Journal Article by Students of COETEC http://localhost/xmlui/handle/123456789/5461 2026-04-07T01:54:59Z 2026-04-07T01:54:59Z Maragara, Gibson K. http://localhost/xmlui/handle/123456789/6812 2025-11-13T10:14:39Z 2025-11-13T00:00:00Z

A model for enhancing the application of value management in construction projects in Kenya Maragara, Gibson K. Value management (VM) has been widely used in the construction industry to facilitate projects for decades in many countries around the globe. The concept began in the US, and then other nations such as China, Japan, South Africa, and Nigeria followed and tested its effectiveness by assessing its impacts on costs, quality, and time. A VM application has a low cost and a high benefit process, and thus, if well-practiced and integrated into project management at the beginning of a project, it would lead to its successful completion. It also helps in improving the value of a project by ensuring low costs, high quality, and completion within the stipulated time frame. In Kenya, there remains a gap in that very little information has been documented about VM applications in construction projects. Therefore, this study seeks to evaluate and develop a model to enhance the application of value management to construction projects. The study sampled all registered key stakeholders in construction projects within Kenya. The stakeholders are comprised of engineers, architects, quantity surveyors, contractors, and project managers. A stratified sampling strategy was employed, and data analysis was conducted using Statistical Package for Social Sciences (SPSS) version 25. The analysis methods used in this research were both descriptive and inferential in nature. Data summaries in terms of frequencies, means, and standard deviations were obtained under descriptive analysis. The inferential analysis comprised Pearson's correlation and regression analysis, which determined the significant determinants of VM application and were used to establish a predictive model. The study showed that team dynamics, procurement policy, government regulations, and VM knowledge are significant predictors of the level of VM application. A model has been developed that can assist in enhancing the application of value management in construction projects in Kenya. Key Words: Project performance, value management, team dynamic, government regulation, procurement practices. MSc Research Publication

2025-11-13T00:00:00Z Wamukoya, Brian Khamatie http://localhost/xmlui/handle/123456789/6794 2025-08-26T07:20:07Z 2025-08-26T00:00:00Z

Optimal deployment of solar PV power plants as fast frequency response source for a frequency secure low inertia power grid Wamukoya, Brian Khamatie power plants (SPVPPs) replacing conventional synchronous generators (SGs). SPVPPs lack any rotating parts resulting in no natural rotational inertia contribution to the grid. Reduced inertia makes the power system more dynamic, making it susceptible to frequency instability caused by minor disturbances. This problem is majorly addressed by limiting the penetration of SPVPPs to ensure a minimum level of critical inertia is maintained or by providing additional virtual inertia from an energy storage system. However, the SPVPPs can be configured to operate below maximum power point tracking (MPPT) (deloaded mode) to provide a reserve capacity that can rapidly be deployed as fast frequency response (FFR) in case of a frequency event. This paper presents a strategy to optimize the FFR capacity of a deloaded SPVPP using particle swarm optimization (PSO) algorithm. DIgSILENT PowerFactory was used to model the deloaded SPVPP and run time domain simulations. PSO algorithm was implemented using a Python script in PowerFactory. The proposed strategy was applied on a modified IEEE 39 bus test system. The results show that optimal deloading of SPVPP can help to successfully arrest frequency decline, reduce power curtailment while adhering to the prescribed constraints. This is an open access article under the CC BY-SA license. PhD Research Publication

2025-08-26T00:00:00Z Wamukoya, Brian Khamatie http://localhost/xmlui/handle/123456789/6793 2025-08-26T07:11:29Z 2025-08-26T00:00:00Z

Improving frequency regulation for future low inertia power grids: a review Wamukoya, Brian Khamatie The modern power system is witnessing an unprecedented increase in the penetration of renewable variable generation (VG) sources. Increased uptake of converter interfaced VG like solar PV and wind power while replacing conventional synchronous generators (SGs) introduces new challenges to grid operators in terms of dynamically handling frequency stability and regulation. Reducing the number of SGs while increasing non-synchronous, inertia-less converter interfaced VG reduces grid natural inertia, which is critical for maintaining frequency stability. To cure inertia deficiency, researchers, broadly, have proposed implementing supplemental control strategies to VG sources or energy storage systems to emulate natural inertia (virtual inertia (VI)). Alternatively, VG sources can be operated below their maximum power point (deloaded mode), making available a reserve margin which can rapidly be deployed in case of a contingency with the help of power electronic devices, to provide fast frequency response. This paper reviews recent solutions proposed in literature to address the low inertia problem to improve frequency stability. Additionally, it highlights the formulation of an optimization problem for VI sizing and placement as well as techniques applied in solving the optimization problem. Finally, gaps in literature that require further research were identified. This is an open access article under the CC BY-SA license. PhD Research Publication

2025-08-26T00:00:00Z Oginga, Movin Ochieng’ http://localhost/xmlui/handle/123456789/6757 2025-07-14T09:24:40Z 2025-07-14T00:00:00Z

Effects of Land Use and Land Cover Change on Potential Ecosystem Service Value in Mathioya Watershed, Murang’a County, Kenya Oginga, Movin Ochieng’ Abstract Wetlands in Mathioya watershed are declining due to continued alterations caused by human and natural factors. This study assessed the effects of spatiotemporal changes in Land Use and Land Cover (LULC), on potential ecosystem service value in Mathioya watershed, Murang’a County, Kenya. We considered the period between 1987 and 2020. Supervised classification using maximum likelihood classifier was performed in ERDAS imagine v.15. The values obtained from the analysis of LULC maps were then used together with the global data for habitats to approximate the ecosystem service value (ESV) change within the watershed. Six LULC classes namely, forestland, wetlands, agricultural land, water bodies, built-up areas and barren lands, were identified. Analysis of Landsat images revealed that between 1987 and 2020, human activity led to decrease in the area covered by wetlands, forestland, water bodies, and barren land. Area under these land cover classes decreased by 45%, 34%, 50% and 27%, respectively. During the study period, agricultural land and built-up areas increased by 43% and 85%, respectively. Changes in LULC resulted in decline of ESV from $368.5 million/ha/year in 1987 to $337.7 million/ha/year in 2020. With respect to individual ecosystem services, regulating services declined. Between 1987 and 2020, water regulation and climate regulation declined by 48% and 16%, respectively. However, provisioning services such as food production increased by 34%. Wetlands play a critical role in the provision of ecosystem services. The loss of wetlands translated to decline of critical ecosystem services such as water regulation. Eventually, this will lead to poor water quality within the watershed and the entire County, thus impacting negatively on the health of the locals. Hence, there is a need for urgent action to prevent the current trend of wetland loss within Mathioya watershed. Keywords: GIS, human activity, LULC, ecosystem service value, wetlands MSc Research Publication

2025-07-14T00:00:00Z