Journal Articles

Permanent URI for this collection

Journal Articles (Mechanical Engineering)

Browse

Recent Submissions

Now showing 1 - 5 of 11
  • Item
    Open Access
    Theory of a mechanical method of peeling cassava tubers with knives
    (Institute of Agrophysics, 2006-03-27) Adetan, D.A.; Adekoya, L.O.; Aluko, O.B.
    A newbut highly promising mechanical cassava peeling concept was investigated. The concept is based on the principle of peel-flesh separation through compression and peel removal with knives. The mechanism of this principle was described and mathematically modelled. Preliminary experiments were carried out on root slices of 100 mm length using a peeling machine developed earlier on the basis of this principle. The data collected were used to validate the model. The model developed predicts the performance index (peel removal efficiency) with a certainty level of 95.46%. Thus, the model adequately explains the peeling concept and it is, therefore, an invaluable and reliable tool for further development and improvement of mechanical cassava peeling machines.
  • Item
    Open Access
    Effects of interatomic potentials on the determination of the minimum depth of cut in nanomachining
    (Inderscience Enterprises Ltd., 2013-01) Oluwajobi, A.O.; Chen, X.
    The minimum depth of cut (MDC) is a major limiting factor on achievable accuracy in nanomachining, because the generated surface roughness is primarily attributed to the ploughing process when the uncut chip thickness is less than the MDC. This paper presents the material removal in a nanomachining process, where a sharp diamond tool with an edge radius of few atoms acts on a crystalline copper workpiece. The molecular dynamics (MD) simulation results show the phenomena of rubbing, ploughing and cutting. The formation of chip occurred from the depth of cut thickness of 1~1.5 nm. Also, the effects of the interatomic potentials on the MDC have been presented
  • Item
    Open Access
    An integrated impact assessment of hydrogen as a future energy carrier in Nigeria's transportation, energy and power sectors
    (Elsevier Ltd., 2014) Amoo, Leye.M; Fagbenle, R.Layi
    A hydrogen economy, the long-term goal of visionary nations, has the potential to provide energy security, along with environmental and economic benefits. The concept of a hydrogen energy economy was first conceived at The Hydrogen Economy Miami Energy (THEME) Conference, held in March 1974 in Miami, Florida, where the International Association for Hydrogen Energy was established. Forty years later, advances in hydrogen technologies have led the world's most developed countries to invest extensively in preparation for a future hydrogen-based economy. However, the transition from a conventional petroleum-based energy economy to a hydrogen economy involves many uncertainties regarding concerns such as the development of efficient fuel cell technologies, problems in hydrogen production and distribution infrastructure, hydrogen safety issues, and the response of carbon-based fuel markets. This paper presents an assessment of the economic impact of hydrogen energy on the transportation and energy use sectors of Nigeria, along with implications for Greenhouse Gas (GHG) emissions. The analysis uses the Long range Energy Alternatives Planning (LEAP) technology database and model to simultaneously consider the impact of alternative and conventional technologies and fuels on these sectors.
  • Item
    Open Access
    Effects of interatomic potentials on the determination of the minimum depth of cut in nanomachining.
    (International Journal of Abrasive Technology, 2013-01) OLUWAJOBI, A.O.; CHEN, X.
    The minimum depth of cut (MDC) is a major limiting factor on achievable accuracy in nanomachining, because the generated surface roughness is primarily attributed to the ploughing process when the uncut chip thickness is less than the MDC. This paper presents the material removal in a nanomachining process, where a sharp diamond tool with an edge radius of few atoms acts on a crystalline copper workpiece. The molecular dynamics (MD) simulation results show the phenomena of rubbing, ploughing and cutting. The formation of chip occurred from the depth of cut thickness of 1~1.5 nm. Also, the effects of the interatomic potentials on the MDC have been presented
  • Item
    Open Access
    Deformation and fracture of dika nut (Irvingia gabonensis) under uni-axial compressive loading
    (Institute of Agrophysics, Polish Academy of Sciences, 2008-01-16) Ogunsina, B.S; Koya, O.A; Adeosun, O.O
    Fracture behaviour of dika nut under quasi-static loading along the longitudinal axis and the transverse axis was investigated. The fracture resistance of the nut was measured in terms of average force, deformation and toughness at nutshell fracture, and nut stiffness. Physical dimensions and shape of the nut, to provide for complementary input in design of handling equipment, were also determined. The force required to crack the nut increased with nut diameter but was not significantly different in both loading orientations. The mean cracking force was in the range of 2.06 to 3.67 kN. The compression of the nut exhibited a pronounced linearity between load and deflection. Dika nuts loaded along the transverse axis required less energy for nutshell fracture than those loaded along the longitudinal axis. Minimum toughness occurred with the small size nuts loaded along the transverse axis, thus providing base-line data in future design of an appropriate nutcracker.