MST-School of Engineering and Technology

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This collections contains bibliographic information and abstracts of Master theses and dissertation in the School of Engineering and Technology held in Kenyatta University Library

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Application of mobile phone in crime prevention within Central division, Nairobi city County
(Kenyatta University, 2017-08) Wambugu, Paul M.
ABSTRACT The study sought to establish application of mobile phones applications by police officers in crime prevention in Central Police Division, Nairobi City County. Application of mobile phone in the police service is underutilized making the organization not to fully benefit from its usage. Understanding use of mobile phone applications by the police officers may assist the organization in crime prevention efforts. Due to its ability to engage consumers in a timely and direct manner at low costs, mobile phone applications are relevant for the police organization. The study was guided by the Mobile Technology Acceptance Model (M-TAM) as the success of the mobile phone implementation depends on perceived usefulness (PU) and perceived ease of use (PEOU).The targeted population in this study was police officers serving at Central Division of Nairobi County (782). A sample of 155 police officers was recruited using random stratified sampling procedure for this study. Questionnaires were used for data collection for both qualitative and quantitative data. Qualitative data was coded and analysed thematically after interpretation of theme while descriptive data was analysed using descriptive statistics by use of Statistical Package for Social Sciences (SPSS version 20.0). Mobile phone was found to be effective tool in prevention of crime in Nairobi Central. Mobile phone applications such as Facebook, Whatsapp, Twitter, emails and short text messages were found through adapted technology acceptance model (TAM) as to effectively contribute to crime prevention based on respondents’ perspective. Police effort to use mobile technology was found to have significant effects on crime prevention. Based on these findings, the study recommends development of customised police mobile phone applications and enhancement of applications use through capacity building among police officers.
Assessment of water resources utilization and management in chahi sub-catchment, Kisoro district, Uganda
(2013-07-23) Tera, Marahi Moses
There is a growing global concern over the future of the world‟s water resources due to the preceding vulnerability. Some of the factors contributing to the increase in water resources vulnerability include population growth and poor land use practices. This study assessed the local uses and management of water resources and the local coping mechanisms, identified the drivers of water resources scarcity and evaluated the opportunities and challenges of managing water resources in Chahi sub-catchment, Kisoro District, Uganda. To achieve the objectives of the study, the following empirical tools were used; a structured questionnaire, key informant interviews and field observation guides. A total of 100 households and 20 key informants were interviewed. Numerical tools for data analysis comprised descriptive statistics and non-parametric test. SWOT analysis tool was used to examine the challenges and opportunities. The study identified pipe borne water (89%), stream (58%), rain (40%) through roof catchment and vendors (8%) as the major sources of water in the sub-catchment, with domestic (100%) and agricultural (24%) being the major local uses of water. Women played a key role in the management of water sources, making use of the water and fetching of water from the water sources. Construction of water points, maintenance of available water points, fencing of the water source, participatory planning in water management, equitable distribution of water tanks and training on water management were identified by households as interventions to ensure sustainable water supply and management in the sub-catchment. Drivers of water resources scarcity in the sub-catchment included climate change (98%), poverty among the households (80%), population growth (77%), pollution (41%), inadequate information on water management (33%), land use practices (20%) and deforestation (16%). Various coping mechanisms; domestic rainwater harvesting (DRWH), water storage during plenty, water pricing, use of earthen pots, moving long distances and innovative agricultural practices were being used by the households. However, not any of all these coping mechanisms considered depicted a significant relationship with the households‟ longevity in the sub-catchment. Major challenges hindering water resources management (WRM) in the sub-catchment are; low coverage of rainwater harvesting technology at household level, lack of internal training on WRM technologies and inadequate support of water initiatives by the households. Conversely, the opportunities established include; location, support from the Central Government through the District Local Government and involvement of different stakeholders in water management. The study concludes that water shortage appears as a powerful incentive to change, eliciting major adaptations and coping strategies from users. This study recommends focus on building more water infrastructure and involvement of the households in the planning and allocation of water resources. This will contribute to improved understanding of the need for efficient water resources utilization and management on household livelihoods and also help design appropriate WRM strategies for the poor peasant farmers and provide guidance for policy makers for similar situations in Uganda and beyond.
