Theses and Dissertations- Doctor of Philosophy

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    Analysis of microbial infections in Camel (Camelus Dromedarius) milk and implications in Kenya
    (Egerton University, 2007-06) Matofari, Joseph W
    Raw camel milk production and marketing chain in Kenya was investigated for microbial infections and implications. Milk samples were taken using simple random sampling method in a clustered sampling plan. There were three cluster levels, the production, and processing and market levels. Analysis of samples in the laboratory for enumeration and characterization was by standard methods as described in the methodology. Data analysis was done by Pearson correlation coefficient and chi-square. At production level, 66% of the 107 samples taken had bacterial load ranging from 103-105 colony forming units per ml (cfu/ml). Over 90% of the samples from the processing and market levels ranged from 106-108 cfu/ml. The total viable counts were higher (P < 0.05) than coliform counts at production level. There were more spores at production than at market level. All the isolated organisms did not survive temperatures above 550 C. Salmonella enterica was prevalent at production and processing level. There was no S.enterica isolation at market level. Gram-negative rods (GNR) occurred at every level of the camel milk chain with an incidence of 54% of the 254 samples taken. Gram-positive cocci (42% incidence) were highest at production level. From the study, the microbial load in raw camel milk chain increased from production to the market. GNR were the majority and included the general Escherichia, Enterobacter and Pseudomonas. S.enterica contamination of raw camel milk chain exists at production and collection level and not at the market level. The S enterica serovars involved were S. enterica Typhi and S. enterica Paratyphi C. Since camels, pastoralists and camel milk handlers may act as carriers of S. enterica in the causation web, it is recommented that another study be done to determine host specificity for the serovars identified.
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    The influence of soil water content and nitrogen supply on growth, yield and polyphenol content of selected tea [Camellia sinensis (l.) O. Kuntze] clones in Kenya
    (Egerton University, 2008-04) Cheruiyot, Erick Kimutai
    Tea is a major foreign exchange earner in Kenya and it accounts for about 24% of the total value of the domestic exports for the last 10 years. The sector employs 10% of Kenya’s population directly and indirectly, and contributes to infrastructural development which includes construction of schools and health facilities, rural access roads and rural industries. However, tea suffers frequent droughts with significant yield decline, often accompanied by plant deaths, a condition which seems to be worsened by fertilizer input. The objectives of this work were to determine: i) the critical minimum soil water requirements in selected tea clones and show how it varies with nitrogen (N) supply ii) the effect of N supply and progressive decline of soil water content on tea shoot growth, leaf yield and black tea quality iii) the levels of tea polyphenols and define their association with water stress in tea and their suitability as indicators for drought tolerance. Two experiments were set up in a rain-out shelter at Tea Research Foundation of Kenya (TRFK) and a field experiment conducted at three different field sites in tea growing areas. The first experiment consisted of six different tea clones which were subjected to 4 levels of soil water content (SWC) (38, 30, 22 and 14% v/v) for 12 weeks. The second experiment consisted of clone BBK 35 treated with 5 different rates of N (0, 75, 150, 225 and 300 kg/ha) using NPKS (25-5-5-5) fertilizer material, and 5 levels of SWC (38, 34, 30, 26, 22, 18% v/v). Shoot and leaf growth, dry matter partitioning, photosynthesis, stomatal conductance, transpiration, leaf anatomy and shoot polyphenol content were determined. The field experiment consisted of clone BBK 35 with five rates of N, similar to the rain-out shelter and where shoot population density and yield were determined during dry months. SWC limit for tea was shown to be about 20% v/v and that fertilizer supply increased the susceptibility of tea to drought. Contrary to earlier speculations that fertilizer raises the optimal SWC for tea, it emerged that fertilizer rates above 200 kg N ha-1 influenced assimilate partitioning to shoot and foliage, making tea more vulnerable to drought effect. Clones with high total polyphenol content and whose levels varied less with changes in SWC were more tolerant to drought. Two catechin variants, epicatechin and epigallocatechin correlated with SWC, water stress index and shoot growth in tea, which suggests they are potential indicators for drought stress in tea.
