Gbako as well as Bida and Lavun LGAs. Significant pairwise differences at pā¤0.05 also existed in the means of percentage incidence of red rot in Bida and Gbako as well as Gbako and Lavun LGAs in this study. The study concluded that smut is of higher incidence in the study area. It is recommended that the local farmers be sensitized to adopt effective control measures for these diseases
Geoelectric Survey of Foundation Beds of the Proposed Faculty of Engineering Building, OSUTECH Permanent Site, Okitipupa, Nigeria
Geoelectric resistivity method was employed to characterize the geo-materials at Ondo State University of Science and Technology (OSUSTECH) Okitipupa, Dahomey Basin, Nigeria, for suitability for foundation purposes. The
methods involved Constant Separation Traversing (CST) using Wenner array and Vertical Electrical Sounding
(VES) using Schlumberger array. The data obtained were processed with Ipi2win and excel software. The results
showed that the subsurface structures were made up of lateritic topsoil with resistivity varying from 85 Ohm-m to
612 Ohm-m and thickness varying from 0.5 to 2.14 m; clayed sand with resistivity varying from 295 to 2,587 ohm-m and thickness vary from 0.67 to 3.4; clay with resistivity varying from 10 to 350 ohm-m and thickness varying
from 3.8 to 26 m; and sand with resistivity ranging from 383 ohm-m to 59,707ohm-m. The clayed sand would have been
the best layer to host the foundation because of its depth to the surface but it is generally less than 1.5 m and
underlay by thick column of clay. The only competent layer that can host the foundation of high-rise building is the
sand layer, therefore, the building foundation should be piled to the sand layer or pilling should be suspended
within the thick column of clay
Analysis of the Influence of Laser Parameters on the Microstructure and Surface Properties of Laser Deposited Aluminum Based Coatings
Investigating the Microstructural Evolution and Characterization of Additive Manufactured Zn-Sn-Ti/Ti-6Al-4V Composite.
Corrosion Performance and Surface Analyses of Laser Cladded Zn-Ni-Fe Coatings on ASTM A29 Steel.
Material characterization and corrosion behavior of hybrid coating TiāAlāSiāCu/Tiā6Alā4V composite
Data related to optimized process parameters influence on hardness, microstructural evolution and wear resistance performance of Al-Si-Sn-Cu/Ti-6Al-4V composite coatings
This study investigated the metallurgical, mechanical properties and quality of coatings fabricated by direct laser metal deposition (DLMD) on Ti-6Al-4V, which were affected by the DLMD optimized process parameters. A 3-kW continuous wave ytterbium laser system (YLS) attached to a KUKA robot was used for the process. An analysis was conducted to determine the quality of the coatings in terms of hardness and wear resistance. Variables such as the time of interlayer deposition, thickness of the substrate, the initial temperature of the substrate, and the number of deposited layers were also investigated. The independent/collective effect that each process parameter had on the metallurgical and mechanical properties of the deposited Ti-6Al-4V were made clear when the processing parameters were varied. Minute pores/defects that significantly affect the metallurgical and mechanical properties of clads were also identified. The results obtained from the designed experiments showed that the depth of Heat Affected Zone (HAZ) was inversely proportional to the thickness of the substrate; as the thickness of the substrate was increased, the HAZ depth decreased. Moreover, the intensity of the laser power also affects the HAZ depth. In addition, it was discovered that the initial conditions of the substrate at room temperature also affected the coatings in relation to pre-heated conditions. The analysis conducted in identifying and quantifying the porosity showed indication that the factors such as scanning speed, laser power and powder feed rate had a predominant influence on the porosity. The grain form and structure as well as the mechanical properties of the cladded layer were significantly affected by the optimized process parameters of DLMD process. The parameters investigated had a significant impact on the hardness and wear resistance performance. Furthermore, the results revealed that the highest hardness of one of the coatings was 1.97-times the substrate which had a hardness value of 302 HV. The outstanding wear resistance performance of Al-Si-Sn-Cu/Ti-6Al-4V composite coating is attributed to major hard intermetallic phases. Keywords: Ti-6Al-4V alloy, Hardness, Wear performance, Microstructure, Al-Si-Sn-Cu coatings, DLM
Influence of Rapid Solidification and Optimized Process Parameters on the Microstructural Evolution of Additive Manufactured Titanium Alloy Grade 5 Composite
