RP-School of Engineering And Technology

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A Hybrid Model for Detecting Insurance Fraud Using K-Means and Support Vector Machine Algorithms
(Open Journal for Information Technology, 2023) Muthura, Brian Ndirangu; Matheka, Abraham
Private stakeholders and governments across the globe are striving to improve the quality and access of healthcare services to citizens. The need to improve healthcare services, coupled with the increase in social awareness and improvement of people’s living standards, has seen an increase in medical policyholders in the insurance industry. Even so, the healthcare sector is grappled with increased costs every other year, leading to revision of premiums and increased costs for the policyholders. One of the main factors contributing to the increased costs is fraudulent claims raised by the service providers and the policyholders, leading to unprecedented risks and losses for insurance firms. The insurance industry has set up fraud detection and mitigation systems to mitigate losses brought about by fraudulent claims, which come in two flavors: rule-based systems and expert claims analysis. With rule-based systems, conditions such as missing details, location of the claim vis a vis the location of the policyholder, among other rules, are evaluated by systems to assess the validity of the claims. On the other hand, insurance firms rely on the human intervention of experts using statistical analyses and artificial rules to detect fraudulent claims. The rule-based and expert analysis methods fail to detect patterns or anomalies in claims, which is central to efficient fraud detection. Data mining and machine learning techniques are being leveraged to detect fraud. This automation presents enormous opportunities for identifying hidden patterns for further analysis by insurance firms. This research aims to analyze a hybrid approach to detect medical insurance fraud using both K Means (unsupervised) and Support Vector Machines (supervised) machine learning algorithms.
Adaptation of technology
(Intercontinental Publishers Limited, 2013-05) Nzomo, M.M.; Mambo, Shadrack Maina
The subject of industrial technology has received significant attention in various international dialogue on economic development issues. This has been due largely to the gradual understanding of the vital role of industry in economic growth and the recognition of the role of technology in the process of industrial development. Technology Technology may be described as a matrix consisting of a set of techniques, each of which is associated with a vector of characteristics. These characteristics include the nature and specifications of the product, the input use, the scale of production, associated managerial techniques etc. The characteristics are designed to fit in with the economic, institutional and technical circumstances of the economy for which they were designed. In a general sense, technology includes choice of material, methods, machinery including equipment and tools, money (amount of sources), for a market (given or potential) appropriate to a country depending on its raw materials resources, availability of labour (level of skills and numbers), climate conditions, other human factors and level of social economic development at any given point of time. The technical know – how is not static, but is a continuous process of growth. For any country, developed or developing, it is not possible to remain in complete isolation. There is a prevailing lead – between developed countries which in some areas like electronics is quite high. Developing countries cannot afford to reduce this lead – time by indulging in own R & D programmes starting from the basics. Any disproportionate effort and money spent on grass root research with a view to catch up with developed countries will only increase the existing lead – time. This lead time can be shortened only by importing the technology initially and then using adaptive research to modify the performance. Even developed countries import technical know-how backed up by an intensive follow up Research and Development activity. Choice and acquisition of technology Choice of technology is a very important factor for the planned and balanced development of any sector of the economy. The investments made in an obsolete or old technology which may look very cheap and attractive to begin with, would prove very costly in the long – run due to high cost of production and non availability of spare parts. On the other hand, the input of very high and sophisticated technology would be costly and would also require a very large scale of production to be economically viable. A phased programme of indigenous manufacture with increasing self reliance and based primarily on domestic market needs is considered essential. Obsolescence of technology Obsolescence occurs with economic development and technical change, and is the product of the interaction between the two. There are many sources of obsolescence: generally speaking, the relevance of the source of obsolescence varies according to the nature of the economy. Some sources of obsolescence tend to make the technique obsolete in any society while others only apply in so far as other changes are occurring and may be applicable to developed countries and not to developing or underdeveloped countries. Obsolescence