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    A knifeless rite: Influence of selected characteristics on the Marakwet of Kenya’s perception of the counselling-based alternative rite of passage and levels of awareness of effects of FGM
    (Egerton University, 2008-10) Kiptiony, Gladys Jerobon
    The Alternative Rite of Passage (ARP) is an intervention programme sponsored by NGOs as an alternative to female circumcision (FGM). FGM is a cherished rite of passage in many communities in Kenya. ARP mimics the traditional rites aspect by putting the initiates in seclusion and counselling them while avoiding the physical operation of the genitals. There is a gap in the analysis of the Marakwets‟ perception of ARP and their level of awareness of effects of FGM as it has not been empirically investigated. The aim of this study was to determine whether selected personal characteristics and socio-economic background factors influenced perceptions of ARP and levels of awareness of effects of FGM. This study focused on the Marakwet people of Kenya, whose population is 152,000, and have interacted with ARP from the year 2000. The study employed the ex post facto research design. Two purposively chosen locations were used in the study. A sample of 415 males and females from different age brackets were identified through quota sampling. Quantitative data was collected through a questionnaire while qualitative data was collected through interviews conducted among Marakwet Elders and ARP Graduates. Validity and reliability of the instruments, in a pilot study, were established through expert opinion and Cronbach reliability test, respectively. The data obtained was analysed by use of descriptive and inferential statistics using the SAS System, Version 9.1. The analysis of variance tests were done at 0.05 alpha level of significance. The content analysis for the qualitative data was done by identifying the key points. The results showed that differences in gender, age, education, religion, wealth and status influenced perceptions of ARP and awareness levels of effects of FGM. In addition, qualitative data on experiences of ARP Graduates indicated that the mechanisms that ensure women undergo FGM are still firmly rooted in the culture. This study is significant in that the outcome may guide the expansion of existing approaches to FGM eradication. One of the recommendations is that ARP proponents should ensure that ARP Graduates are given enough support to sustain their resistance to FGM pressure.
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    The role of career guidance and counselling in career awareness and planning among public secondary school students in Kenya
    (Egerton University, 2008-12) Ndung’u, Owen Ngumi
    Guidance and counselling programme has become an important integral part of the school system in Kenya. Career guidance and counselling services which are components of the guidance and counselling programme are vital activities because one of the long-term goals of education is career placement. If education is to realise this goal, then learners should have appropriate career information and undertake career exploration before making career choices. This aspect of learning can only be effectively handled under the context of guidance and counselling; to create career awareness and career planning that will then influence learners’ career decisions. The purpose of this study was to assess the career awareness and planning among secondary school students and the role that career guidance and counselling plays in their career decision-making process. Further, the study looked into the perceptions of students, school counsellors, and class teachers about the role of career guidance and counselling. The study was a descriptive survey, and adopted the ex-post-facto research design. The study was conducted in Nyeri District, Nakuru District, and Nairobi Province of Kenya. The target population was 22,746 Form Three students in the 290 public secondary schools in the study areas. Stratified random sampling was used to select 392 students from 31 schools, for the study. In addition, purposive sampling was used to select 62 school counsellors and 62 class teachers to be included in the sample. The data was collected using three different questionnaires and analysed using the Statistical Package for Social Sciences (SPSS) Version 11.0 computer programme. Descriptive statistics (frequency tables, percentages and cross tabulations), and inferential statistics (One-way ANOVA, Pearson’s correlation, and Chi-Square test) were used in data analysis. The findings of the study showed that students, school counsellors, and class teachers perceived that career guidance and counselling played a significant role in the career awareness and career planning of secondary school students. Majority of the students in Kenya’s secondary schools were found to have high levels of career awareness and career planning. From the findings it was observed that demographic characteristics such as category of school and setting of the school did not influence the career awareness and career planning of students. There were no gender differences in students’ career awareness, but female students had higher levels of career planning than male students. The results were expected to be significant in enriching the national human resource development process, through provision of appropriate career guidance and counselling services to secondary school students and beyond.
