Scholarly Publication

Permanent URI for this collection

https://kwasuspace.kwasu.edu.ng/handle/123456789/1512

Browse

Recent Submissions

Now showing 1 - 5 of 11
  • Thumbnail Image
    Item
    Kinetics of the Antioxidant Activities of Solanum macrocapon and Crassocephalum rubens by DPPH Radical Scavenging Method
    (Journal of Chemical Society of Nigeria, 2020-02-11) Yusuff, K. O.; Omotosho, K.; Mustapha, K.; Abdulraheem, A. M. O.
    Solanum macrocapon (S.macrocapon) and Crassocephalum rubens (C.rubens) was investigated. The methanolic extracts of the samples were tested with 2,2-diphenyl-1-picrylhydrazyl (DPPH) at different times (30, 50, 70 and 90 minutes). UV-Visible Spectroscopy technique was employed  to evaluate the ability of the plant extracts to scavenge DPPH radicals by measuring the absorbance at the various experimental times. The concentration of sample required to inhibit 50% of the DPPH free radical (IC50) and kinetic parameter (rate constant k2) were determined from the absorbances values. S.macrocapon and C.rubens had DPPH scavenging potency with IC50 values of 2.18 x 10-2 mgml-1 and 6.27 x 10-2 mgml-1 respectively. This implied that S.macrocapon is a more potent antioxidant than C.rubens. The rate constant for the hydrogen atom abstraction by DPPH (k2) in the presence of S.macrocapon is 2.70 x 10-3 ± 0.0006 mlmg- 1min-1 with R2 value of 0.709 while for C.rubens, the rate constant is 6.89 x 10-4 ± 0.03 x 10-4 mlmg-1min-1 with R2 value of 0.987 using Pseudo-first order kinetics model. However, under second order kinetics, the rate constant, k2, for S.macrocapon is 4.73 x 10-1 ± 0.020 mM-1min-1 with R2 value of 0.993 while C.rubens has k2 value of 5.55 x 10-2 ± 0.00236 mM-1min-1 with R2 value of 0.795. Thus, the depletion of DPPH by S.macrocapon followed a second order kinetics while that of C.rubens followed a Pseudo first order kinetics. Keywords: Kinetics, DPPH, Antioxidant, UV-Vis spectroscopy, IC50Â
  • Thumbnail Image
    Item
    Theoretical modeling of flow for frustum - shaped ceramic water filters via disc-shaped ceramic water filters
    (ARPN Journal of Engineering and Applied Sciences, 2019-12-24) Bensah, Yaw Delali; Damoah, Lucas N. W.; Nyankson, Emmanuel; Yaya, Abu; Nukpezah, Daniel; Azeko, Salifu Tahiru; Mustapha, Kabiru; Annan, Ebenezer
    In the past two decades, research on household technologies has been on the increase. Ceramic water filters are simple and appropriate technology proven to have capability to provide improved drinking water especially in rural and peri-urban communities. These filters can be fabricated into various shapes with careful consideration of their mechanical robustness. This paper gives an overview of various flow models in estimating flow rate for ceramic water filters, in particular frustum-shaped ceramic water filters. Analytical approach to estimate the quantity of water considering the geometrical shapes; frustum and cylindrical shapes of the Ceramic water filters are adopted. The analytical expressions deduced for the flows are applicable on the assumption that the materials used in the fabrication of the filters are the same, thus same material properties (chemical and thermal properties) and porosimetry characteristics. Also, the comparative flow equation is largely dependent on dimensions of the ceramic water filters. The scholarly articles on flow through ceramic water filters for frustum-shaped filter are theoretically explored.
  • Thumbnail Image
    Item
    Effect of Chemically Modified Banana Fibers on the Mechanical Properties of Poly-Dimethyl-Siloxane-Based Composites
    (Journal of Materials and Engineering Structures, 2019-05-18) Danyuo, Yiporo; Zakariyyah, Taiwao; Nasiru, Suleman; Mustapha, Kabiru; Azeko, Tahiru S.; Bello, Sefiu A.; Abade-Abugre, Miriam; Yirijor, John; Anyidoho, Victor; McBAGONLURI, Fred
