Browsing by Author "Yusuf, M.A."

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    An Appraisal of Some Tree Species Diversity Loss in Keffi Region, Nasarawa State - Nigeria
    (Department of Geography, Nasarawa State State University Keffi, 2013-01-03) Abubakar, Mahmud; Yusuf, M.A.; Rabiu, M.U.
    In Nigeria the felling of savanna woodlands has frequently led to soil erosion, reduced crop yield and lost of land quality, thereby exacerbating the process of global warming, which is a critical factor of Climate Change. Vegetation samples were collected along transects in Keffi. Data were collected from quadrants measuring 40m x 25m totaling 30 sampled quadrants. On each quadrant, information collected includes: type of tree species; percentage of vegetation coverage; the number of common species present; soil samples on each direction as well as data on environmental change. Descriptive statistic of mean, median and percentage with some representation in form of table and graph provide additional description and explanation in addition to Spear man rank correlation coefficient. Test on particle size distribution (PSD), available phosphors (AP), soil pH, electrical conductivity (EC), and organic carbon (OC) content were also analyzed. The results revealed that soil is generally sandy (about 76% and of low nutrient status with low organic carbon (1.38%) and low organic matter (2.30%), thus low vegetation growth. In this case, low vegetation growth rate can be sustained through improved biodiversity management. In addition to the cutting of trees for crop production, fuel wood and increasing aridity (salinity, 3.25), the construction work embarked upon by the people had led to further clearing of site (destruction of vegetation) for erecting building structures. The study recommends that: a large percentage of the land area- be carved out and designated as “GREEN AREA”. This green area will in the short run preserve some native species of the Keffi region for the purpose of observation and experimentation, while in the long run will contribute to the reduction of Green House Gas (GHG) emission as suggested by the Clean Development Mechanism (CDM) of the Kyoto Protocol (1997), the Nigeria REDD+ (2010); and also improve land productivity, thereby contributing to the Sustainable Development and Agenda 21“ focus on meeting basic needs as part of adaptation and mitigation measures.
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    Gravitomagnetic Coupling in a Weak Field Approximation
    (Department of Physics, Nasarawa State University Keffi, 2019-06-12) Sarki, M.U.; Ewa, I.I.; Mustapha, I.M.; Yusuf, M.A.; Isah, S.H.
    According to general relativity, a moving or rotating matter should produce contribution to the gravitational field which is in analogy to the magnetic field of a moving charge or magnetic dipole; we can thus express the general relativity in a Maxwellian structure with the existence of single operator for both fields. In this research work, we studied the coupling of Maxwell's dynamical theory of electromagnetism in a non-static gravitational field by applying an obtained gravitational scalar potential to the Riemann's laplacian operator. In the limit of weak gravitation, we obtained the dynamical gravitomagnetic scalar potential across the fields. While in the boundary conditions the results are generalized gravitomagnetic potential. our results will thus widen the scope into study of gravitomagnetic coupling.