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    Factors influencing the application of information and communication technology in the management of agricutural informtation in Nakuru District, Kenya
    (Egerton University, 2009) Ombati, Justus Moturi
    Agriculture is an important sector in the Kenyan economy. It contributes 26.6% to the GDP, creates employment to about 80% of the rural population, supplies raw materials to industries and earns the country the much-needed foreign exchange. There is need, therefore, to develop this sector. Agricultural infonnation is one critical resource in agricultural development. It is the basis of a modern and progressive agricultural sector. This, therefore. demands that agricultural infomiation be generated, tested, packaged and readily made available to the users. Effective use of infonnation and communication technology (ICT) would greatly improve agricultural information management for overall development of the sector. Studies, however, indicate the use of ICT-based systems for the management of agricultural infonnation within and between me various subsystems of the agricultural sector is limited. The overall purpose of the study was to establish the actual status of ICT usage in management of agricultural information and determine conditions inhibiting the implementation of the ICT usage. It investigated the current state of agricultural information management and determined the factors that influence the effective application of ICT-based systems in this Work. It further determined and documented the requirements for implementing an ICT-based system that would interface the management of agricultural information within and between the agricultural research, extension service, training institutions and farmers in Nakuru District Kenya. A modified Delphi technique was used to obtain both qualitative and quantitative data. Respondents in the study Were drawn using proportionate random sampling from research scientists, the technical extension staff, teaching staff of agricultural training institutions, and farmers in the district. Questionnaires were used to collect data. The statistical package for social sciences (SPSS) was used for data analysis. T-test at on 5 0.05 was used to test hypotheses, accordingly. The study established that there were low levels of infonnation processing using ICT within and between the major subsystems of the agricultural sector in the district. Lack of resources, computer illiteracy, poor infrastructure and insufficient govemrnent initiative has been found to be major impediments on the utilization of this technology. lnvestrnent in science and technology, infrastructure development, and promotion of education are some of the measures that would enhance adoption of ICT in the management agricultural information for agricultural development.
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    Diversity of banana streak virus in Kenya
    (Egerton University, 2009-04) Karanja, Laura Shali
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    Diversity of banana streak virus in Kenya
    (Egerton University, 2009-04) Laura, Shali Karanja
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    A comparative analysis of the structure and performance of Agricultural science and Technology policy system in Kenya and Uganda
    (Egerton University, 2009-09) Godiah, Lawrence Mugunieri
    Despite the acknowledged importance of agricultural science and technology (AS&T), little is known about the structure and performance of AS&T policy system in developing countries. The structure and performance of this policy system in Kenya and Uganda was analysed using a preliminary ‘system components-shift effects’ framework. The system components comprised of agricultural research, extension, education and transboundary technology transfer. The impact of these components was modified by three-levels of shifteffects: policy environment, institutional arrangements and micro-conditions to give a 3x4 matrix of potential determinants of system structure. The structure was hypothesised to exist in three different generations: first, second and third. Uganda was presumed a first generation system and Kenya second. The potential system structure was separately related to three performance indicators, namely; technical efficiency, technical change and efficiency change using different econometric techniques in order to delineate important determinants of structure. The results indicated that the preliminary three-level framework can be used as an effective tool for delineating the structure of AS&T policy system in developing countries. Furthermore, the structure of the policy system differed between the first and second generation systems. At policy level, transboundary technology transfer was significant and positive only in second generation systems whereas agricultural education and research expenditures were important in both. At institutional level, intellectual property rights regulatory system had impact only in second generation systems, agricultural extension decentralisation had negative effect in first generation systems, whereas agricultural research coordination had no impact in both systems. At micro-level, literacy within the agricultural labour force was significant in second generation but not in first. However, domestic research outputs had significant impact in first generation systems but not second. The same applied to policies geared towards reducing transaction costs in accessing technologies. These results imply that generation specific AS&T policies should be encouraged instead of collective generic policies for all developing countries. Although lack of data precluded effective application of the three-level framework, this study offers opportunities for further research in this area, which has previously been driven by data and not ideas.
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    Influences of creativity teachings strategy on students performance and motivation in the topic energy in secondary school physics in Nakuru District, Kenya
    (Egerton University, 2009-10) Samuel, Hungi K.