    The study presents the mechanical properties of polymer-based composites reinforced with chemically modified banana fibers, by alkalization in different concentrations of sodium hydroxide (NaOH). The fiber weight fraction has a great effect on the mechanical properties of the composites. Stiff composites were obtained at 6 wt% fiber fractions with Young’s modulus of 254.00 ±12.70 MPa. Moreover, the yield strength was 35.70 ±1.79 MPa at 6 wt% fiber fractions. However, the ultimate tensile strength (UTS) and toughness of the composites were obtained at 5 wt% fiber fractions. Statistical analyses were used to ascertain the significant different on the mechanical properties of the fibers and composites. The implication of the results is then discussed for potential applications of PDMS-based composites reinforced with chemically modified banana fibers.
  • Thumbnail Image
    Item
    Mechanical Properties, Durability and Microstructure of Palm Kernel Shell Concrete Produced from Different Grades of Portland Limestone Cement
    (Nigerian Research Journal of Engineering and Environmental Sciences, 2024-06-30) Odeyemi, S. O.; Adegolu, E.R.; Adisa, M.O; Atoyebi, O.D; Mustapha, K.; Adeniyi, A.G.
    The need for lightweight structures and to reduce environmental waste which leads to pollution has necessitated the utilization of agro-based materials as aggregates for concrete. Notable among these wastes is the Palm Kernel Shell (PKS). This study investigated the compressive and tensile strength, durability and internal structure of PKS concrete made with 32.5N and 42.5N grades of Portland Limestone Cement (PLC). A designed mix of Grade 20 culminating into a combined ratio of 1:1:1 for cement, sand and PKS batched by volume adopting a water-cement ratio (w/c) of 0.45. The compressive and tensile strengths of the concrete were tested, the durability of the concrete was determined using a water absorption test and Scanning Electron Microscopy (SEM) was conducted to correlate the test results. The outcome of investigations showed that PKS concrete from the cement of grade 42.5N has higher compressive and tensile strengths than grade 32.5N. Microstructural images from SEM showed non-uniformly distributed voids which are higher in concrete produced from 32.5N grade cement. Hence, the PKS concrete from grade 32.5N PLC absorbed more water than the concrete made from 42.5N PLC. Therefore, cement grade affects the strength, durability and microstructure of PKS concrete.
  • Thumbnail Image
    Item
    Mechanical properties of calcium carbonate/eggshell particle filled polypropylene Composites
    (MRS Advances, 2020) Kabiru Mustapha; Rashidat Ayinla; Abdulraman Sikiru Ottan; Tunji Adetayo Owoseni
    Calcium carbonate is widely used as a filler material in the production of polymer matrix composites and studies have shown that eggshell contains about 94% calcium carbonate. The effect of calcium carbonate from eggshell particles in polypropylene was studied in this work and the result compared with unreinforced polypropylene. Industrially synthesized calcium carbonate/eggshell particles were used as filler in polypropylene matrix with varying mass fractions from 5 to 20 wt. % at 5 wt. % increment. The produced samples were mechanically characterized for indentation hardness and uniaxial tensile properties using a Rockwell hardness tester and universal mechanical testing machine respectively. These properties were measured at different compositions to determine its compositional dependence. Microstructural analysis of the composites top and fracture surface was also carried out using scanning electron microscope to examine possible failure mode. The results were compared to measure the effect of reinforcement and the replacement criteria for the conventional calcium carbonate. The results obtained showed that calcium carbonate reinforced polypropylene has its highest tensile strength, elastic modulus and modulus of rupture at 5 wt. %, ductility and modulus of resilience at 10 wt. %, and hardness at 15 wt. %. The results also showed that granulated eggshell can provided appreciable improvement in the mechanical properties of polypropylene as obtainable in mineral calcium carbonate reinforced polypropylene.