Nyika J.,Technical University of Kenya
Water Practice and Technology | Year: 2017
Nairobi River Basin (NRB) remains an important ecosystem owing to its endowment with natural resources and its socio-economic value to Kenyans. However, it is vulnerable due to poor resource management, pollution and an increase in the rising population. Environmental flow is thus necessary to assess and plan on how best to maintain adequate quality and quantity of water resources that people in the area depend on. The study used the Tennant and Tessman methods in EF assessment and recommended an annual environmental flow requirement (EFR) of 291 m3/sec equivalent to 37% of mean annual flow. It also recommends an EFR range of 148–577 m3/sec equivalent to 28% and 108% of LF and HF, respectively and a flushing flow of 1,580 m3/sec to be released in October to maintain the river basin’s ecological integrity. EF flows in NRB should be corrected using appropriate management measures derived from this study. © IWA Publishing 2017.
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: ICT-39-2015 | Award Amount: 3.93M | Year: 2016
its4land delivers an innovative suite of land tenure recording tools that responds to sub Saharan Africas immense challenge to rapidly and cheaply map millions of unrecognized land rights in the region. ICT innovation will play a key role. Existing approaches have failed: disputes abound, investment is impeded, and the communitys poorest lose out. its4land reinforces strategic collaboration between the EU and East Africa via a scalable and transferrable ICT solution. Established local, national, and international partnerships drive the project results beyond R&D into the commercial realm. its4land combines an innovation process with emerging geospatial technologies, including smart sketchmaps, UAVs, automated feature extraction, and geocloud services, to deliver land recording services that are end-user responsive, market driven, and fit-for-purpose. The transdisciplinary work also develops supportive models for governance, capacity development, and business capitalization. Gender sensitive analysis and design is also incorporated. Set in the East African development hotbeds of Rwanda, Kenya, and Ethiopia, its4land falls within TRL 5-7: 3 major phases host 8 work packages that enable contextualization, design, and eventual land sector transformation. In line with Living Labs thinking, localized pilots and demonstrations are embedded in the design process. The experienced consortium is multi-sectorial, multi-national, and multidisciplinary. It includes SMEs and researchers from 3 EU countries and 3 East African countries: the necessary complementary skills and expertise is delivered. Responses to the range of barriers are prepared: strong networks across East Africa are key in mitigation. The tailored project management plan ensures clear milestones and deliverables, and supports result dissemination and exploitation: specific work packages and roles focus on the latter.
Maringa P.M.,Workforce Development Authority |
Maringa M.,Technical University of Kenya
Global Journal of Engineering Education | Year: 2013
Technical Vocational Education and Training (TVET) in Rwanda is undergoing drastic reform, moving towards becoming a well regulated, integrated TVET system. With the prevailing un-harmonised TVET and little consistent scientific data or mapping of access, it has not been possible to determine the quality of the prevailing TVET on offer. A sample of Ecole Technique Officiels (ETOs) and Agroveternaires (EAVs) were surveyed, with respondents being identified using a complex sampling approach. Well-structured, coded and graded interview schedules were used to guide enumerators. Descriptive and inferential statistical analysis was carried out to bring out the inherent patterns in the prevailing status quo. Cleary, access to TVET is unequal with respect to spatial distribution/location, age, specialisation and ownership. It is necessary for the Government of Rwanda (GoR) to adopt policies that enable improved equity of access to training opportunities. For sustainability in the future to ensue, models of TVET financing that embrace more private sector participation need to be given emphasis. © WIETE 2013.
Okwadha G.D.O.,Technical University of Kenya |
Nyingi P.W.,Technical University of Kenya
International Journal of Environmental Science and Technology | Year: 2016
The high cost of traditional stabilizing agents such as lime and cement has led to the research on industrial and agricultural wastes as suitable alternatives. Rice growing areas of Kenya accumulate large quantities of rice husk which pose serious disposal problems. When burnt as a means of disposal, the rice husk ash formed is difficult to coagulate and thus contribute to air and water pollution, require a large space for disposal, and cause respiratory health problems when inhaled. Red coffee soil poses serious engineering problems such as swelling due to wetting, shrinkage due to drying, low bearing capacity, and differential settlement leading to cracks and needs improvement for strength and stability in service. Red coffee soil and rice husks samples were obtained from Gatundu and Mwea, respectively. The rice husk was burnt at temperatures between 500 and 700 °C to ensure maximal formation of siliceous component. Chemical analysis on the rice husk ash gave the sum of SiO2, Fe2O3, and Al2O3 as 85.5 % indicating that it has pozzolanic activity. Rice husk ash was applied at 4, 6, 8, and 10 % by weight of dry soil. Plasticity index, liquid limit, and linear shrinkage decreased from 26.1, 67.1, and 13.0 % for lean sample to 18.5, 63.6, and 9.2 %, for 10 % rice husk ash stabilized samples, whereas plastic limit increased from 41.0 to 45.15 %. The soaked California bearing ratio value for rice husk ash stabilized samples increased from 5 to 22 % corresponding to soil subgrade class S4. However, lime-stabilized samples gave higher values. © 2016, Islamic Azad University (IAU).