may be one of the methods of production to produce a given product. This is called product obsolescence associated with changes in the economic structure – obsolescence which would not occur without such changes; and obsolescence associated with increase in efficiency that makes previous technique obsolete irrespective of economic changes. In addition there is obsolescence independent of economic changes and of changes in the efficiency of substitute techniques, such as occurs with changes in the technology used in use in the rest of the system. Transfer and development of technology The process of assimilation of new techniques of industrial production and their adaptation to the condition prevailing in a particular country entails far more than the introduction of new equipment and the training of staff to operate it. The country’s technological capability is developed to other sectors of the economy and to society as a whole. The benefits are maximized if technology is transferred in such a way that the recipient country develops a capacity to modify and improve the technology in the future. The government of a developing country faces two main policy issues in connection with the transfer and development to technology for industrialization. The first is the extent to which policies and institutional arrangements are needed to ensure that the technology of modern manufacturing processes used in industrially advanced countries is adapted to the special needs and circumstances of developing countries using those processes. The second is the extent to which the Government should rely on imported technical know-how and, the nation’s technological capability. Insufficient attention has in the past been paid to the development of new types of technology for use by industrial enterprises in developing countries. Each developing country has different resource endowments and it is therefore usually worth while creating a national industrial research institution to tackle this and other problems encountered in adapting technological processes originally developed in industrial advanced countries with different resources endowments. In the industrially advanced countries, many branches of industry have formed research organizations on their own initiative and at their own expenses. It is difficult to say at what stage of the development of a branch of industry this form of organization will be appropriate in a developing country. However in those branches of industry where a government is especially desirous of developing a national and self supporting process of technological development, some initial financial support from government might be considered. Role of engineering education in generation & transfer of technology It has been argued that one of the major sources of bias in the generation and choice of technologies used in developing countries is the character of the education received by their engineers. Many of the engineers from developing world still receive their education in the universities of industrialized countries, because resources for their training and the technical assistance received for their establishment are often strongly influenced by the intellectual patterns of the industrialized countries. It is claimed, therefore, that engineers from developing countries trained in the molds receive “inappropriate education”. Absorption and adaption of technology The absorption and adaptation of technology can be described as a three-stage process after a foreign collaboration agreement has been entered into. Depending on the type of collaboration agreement and management decision, these three stages may start simultaneously or they can follow in a sequence. During the first stage, the emphasis is on setting up plants and facilities and leaving to manufacture the given product for which the collaborator supplies the complete set of drawings and manufacturing technology. Initially some of the components requiring complex production processing or proprietary technology may be imported from the collaborator, but the complete assembly is carried out at the local plant. The second stage of technology absorption starts when the local firm learns to design either new products or carry out alterations in the basic product design supplied by the collaborator following the design know-how and principles supplied by the collaborator. During the final stage of technology absorption, the local firm generates its own design know-how and principles based on indigenous research and development in the product areas, as well as in the basic sciences or engineering applicable to the product. If developing countries are to be able to choose and adapt technology, they must have available range of choices. First and foremost developing countries’ priority problem has been to find employment for large reserves of manpower by investing in industries which were sometimes of doubtful profitability and often based on the wrong choices of technology. In addition the engineering farms commissioned to make the techno-economic studies are often connected with plant manufacturers and slant their reports towards the choice of certain processes and types of plant.
Adsorption of Hexavalent Chromium from Aqueous Solution by Pumice: Equilibrium and Kinetic Study
(SRI, 2022) Muriuki, Cecilia W.; Mutwiwa, Urbanus N.; Home, Patrick G.; Kilonzo, Fidelis N.