Automated Examination Generation using Natural Language Processing and Artificial Neural Network
(Kenyatta University, 2023) Ndirangu, Peter Ndegwa; Elizaphan Maina
The examination process is a key activity in evaluating what the learner has gained from the study. Institutions of Higher Learning (IHL) perform the activity by administering tests which comprises of questions and answers. Cognitive level, weight of the question, and topic coverage are key factors to consider when setting exams. The world today has largely focused on the automation of exam generation which has been ongoing with dire need during the period of the Covid-19 pandemic when education was greatly affected, leading to embracing online learning and examination. The process has taken shape; however, the automation process can be improved by incorporating machine learning algorithms in the process of setting examination. In view of this, the project focused on implementation of a question classification model that uses Neural-Network algorithm (NN) and Natural Language Processing (NLP) to determine questions cognitive levels based on the revised Bloom's Taxonomy. The iterative method of software development was adopted to provide room for continuous improvement. The developed model was put under test with a couple of questions obtained online. The effectiveness of the model was determined by subjecting it into database of 600 questions resulting to an accuracy of about 71%. An Application Programming Interface (API) and Moodle Learning Management System (LMS) plugin were consequently developed to allow integration of the model with an existing system. The deep learning approach was applied to predict cognitive levels of questions based on Bloom’s taxonomy and the resulting questions were made available to the instructor through the LMS interface. Future research should focus on the use of convolutional reinforcement learning to establish its effectiveness in question classification as well as perform comparison with various algorithms.
Calcium Chloride Supported on Purified Spent Bleaching Earth as Potential Adsorptive Material for Air Dehumidification Application
(2013-03-22) Mathaga, Kihara John
Thecosmic limitation of high humid environment in tropic regions spurs a lot of interest to the developmentof low cost desiccants. Calcium chloride has been indicated as the oldest adsorbent desiccant among chemicals and gas dehydration industries. However, calcium chloride dissolution behaviour makes it difficult to be utilized well as desiccant. The first attempt to suppressdeliquescence behavior for dehumidification purpose was in 1976 where silt loam was usedas the host material. Further work has been presented to achieve the same goal using pure clay.The pollution effect of the spent bleaching earth (SBE) necessitated an investigation to determinewhether SHE could be used to eradicate the deliquescence behaviour of calcium chloride.The spent bleaching earth was purified to remove the entrained hydrocarbons through three steps; solvent extraction using hexane, oxidation of the hexane residues using 30% hydrogenperoxide and thermal oxidation. The ratio of 1 gram spent bleaching earth to 5 ml hexane and reactivation temperature of 550 DC in thermal oxidation were established as the optimalconditions for reactivation of spent bleaching earth. Hexane was found to remove about 25% of the entrained hydrocarbons mainly oil which was characterized. The results for the characterization indicated that the oil recovered could be utilized in non-food applications such as bio-lubricant, detergents, soap and other oleochemicals. Hydrogen peroxide removed about 10%of the remaining hydrocarbons after hexane extraction and thermal treatment about 5% after the two preceding steps. Laboratory studies were conducted to assess the mixing ratio of the inorganic salt, auxiliary binder and purified spent bleaching earth in the development of the composite adsorbent. Samples with different ratios were subjected to a humid environment of 88%relative humidity, by preparing a saturated solution of potassium chromate in a sealed beaker.The samples which recorded.minirnum surface wetting, spalling and cracking as well as high water uptake were further subjected to multiple sorption cycle tests. For all the tests performed, sample ratio of 3 :1 :0.25 of PSBE :CaCb :starch recorded the best results and was furthertested for its sorption properties at different relative humidity's. Sorption properties were carried out in a humidity chamber at 11.3, 32.78, 43.16, 52.89, 75.5 and 93.58% relative humidity where the sorption capacity recorded 14.88, 17.60, 20.95, 24.40, 33.40 and 45.55% water uptake respectively. The desiccant developed was found to be effective in high moisture content and thus viable in tropic regions where such environs are common. The sorption data obtained were subjected to the Langmuir, Freundlich and Brunaeur-Emmett- Teller (BET) adsorption models in order to determine the type of adsorption isotherm that best interpreted . water sorption by the material. Results indicated that, water adsorption onto adsorbent developed followed BET and Langmuir type III isotherm which indicated the formation of multilayer. The sorption capacity of the adsorbent matrix developed recorded 40 to 45% water uptake which cohered with commercially available desiccant such as silica gel. Since the SBE is normally disposed on potential land and limitations for this method of disposal is enormous, it is recommended that, oil manufacturing industries should emphasis on regenerating and re-using this waste in making products such as desiccants which they can use to preserve their products as well as sell to other consumers.