Oduor A.M.O.,University of Konstanz |
Oduor A.M.O.,Technical University of Kenya |
Leimu R.,University of Oxford |
van Kleunen M.,University of Konstanz
Journal of Ecology | Year: 2016
Concerns over the ecological impacts of invasive alien plant species have generated great research interest in understanding the mechanisms that underlie the capacity of such plants to occupy a broad range of habitats. It has been repeatedly suggested that rapid evolution of local adaptation to novel environments may enable invasive plants to occupy a broad range of habitats. However, the classical Darwinian view on evolution by natural selection is that the process is slow and gradual, occurring over thousands of years. Invasive plants typically have a relatively short residence time in their introduced ranges (decades or just a few centuries). Besides the time constraint, founder effects (reduction in population size and genetic diversity) may also limit the capacity of invasive plants to rapidly evolve local adaption. Thus, invasive plants may be less likely than native plants to evolve local adaptation. Interestingly, however, an expanding body of literature documents the existence of local adaptation in invasive plant species within their exotic ranges. Here, we did a phylogenetically controlled meta-analysis to compare invasive and native plant species for differences in the frequency and magnitude of local adaptation. The meta-analysis was based on different experiments performed in various habitats including grasslands, steppes, deserts, forests, mountains, wetlands and dunes, and used a total of 134 plant species in 52 families. Forty seven of these species (in 24 families) are alien invaders in the region where the studies were undertaken, while the other 91 species (in 38 families) are native. On average, local plants performed better than foreign plants, and invasive plant species expressed local adaptation just as frequently, and at least as strongly as that exhibited by native plant species. An analysis performed while taking into account different plant life-history traits showed that self-incompatible invasive plants exhibited significantly higher frequencies of local adaptation than native plants characterized by the same breeding system. Synthesis. The present results support the suggestion that rapid evolution of local adaptation may enable invasive plant species to occupy a broad range of novel habitats. © 2016 The Authors. Journal of Ecology © 2016 British Ecological Society
Yizengaw E.,Boston College |
Retterer J.,Boston College |
Pacheco E.E.,Boston College |
Roddy P.,Air Force Research Lab |
And 3 more authors.
Geophysical Research Letters | Year: 2013
While the mechanism for producing plasma irregularities in the dusk sector is believed to be fairly well understood, the cause of the formation of irregularities and bubbles during the postmidnight sector is still unknown, especially for magnetically quiet periods. This paper presents a case study of the strong postmidnight bubbles that often occur during magnetically quiet periods primarily in June solstice, along with a 4 year (2009-2012) statistical study that shows strong occurrence peak during June solstice predominantly in the African sector. We also confirm, for the first time, the presence of Rayleigh-Taylor (RT) instability during postmidnight hours by using the physics-based model for plasma densities and RT growth rates. Finally, we consider several possible sources of the eastward electric fields that permit the RT instability to develop and form bubbles in the postmidnight local time sector. Key Points Strong postmidnight bubbles occurrence during magnetically quiet periods The presence of Rayleigh-Taylor (RT) instability during postmidnight hours. Strong occurrence peak occurs during June solstice predominantly over Africa ©2013. American Geophysical Union. All Rights Reserved.
Kwanya T.,Technical University of Kenya
Lecture Notes in Business Information Processing | Year: 2015
Indigenous knowledge plays a pivotal socioeconomic development role in indigenous communities. In Kenya, one of the economic sectors where indigenous knowledge can be applied is tourism which is among the country’s major income earners besides tea and horticulture. This study investigated the potential and the actual use of indigenous knowledge in leveraging the other efforts being made to develop and cushion tourism in Kenya. The study was designed as a survey to capture the current status of the application of indigenous knowledge in the tourism sector in Kenya. Primary data was collected through key informant interviews with tourism industry stakeholders in the country. 56 participants in the study were selected through a mix of stratified, purposive and snowballing sampling techniques. The interviews were conducted using semi-structured questionnaires administered by the researcher. Secondary data on indigenous knowledge in Kenya, indigenous tourism as well as tourism sector statistics was collected through documentary analysis. The data was analysed using content analysis. The findings of the study indicate that although indigenous tourism holds a great socioeconomic potential in Kenya, it has not been harnessed fully. Its potential is still being held back by myriad challenges such as lack of relevant business development skills; lack of adequate capital to develop and promote indigenous tourism products, services and facilities; remoteness of indigenous tourism sites; insecurity; poor infrastructure; modernisation; environmental degradation and consequences of climate change; stiff competition; and intra or inter-ethnic resource-based conflicts. The findings can be used by the Government of Kenya to mainstream indigenous knowledge into tourism by developing the requisite policies, structures and implementation frameworks. The findings may also be used by the tourism sector stakeholders in Kenya to identify, enhance, package and promote indigenous tourism products, services and facilities effectively. © Springer International Publishing Switzerland 2015.