—Chromium released into the environment primarily as a result of industrial activity such as leather and electroplating manufacturing process. This heavy metal has caused serious contaminations of water and soils with significant environmental and occupational concerns. Conventional methods of chromium removal are expensive especially for developing countries. This study investigates the use of pumice as a low cost and biosorbent material. Sorption of hexavalent Chromium (Cr (VI) onto pumice were carried out in batch at room temperatures, with parameters of initial chromium concentrations, and contact time being investigated. Removal of hexavalent chromium increased by increasing contact time, and reduced with increasing initial chromium concentration. Kinetic studies were conducted using the Pseudo-first-order and Pseudo-second- order models, while equilibrium data were fitted using Langmuir and Freundlich isotherm models. Fittings of obtained data onto kinetic models show that the pseudo-second –order kinetic model (R2=0.999) best describes the kinetic sorption of chromium ions onto pumice. Results also showed that Langmuir (R2=0.999) and Freundlich (R2=0.999) model agrees very well with experimental data. The RL and n values has proved the favorability of hexavalent chromium adsorption onto pumice
Advances in wind energy resource exploitation in urban environment: A review
(Elsevier, 2014) Ishugah, T.F.; Li, Y.; Wang, R.Z.; Kiplagat, J.K.
Wind energy continues to stand out as a more established and mature technology to offset a large proportion of power. Efforts aimed at improving wind energy use to meet the energy demand in turbulent urban wind environment have been the main technical focus. In previous studies on wind resource and behavior in urban environment, different designs of horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) have been reviewed. This paper vividly captures the fact that wind resource has a great potential to be fully explored and developed in the urban environment. Varying ways of application and application techniques being applied for electrical generation, ventilation and pollution dispersion, onshore cooling and dehumidification of coastal urban cities, and economics and environmental benefits of applying wind energy in urban environments are summarized. Although many new ideas and solutions that factor technical, economical and environmental sustainability in urban areas are coming up every day, challenges in design are gradually being solved to take advantage of urban low and turbulent wind speed characteristics, installation space challenges, vibration and noise reduction, among others. Some of the unique solutions that have been and are being developed in the applications of wind energy technology in urban environments are also reported in this paper
Advances in wind energy resource exploitation in urban environment: A review
(Elsevier, 2014-09) Kiplagat, J.K.
Wind energy continues to stand out as a more established and mature technology to offset a large proportion of power. Efforts aimed at improving wind energy use to meet the energy demand in turbulent urban wind environment have been the main technical focus. In previous studies on wind resource and behavior in urban environment, different designs of horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) have been reviewed. This paper vividly captures the fact that wind resource has a great potential to be fully explored and developed in the urban environment. Varying ways of application and application techniques being applied for electrical generation, ventilation and pollution dispersion, onshore cooling and dehumidification of coastal urban cities, and economics and environmental benefits of applying wind energy in urban environments are summarized. Although many new ideas and solutions that factor technical, economical and environmental sustainability in urban areas are coming up every day, challenges in design are gradually being solved to take advantage of urban low and turbulent wind speed characteristics, installation space challenges, vibration and noise reduction, among others. Some of the unique solutions that have been and are being developed in the applications of wind energy technology in urban environments are also reported in this paper.
Analysis of Determinants of M-Commerce Adoption by Online Consumers
(Center for Promoting Ideas, USA, 2014) Gitau, L.; Nzuki, D. M.
M-Commerce is the making of payments for products and services through the use of mobile devices. The proliferation of mobile devices has resulted to into substantial growth of M-commerce. This is as a result of anytime anywhere connectivity, low cost of business, increased new sales avenues and customer loyalty. But even with the high penetration rate of Mobile phones, a relatively low adoption rate of M-Commerce has been observed in the developing countries. This study provides the theoretical underpinning for various interventions to promote M-Commerce Adoption. The study uses the literature review to identify the factors which influence the adoption of M-Commerce by consumers. The results from this study will be useful to m-commerce companies in formulating appropriate marketing strategies, as well as developing appropriate applications that address the needs and resources of various stakeholders. The outcome of this study will guide companies that offer MCommerce related products in the selection of digital products and in pursuance of future commercial opportunities. The finding of this study recommends that the government should set up legislation that would ensure customer security in order to enhance trust and hence enhance M-Commerce adoption.