Characterization Of Snse-Cdo:Sn P-N Junction For Solar Cell Applications
(2014-08-26) Nyakundi, Makori Evans
Energy crisis occasioned by a decline in the availability of fossil fuels and increasing carbon dioxide emissions that are causing global warming has enhanced interest in the development of clean and renewable sources of energy. Solar energy has a great potential of meeting a large fraction of energy needs using photovoltaics. While most PV cells in use today are Silicon-based, cells of other semiconductor materials have been manufactured. Considerable research has been focused in search of thin-film PV cells with high conversion efficiency. In this study, SnSe and CdO:Sn thin films were optimised for photovoltaic applications. SnSe and CdO:Sn thin films were successfully deposited by thermal and reactive thermal evaporation respectively using Edward’s Auto 306 Magnetron Sputtering System . Their optical and electrical properties were studied using Solid Spec-3700 DUV Spectrophotometer and Keithley 2400 Source Meter respectively. Transmittance of the SnSe thin films deposited had transmittance ranging between 19-50% while reflectance ranged between 10-50%. The band gap values of SnSe thin films obtained were in the range of 1.71-1.76eV. SnSe thin films showed decrease of resistivity from 181-120Ωcm with increase in film thickness from 112-148nm. The optical properties of CdO:Sn showed high transparency in the visible region which varied with Sn doping, this makes CdO:Sn an excellent candidate for optoelectronic applications as a window layer. CdO and CdO:Sn had a transmittance of 70-85% and 50-89% respectively within the visible range of the electromagnetic spectrum. Reflectance of doped and undoped CdO was between 19-28%. Band gap energy for undoped CdO was 2.43eV while that of tin doped CdO ranged between 3.19-3.29eV for tin doping of 1-7%. Resistivity of CdO and CdO:Sn ranged between 16-93Ωcm. The optimised thin films were used to fabricate SnSe-CdO:Sn P-N junction. The I-V characteristics obtained were; Isc=0.993mA, Voc=273mV, Imax=0.905mA, Vmax=207mV, FF=0.69 and η = 0.59%.
Characterization, Evaluation and Performance Optimization of Wheat Straw – Bagasse Fuel Pellets
(Kenyatta University, 2024-11) Matasyoh, Isabel Musula
The current transition of the utilization of fossil fuels to sources of renewable energy has led to the exploitation of biomass energy from agricultural residues such as wheat straw and bagasse. The conversion of biomass waste into fuel pellets will provide an alternative source of reliable and affordable energy for cooking. This would help to curb the issue of over-dependence on fuel wood which results in deforestation. This research focused on the characterization, evaluation and performance optimization of wheat straw – bagasse fuel pellets. Wheat straw and bagasse were compacted to form fuel pellets. However, the fuel pellets could not be utilized directly before investigating their properties in order to determine their quality. The physical characteristics of the fuel pellets that were investigated included the moisture content, volatile matter, fixed carbon, ash content, calorific value, bulk density and mechanical durability. The effect of blend ratio, moisture content and raw material particle size on the ignition time, burning rate and specific fuel consumption of the wheat straw – bagasse blended fuel pellets was also studied. The water boiling test was used to determine the ignition time, burning rate and specific fuel consumption of the fuel pellets. This study involved varying four particle sizes (2 mm, 4 mm, 6 mm, 10 mm), four levels of moisture content (9.1%, 10.6%, 12.6%, 14.7%) and four blend ratios (10:90, 30:70, 70:30, 90:10). The results revealed that the fuel pellets with larger particles size, low moisture content and blends containing more bagasse had favorable burning characteristics. By using Response Surface Methodology, an optimization of the parameters was achieved. The results indicated that an optimum combination of blending ratio 10:90, moisture content of 14.70 % and a raw material particle size of 9.0481 mm resulted in the lowest ignition time of 38.001 seconds, highest burning rate 15.9511 g/min and lowest specific fuel consumption of 153.1153g/l. The findings of this work reveal that wheat straw – bagasse blended fuel pellets can be produced at optimal conditions by the use of optimization tools and practically utilized as a source of biomass energy.