Ondore F.,Technical University of Kenya
American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM | Year: 2014
A square duct with a 90-degree streamwise curvature is representative of complex flow domains. Such flow domains are encountered in the designs of fluids engineering systems, especially in the aerospace turbo-machinery components. Examples include the gas turbine engine axial compressor interstage spaces, where the rise in air pressure (and hence compressor efficiency) is dependent on suppression of turbulence. In the case of the centrifugal compressor, pressure rise in the Ushaped diffuser assembly where the suppression of turbulence is critical to the attainable pressure ratio. The results obtained from numerical calculations are analysed and discussed along with the corresponding hot-wire measurements and flow visualization result from a wind-tunnel of identical configuration. Calculations are implemented in four turbulent models, i.e. Standard k-e Module, Algebraic Stress Model (ASM), Non-linear Renormalization Group (RNG) - k-e Model and Differential Stress Model (DSM). The discretization up-winding scheme is the Quadratic Up-winding with Interpolation Kinematics (QUICK). Two high Reynolds number turbulent flows are investigated, with mainstream velocities of 12.3 m/s and 20.4 m/s, representing Re=3.56x105 and Re=6.43x105 respectively. Generally strong correlation between theory and experimental data are recorded. Further, as reported in similar studies, the turbulence modules that are formulated to account for turbulence anisotropy return results that more closely match experimental measurements. Uniquely for this configuration, a massive flow detachment is predicted along the convex wall at about the 90 position. Also, the core of the fluid flow is observed to shift from the outer to the inner areas of the bend in proportion to the secondary (recirculating) flow generated by the bend. Copyright © 2014 by ASME.
Micheni E.,Technical University of Kenya |
Murumba J.,Technical University of Kenya
2016 IST-Africa Conference, IST-Africa 2016 | Year: 2016
This paper presents an attempt of providing grid computing as an avenue to heterogeneous e-learning platforms that can be accessed by different hardware and software platforms. E-Learning involves using internet technologies to access learning resources online such as school timetable, courseware, research material, and to run virtual communities for sharing and creating knowledge. Grids can be used as a means to provide education and training through such internet technologies. Literature review is used through examination of scientific research papers in journals and conference proceedings. The objective of the paper is to contribute towards knowledge and lessons that can be applied in Kenya towards effective approaches for development of an e-learning grid infrastructure. © 2016 IIMC.
Kagumba M.,Missouri University of Science and Technology |
Kagumba M.,Technical University of Kenya |
Al-Dahhan M.H.,Missouri University of Science and Technology
Industrial and Engineering Chemistry Research | Year: 2015
Bubble columns have been used in a wide range of applications in industry including the production of alternative clean fuels via Fischer-Tropsch synthesis and liquid phase methanol synthesis, among others. The effects of dense internals encountered in Fischer-Tropsch synthesis with different diameters and covering the same cross-sectional area and hence configuration on bubble properties are lacking in the open literature. Therefore, the focus of this study is to investigate the effects of dense internals with different diameters and covering the same cross-sectional area and hence configuration on the bubble dynamics such as local and overall gas holdup, specific interfacial area, axial bubble velocity, bubble passage frequency, and bubble chord lengths using a four-point fiber optical probe. The experimental work was carried out in a 0.14 m inner diameter Plexiglas bubble column for an air-water system. The superficial gas velocities applied based on both total cross-sectional area and free cross-sectional area available for the flow were in the range 0.03-0.45 m/s covering the bubbly flow regime through the churn turbulent flow regime. The internals used were both Plexiglas rods of 0.5 in. diameter and 1 in. diameter occupying 25% of the column cross-sectional area. The experimental data obtained suggest that 0.5 in. internals gave consistently higher overall and local gas holdup, specific interfacial area, and bubble passage frequency than the 1 in. internals or empty column, particularly at the column center. The effect of the internals diameter was insignificant for the gas holdup, particularly in the churn turbulent flow regime. Lower axial bubble velocity was obtained with the smaller diameter internals. Worth noting is that the insignificant difference in the local gas holdups at the velocity based on free cross-sectional area indicates that it is possible to extrapolate the local gas holdup results obtained from empty bubble columns to those with dense internals, but the effect of dense internals on the other bubble properties still needs to be done in columns equipped with dense internals. © 2015 American Chemical Society.