Analysis of Land Cover Change Impact on Flood Events using Remote Sensing, GIS and Hydrological Models: A Case Study of the Nyando River Basin in Kenya
(2009) Olang, L. O.
In this study, land cover changes in the Nyando River basin (3500 km2) of Kenya were analyzed and their impact of floods quantified. Three Landsat satellite images for 1973, 1986 and 2000 were acquired, processed and classified based on seven major land cover classes prevalent in the basin using a hybrid of supervised and non supervised classification procedures. The detected land cover changes, together with a DEM and a soil map of the basin, were then used to estimate physically based parameters for the selected hydrological models. The models were then used to estimate local and flood peak discharges and volumes arising from selected storm events for each state of the classified land cover dataset. To further understand how changes in the land cover may impact on the flood hydrology, three scenarios that represent quite extreme alternatives were formulated to study the possible bandwidth during floods. Land cover classification results revealed immense land degradation over the span of study. Forests reduced by an area of 488 km2 representing a 20% decline, while agricultural fields expanded by 581 km2 representing a 16% increase over the same period of time (1973-2000). Hydrological modeling results indicated that the basin underwent significant increase in the peak discharge value. The flood peak discharges in the whole basin were noted to have increased by at least 16% over the period of 1973 -2000.Flood volumes were also noted to have increased by at least 10% over the same period of time. (author)
Analysis of Rainfall Trends and Periodicity in Ruiru Location, Kenya
(The International Journal of Scientific and Research Publication (IJSRP), 2017) Nyakundi, R; Mwangi, J; Makokha, M; Obiero, C
- Climate change is a serious issue in the world today with extreme weather conditions being experienced globally as characterised by devastating floods and prolonged droughts. This has often led to destruction of property and loss of life. These conditions are viewed as disasters requiring mitigation. Ruiru location being a peri-urban area has a lot of farming taking place and increased population due to settlement. This has increased the demand for water as stream flow is decreasing and boreholes are drying, with water scarcity prominent during droughts. Moreover during floods there is high surface runoff in the paved areas. The study sought to determine rainfall trends across the year for 31 years if any in Ruiru location. Monthly rainfall data for 31 years (1984-2014) obtained from four stations located within the location; Ting’ang’a, Ruiru mills, coffee research foundation and Doondu were used. Graphs were constructed to show trends within months and years and statistical significance of the observed trends tested using a linear regression model. Statistical analysis using Mann- Kendall, Spearman’s Rho, Linear Regression and Student’s t was employed to determine the significant difference among the four stations. High annual mean rainfall of 170mm and low annual mean rainfall of 37 mm were observed. Mann- Kendall, Spearman’s Rho, Linear Regression and Student’s t showed no significant difference of rainfall means between Ting’ang’a and Ruiru Mills stations, while the other stations were statistically insignificant. Linear regression models showed an upward trend which was statistically insignificant in all the four stations. There was no significant trend across the year for the past 31 years. The research findings will help in prediction of the occurrence of high and low rainfall amounts for proper planning and water resources management.
Analysis of spatiotemporal land cover changes for hydrological impact assessment within the Nyando River Basin of Kenya.
(Springer, 2011) Olang, L. O.; Kundu, Peter; Bauer, Thomas; Josef, Fürst
The spatio-temporal changes in the land cover states of the Nyando Basin were investigated for auxiliary hydrological impact assessment. The predominant land cover types whose conversions could influence the hydrological response of the region were selected. Six Landsat images for 1973, 1986, and 2000 were processed to discern the changes based on a methodology that employs a hybrid of supervised and unsupervised classification schemes. The accuracy of the classifications were assessed using reference datasets processed in a GIS with the help of ground-based information obtained through participatory mapping techniques. To assess the possible hydrological effect of the detected changes during storm events, a physically based lumped approach for infiltration loss estimation was employed within five selected sub-basins. The results obtained indicated that forests in the basin declined by 20% while agricultural fields expanded by 16% during the entire period of study. Apparent from the land cover conversion matrices was that the majority of the forest decline was a consequence of agricultural expansion. The model results revealed decreased infiltration amounts by between 6% and 15%. The headwater regions with the vast deforestation were noted to be more vulnerable to the land cover change effects. Despite the haphazard land use patterns and uncertainties related to poor data quality for environmental monitoring and assessment, the study exposed the vast degradation and hence the need for sustainable land use planning for enhanced catchment management purposes.
