JKUAT Journalshttp://localhost/xmlui/handle/123456789/21612024-03-29T07:23:27Z2024-03-29T07:23:27ZCommon occupational machinery hazards in mechanical engineering workshops in TVET institutions in Nairobi metropolitan, KenyaRonoh, Patrick Kipkuruihttp://localhost/xmlui/handle/123456789/61632023-07-31T17:04:22Z2023-07-31T00:00:00ZCommon occupational machinery hazards in mechanical engineering workshops in TVET institutions in Nairobi metropolitan, Kenya
Ronoh, Patrick Kipkurui
The metal fabrication sector involves a variety of processes, activities, products, and by-products.
This involves various interventions such as milling, turning, welding, drilling, and grinding. Firms in
this sector use one or a combination of these interventions where machinery is used, which can
expose workers to machinery hazards if proper safety procedures are not observed. Occupational
Safety and Health (OSH) is vital in Technical Vocational Education and Training (TVET) institutions,
especially in mechanical engineering programmes where metal fabrication is practised. The
objective of this study was to assess the awareness of occupational machinery hazards in
mechanical engineering workshops in TVET Institutions. The study adopted a descriptive research
design and employed a structured questionnaire for data collection. Purposive sampling was used
to identify institutions participating in the study. SPSS version 25 was used to analyse the data and
present it in tables and graphs. Noise (90.4%) and vibration (71.9%) were reported as the most
common occupational hazards, respectively, in mechanical engineering workshops. Regarding
workstations, the grinding section (39.4%) and milling section (15.8%) were reported as
experiencing high levels of noise. The study recommends that adequate control measures be put
in place to mitigate against these hazards.
2023-07-31T00:00:00ZKenya Medical Training College laboratory student perception on adequacy of teaching and learning resources in the advent of COVID-19.Kondo, Benson Mbatihttp://localhost/xmlui/handle/123456789/61622023-07-31T16:51:46Z2023-07-31T00:00:00ZKenya Medical Training College laboratory student perception on adequacy of teaching and learning resources in the advent of COVID-19.
Kondo, Benson Mbati
The emergence of COVID-19 presented a big challenge in medical education, especially with
regard to the adequacy of teaching and learning resources. In addition, an increase in student
intake and demand for Kenya Medical Training College courses could compromise these
resources. This study investigated the perceptions of students towards the adequacy of teaching
and learning resources at Kenya Medical Training College in the advent of COVID-19. The general
objective was to determine the perceived adequacy of teaching and learning resources in the
advent of COVID-19 by students in the department of Medical Laboratory Sciences at Kenya
Medical Training College. A descriptive cross-sectional study design using mixed methods
(triangulation) was used. Simple random sampling of the eight regions in the country was used
to select one region (the Eastern Region). Census sampling was used to select all the four
campuses in the region namely Machakos, Meru, Embu, and Kitui, which offer medical
laboratory sciences. The study population was students in the department of medical laboratory
sciences on these campuses, with 220 students participating. The data collection instrument
was a self-administered closed- and open-ended questionnaires. Quantitative data collected
was analysed using SPSS software, while qualitative data was analysed using themes. The
response rate was 100% (220 students). The gender distribution among students showed a
higher percentage in male (58%). Majority of the students were 21-23 years (35%). One-way
ANOVA presented a statistically significance between and within groups (P<0.05). Majority of
students (51.8%) were not satisfied with adequacy of human resources. Majority of students
perceived the state of physical facilities to be in poor state with a mean of 1.76, while the
satisfaction level of majority of students’ on teaching aids was below 3.40 representing very
inadequate to neutral. Ordinal regression tests on satisfaction level on teaching aids in relation
to gender, year of study and campus was significant (chi-square test p<0.000) while the
goodness of fit model was (p=1.000) indicating it was a good model. R^2 value (Nagelkerke=99%)
indicated that the study factors had great variations. The spearman’s rank test showed that
laboratory equipment and computer assisted aids, internet, learning systems have negative
correlation but with very strong coefficient correlation of 1.0000. Satisfaction levels with
teaching aids in relation to gender, year of study, and campus were significant with a chi-square
test of P < 0.000. The study concluded that there were inadequate teaching and learning
resources on the four KMTC campuses before COVID-19.
