Postgraduate Student-Faculty Co-authored Publications

Influence of Logistics Management on Export Performance of Avocado Fruit in Meru County, Kenya

2026-08-11T07:17:48Z

Influence of Logistics Management on Export Performance of Avocado Fruit in Meru County, Kenya Manyara, Kennedy; Nzomo, Mathias; Thiaine, Kubaison Purpose: This research explored the influence of logistics management on the export performance of avocado fruit in Meru County, Kenya. Methodology: The research adopted a descriptive survey design for this work. Data were collected from 18 cooperative leaders and 640 farmers belonging to two major avocado cooperatives. From this pool, 326 farmers were selected through stratified random sampling, while cooperative leaders were selected purposively. The data collection relied on questionnaires and interview guides, and their reliability was verified through pilot testing. For quantitative analysis, SPSS version 26 helped run descriptive statistics, correlation tests, and multiple regression. Qualitative data were handled through thematic analysis. Findings: The evidence shows that logistics management exerts a significant positive influence on export performance. Nonetheless, ongoing logistical shortcomings, especially poor infrastructure and insufficient cold storage, continue to restrict export volumes, compromise fruit quality, and limit market penetration. Unique Contribution to Theory, Policy and Practice: This study provides the first empirical evidence from Meru County quantifying the relationship between logistics management and export performance (β = 0.322, p < 0.001), demonstrating that while cooperatives recognize logistics as critical, current practices, particularly in cold chain management and digital integration, remain severely underdeveloped. Unlike previous studies focused on large-scale exporters, this research reveals that smallholder cooperatives face distinctive constraints requiring collective solutions rather than individual investments.

Health Communication Strategies Used by Health Care Workers on HPV Vaccine Uptake for Cervical Cancer Prevention among Caregivers of Young Adolescent Girls Aged 10 -14 Years in Kajiado County

2026-04-08T09:41:21Z

Health Communication Strategies Used by Health Care Workers on HPV Vaccine Uptake for Cervical Cancer Prevention among Caregivers of Young Adolescent Girls Aged 10 -14 Years in Kajiado County Thuo, Samson Chege; G., Musuruve Inimah; Amatu, Mary Purpose: This study sought to establish health communication strategies used by Health Care Workers on HPV vaccine uptake for cervical cancer prevention among caregivers of young adolescent girls aged 10 -14 years in Kajiado County. Methodology: The study applied a mixed method research design. It combined qualitative and quantitative study approaches. This study utilized Health Belief Model (HBM) and Protection Motivation Theory (PMT). The population of the study included all the parents/caregivers of the young adolescent girls 10 – 14 years in Kajiado County who passed the inclusion and exclusion criteria. The study adopted multi-stage sampling to select the respondents and the location of study. Purposive sampling was applied to choose Kajiado County. Four out of all the 5 sub counties/constituencies namely; Kajiado Central, Kajiado South, Kajiado East and Kajiado West were included in the study. Findings: The study found that messages create awareness that women can take control of their reproductive health situation with regard to cervical cancer prevention. The findings also showed that creating awareness on cervical cancer and HPV vaccines by healthcare workers can reduce HPV vaccine misconceptions amongst caregivers/guardians. This can also lead to an increase in HPV vaccine uptake. Unique Contribution to Theory, Practice and Policy: HPV vaccination programs should focus on raising awareness about cervical cancer disease prevention, including information on HPV vaccination, screening, and healthy lifestyle choices. The study therefore recommended that there is need to intensify health communication awareness programs that specifically target adolescent girls.

Mathematical Modelling of Turbulent Natural Convection of Heat Transfer with Localized Heating and Cooling on Opposite Surface of a Vertical Cylinder