Analysis of the Risk of Landslids in Kebomas, Gresik District
(Calamity, 2024-01) Setiawan, Romy; Aji, Priatmojo; Arifin, Syahdan; Irmansyah, Rizal; Raenaldy; Kinyua, James Gitonga
The landslide disaster occurred during the rainy season in Kebomas District, Gresik Regency, which has topography in the form of hills left over from lime mining in 1960-1990. A field survey conducted from December 2021 to March 2022 stated that landslides occurred during the rainy season in Kebomas District and caused damage to surrounding settlements. Land slope, rainfall, rock type, soil type, and land use are factors that influence the occurrence of landslides. The aim of this research is to map the level of landslide vulnerability in Kebomas District using the Geographic Information System. The research results show that there are three levels of landslide vulnerability in Kebomas District, namely, low, medium and high. The low vulnerability class is found in all villages in Kebomas District, most of which are in six villages or sub-districts in the south, west and north, namely; Dahanrejo, Kedanyang, Pambangan, Kembangan, Randuagung, and Segoromadu. The moderate vulnerability class is found in all villages in Kebomas District, most of which are in six villages in the southeast, northwest and north, namely; Randuagung, Pambangan, Dahanrejo, Kembangan, Sidomoro, and Ngargosari. Areas with a high vulnerability class are in the central part of the sub-district
Application of Unmanned Aerial Vehicles in Improving Land Registration in Kenya
(International Journal of Research in Engineering and Science (IJRES), 2017-05) Wayumba, Robert; Mwangi, Patricia; Chege, Patrick
This paper explains why and how Unmanned Aerial vehicles (UAVs), also known as drones, can be used to improve land registration in Kenya. According to a World Bank report that was released in 2003, only about ten percent of land in Sub-Sahara Africa has been formally registered. A more optimistic figure for developing countries in the whole World was released in 2013, which shows that only about thirty percent of land is registered. Thus, a majority of the people are unable to gain from the benefits of registration. An effective land registration system can contribute towards improving: tenure security, real estate markets, access to credit, taxation, dispute resolutions and urban planning among others. A key requirement for improving the extent of registration is to map property boundaries. A means of rapidly mapping the boundaries is to use UAVs. However, it is not clear how UAVs can be used in a county like Kenya. This paper employs case study methodology to explain why and how the UAVs can be used in Kenya. The results section explains different types of UAVs that may be used, legal regulations for using the UAVs and techniques that are required for land registration. The hope of this paper is that it might contribute towards the use of UAVs for improving land registration not only in Kenya but also in other developing countries.
Application of water demand management strategies in Kenya journal of civil engineering research and practice under review.
(Kenya journal of civil engineering research and practice, 2013) Omosa, I.B.; Nyangeri, E.N.