The study experimentally investigates the effects that Ytterbium Laser System process parameters, such as laser power, powder feed rate and traverse speed, has on the resultant microstructure of Ti- 6Al-4V grade 5 alloy. The deposition process was conducted employing a 3kW (CW) Ytterbium Laser System (YLS-2000-TR) machine, coaxial to the reinforcement powder. The laser scanning speed and power were varied between the intervals of 1-1.2 m/min and 900-1000 W. All other parameters kept constant where the rate of gas flow, the spot diameter, and the rate of powder flow. The microstructure was characterized by grain size and morphology by using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). The microstructural and mechanical properties were ascertained and the relationships with the process parameters were achieved. As a result of rapid cooling, the morphological features of Ī± and Ī±ā are distinctive and appear acicular. The structures appear coarsened. The metallurgy of the samples identifies with a morphology of multi-scale; with the coarsened alpha structures being reduced, plate-like, discrete and finer. The alpha grains closer to the fusion zone grew epitaxially, and the ones above these are acicular and lamellar. The results also indicated that slow traverse speeds increase the scale of columnar grains, while other process parameters were kept constant. Columnar microstructures became prevalent due to the dynamic temperature gradients/spikes, and sustainable cooling rates, pertaining to fabricating direct laser deposited Ti-6Al-4V grade 5 alloy. It was ascertained that by increasing the traverse speeds, the cooling rates increased, which resulted in a decrease in the width of the columnar grains
Stress Analysis of Hole Orientation and Laminate Geometry Impacting on Boron/Epoxy Composites Laminates
Boron/epoxy laminates are used in aircraft and space vehicles for their high strength. Evaluation of stresses and residual strength of the laminate with square cutout are not analyzed in the literature. The present work is focused on studying the effect of hole orientation and laminate geometry on Boron/Epoxy composites laminates under in-plane loading. The analytical solution for stresses around holes in laminates is derived using Savinsās complex variables method to consider a multilayered plate with different hole shapes and orientations of loading. The basic equations of failure criteria available for plain laminates are derived to calculate the residual strength of the laminates with hole using the stresses obtained from the analytical solution. The derived analytical solution is validated by reproducing exactly the same results of earlier researchers even by other formulations and also by the results of finite element analysis using ANSYS. The [0/0]s laminate is not preferred due to highest stress concentrations at the corners that range between 12 to 12.45. Similarly, [45/-45]s laminate is also not preferred due to its higher values of stress concentrations which range from 9.5 to 28. The normalized stress for [0/90]s under x-axis loading is 9.6 and for y-axis loading it is 9.5 which is almost the same. Even for equi-biaxial loading, it is 8.5 and for shear loading, it is 12.45. Except for shear loading, [0/90]s laminate seems to be a better choice for a reasonable value of stress concentration for any general case loading. The analytical solution derived in the present work is the most general and unique as it can yield the stresses around any shape of hole and laminate geometry and all types of in plane loading. This solution will be able to reproduce the results of all other solutions available in the literature by different formulations
Thermal Analysis and Impart of Temperature Distribution on the Performance of Additive Manufactured Titanium Alloy Based Composite Coatings
Finite element numerical analysis can be used to solve problems of boundary values. The accuracy of model is depended on the meshing refinement. In aerospace industry, finite element analysis has been used by several researchers to know the influence of temperature distribution on the performance of additive manufactured component parts. Accuracy is better with finer mesh. Complex nature of the additive manufacturing process due to rapid heating and cooling made many researchers to adopt numerical investigation which is made easier than the experimental method. Proper modelling of the process must be thoroughly done for the numerical modelling results to be analyzed. The experiment of ternary titanium alloy of Ti-Al-Si-Cu was carried out with cladding machine of 3000 Watts (CW) Ytterbium Laser System (YLS-2000-TR). This machine is situated at the National Laser Centre in the Council of Scientific and Industrial Research (NLC-CSIR). The characterization was done using the standardization ASTM E3-11 procedure. The results shiw the impart of temperature distribution on the dendritic arm spacing in the microstructures. The rate of cooling imparts on the space between the dendritic arms. The more the space, the more the influence on the coatingās propertie