Customers’ Perception of Mobile Banking and Financial Performance of Commercial Banks in Nairobi City, Kenya
(Kenyatta University, 2023-11) Munyasia, Nelima Rose; Stephen Titus Waithaka
Design and Fabrication of a Greenhouse Monitoring and Control System Based on Global System for Mobile Communication and Bluetooth
(Kenyatta University, 2020) Nyaga, Stephen Gitonga
Greenhouse technology should be embraced as a way of minimizing food insecurity in Kenya. The insecurity is brought about by climate uncertainties. Greenhouses have attempted to solve this problem by enclosing crops in a climatically controlled environment. Each greenhouse has distinct parameters. Data on these parameters need to be collected at regular intervals. Depending on the type of crop, these parameters need to be controlled within the specified limits to achieve the maximum efficiency and yields. In the past, greenhouses utilized electromechanical devices such as thermostats to monitor and control the environment. Mechanical systems lack the flexibility and precision required for greenhouse control. Some modern greenhouses use computers to control the environment. Computers based controllers are station based, bulky and costly. In this study a wireless prototype greenhouse monitoring and control system that is flexible, cheap, easy to maintain and easy to assemble was developed and implemented. The general objective of this research work was to design, fabricate and implement a microcontroller-based prototype to monitor and control greenhouse parameters using sensors, SMS technology and Bluetooth signals. The hardware consisted of ATmega328 microcontroller, Global System for Mobile communication (GSM) SIM800L module, HC05 Bluetooth module, HD44780U Liquid Crystal Display (LCD) module, 5 volt 4 channel relay module, Light dependent resistor (LDR) sensor and digital humidity and temperature (DHT11) sensor. The LDR sensor was utilized to measure light intensity while the DHT11 sensor was utilized to measure humidity and temperature levels in the prototype greenhouse. The DHT11 and LDR sensors, the relay, the LCD, the GSM and the Bluetooth modules were interfaced to the ATmega328 microcontroller. Through Arduino software, a program was written in C language, developed and uploaded to the ATmega328 microcontroller to run the greenhouse prototype. The program is designed to operate in automatic or manual mode. In automatic mode, the microcontroller constantly monitors the digitized values from the sensors and compares them with the optimized values and checks if any control procedures needs to be taken. In manual mode, the system could be operated wirelessly by use of GSM or Bluetooth module. The designed prototype greenhouse system is able to measure temperature, humidity and illuminance levels in the prototype greenhouse and display the values on the LCD. The system transmits the sensor measured values to owner’s phone via Bluetooth or a GSM and keeps these parameters at optimum levels by use of two fans, heater, bulb and a sprinkler. The GSM module is used for remotely monitoring and controlling the devices via a smart phone by sending and receiving Short Messaging Service via GSM network. If the user is in the vicinity of the prototype, the Bluetooth and a software installed in the smart phone provides a wireless link between the prototype and the cell phone. This project therefore provides a cost effective and efficient means of monitoring and controlling greenhouse parameters. In addition the system allows mobility during monitoring and control process. The reliability of the designed system can be exploited to build a network of such monitoring and control systems for several greenhouses. A website can be incorporated in the designed system to monitor the actual greenhouse values and save the data in an online database for future reference. The designed prototype greenhouse can be applied in the agricultural sector in the design and implementation of greenhouses.