    Agricultural extension is a critical agent for transforming subsistence farming to modern and commercial agriculture through the dissemination of agricultural information to farmers. Despite this, extension services are still limited in most parts of the Kenya. This has necessitated a move towards more innovative methods of extension service delivery for effective coverage by the Government of Kenya through the introduction of ICT-based e- Extension programme. The adoption and usage of ICTs in accessing agricultural information among farmers remain low. This has been attributed to socio-economic, cultural and technological factors. The overall objective of this study therefore, was to establish the influence of technology-related factors on usage of e-Extension services among smallholder farmers in Nakuru County, Kenya. Descriptive survey research design was used in the study whereby questionnaires and focus group discussion guides were used to collect data from l30 smallholder farmers, 25 extension agents and three focus group discussions held with eight participants each. The face and content validity of the instruments were examined by five experts from the Department of Agricultural Education and Extension, Egerton University.The questionnaires were piloted and reliability coefficients were 0.87 and 0.71 respectively. Statistical Package for Social Sciences (SPSS) was used for data analysis. Descriptive statistics, namely frequencies, percentages, means and standard deviation were used to describe and summarize qualitative data. Ordinal logistic regression and Chi square tests were used to test the hypotheses at or = 0.05 level of significance. Results of hypotheses testing indicated that access to ICTs and ICT skills of farmers’ influences usage of e- Extension services among smallholder farrners. Furthermore, the study established that availability and characteristics of digital content had an influence on usage of e-Extension services. In addition, the findings of the study indicated that the type of e-platforms had a significant influence on the usage of e-Extension services. This study therefore, concludes that e-Extension services can be used to complement other extension methods in dissemination of agricultural information to smallholder farmers. The study recommends that for this to be achieved there is need for national and county governments to invest in the development of ICT skills of farmers as well as coordination and regulation of available agricultural digital content. It also recommends partnership between the national government, county governments and other stakeholders in the provision of e-Extension services. The County govemment of Nakuru should also create awareness and sensitize of farmers on the availability of e-Extension services through the Nakuru Farmer Call Center (NF CC).
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    Factors influencing adoption of drought tolerant wheat varieties in the arid and semi-arid lands of Narok and Kajiado Districts-Rift valley Province of Kenya
    (Egerton University, 2010-04) Ndiema, Alice Chesambu
    Adoption of agricultural technologies by farmers is influenced by a number of factors, which include the farmer and farm attributes, technology characteristics and institutional factors. It is on this premise that drought tolerant varieties (DTV) of wheat were developed for production in Arid and Semi Arid Lands (ASAL). This study was designed to assess low adoption by describing and comparing factors that have influenced adoption of DTV in the (ASALs) of Narok and Kajiado districts of Rift Valley Province-Kenya. A sample size of one hundred and eight (108) wheat farmers with seventy two (72) from Ololung‟a division of Narok district and thirty six (36) from Isinya division of Kajiado district were randomly selected by use of random numbers sampling technique. Farmers‟ perceptions of DTV of wheat, adoption levels and the influence of personal, socio-economics and institutional factors on adoption were investigated. The data was collected using a validated questionnaire and analyzed using SPSS for windows. Generally, the adoption levels were very low. Farmer perception on (DTV) was very low (0.9%) with majority of the farmers (77.8%) being uncertain of the objective of the technology and its benefits Eighty seven point nine percent (87.9%) of the farmers identified input cost as a major constraint and 85.1% lacked the relevant information. Opportunities for adoption cited by 91.6% of the respondents included the availability of the required seed. There was no statistical significant difference in perception between the farmers of Narok and Kajiado districts. However, there were significant differences in adoption levels with the average percentage for Narok mean of 1.58 being higher than Kajiado mean of 1.33 with a t-test value of -2.497; (P<0.014; α=0.05. Age, gender, and education did not have any statistical significance relationship in the adoption of DTV but farm size, land tenure system and extension services were statistically significant.
