PubMed | Mount Kenya University, Jomo Kenyatta University of Agriculture and Technology, JKUAT and Kenya Methodist University
Type: | Journal: BioMed research international | Year: 2016
Siringi D.O.,JKUAT |
Home P.,JKUAT |
Chacha J.S.,University of Nairobi |
Koehn E.,Lamar University
ARPN Journal of Engineering and Applied Sciences | Year: 2012
Although electro coagulation is an evolving technology that is being effectively applied today for wastewater treatment, the paucity of scientific understanding of the complex chemical and physical processes involved is limiting future design and hindering progress. The objective of this review through a survey of the literature is to bring the chemistry and physical processes involved into perspective and to focus attention on those areas critically needing research. © 2006-2012 Asian Research Publishing Network (ARPN).
Maobe M.A.G.,Jomo Kenyatta University of Agriculture and Technology |
Gitu L.,Jomo Kenyatta University of Agriculture and Technology |
Gatebe E.,Jomo Kenyatta University of Agriculture and Technology |
Rotich H.,Kenya Bureau of Standards |
And 4 more authors.
World Journal of Medical Sciences | Year: 2013
A diploid fungus, Candida albicans, is a form of yeast that is a casual agent of opportunistic oral and genital infections in humans and is traditionally treated using herbs. Amongst the indigenous herbs used for the purpose in Kisii region, southwest Kenya are: Carissa spinarum, Urtica dioica, Warburgia ugandensis, Senna didymobotrya, Physalis Peruviana, Bidens pilosa, Leonotis nepetifolia and Toddalia sciatica. A study was carried out on these herbal plants in the year 2011and 2012. The objective was to determine the antifungal activity of these herbs that are also used for the treatment of diabetes, malaria and pneumonia. In the study, leaf samples of these plants were obtained from Kisii region, washed, air-dried and milled. The samples were extracted with four solvents namely hexane, dichloromethane, ethyl acetate and ethanol. Portions of the crude extracts were screened against Candida albicans, by the well diffusion method. Results showed that the standard antibiotics namely chloramphenicol, minocycline, erythromycin and cotrimoazol had diameters of the inhibition zones measuring (mm), 33, 32, 31 and 25, respectively which indicated inhibition of microbial growth. However, the extracts of hexane and solvents had no antifungal activity against the Candida albicans as they had diameters of the inhibition zones of 12 mm. The dichloromethane extracts of Leonotis nepetifolia and Bidens pilosa showed antifungal activity of diameters of the inhibition zones measuring 19 mm and 16 mm respectively. The ethyl acetate extracts of Leonotis nepetifolia, Bidens Pilosa, Senna didymobotrya, Toddalia asiatica and Physalis Peruviana recorded antifungal activity with diameters of the inhibition zones measuring (mm) 24, 18, 18, 17 and 15 respectively. The ethanol extracts of Leonotis nepetifolia and Physalis Peruviana displayed antifungal activity with diameters of the inhibition zones 27 mm and 19 mm, respectively. The dichloromethane, ethyl acetate and ethanol extracts of Leonotis nepetifolia recorded maximum antifungal activity against Candida albicans. The findings suggest that the herbal extracts of Leonotis nepetifolia, Bidens Pilosa, Senna didymobotrya, Toddalia asiatica and Physalis Peruviana have a potential to control Candida albicans as they have diameter zone of inhibition above 12 mm. © IDOSI Publications, 2013.
Njiri J.G.,JKUAT |
Ikua B.W.,JKUAT |
World Academy of Science, Engineering and Technology | Year: 2011
Optimization of cutting parameters important in precision machining in regards to efficiency and surface integrity of the machined part. Usually productivity and precision in machining is limited by the forces emanating from the cutting process. Due to the inherent varying nature of the workpiece in terms of geometry and material composition, the peak cutting forces vary from point to point during machining process. In order to increase productivity without compromising on machining accuracy, it is important to control these cutting forces. In this paper a fuzzy logic control algorithm is developed that can be applied in the control of peak cutting forces in milling of spherical surfaces using ball end mills. The controller can adaptively vary the feedrate to maintain allowable cutting force on the tool. This control algorithm is implemented in a computer numerical control (CNC) machine. It has been demonstrated that the controller can provide stable machining and improve the performance of the CNC milling process by varying feedrate.