Design and Optimization of a Solar Photovoltaic Mini-Grid: Case Study of Rwumba Village of Nyamasheke District, Rwanda
(Kenyatta University, 2021) Augustin, Munyaneza; Maurice Kizito Wafula Mangoli; Keren Kaberere
Universal access to clean energy is very paramount and brings along with it a lot of socio-economic benefits to the citizens in terms of poverty reduction, cost effectiveness and safeguarding the environment. However, most rural areas in developing countries have no access to electricity due to the high cost of power transmission and this hinders their development. In this perceptive, Rwumba Village of Nyamasheke district of Rwanda has no access to electricity from the grid. This research focused on the design of an optimum solar photovoltaic (PV) mini-grid system that can provide the required power and energy to the village. The solar PV mini-grid was designed and optimized using HOMER software. To achieve good results, two sites were visited and specific data were collected for each site by means of questionnaires. The first site visited is an existing standalone solar PV system known as Banda solar PV mini-grid and the second site is Rwumba village which is the case under study. The data collected from the existing Banda solar mini-grid include among others installed capacity and size of various system components, load data, energy and power requirements. Analysis of these data showed that this system is not optimum. The PV panels were found to be oversized whereas the storage batteries are undersized. Thus, using HOMER software, a model for optimizing this existing mini-grid was developed, simulated and validated using the data collected from the same mini-grid. The software simulated the combinations of inputs (PV panel, battery, power inverter and cost) at different capacity shortages and proposed the most optimum combinations. The best results corresponding to the optimum PV mini-grid were obtained at the capacity shortage of 3% which means that the mini-grid can meet the load at the reliability of 97% throughout the year. The estimated peak power and daily energy requirement was found to be about 7.5 kW and 51 kWh respectively. This is to be provided by PV panel capacity of 16 kW, battery bank storage of nominal capacity of 192 kWh that will be able to store energy for 3 days during cloudy days and power inverter of 12 kW. Then, the same procedure was followed to achieve most optimum results for Rwumba solar PV mini-grid. The optimum system size was found to have PV Panel capacity of 34 kW, a battery bank storage of 384 kWh nominal capacity, and power inverter of 15 kW serving an estimated daily load of 111 kWh. The power distribution system for the mini-grid was designed to be single phase supply two wire with distribution voltage of 230 V. The layout of households in the village dedicated the power to be distributed using three feeders from the power generation point. Feeder 1 is 0.4 km long, with power demand of 4.2 kW and a voltage drop of 4.5%; feeder 2 is 0.45 km long, power demand of 3.9 kW and voltage drop of 4.7% while feeder 3 is 0.45 km long, power demand of 5.9 kW and voltage drop of 4.4%. These results revealed that, the same size of the conductor present different voltage drop and power losses depending on the power demand and the location distance of the load being electrified from the generation plant. Economic analysis of the designed system was done using the life cycle cost technique. An annual interest rate of 6% and 20 years project life were used. The initial capital was found to be about USD 143,660. The payback period was found to be around 10 years at the system’s annual cash inflow of USD 13,435 and cost of energy of USD 0.419 per kWh. This means that there will be around 10 years of realizing the profit. Therefore, it was concluded that the project is financially feasible since the payback period is less than the project lifetime.