This study set out to examine the policy position in Kenyan health care financing, with regard to implementation of the proposed social health scheme (NSHIF) and its performance potential. The specific objectives were to: examine the existing social scheme (NHIF), its role and challenges in health care financing; establish whether or not Kenya has the key pre-requisites for introduction and sustainability of a social health scheme and to provide recommendations on the way forward. This was largely a desk study, supplemented with limited primary data from key informants. The analysis indicates that: i) For a universal social health plan to be sustainable, favorable economic indicators and availability of essential infrastructures are critical prerequisites. Resources must be available, government must be in a position to afford high subsidies, the population must be ready to pay high premiums and the supply of health services must be adequate to cater for the expected increase in demand; ii) Countries that have successfully embraced social health plans introduced their schemes carefully and gradually (overtime) in terms of coverage; iii) Kenya compares unfavorably with these countries in terms of prerequisites for sustainability of a social health scheme, due largely to a poor economy, high poverty levels and shortfalls in facilities and services. The study concludes that Kenya lacks the key prerequisites for introducing and sustaining a universal social health scheme. The scheme can hardly be supported by the current status of the economy and healthcare infrastructures. The study recommends: i) Expansion and development of health care infrastructural capacities through subsidies and tax concessions for those investing in health care and providing subsidized services, particularly to the poor and rehabilitation of the GoK facilities; ii) Increasing the health budget from 7 per cent of government expenditure to above 10 per cent and directing more resources and efforts towards preventive/promotive and primary health care (P&PH); and iii) Other recommendations include subjecting the proposed scheme to an actuarial evaluation and comprehensive policy plan in order to determine the attendant and corresponding premium and benefit levels and pursuing a phased approach in the implementation of the scheme.
Assessing Distribution Changes of Selected Native and Alien Invasive Plant Species under Changing Climatic Conditions in Nyeri County, Kenya
(Public Library of Science San Francisco, CA USA, 2022) Waititu, Julius Maina; Mundia, Charles Ndegwa; Sichangi, Arthur W
The role of climate change in enhancing bio-invasions in natural environments needs to be assessed to provide baseline information for effective species management and policy formulations. In this study, potential habitat suitability maps were generated through Ecological Niche Modeling for five problematic alien and native species in current and future climate simulations for the periods 2050s and 2070s under RCP2.6, RCP4.5, and RCP8.5 emission scenarios. Projected current binary suitability maps showed that 67%, 40%, 28%, 68%, and 54% of the total study area ~ 3318 Km2 is suitable for C. decapetala, L. camara, O. stricta, S. didymobotrya and S. campylacanthum species, respectively. Assuming unlimited species dispersal, two of these species, C. decapetala and S. didymobotrya, were observed to have consistent gradual increase in potential habitats and no habitat losses under the three RCPs by the end of the 2050 and 2070 future periods. The highest recorded relative potential habitat increase was observed for O. stricta at ~205% under RCP2.6 and ~223% under RCP8.5. Although L. camara and O. stricta were observed to have habitat losses, the losses will be very low as compared to that of S. campylacanthum. L. camara and O. stricta relative habitat losses were predicted to be between ~1% under RCP2.6 to ~4.5% under RCP8.5 by 2070 while that of S. campylacanthum was between ~50% under RCP2.6 to ~68% under RCP8.5 by the year 2070. From this study we conclude that the target study species are expected to remain a big threat to inhabited areas as well as biodiversity hotspot areas especially in the Mt. Kenya and the Aberdare forest and national park reserves under climate change. The information generated through this study can be used to inform policy on prioritizing management of these species and subsequent determination of their absolute distributions within the area.
Assessing impacts of climatic changes on Hydrology and Water Resources
(2012-04-27) Kilonzo, Fidelis
Assessing Spatio-Temporal Land Cover Changes Within the Nyando River Basin of Kenya Using Landsat Satellite Data Aided by Community Based Mapping – A Case Study
(2014-07-28) Olang, L. O.; Kundu, Peter; Bauer, Thomas; Josef, Fürst
Spatio-temporal land cover changes witnessed within the Nyando River Basin of Kenya were assessed in this study. The land cover changes were mapped by classifying the predominant land cover classes on selected Landsat satellite images. The accuracy of the classifications were assessed using reference datasets developed and processed in a GIS with the help ground based information obtained through participatory community based mapping techniques. The results of the analysis indicated significant deforestation in the headwaters of the basin. Obviously apparent from the land cover conversion matrices was that the majority of the forest decline was a consequence of agricultural expansion. Despite the haphazard land use patterns and uncertainties related to poor data quality for environmental change assessment, the study successfully exposed the vast degradation and hence the dire need for both sustainable landuse planning and catchment management strategies.