Muvengei O.,JKUAT |
Kihiu J.,JKUAT |
World Academy of Science, Engineering and Technology | Year: 2011
This paper numerically investigates the effects of input speed on the overall dynamic characteristics of a multi-body system with differently located revolute clearance joints without friction. A typical planar slider-crank mechanism is used as a demonstration case in which the effects of the input speed on the dynamic performance of the mechanism with a revolute clearance joint between the crank and connecting rod, and between the connecting rod and slider are separately investigated with comprehensive observations numerically presented. It is observed that, changing the driving speed of a multibody system makes the behavior of the system to change from either periodic to chaotic, or chaotic to periodic depending on which joint has clearance. The location of the clearance revolute joint and the operating speed of a multi-body system play a crucial role in predicting accurately the dynamic responses of the system. Therefore the dynamic behavior of one clearance revolute joint cannot be used as a general case for a mechanical system.
Ndiritu H.M.,JKUAT |
Oketch P.O.,JKUAT |
Kihia J.W.,Kenya Power
Proceedings of the 27th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2014 | Year: 2014
Energy is a key driver of the economic progress and it is expected to play a significant role in Kenya's socio-economic development. The current amount of power generated in Kenya stands at 1,600 MW and this is insufficient to meet the industrial needs for the current population that is about 40 million people. There is urgent need to increase the amount of power to at least 15,000 MW for industrial goals to be met by the government as captured by Kenya, Vision 2030 economic blueprint. The main source of power in Kenya is hydroelectricity that contributes more than 50% of electricity. Thermal sources (petroleum) contribute about 30% while geothermal and other renewable sources contribute more than 10%. This distribution changes during drought season with thermal component increasing to more than 50%. It is notable that nonrenewable forms such as petroleum contribute a significant portion of power. This is in form of heavy fuel oil running internal combustion engines. There are a number of energy sources that are being sort to further increase amount of power in Kenya. These include use of waste biomass and waste heat to generate additional power from existing power plants. This paper explores the status of power production in Kenya with a focus on the level of utilization of waste biomass and waste heat for power generation.
Kamau A.,JKUAT |
2013 IST-Africa Conference and Exhibition, IST-Africa 2013 | Year: 2013
Healthcare data are naturally sparse, high dimensional, and require frequent schema change during storage. To overcome the above challenges, both simple and multi-data-type Entity-Attribute-Value (EAV) data storage models are often used in place of the traditional horizontal data model. However, representing data in either of the formats generally result into queries that are both inefficient and rather complex. In this paper we present an enhanced data model for representing this class of data which dramatically improves the efficiency and reduces the complexity of the queries thereof. This is achieved by finding a compromise between the conventional horizontal data model and the EAV data models. To attest the validity of the new crossbreed model, Enhanced Entity-Attribute-Value (EEAV), its performance is evaluated against that of conventional horizontal data model, simple EAV data model and multi-data-type EAV data model with regard to querying of data sets of varying sizes. © 2013 The Authors.
Kimotho J.K.,JKUAT |
Hwang P.,Yeungnam University
SAE Technical Papers | Year: 2011
Overreliance on petroleum products and environmental pollution from combustion emissions produced by automobiles has led to extensive research on hybrid electric vehicles, electric vehicles and their components. A key component in these vehicles is the electric motor, used for traction as well as powering other appliances like the compressor. Overheating in electrical motors results in detrimental effects such as degradation of the insulation materials, magnet demagnetization, increase in Joule losses and decreased motor efficiency and lifetime. Hence, it is important to find ways of optimizing performance and reliability of electric motors through effective cooling and consequently reduce operating and maintenance costs. This study describes 3D CFD simulations performed on a totally enclosed air over fan cooled brushless D.C. motor to identify the temperatures of the critical components of the motor. The energy sources are obtained from electromagnetic losses computed using MAXWELL, a commercial FEA software and bearing losses obtained through numerical methods developed by the authors. A finned casing is used as the heat sink and the effect of varying the fin geometry on the cooling performance is examined using three heat sink designs. The results show that the highest temperature occurs at the end windings and that this temperature can be reduced by up to 15% by introduction of a suitable finned housing. These results show that CFD can be effectively used to optimize the cooling performance of electric motors. Experimental tests are undergoing in order to validate the CFD results. Copyright © 2011 SAE International.