Design and Performance Evaluation of a Biomass Gasifier: Case Study of Coffee and Rice Husks
(Kenyatta University, 2021) Mutuku, Kilaka; Thomas F. N. Thoruwa; Jeremiah Kiplagat
About 36.1% of Kenya’s population lives below the poverty line. Low income has forced most of the Kenyans to opt for the cheapest available sources of energy. Biomass fuels are the most important source of energy in Kenya with wood-fuel (firewood and charcoal) accounting for over 68% of the total primary energy consumption. In spite of past efforts to promote substitutes for wood-fuel, the number of people relying on them is not decreasing. Consequently, it is projected that biomass will continue to be the main source of energy for the majority of the rural population and urban poor. Each year, over 2.8 million people in the world die prematurely from diseases caused by inhaling smoke from indoor fires due to incomplete combustion of biomass fuels in open fires and inefficient stoves. As a result of deforestation, biomass resources (fire wood and charcoal) are getting scarce. Waste products from agro-processing industries such as coffee husks, rice husks have been a major challenge in disposal. Biomass gasification is one of the few technologies that can potentially turn these wastes into energy for both industrial and domestic use. Although gasification has been around for more than 200 years, the technology is still new in Kenya. This study involved designing and developing a household-size biomass gasifier for the production of syngas using locally available biomass fuels namely; rice husks and coffee husks. Characterization of test fuels was based on their calorific value, percentage moisture content, volatile matter, ash content, fixed carbon, bulk density and porosity. Calorific value of rice husks and coffee husks was 15.9±0.8kJ/g and 18.1±0.8 kJ/g respectively. Bulk density of sampled rice husks and coffee husks was 127.4±1.2 kg/m3 and 218.0±1.6 kg/m3 respectively. Porosity of sampled rice husks and coffee husks was 87.4±0.9% and 71.9±0.6% respectively. Moisture content of sampled rice husks and coffee husks was 8.0±0.0% and 8.8±0.3% respectively. The percentage volatile matter of sampled rice husks and coffee husks was 62.8±0.3% and 78.4±0.0% respectively. The percentage ash content of sampled rice husks and coffee husks was 20.2±0.4% and 3.9±0.1 respectively. The percentage fixed carbon of sampled rice husks and coffee husks was 17.0±0.7% and 17.7±0.1% respectively. The maximum temperature obtained inside the gasifier reactor was mainly in the range 800°C to 1100°C. 1.5 liters of water at an average temperature of 24°C boiled in the stove within 4.7 to 8.5 minutes. Economic analysis of the gasifier found out that if a family shifts from LPG to using the constructed gasifier the payback period is 1.09 years, net benefit is Ksh45,000 (450USD) and rate of return on investment is 214.29%.
Design of a solar tracking concentrator system for process heat generation
(2011-12-07) Githuku, Simon Mwangi
In Kenya, biomass energy accounts for 75% of the energy consumed for domestic heating and industrial process applications. This has lead to massive deforestation and environmental degradation. In seeking solutions, this project was undertaken to develop a solar concentrating system for process heat generation in Kenya. The goal of the study was to design, construct and evaluate the thermal performance of the solar tracking concentrator for process heat generation. The solar tracking concentrator was designed, constructed and tested under field conditions in Kenya from February to August 2004. About 70 trials were conducted to investigate its thermal performance. The system components included rotating support structure, tracking unit with cylinders loaded with evaporative solvents, collector assembly (parabolic concentrator and receiver) and heat recovery unit. Locally available materials (including shock absorbers, solvents, square metal tubes & plywood) were used to construct the system. The measured parameters included solar radiation, ambient temperature, wind speed, tracking cylinders temperatures, water inlet and outlet temperatures, water flow, air inlet and outlet temperatures, airflow and tracking angle. The tracking unit utilized solvents for its operation. Three types of solvents used included chloroform, carbon tetrachloride and methylated spirit. The tracking angle was read and recorded manually at a regular interval of 10 minutes. Average process temperature ranging between 41.8 ± 9.7°Cand 59.3 ± 147.7°C was generated with an average insolation of 665 ± 302.1 W/m2 and 684.4 ±147.7 W/m2 for the non-tracking and the solar tracking systems respectively. From 70 field tests conducted in Kenya with system loaded with methylated spirit, chloroform and carbon tetrachloride the following was concluded: (a) Chloroform solvent with an average tracking accuracy of 82+13.2% proved to be better than that of carbon tetrachloride that had tracking accuracy of 74.1± 2.5%. (b) The use of mirrors on the solar concentrator's surface and integration of a solar tracking system increased the thermal efficiency by an average of 9.0 ± 1.5%. (c) Concentrating system loaded with chloroform showed potential to generate 82.5± 5kWh per day when operating with averaged solar radiation of 644.3 ± 30.5 kW/m2. (d) The solar tracking concentrator loaded with chloroform solvent demonstrated great potential for use in process heat generation, industrial and agricultural drying operations in sunny countries.