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    Genetic parameters and quantitative trait loci mapping in tea, Camellia sinensis (l.) O. Kuntze
    (Egerton University, 2010-06) Kamunya., Samson Machohi
    Efficient breeding and selection of elite tea (Camellia sinensis (L.) O. Kuntze) clones require sound knowledge and understanding of genetics associated with yield, quality and tolerance to biotic and abiotic stresses. A series of experiments were carried out to elucidate the genetic parameters and map quantitative trait loci (QTL) for agronomic and quality attributes in tea. The combining abilities and heterosis for yield, drought tolerance (DT), and quality traits (percent total polyphenols (%TP), fermentability (FERM), theaflavins (TF), thearubigins (TR) and pubescence (PUB)) in tea were estimated in a 4 x 4 full diallel analysis. Generally, parents with good combining ability produced progeny with above average performance for all the evaluated traits. The general combining ability (GCA) effects were significant for yield, %TP, FERM, DT, TF, TR, PUB and bud weight, while specific combining ability (SCA) effects were significant for %TP, FERM, PUB and bud weight. Strong maternal effect for all traits was evident except for thearubigins and bud weight signifying the importance of female parents in breeding for yield, DT, and diversified tea products such as silvery tips. The heterosis analysis revealed that the mid-parent heterosis (MPH) and the betterparent heterosis (BPH) averaged across the families, were high for fermentability (MPH: 108.5%; BPH: -12.82) and DT (MPH: 16.44 %; BPH: 2.30%) but not so for yield (MPH: 2.17%; BPH: -5.09%) and total polyphenols (MPH: -2.81%; BPH: -5.71%). The heritability estimates for yield (h2 = 0. 44 ± 0.16; H2 = 0.56 ± 0.15), DT (h2 = 0.61 ± 0.06; H2 = 0.96 ± 0.01) and fermentability (h2 = 0.45 ± 0.04; H2 = 0.98 ± 0.01) were high indicating that the three traits are highly heritable and could be improved through hybridization and judicious clonal selection. Estimates of genetic gains indicated that moderate gains are achievable on clonal selection for characters such as yield and fermentability at 14.1% and 8.9%, respectively, while DT and PUB registered higher gains at 20.6% and 30%, respectively, based on h2. Mapping of QTL linked to yield, %TP, DT and shoot traits was assessed on a pseudotest cross comprising 42 clonal progeny between clones TRFCA SFS150 and AHP S15/10. QTL associated with root knot nematode resistance were investigated on a different cross consisting of 41 clonal progeny arising from TRFCA SFS150 and TRFK 303/577. Bulk segregant analysis was performed followed by complete genotyping. Out of 260 informative markers, 100 markers that showed 1:1 segregation were used to construct a linkage map. The map contained 30 (19 maternal and 11 paternal) linkage groups that spanned 1411.5 cM with mean interval of 14.7 cM between loci. A total of 64 QTLs controlling various traits across the two sites were detected. Of these, QTLs linked to YLD-T, YLD-K, DT-K and PUB were localised at 2 cM, 2.7 cM, 3 cM and 1.4 cM from markers OPG-07-2800, E-AGC/M-CAG- 725, OPT-18-2500 and OPO-02-650, respectively. No QTL was detected at both sites, which showed strong genotype x site interaction (G x E). Marker OPF-09-600 that co-segregated (P < 0.0000) with susceptibility to the root knot nematode was mapped at 0 cM from locus OPF- 09-600 on linkage group 8. Considering the long time expended in developing improved tea varieties, the identification of putative QTLs tightly linked to agronomic traits augmented by known genetic parameters provide room for marker-assisted selection thereby hastening tea improvement efforts.
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    Relationship between realization of right to adequate food and food security: A study among pastoral and small farm holder households
    (Egerton University, 2010-08) Muthoka, Stellamaris
    The Universal Declaration of Human Rights and International Convention on Economic and Social Cultural Rights underpin freedom from hunger and dignified lives for all. The study aimed at developing an innovative methodology for assessment of realization of the right to adequate food at household level and its validation; investigation of realization of the right to adequate food and its influence on food security, perception of rights to adequate food among pastoral and small farm holder households and duty bearer challenges in their realization of their obligation towards attainment of realization of right to adequate food. The study developed the right to adequate food tool based on the rights obligation parameters „to respect‟, „to protect‟ and „to fulfil‟. Validation of methodology was achieved through a comparative cross-sectional survey among 249 pastoral and farming households. Data was collected using a general household questionnaire, rights to adequate food questionnaire, perception of right to adequate food questionnaire, 24 hour food recall, food frequency questionnaire, household food insecurity access scale and focus group discussions. Quantitative data was analysed using SPSS version 16 software. Qualitative data was analyzed based on thematic content analysis. A 34 item rating tool was developed, able to assess realization level of right to adequate food at household level and also articulate aspects of knowledge, entitlement, capacity, capability, empowerment and decision making. Household Right to Adequate Food Index (HRTAFI) was computed as a measure of level of realization of the right at household level. The farming community had better level of realization of both the right to adequate food and household food security compared to the pastoral community (p<0.01). The pastoral group had higher realization of the obligation parameter of fulfilment (p<0.01) compared to the farming group. Female headed households had better realization of the right to food (p<0.05) although they experience more