MST-School of Pure and Applied Sciences
http://ir-library.ku.ac.ke/handle/123456789/206
2021-03-12T05:24:47ZCognitive Enhancing, Antioxidant Activities and Phytochemical Profile of Aqueous and Methanolic Extracts of Piliostigma Thonningii (Schum.) and Lonchocarpus Eriocalyx (Harms)
http://ir-library.ku.ac.ke/handle/123456789/21891
Cognitive Enhancing, Antioxidant Activities and Phytochemical Profile of Aqueous and Methanolic Extracts of Piliostigma Thonningii (Schum.) and Lonchocarpus Eriocalyx (Harms)
Apiri, Moriasi Gervason
2020-01-01T00:00:00ZHuman Use of Forest Trees and its Impact on Tree Diversity and Abundance in Chemususu Forest, Baringo County, Kenya
http://ir-library.ku.ac.ke/handle/123456789/21882
Human Use of Forest Trees and its Impact on Tree Diversity and Abundance in Chemususu Forest, Baringo County, Kenya
Kipkoech, Morogo Hosea
Trees provide both direct and indirect benefits to humans, who depend on them for their
livelihoods. Forest ecosystems are vulnerable to over-utilization and exploitation due to
the sensitivity of its complex and highly diverse ecosystem. The aim of the study was to
determine the human impact on tree species diversity, abundance, plant population
structure and uses of forest trees by local communities adjacent to Chemususu forest
Reserve in Koibatek Sub-County, Baringo County. Questionnaires and interview
schedules were used to collect data on uses of trees; the target group were households
within 3km stretch from the forest edge. The data on trees species, diversity, abundance
and plant population structure was collected by systematic sampling using six parallel
belt transects each starting from the forest edge. Sampling was conducted in quadrats of
20m x 20m (for trees) located along the transects at 500m intervals. In each of the
quadrats, all the trees species were identified, counted and diameter at breast height
(DBH), measured at 1.36m outside the bark to the nearest cm. Indicators of human
disturbance were assessed to determine the extent of human impact. The Statistical
Package for Social Sciences (SPSS) was the main tool for quantitative data analysis from
both questionnaires and interview schedules. Analysis of Variance (ANOVA) was used
to test whether the mean number of cut stems and debarked trees varied with distance
from forest edge. ANOVA was also used to test for variation in the mean diversity
indices, tree species abundance and DBH with distance from forest edge. In both cases,
tukey test was used to separate the means. Shannon-Wiener Diversity index (Magurran,
1988) was computed. Pearson’s correlation was carried out to determine the relationship
between abundance of cut stems and debarked trees with distance from human settlement
in each study plot and to investigate the relationship between mean species abundance,
diversity, and DBH with distance from human settlement. Majority of the local residents
had stayed in the region for more than 15 years and perceive the forest as important for
various uses, 98.4% for spiritual and cultural purposes, timber (97.52%), tourism and
recreation (96.3%) and hunting (97.1%).Three trees species, Olea europaea, Dombeya
torrida and Olea capensis were used for firewood as well as charcoal and formed a large
proportion of used trees. Trees used for timber Juniperus procera, Podocarpus falcatus
and the exotic cupressus lusitanica had been heavily extracted. There was no significant
relationship between the number of charcoal kilns and distance from the forest edge (r = -
0.849; P=0.069). This also applied to the number of plots with evidence of pit sawings
with distance from the forest edge (r = 0.555; P =0.333) but the number of plots with split
stems decreased significantly with distance from the forest edge (r = -0.892; P =
0.043).There was no significant variation in the mean number of cut stems and mean
number of debarked trees with distance from human settlement (F(4, 25) =0.082; P= 0.546)
and (F (4, 25) =1.795; P=0.162), respectively. Tree diversity did not vary with distance
from human settlement (F (4, 25) = 1.67; P=0.189).There was a significant difference in the
mean number of trees in different DBH classes (F (4, 25) = 5.181; P =0.002). The number
of trees on the lower DBH classes was more than those on the higher classes at various
distance intervals, but this difference was not statistically significant. The study showed
that the community role in forest degradation was significant and they highly depended
on it for their livelihood. Thus, it was important to understand the relationship between
the community and the forest. Alternative sources of trees used for timber and charcoal
should be encouraged to reduce pressure on forest trees.