Assessing the Impacts of Environmental Changes on the Water Resources of the Upper Mara, Lake Victoria Basin: UNESCO-IHE PhD Thesis
(CRC Press, 2014) Kilonzo, Fidelis
Growing population and unregulated access to forest land have exerted high pressure on the land and water resources of the recharge areas of the transboundary Mara river, in the Lake Victoria region leading to changes in land and water use patterns in the basin. This thesis considers the interactions among climate change and variability, water quality, land surface cover, hydrology, and human systems, including societal adaptations to changing environmental conditions. The thesis explores the interaction between trends in climatic variables and the feedback response of vegetation variables. The effect of different land cover types on water quality is addressed, and alternative methods to treat data quality for hydrological model inputs and validation are discussed. The Soil and Water Assessment Tool (SWAT) hydrological model was adapted to the tropical watershed experiencing data scarcity, and used to assess the impacts of changes to the climate, land use and management practices. Different scenarios driven by the prevailing natural trends, strategic national development and economic policies were used to asses the potential impacts of changes.
Assessment of environmental and public health hazards in wastewater used for urban agriculture in Nairobi, Kenya
(Universidad Autonoma de Yucatan, 2010) Githuku, C.; Karanja, N.; Njenga, M.; Prain, G.; Kang’ethe, E.; Kironchi, G.; Kinyari, P.; Mutua, G.K.
Thirty percent of residents in Nairobi practise urban agriculture (UA) with a majority of the farmers using untreated sewage to irrigate crop and fodder. Due to the environmental and health risks associated with wastewater irrigation, a study was carried out in partnership with farmers in Kibera and Maili Saba which are informal settlements along the Ngong River, a tributary of the Nairobi River Basin. Soil, water, crops and human faecal samples from the farming and non-farming households were analysed to elucidate sources, types and level of heavy metal pollutants in the wastewater and the pathogen loads in humans and vegetable crops. Heavy metal accumulation in soils collected from Kibera and Maili Saba were Cd (14.3 mg kg-1), Cr (9.7 mg kg-1) and Pb (1.7 mg kg-1) and Cd (98.7 mg kg-1), Cr (4.0 mg kg-1) and Pb (74.3 mg kg-1), respectively. This led to high phytoaccumulation of Cd, Cr and Pb in the crops that exceeded the maximum permissible limits. No parasitic eggs were detected in the vegetables but coliform count in the wastewater was 4.8 x108±2.2 x1011/100ml. Soils irrigated with this water had parasitic eggs and non-parasitic larvae counts of 54.62 and 27.5/kg respectively. Faecal coliform and parasitic eggs of common intestinal parasites increased in leafy vegetable sampled from the informal markets along the value chain.
Assessment of Land Cover Changes in Lake Olbolosat Region of the Central Kenyan Highlands using Landsat Satellite Imagery Aided by Indigenous Knowledge
(SciTechnol., 2013-04-18) Muriithi, Zacharia; Ako, E. O.; Kiplagat, Jeremiah; Maingi, S. M.; Olang, L. O.