2023-07-31T00:00:00ZDetermination of gold nanoparticles sizes from their plasmon resonance within the optical spectrumGitonga, Mbae Johnhttp://localhost/xmlui/handle/123456789/61612023-07-31T16:46:00Z2023-07-31T00:00:00ZDetermination of gold nanoparticles sizes from their plasmon resonance within the optical spectrum
Gitonga, Mbae John
Nanoparticles have exciting properties that can be tailored by altering their size, density, and
shape. A number of important properties of the nanoparticles have been investigated for
various applications. One such property that is strongly affected by nanoparticle size is localised
surface plasmon resonance (LSPR). The resonance from metal nanoparticles has been used in
dye-sensitised solar cells to improve their performance. In this work, the dependence of
plasmonic properties on nanoparticle sizes is shown. The gold nanoparticles were prepared
using a reduction process where hydrogen tetrachloroaurate acid was used as the base gold salt
and reduced by sodium citrate at different molarities ranging from 0.015 to 0.035 mol/L. The
method produces monodispersed nanoparticles whose sizes are sensitive to the concentration
of chemicals used and the completeness of the reduction process. The process took
approximately 18 minutes, and the colour changed from pale yellow to wine-red. The
absorbance of the resulting gold nanoparticles was determined using a UV-Vis
spectrophotometer within the range of 300 nm to 800 nm. The LSPR peaks were found to occur
within 518 nm to 520 nm, and from a Gaussian fit, the FWHM ranged from 45.5 to 51.0 nm. The
absorption peaks had a narrow range of 14 nm over the range of molarity of sodium citrate. A
high molarity concentration of 0.035 mol/L produced a small particle with a diameter of 17.04
nm, while a low concentration of 0.015 mol/L produced a size of 26.55 nm. The interaction of
electrons in the specific orbitals, sp- and d-, of nanoparticles exhibited pronounced multiple
resonances with the reduction of nanoparticle sizes.
2023-07-31T00:00:00ZEvaluation of crushed slates as a suitable capping material for rapid gravity sand filtersKakoi, Beatrice Katheuhttp://localhost/xmlui/handle/123456789/61602023-07-31T15:58:22Z2023-07-31T00:00:00ZEvaluation of crushed slates as a suitable capping material for rapid gravity sand filters
Kakoi, Beatrice Katheu
In the potable water treatment process, Rapid Gravity Sand Filters (RGSF) are commonly
adopted as the last solid-liquid separation stage. Cleaning of the RGSF is done through
backwashing. RGSF is widely adopted all over the World due to its ease of operation and high
filtration rates. However, these filters suffer from stratification of the sand media, which causes
floc removal to occur only at the topmost layer of the filter bed, leaving the remaining depth
unutilized. Capping is a technique whereby a thin layer of sand filter media is replaced with a
suitable coarse material to overcome the problem of stratification and transform a single media RGSF into a dual-media filter. The objective of this study is to determine the suitability
of crushed slates as a capping material. The study evaluated the performance of a crushed
expanded slate-capped filter against a conventional single-media RGSF, the effects of its
physical and chemical characteristics, and varying the depth of the capping material.
Laboratory tests were conducted to assess the physical and chemical characteristics of slates
from Maji ya Chumvi (Coast, Kenya). This included specific gravity, acid solubility, water
extractable substances, silica content, and friability. A performance comparison was carried
out by means of a fabricated model filtration unit set up within an existing community water
treatment plant. The model filtration unit was fed with pretreated raw water of varying influent
turbidities. Crushed expanded slates met the minimum physical and chemical requirements
for use as a capping material for RGSF. The crushed expanded slate-capped RGSF model
demonstrated high robustness under high shock turbidity loads (above 150 NTU), which is
illustrated by an increased length of filter run of 27% (50–150 NTU) and 45% (150–300 NTU).
Increasing the depth of capping material from 25mm to 50mm did not yield any significant
improvement or deterioration in the filter run length. At influent turbidities below 150 NTU,
the effluent water quality for all three scenarios (uncapped, 25 mm, and 50mm crushed
expanded slates capped) is below 5 NTU and therefore meets the Kenyan drinking water
standards. Above 150 NTU influent turbidity, the effluent water quality for the uncapped RGSF
deteriorates, whereas for the 25mm and 50mm capped RGSF, it remains consistently below 5
NTU. This demonstrates the usefulness of the crushed expanded slates in improving the
turbidity removal of RGSF for high (above 150 NTU) turbidity loads. This study recommends a
full-scale trial of crushed expanded slates to facilitate a more precise estimation of the overall
benefit of full-scale community water filtration systems.
2023-07-31T00:00:00Z