Mwangi R.W.,Jkuat |
Waweru R.,Jkuat |
Journal of Theoretical and Applied Information Technology | Year: 2011
This research seeks to look into the design process that promotes the development of an educational computer game that supports teaching and learning processes. The research specifically looks at the design of an educational computer game for teaching and learning of the topic of functions. The topic is essential in the teaching and learning of Mathematics courses such as Discrete Mathematics, Real Analysis and Calculus among others at Jomo Kenyatta University of Agriculture and Technology (JKUAT) Kenya. The computer game was developed using the Basic Unified process (BUP) which is a streamlined version of the rational unified process (RUP). This is an Object Oriented methodology mostly used for small projects with few end users. Due to the few numbers of end users we used interview method of data collection to gather requirements for the computer game. A paper prototype was used to validate the requirements. Use cases were used for both analysis and design of the game while Class diagrams and activity diagrams were purely used for the design of the game. Owens' six top level design anatomy aided in the design of the computer game. The overall computer game design was based on Craw fords' computer game design sequence model. The well designed and developed game met all its user requirements and was able to facilitate the teaching and learning of Functions to Bachelor of Science in Mathematics and Computer Science students who were taking Discrete mathematics in their first year of study at JKUATs' Taita/Taveta campus. Development of heuristics for measuring interest, fun and motivation are recommendations given to aid in the evaluation of user satisfaction of educational computer games. © 2005-2011 JATI & LLS. All rights reserved.
News Article | November 28, 2016
LONDON, 28-Nov-2016 — /EuropaWire/ — Ambitious plans to boost IT literacy in Kenya by supplying thousands of primary schools with brand-new laptops are being supported by G4S. The Kenyan government has pledged to provide 22,000 schools across 47 counties with the portable computers over the next two years. It believes that the ‘Digischool’ programme will boost both education by putting Kenyan schoolchildren on a par with their global counterparts, as well as the country’s economy. G4S has signed an agreement to store, secure and deliver the devices on behalf of one of the two universities chosen to supply and install them, the Jomo Kenyatta University of Agriculture and Technology (JKUAT). The £600,000 contract involves supplying the devices to 8,600 primary schools in 21 counties – some 365,737 devices in total. Work has already begun on delivering them to an initial 75 schools. Already being kept in secure storage at G4S Kenya’s main hub in Nairobi, the team will distribute the laptops through its existing extensive courier services network. “The size of our courier operation – with more than 600 vehicles and 141 offices across the country – is one of the reasons G4S was selected for this programme,” said Geoffrey Mwove, Director – Courier, G4S Kenya. “Our team is also skilled and experienced, with around 70 per cent of our couriers having worked with us for more than seven years.” With that experience comes knowledge of both the terrain of the country and locations of the schools, with the team having previously carried out the distribution of books to the same establishments. Beyond its ability to handle a distribution operation of this size, the secure storage facility in the country’s capital was another factor that persuaded the university to accept the G4S bid. It is also being used to keep safe projectors, servers, teachers’ laptops and spare parts prior to delivery. “Having a security division was a major attraction for the customer, as it wanted a supplier who could store as well as deliver these devices in a secure manner,” Geoffrey said. “We handle 90 per cent of Kenya’s bank shipments, which gave them confidence we can handle this programme. “Our flexibility and ability to tailor solutions were other major plus points.” He added: “We’re delighted to be involved in such an important programme for Kenya, which will empower our young people with advanced IT knowledge and help secure the future of our country.” The business is currently in talks regarding future opportunities, as the Kenyan government has plans to eventually extend the programme to pupils joining Grade 1 and even secondary schools. What they say “We are now starting on a journey that will without a doubt transform not just the education sector but the entire economy. “When we put these devices in the hands of our children, we are securing not just their future but that of the country and look forward to being a global IT powerhouse in a few years.” “So far we have trained 80,000 teachers across all primary schools in readiness for this massive programme. We have also ensured that each school is connected to electricity. “This programme will revolutionise the process of learning in this country and put our children on a par with their global counterparts.” ABOUT G4S G4S is the world’s leading global, integrated security company specialising in the delivery of security and related services to customers across six continents. The group is active in more than 100 countries*, and is the largest employer quoted on the London Stock Exchange with over 610,000* employees and has a secondary stock exchange listing in Copenhagen. *Includes 44,000 employees in businesses in 15 countries that are being sold or exit For any media enquiries, please contact the G4S Press Office, on +44 (0)20 7963 3333 If you are a journalist and have an urgent enquiry outside of office hours, please contact us on +44 (0)7710 950 346