The region around Lake Olbolosat in the central Kenyan highlands has witnessed significant land-use changes, which are believed to be major cause of the dwindling Lake volumes. Very few studies have been carried out in the region due to limited observed insitu data necessary for monitoring the land surface conditions. It is hence important that feasible, straightforward and cost-effective techniques are explored to asses the space and time variations with a view of providing the essential information for improved land and water management. This study investigated the land cover changes around Lake Olbolosat region using data obtained from Landsat satellite remote sensing. Five predominant land cover classes including farmland, floodplain, build-up area, forests and water body were selected for study. Two imageries for 1989 and 2010 when significant changes were witnessed in the area were subsequently selected. The Maximum-Likelihood function of the supervised classification scheme was applied to discern the space and time changes with the support of the indigenous knowledge of the area. From the results obtained, the size of Lake Olbolosat was noted to have significantly shrunk by 68% between the periods of study. Farmlands were noted to have increased by about 31% owing to the rapid rise in commercial and subsistence agriculture favored by the humid tropical climatic conditions of the highlands. The study revealed intense deforestation of the upstream area, which reduced the forested area by about 30% during the study period. The floodplains were also noted to have reduced by about 26%, with a majority of the area being gradually turned to farmland. Built-up area generally increased by about 33% consequent of the rising human population. In summary, the study revealed significant negative land cover changes in the area and hence a critical need for improved land-use planning to curtail further decline of Lake Olbolosat.
Assessment of land cover changes in Lake Olbolossat region of the Central Kenyan highlands using Landsat satellite imagery
(2013-04) Olang, L. O.; Muriithi, Zacharia
The region around Lake Olbolossat located in the central Kenyan highlands has witnessed significant land-use changes, which are today believed to be major cause of the dwindling Lake volumes. Very few studies have been carried out in the region due to limited observed in-situ data important for monitoring purposes. Itis thus urgent that contemporary cost effective techniques are explored to asses the space and time land cover changes with a view to provide information required for appropriate land and water resource management. In this preliminary study, the land cover changes around Lake Olbolossat region were investigated using remotely sensed data obtained from Landsat satellites. Two imageries for 1989 and 2010 when significant changes were witnessed in the area were selected for the study. The maximum-Likelihood function of the supervised classification technique was applied to classify and discern the changes. Five predominant land cover classes that included forestland, built-up area, water body, flood plain and farmland were selected for the study. From the results obtained, the area of the Lake (water body) was noted to have shrunk significantly by 68%. Farmlands in the region were noted to have increased by about 31% largely due to the favorable humid climatic conditions for commercial and subsistence agriculture. The study also revealed that built-up areas increased by about 33% consequent of the rise in the human population. The flood plain area was noted to have reduced by about 26% as most of the area were gradually been turned to farmland. The study also revealed intense deforestation in the upstream Aberdare forest, which was noted to have reduced in area by about 30% during the study period. In general, the study revealed significant land cover changes worth provoking the need for a better land-use planning system to avoid further decline and extinction of Lake Olbolossat.
Assessment of the Biological Treatability of Black Tea Processing Effluent
(2007) Omosa, I.B.; Oonge, Z.N. I.
The anaerobic degradability of tea beverage processing effluent was assessed using a stationary upflow anaerobic filter. The filter, with an active column of 1.2m height, inner diameter of 100 mm and filled with rock as the attachment medium was operated at room temperature ranging between 20-250C throughout the study period in both batch and continuous modes. It was seeded with an anaerobic sewage sludge inoculum from an anaerobic pond of a Municipal Sewage Treatment Plant of the City of Nairobi at Ruai. The tea beverage processing effluent obtained from factory washing after processing operations at Kambaa Tea Factory was used as substrate The start-up took over three months for the anaerobic colonies to develop and to start digesting the factory effluent. The long period was for acclimation of the organisms to the new substrate. During this period the filter was operated in a batch mode at a hydraulic retention time (HRT) of 7 days. The operation lasted for 105 days. Immediately after introduction of the black tea effluent (substrate) from Kambaa Tea Factory, the system was in a shock for 28 days. However, it recovered from the shock from day 29 and by day 105 while maintaining the HRT of 7 days a chemical oxygen demand (COD) removal efficiency of 74% was achieved. From day 106 to day 162, the filter was operated on a continuous mode at a HRT of 36 hours with the substrate being fed at an organic loading rate (OLR) of 0.67 kg COD/m3-day. A COD removal efficiency of about 90% was achieved by the end of the period. Removal of suspended solids was 100% in this operation. Removal of colour was more than 85%

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