Browsing by Author "Omollo, Edison"

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    Clustering and Classification of Cotton Lint Using Principle Component Analysis, Agglomerative Hierarchical Clustering, and K-Means Clustering
    (Journal of Natural Fibers, 2017) Kamalha, Edwin; Kiberu, Jovan; Nibikora, Ildephonse; Igadwa Mwasiagi, Josphat; Omollo, Edison
    Cotton from the three cotton growing regions of Uganda was characterized for 13 quality parameters using the High Volume Instrument (HVI). Principal Component Analysis (PCA), Agglomerative Hierarchical Clustering (AHC) and k-means clustering were used to model cotton quality parameters. Using factor analysis, cotton yellowness and short fiber index were found to account for the highest variability. At 5% significance level, the highest correlation (0.73) was found between short fiber index and yellowness. Based on Cotton Outlook’s world classification and USDA Standards, the cotton under test was deemed of high and uniform quality, falling between Middling and Good Middling grades. Our suggested classification integrates all lint quality parameters, unlike the traditional methods that consider selected parameters.
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    A study of the characteristics of hollow glassmicrospheres reinforced thermoplastic polyurethane composite foam
    (Trade Science, 2015) Nzioka Mutua, Fredrick; Omollo, Edison; Khamala, Edwin; Igadwa Mwasiagi, Josphat; Ciera, Lucy; Wang, Yimin
    Current foam materials do not meet the requirements for high performance. Minimal research has been done on thermoplastic polyurethane (TPU) foams fabricated by non-synthesis approach. In this study, Hollow GlassMicrospheres (HGMS) reinforced TPU foamwas fabricated by compression molding using TPU polymer. Interfacial adhesion between the filler and the matrix was enhanced by surface modification of the HGMS. The morphology of fabricated foam was studied using Scanning Electron Microscope (SEM). Density, hardness and mechanical tests were done to study the foam properties. Increasing the foaming agent content from 1% to 2% led to a decrease in tensile strength of the foam by about 50%. The tensile strength decreased by about 40% when the filler content was increased from 0% to 3%, while the compressive strength of the composite foam increased by about 47% when the filler content was increased from 0% to 7%. Increasing filler content led to a decrease in the density and increase in hardness of the foam. After a 75% compressive force, SEM observation of 7% HGMS reinforced TPU foam had a more stable structure than 5% HGMS reinforced foam which depicts enhancement in mechanical properties, a property desired for high impact absorption applications.