Kenyatta University Repository

Kenyatta University Institutional Repository is a digital archive that collects, preserves and disseminates scholarly outputs of Kenyatta University.

Photo by @inspiredimages
 

Recent Submissions

Item
Dietary Mycotoxins: An Overview on Toxicokinetics, Toxicodynamics, Toxicity, Epidemiology, Detection, and Their Mitigation with Special Emphasis on Aflatoxicosis in Humans and Animals
(MDPI, 2024-11) Kibugu, James; Munga, Leonard; Mburu, David; Maloba, Fredrick; Auma, Joanna E.; Delia, Grace; Lindahl, Johanna F.
Mycotoxins are secondary metabolites of filamentous fungi and ubiquitous dietary contaminants. Aflatoxins, a group of mycotoxins with high prevalence and toxicity, have raised a high level of public health concern, the most prevalent and toxic being aflatoxin B1 (AFB1). Many aspects appertaining to AFB1 poisoning are not well understood. Yet this information is necessary to devise appropriate surveillance and mitigation strategies against human and animal aflatoxicosis. This review provides an in-depth update of work carried out on mycotoxin poisoning, particularly aflatoxicosis in humans and animals, to identify gaps in knowledge. Hypotheses explaining the functional significance of mycotoxins in fungal biology and their dietary epidemiological data are presented and briefly discussed. The toxicology of aflatoxins and the challenges of their mitigation are discussed in depth. It was concluded that the identification of potential mycotoxin-hazard-prone food items and quantification of the associated risk of cancer ailments in humans is a prime priority. There is a dearth of reliable sampling methodologies for estimating AFB1 in animal feed. Data update on AFB1 in animal feed and its implication in animal production, mitigation strategies, and elucidation of risk factors to this hazard is required. To reduce the burden of aflatoxins, surveillance employing predictive technology, and biocontrol strategies seem promising approaches.
Item
Optimizing Sunflower Production Through the Use of GIS-Based Soil Fertility Management Strategy
(Taylor & Francis Group, 2024-08) Nungula, Emmanuely Z.; Massawe, Boniface J.; Chappa, Luciana R.; Nhunda, Daniel M.; Seleiman, Mahmoud F.; Ali, Nawab; Gitari, Harun I.
This study aimed to use a GIS-based approach in producing soil fertility maps and utilize the spatial data on achieving site-specific management of major nutrients in Morogoro, Tanzania. Soil samples were collected in six mapping units and analyzed for chemical properties such as pH, cation exchange capacity and electrical conductivity. ArcGIS 10.8 was used to produce nutrient variability maps of organic carbon, available P, total nitrogen and exchangeable K, Ca and Mg using the Inverse Distance Weight (IDW) interpolation method. The soil pH values ranged from 5.5 to 7.2. OC varied between 1.2 and 4.9g kg−1, TN ranged from low to medium (1.0 to 5.0g kg−1) whereas Av. P varied between l3.3 and 14.3mg kg−1. Exchangeable K, Ca and Mg had ranges (in cmol kg−1) of between 0.1 to 0.8 (low to medium), 3.8 to 15.6 (low to high) and 0.3 to 0.5 (low), cmol kg−1. The recommended amounts were 74, 44, 36, 35 and 12kg ha−1 for N, P2O5, K2O, MgO and CaO, respectively. Conducting soil analysis is key for monitoring the amount of nutrients that are available in the soil at time and space, to achieve site-specific nutrient management.
Item
Numerical Investigation of Turbulent Convection Flow in a Rectangular Closed Cavity
(JMAM, 2024-11) Manoti, Geofrey Moturi; Awuor, Kennedy
Natural turbulent convection in closed cavities has many practical applications in the field of engineering such as the design of electronic computer chips, atomic installation and industrial cooling among others. In particular, it enables in achieving a desired micro-climate and efficient ventilation in a building. Recent studies show that turbulent flow is affected by variations in Rayleigh numbers, aspect ratio, and heater position among others. Temperature is kept constant in all these studies hence inadequate literature on the effects of temperature on a turbulent flow. In this study, aspect ratio and Rayleigh numbers are kept constant at 2 and 1012 respectively and natural turbulent convection flow in a closed rectangular cavity is investigated numerically as the operating temperature is varied from 285.5K to 293K. The rectangular cavity’s lower wall was heated and cooling done at the top face wall while the rest of the vertical walls were kept in adiabatic condition. Material properties such as density of the fluid kept on changing at any given temperature. The thermal profile data generated influenced the nature of the turbulent flow. The non-linear averaged continuity, momentum, and energy equation terms were modeled by the SST k − ω model to generate streamlines, isotherms, and velocity magnitude for a different operating temperature and presented graphically. The finite difference method and FLUENT were used to solve two SST k − ω model equations, vortices, and energy with boundary conditions. It was discovered that, as the operating temperature increased turbulence decreased due to a decrease in the velocity of the elements and vortices became more parallel and smaller.
Item
Type of Venture Capital Investment, Venture Capital Control and Financial Growth of Funded Small and Medium Enterprises in Nairobi City County, Kenya
(IAJEF, 2024-11) Maragia, Dancan S.; Gatauwa, James M.
Global venture capital industry expansion has boosted entrepreneurship and innovation, leading to the generation of wealth and jobs in a number of countries. SMEs play a crucial role in socioeconomic development by promoting wealth generation, economic growth, and job creation in their individual economies. These SMEs nevertheless have uneven and restricted access to sustainable finance, which is essential to their survival and expansion, despite their prominence and importance in developing countries such as Kenya. This study aimed to examine how type of venture capital investment and venture capital control affect the financial growth of selected SMEs in Nairobi County, Kenya. Both a descriptive research design and quantitative research methods were applied. The target population for the analysis consisted of 139 SMEs that have received venture capital funding. Data was analyzed using descriptive and inferential statistics. Results indicated that type of venture capital investment had a positive and significant effect on SMEs’ financial growth. SMEs' financial growth was positively, but not significantly, impacted by venture capital control. The study concluded that venture capital control had a positive but insignificant effect on SMEs’ financial growth. The study recommended that entrepreneurs should consider a diverse syndicate of venture capitalists. This is key for improved risk management, survival rate, access to more strategic collaboration and attraction to resources and expertise. In addition, the study recommended that entrepreneurs should review the venture capitalists’ level of control in the business. This would help to mitigate negative impact resulting from venture capital-imposed restrictions on managerial autonomy.
Item
Innovation Capability and Growth of Micro and Small Enterprises in Kenya
(Kenyatta University, 2019-04) Njiraini, Peter Gachanja