2025-08-01T13:31:59Z

Mathematical Modelling of Turbulent Natural Convection of Heat Transfer with Localized Heating and Cooling on Opposite Surface of a Vertical Cylinder Ong'era, Omariba Geofrey; Sigey, Johana Kibet; Okelo, Jeconia Abonyo; Karanja, Stephen Mbugua Turbulent natural convection in cylindrical enclosures is a significant phenomenon in most engineering and industrial applications, such as thermal insulation, electronics cooling, and building climate control. An explicit understanding of the transition of flow from laminar to turbulent and its influence on heat transfer is essential in terms of optimizing system performance. The study solves two major objectives: Model the governing equations of turbulent natural convection in a cylindrical enclosure using K-Omega turbulence model, and compute the effective thermal conductivity, turbulence intensity, and streamline distribution as functions of Rayleigh number. The enclosure that has been considered is an insulated vertical sidewall enclosure with a top wall at 298 K and a bottom wall at 320 K. The mathematical formulation consists of the Reynolds-Averaged Navier–Stokes (RANS) equations, the energy equation, and transport equations for turbulence, subject to the Boussinesq approximation to model buoyancy. A low-Reynolds-number two-equation model is used to model turbulence close to the walls, and the Prandtl number is set to 0.71 to model air as the working fluid. Numerical solutions are achieved by the use of the finite difference technique and verified by simulations done in ANSYS Fluent. The simulation identifies how structures flow and mechanisms of heat transfer change with increasing Rayleigh numbers. At small Rayleigh numbers, the flow is steady, conduction-dominated, with smooth streamlines and little or no turbulence. It is noted that as the Rayleigh number increases, buoyancy-driven convection becomes more significant, leading to the formation of vortices, intensified turbulence, and enhanced mixing, which collectively improve the effective thermal conductivity. The streamline distribution becomes increasingly complex and disordered, reflecting the transition to chaotic flow. These results demonstrate that the Rayleigh number is a key parameter influencing thermal and flow characteristics in cylindrical enclosures. The study provides practical insights in designing and optimizing systems involving buoyancy-induced turbulent heat transfer.

Genetic Diversity of Selected Antibiotic Resistant Bacterial Strains from Industrial Effluents in Nairobi County, Kenya

2025-07-15T06:16:24Z

Genetic Diversity of Selected Antibiotic Resistant Bacterial Strains from Industrial Effluents in Nairobi County, Kenya Muthoni, Esther; Mbogo, Kevin; Mutoro, Christine; Kagendo, Dorothy; Marangu, Victor Mwiti Abstract Antibiotic resistance represents a critical global health challenge driven by the dissemination of resistant bacterial genes across households, livestock and environmental reservoirs. Horizontal gene transfer and mutations play substantial roles in the existence and persistence of antimicrobial resistance significantly diminishing the effectiveness of current antibiotic therapies. This study aimed to investigate the genotypic and phenotypic resistance profiles of bacterial strains isolated from industrial effluent samples. Conducted in Nairobi County, Kenya, between January and December 2024, the study involved analysis of four bacterial strains isolated from industrial effluent samples collected via systematic sampling across multiple industrial sites. Bacterial identification was performed using API® 20E biochemical identification kit (BioMérieux, France). Antibiotic susceptibility testing encompassed several antibiotic classes including cephalosporins, penicillins, aminoglycosides, sulfonamides, tetracyclines, fluoroquinolones and carbapenems. DNA extraction from antibiotic-resistant isolates was conducted using ZyppyTM Plasmid Miniprep Kit (Zymo Research, USA) following the manufacturer’s protocol. Conventional PCR assays targeted resistance genes bla-TEM, bla-OXA, bla-KPC-1, bla-NDM and ParC. Sequence alignment was performed using MUSCLE software while phylogenetic analyses were conducted with MEGA 11 employing the Maximum Likelihood method to infer evolutionary relationships. All tested bacterial isolates including Pseudomonas aeruginosa, Escherichia coli, Aeromonas spp., Klebsiella pneumoniae, and Bacillus spp., exhibited 100% resistance to penicillin. Resistance to tetracyclines, cephalosporins and sulfonamides was notably prevalent in Aeromonas spp. In contrast, carbapenems and aminoglycosides maintained substantial efficacy particularly against Aeromonas spp. and Pseudomonas aeruginosa strains. Multiplex PCR analysis revealed widespread distribution of resistance genes with bla-TEM being the most prevalent followed by bla-KPC, bla-OXA, bla-NDM and ParC underscoring the molecular basis for the observed resistance phenotypes. Phylogenetic analysis demonstrated high sequence homology with globally distributed pathogenic strains highlighting the clinical relevance and potential public health impact of these findings. These findings underscore the urgent need to integrate comprehensive surveillance systems and implement multifaceted antimicrobial strategies to curb the spread of multidrug-resistant bacterial strains across environmental, healthcare, and aquatic ecosystems.