violation with respect to the obligation parameter of protection (p<0.05).Both communities experienced violation of the right with respect to the protection parameter. Realization of the right to adequate food correlated positively with education, health and gainful occupation (p<0.01). The pastoral community however had better annual income (p<0.01) compared to the farming counterparts. Both communities had a reasonable understanding of human rights; however, the practice was contextual. Retrenchment was perceived as an opportunity to enhance livelihoods among the study group (p<0.05). Causes of violation of the right included unstable livelihoods, high food price hikes, marital conflict, civil unrest, and changing climatic conditions. Manifestation and mechanisms of redress varied among the study groups and by gender. Primary duty bearer‟s challenges included livelihood stability and changing policies. However, secondary duty bearer‟s support was crucial in fostering primary duty bearer‟s realization of the right. Single mothers had more challenges in meeting their obligations of right to adequate food for the infant. Perception of breast feeding was contextual and varied along gender lines. The pastoral community significantly breast fed the boy child longer (p<0.05). Realization of the right to adequate food increased with awareness on human rights accounting for 5% variation and varied with seasonality. It accounted for 4-14% variation in food security during wet season compared to 5-8% during the dry season. Realization of right to adequate food enhances food security. Meeting primary duty bearer needs is fundamental in capacitating them to realize their obligations in realization of the right xv to adequate food. Perceptions of human rights are not new among communities and are consistent with conventional definition of human rights, however practice is contextual. Violations of rights are based on both human and non-human factors. Realization of the right to adequate food is influenced by realization other rights such as education, health and work. The developed HRTAFI can be used as an alternative measure of food security at household level.
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    Performance and emission characteristics of spark ignition engines based on engine operating parameters
    (Egerton University, 2010-11) Langat, Langat Kipkirui
    Poor vehicle maintenance culture and high proportions of old vehicles are major contributing factors to high vehicle emission levels. The purpose of this study was to determine performance and emission characteristics of vehicles that were taken for inspection at the Vehicle Inspection Centre in Nairobi City based on engine operating parameters and to develop performance and emission prediction models. The specific objectives were; to determine vehicle exhaust emission levels, engine’s performance and emission characteristics and to develop performance and emission models. The sample size comprised 384 petrol vehicles randomly selected. The key observations included vehicle usage, compression pressure, ignition angle, engine speed, spark plug gap, and vehicle category. The key variables examined were emission of CO, HC and CO2, excess air factor (_) and factors that influence emissions. Logistic regression model was fitted to determine the probability of tested vehicles failing emission tests based on the test variables. Field data were simulated using engine test bed and the effects of engine input variables on engine performance and emission were determined. Sub-model equations were generated from engine performance and emission curves and superimposed to develop engine performance and emission models. Validation, optimization and sensitivity analysis of the models were done. The mean vehicle usage ranged between 14328 km/yr and 19640 km/yr and the lowest compression pressure of 6.8 bar was recorded in the non-catalytic vehicles manufactured before 1986. Both categories of non-catalytic vehicles operated at a rich mixture. There was significant difference between the measured and standard values of exhaust emission gases. The models developed predicted well for engine performance and emission as expressed by low percentage error in most of the points. Optimization of Specific Fuel Consumption (SFC) model gave input variables of 2839 rpm, 16o BTDC, 1.05 _ and spark plug gap of 0.8 mm. Excess air factor was found to be the most sensitive variable when adjusted by ±10%, it mostly affected engine performance and emissions. In conclusion, exhaust emission levels from vehicles measured in Nairobi City were 6.8% vol., 4.41% vol., 1.16% vol. and 0.46% vol. CO for non-catalytic vehicles manufactured before 1986, non-catalytic vehicles manufactured between 1986 and 2002, catalytic vehicles manufactured between 1986 and 2002, and catalytic vehicles manufactured after 2002 respectively. The mean values for HC were 1814 ppm, 1884 ppm, 333 ppm, and 253.4 ppm for non-catalytic vehicles manufactured before 1986, non-catalytic vehicles manufactured between 1986 and 2002, catalytic vehicles manufactured between 1986 and 2002, and catalytic vehicles manufactured after 2002 respectively. These values were significantly different from the limits given in KS 1515-2000. Excess air factor for noncatalytic vehicles manufactured before 1986 and those manufactured between 1986 and 2002 oper were 1.14 and 1.08 respectively, while for catalytic vehicles manufactured between 1986 and 2002, and catalytic vehicles manufactured after 2002 were within the required limit of 1±0.03. There were significant changes in engine performance and emissions when the input variables were changed from optimal values. The models developed predicted well engine performance and emission characteristics. It is recommended that emissions control mechanisms be put in place to reduce emission levels. There is also need to include more test parameters in the models so as to improve on the prediction levels.