A Thesis Submitted In Partial Fulfillment Of The
Requirement for the Award of the Degree of Master of
Science (Plant Ecology) in the School of Pure and Applied
Sciences of Kenyatta University
2020-01-01T00:00:00ZGraphs Whose Automorphism Groups Contain or Represent the Alternating Groups, An and Symmetric Groups, Sn
http://ir-library.ku.ac.ke/handle/123456789/21770
Graphs Whose Automorphism Groups Contain or Represent the Alternating Groups, An and Symmetric Groups, Sn
Otieno, Hosea Odhiambo
There have been many investigations on the combinatorial structures and invariants over the group actions on the subsets of its elements. Studies on Group Theory have yielded varied and important results in the advancement of Algebra. Several studies have also been made on Graph Theory. Some Mathematicians have studied the concept of automorphisms on graphs thereby yielding important results. Automorphism groups from graphs containing the cyclic and dihedral groups, Cn and Dn respectively have been constructed using Schur’s Algorithm. In this project, we have extended the work to graphs whose Automorphism groups contain the Alternating Group An as well as those representing Symmetric group Sn. The graphs whose Automorphism groups contain or represent the Alternating Group An and Symmetric group Sn respectively have been constructed. Schur’s algorithm has been employed to construct these graphs. The actions of the Alternating Group An and the Symmetric group Sn have been shown to be transitive using the Cauchy- Frobenius Lemma and the Orbit-Stabilizer Theorem. The Automorphism graphs for the groups An and Sn have been constructed for 𝓃=3,4,𝐴𝑛𝑑 5.. The number of graphs whose groups of Automorphism contain An is 2 being the null and the complete graphs. The number of graphs whose groups of Automorphism represent Sn is 2 being the null and the complete graphs. We have presented the results of our findings from our workings as theorems and constructed the applicable graphs.
A Project Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science (Pure Mathematics) in the School of Pure and Applied Sciences of Kenyatta University. November, 2020
2020-11-01T00:00:00ZFlow of Contaminants in Urban Ground Water
http://ir-library.ku.ac.ke/handle/123456789/21769
Flow of Contaminants in Urban Ground Water
Mukabwa, Musavi Sammy
Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. Drinking contaminated groundwater can have serious health effects. Diseases such as hepatitis and dysentery may be caused by contamination from septic tank waste. Poisoning may be caused by toxins that have leached into well water supplies. Wildlife can also be harmed by contaminated groundwater. Other long-term effects such as certain types of cancer may also result from exposure to polluted water. In this study the flow of contaminants in urban ground water is investigated. An analytical model for predicting groundwater contamination in isotropic and homogeneous porous formations was derived. The impact of dispersion and diffusion coefficients was included in the solution of the advection-dispersion equation (ADE), subjected to transient (time-dependent) boundary conditions at the origin. A retardation factor and zero-order production terms are included in the ADE. Analytical solutions were obtained using the Laplace Integral Transform Technique (LITT) and the concept of linear isotherm. Analytical solutions for linearly space- and time-dependent hydrodynamic dispersion coefficients along with molecular diffusion coefficients are presented. Analytical solutions are explored for the Peclet number. Numerical solutions are obtained by explicit finite difference methods and are compared with analytical solutions. Numerical results are analysed for different types of geological porous formations i.e., aquifer and aquitard. The accuracy of results is evaluated by the root mean square error (RMSE). The results of this study reveal that there is a very good agreement between the analytical solution and the numerical solution. It’s also clear from the results that the concentration values are less in aquifer than in aquitard. The Peclet number is found to be significant at very large values.
A Project Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science in Applied Mathematics in the School of Pure and Applied Sciences of Kenyatta University. June, 2020
2020-07-01T00:00:00Z