http://ir.mu.ac.ke:8080/jspui/handle/123456789/13 2026-04-20T20:11:39Z 2026-04-20T20:11:39Z Jolayemi, Omamuyovwi Rita Mule, G. M. Uto, O. Timothy Olawole, O. C. http://ir.mu.ac.ke:8080/jspui/handle/123456789/9438 2025-01-09T09:55:14Z 2025-01-01T00:00:00Z

Highly efficient XCoSi (X=V, Nb, Ta) compounds for thermoelectricity: a density functional theory approach Jolayemi, Omamuyovwi Rita; Mule, G. M.; Uto, O. Timothy; Olawole, O. C. Half-Heusler compounds hold great promise for thermoelectricity due to their excellent thermal stability and electronic transport properties. This study unveils the physical characteristics of half-Heusler compounds XCoSi (X = V, Nb, Ta) as potential materials for thermoelectric using the Quantum ESPRESSO and PHONOPY codes with PBEsol-GGA correlation functional. The electronic band structure calculations revealed the semiconducting nature of the compounds with an indirect band gap (X → W) of size 0.55 eV, 0.84 eV, and 1.25 eV for VCoSi, NbCoSi, and TaCoSi, respectively. The XCoSi(X=V, Nb, Ta) compounds demonstrate dynamic and mechanical stability, with ionic bonds and predicted ductility of these alloys. Additionally, critical parameters for thermoelectric application are computed, including the Seebeck coefficient (S), electrical conductivity (σ), thermal conductivity (κ), and the figure of merit (ZT). At room temperature, both p-type and n-type XCoSi (X = V, Nb, Ta) exhibit figure of merit values close to unity: 0.96 for VCoSi, 0.98 for NbCoSi, and 0.99 for TaCoSi, based solely on the electronic contribution to thermal conductivity. Including the lattice thermal conductivity provides a more accurate assessment of the thermoelectric potential of XCoSi (X = V, Nb, Ta). Among them, VCoSi shows greater potential for thermoelectric applications compared to TaCoSi and NbCoSi.

2025-01-01T00:00:00Z Starovoitova, Diana Odido, Daniel http://ir.mu.ac.ke:8080/jspui/handle/123456789/7463 2023-03-24T06:10:46Z 2014-01-01T00:00:00Z

Assessment of toxicity of textile dyes and chemicals via materials safety data sheets Starovoitova, Diana; Odido, Daniel The textile industry has been condemned as being one of the world ís worst offenders in terms of pollution. Chemical companies market a vast range of products such as dye formulations, colorants and finishing chemicals to the textile industry. This study was carried out in a textile mill. The research revealed that twenty two dyes and twenty five chemicals were used in the mill during twelve month period of the study. Thirty six Materials Safety Data Sheets (MSDSs) were collected from manufacturing companies/sup- pliers. Analysis of MSDSs together with the information provided on re- quest by International Agency of Research on Cancer (IARC), France iden- tified that various chemical substances used in the mill were harmful/toxic, carcinogenic, probably carcinogenic, and water polluting. Furthermore, it was identified that two out of three compounds classified as carcinogenic to humans were used in the mill either as chrome/metal/complex dye itself or as its mordants. It was therefore recommended to substitute chromium by hydrogen peroxide fixation. In addition, numerous problems with MSDSs and in occupational and safety practices on handling chemical substances in the mill were documented. The study consequently made several spe- cific recommendations towards improvements.

2014-01-01T00:00:00Z Mwenda, Ngugi http://ir.mu.ac.ke:8080/jspui/handle/123456789/7424 2023-03-21T08:29:49Z 2021-01-01T00:00:00Z

Determining factors that influence the distance travelled by patients seeking for outpatient health care in Kenya Mwenda, Ngugi Access to uncompromised health care is a basic human right championed by both the UN and enshrined in the Kenyan constitution 2010. Every citizen is supposed to have ease of access to a health facility and get proper medical care irrespective of their financial status. Outpatient care is a key determinant of a healthy population in two main ways. (1) The progression from a simple to a complicated health problem, if well attended to earlier could be diverted and (2) it has a direct effect on the financial effect on households in Kenya. Previous studies have reported catastrophic effects as a result of Out of Pocket (OOP) spending on health care leading to as many as 1.1 million Kenyans to poverty every year. Report by the Kenya Household Health and Utilizatio n Survey indicated that Kenyans spend 48.4 Billion on health care through OOP spending of which outpatient care accounted for 78%. This shows the need to investigate the outpatient care access as it is a huge contributor to catastrophic spending among individuals in Kenya. The main aim of the study was to determine factors affecting patients’ distance in seeking for outpatient health care in Kenya. This study utilized the binary probit regression model to assess the covariates that predict distance travelled to access outpatient care. The data utilized, was a secondary analysis of the Kenya Household Expenditure and Utilization Survey (KHHEUS) that was collected in 2018 with a primary focus of monitoring how Kenyans utilized outpatient and inpatient care in Kenya. We analyzed individual data on 6191 individuals who had complete data. Using the binary probit regression model, we reported results at 95% confidence interval whereby we determined that residence, facility type, mode of transport, education, and wealth index were associated with distance travelled to seek outpatient care. It is noteworthy that those who live in rural residence and the poorest travel long distance to access outpatient care. Therefore, the government should make policies that target increasing the number of outpatient health facilities, that are well equipped to handle more health cases that will see the rural travel short distance for care. Policies that will see a decrease in poverty also need to be formulated so that people can have financial freedom of accessing care wherever they wish and close to where they live

2021-01-01T00:00:00Z Mutitu, K. E. Otieno, B. O. Nyeko, P. Ngae, G. N. http://ir.mu.ac.ke:8080/jspui/handle/123456789/7341 2023-03-16T06:19:07Z 2010-01-01T00:00:00Z

Variability in the Infestation of Leptocybe Invasa (Hymenoptera: Eulophidae) on Commercially Grown Eucalyptus Germplasm in Kenya Mutitu, K. E.; Otieno, B. O.; Nyeko, P.; Ngae, G. N. The growing of Eucalyptus trees in Kenya is widespread and there is high demand for their products. Infestation of Eucalyptus germplasm by Leptocybe invasa Fisher & LaSalle, a new pest, is causing a lot of worry since very little is known about the pest. Variability in the infestation of L. invasa on commercially grown Eucalyptus germplasm was examined in two trial sites established in western Kenya. The crown foliage gall density and gall count on a sample unit were used to determine the levels of infestation. Using analysis of covariance procedure and separation of means using least significant difference, the tested germplasm was classified into four susceptibility groups. The incidence and severity of L. invasa increased with age and were generally high in Eucalyptus hybrid clones as compared to improved Eucalyptus hybrids and species. However, Eucalyptus henrii and GC581 were found to be resistant to L. invasa. There was a significant positive correlation (corr. = 0.712) between the mean L. invasa gall count and the mean crown damage thus reinforcing use of the latter as a cost-effective method of assessing infestation of L. invasa. The use of resistant germplasm to L. invasa requires promotion for adoption as a management strategy. However, further research needs to be carried out on identifying the genes responsible for this resistance

2010-01-01T00:00:00Z