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    Lexico grammatical errors among Tugen learners of english
    (2010-11) Kandagor, Daniel C.
    This research sought to determine and describe lexico-grammatical errors made by students in upper primary school. The objectives of the study were to describe the nature of lexico.-grammatical errors, investigate the extent to which L1 contributed to these errors and establish the effect of these errors on the learner language. The study was based on Error Analysis and Interlanguage theories. A simple random sample of seventy five standard six Tugen speakers ii-om Baringo district in Rifi Valley province was selected. The researcher then collected data fiom this sample and classified the various lexico-grammatical errors. The following tools were used for elicitation of data: written composition, passage rewriting, cloze test and a questionnaire. The errors that were identified were grouped into seven categories and later the frequency of occurrence analyzed. The study in the end established that there were indeed a number of lexico-grammatical errors. For instance, sound similarity errors posted a higher percentage compared to the other errors showing that the L; learners still needed attention to correct them. Language switch had fewer errors that were picked from this research. The research also established that a majority of these errors are caused by the process of learning the second language while others could be attributed to first language interference. In short, the causes remain varied. The research observed that Tugen L1 speakers make a lot of lexico-grammatical errors, some hampering their communication while the other errors did not cause miscommunication. The findings fi-om this study will be a source of knowledge to linguists and curriculum developers will gain insights towards the re-arrangement and re-alignment of the language syllabus.
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    Determinants of adoption of shade coffee technology and the role of agroforestry in the productivity and profitability of coffee in Imenti South District, Kenya
    (Egerton University, 2011-03) Ithinji, Gicuru Kirimi
    Agro-forestry has continued to receive increasing attention from researchers and policy makers’ especially in coffee farming systems but there is lack of sufficient evidence on its role in productivity and profitability of coffee farming in Kenya. There is also lack of empirical evidence on whether factors that influence adoption of shade technology have the same effect on productivity and profitability of coffee. The general objective of the study was to examine the adoption of agroforestry-based coffee management systems and the role of these systems in increasing the productivity, and profitability of smallholder coffee enterprise in Imenti South District. The study also extends the application of the Tobit model in the realm of analysis of farm productivity and profitability. Specific objectives included categorization of smallholder farmers into adopters and non-adopters of shade technology, productive and non-productive farmers, profitable versus non-profitable coffee farms using the local means as cutoff points. A structured questionnaire was administered to a representative sample, chosen through multistage sampling, of 346 smallholder farmers in Imenti South District of Kenya. First, descriptive statistics, t-tests and chi-square analyses were used to explore socioeconomic characteristics of adopters and non-adopters of shade coffee technology, productive versus non-productive farmers, as well as profitable versus non-profitable coffee farms. Using the sample mean for binary categorization of coffee farming households, 40 percent of the sample farm households were effectively classified as adopter of shade coffee, 44 percent was classified as productive coffee farmers, while about 43 percent of the farm households were classified as profitable coffee farming households. Socioeconomic characteristics of the productive and non-productive farmers, as well as profitable versus non-profitable farming households, were different and hence requiring different sets of stimuli to increase productivity and profitability. Second, separate Tobit models were then used to examine factors that determine the rate and intensity of adoption of shade technology, as well as determinants of productivity and profitability of coffee/agroforestry system. The Tobit results show that different sets of socioeconomic factors determine the rate and intensity of adoption of coffee shade technology, productivity and profitability requiring proper understanding of the interplay of these factors in order to promote appropriate policy incentives. Policy implications are drawn.