Design, development and testing of a liquefied petroleum gas powered tomato dryer with water energy stotage
(Kenyatta University, 2015) Njoroge, John Kamindo
Determinants of Soil Water Conservation and Nutrient Flow Management in Bufundi Sub-Catchment.Kabale District,Uganda
(2013-03-20) Kaliisa, Robert
Soilerosion and declining soil productivity still continue to manifest in most of the agricultural systemsfound in Sub-Sahara Africa and this has threatened the agricultural productivity, biodiversity,water quality and availability as well as the livelihoods of the poor who depend on land.In Uganda, this has been attributed to poor land use practices with inadequate SWC measuresand persistent nutrient mining of the soils with little or no replenishment. Highland areasofKabale are reported to be severely affected by soil erosion and declining soil fertility despitecontinued efforts by farmers to conserve soil and water resources. The study examined thedeterminants for SWC and nutrient flow management in Bufundi sub-catchment. The study waspremised on analyzing physical, institutional and social economic factors as they were perceivedto stronglyinfluence'SwC and nutrient flows within the different farm slope positions ofBufundi sub-catchment. Ni~ety five (9S) structured questionnaires, key informant interviews andtransects were conducted in the month of January 2011. Also 30 soil samples were collected fromagricultural fields on the predominant SWC measures (terrace benches) in addition to nutrientmonitoring using the NUTMON questionnaires, transfer functions and a NUTMON monitoringguide. Data analysis was done using SPSS 17.0, E-view 3.0 and NUTMON 3.6 softwarefor the different types of data. The results of the survey show that family size, age, land , . tenure,perception of soil erosion, sources of income, formation of Innovation Platforms (IPs), farmsize, collective marketing under IP, slope, collective action and training in SWC are among themajor factors that positively and significantly influence adoption and use of soil and water conservationmeasures. Education, sex, off-farm activities, visits by extension agent, showed no significantinfluence on adoption and use of soil and water conservation measures. Soil data in thepredominant SWC measures (terrace benches) revealed that: pH, organic matter, and nitrogen werebelow the critical values on all the"t~rrace farms. It was revealed that organic manure (IN2) wassignificant at (p
Development and Performance Evaluation of Solar green house Dryer with Desiccant Energy Storage system for Tomatoes
(Kenyatta University, 2021) Mbacho, Susan Andrew; Thomas F.N. Thoruwa; Nickson K. Lang’at
Tomato is one of the most important horticultural crops widely grown in the tropical East Africa countries. It is mostly used as vegetable recipe for food preparation at most homes or consumed raw as a salad. However, during the rainy season, tomato farmers experience widespread post-harvest losses due to insect and molds infestation. Also, during harvesting seasons, most markets in East Africa are flooded with the produce leading to over- supply against low demand resulting to heavy postharvest losses. Therefore, it is necessary to use appropriate drying technologies especially solar drying technology to reduce these losses. The use of solar drying technology is a good alternative solution to the problem of crop drying and especially the perishable tomato crop. Literature review show that most solar crop drying technologies developed for the past 50 years have very small loading capacity and cannot operate during the night. Therefore, in this study, we developed an integrated greenhouse solar dryer with Clay-CaCl2 solid desiccant energy storage system. Solar greenhouse drying systems have an advantage over other solar drying systems because its structural simplicity combined with high loading capacity. In addition, they have relatively good thermal crop drying performance compared to most solar dryers. The system was tested under no-load and load conditions. The experimental study with no-load condition exhibited the mean collector temperature of 41.9 °C giving an average temperature rise of 14.7 °C (35%) above the ambient (27.2 °C) with an average R.H. value of 32.6% at the flow rate of 0.28 m3/s on the test date. When the desiccant energy storage was used during night an average greenhouse temperature recorded within the drying chamber was 26.5 °C higher than the ambient temperature of 15.9 °C (40 % temperature rise). The results obtained under desiccant energy storage showed that at a 0.07 m3/s air flow rate with an average rise in temperature of about 13.6 (32.3%) against the average ambient temperature of 28.5°C. The average relative humidity within the system was found to be 36.5% lower than the ambient R.H. (84.1%). The collector efficiencies obtained from no load test was 46.2% and 40.8% for the dryer and desiccant chamber respectively. The performance of the dryer was evaluated with fresh tomato load during the month of September - December 2019 at Kenyatta University field site. The dryer demonstrated capacity to dry fresh tomatoes from 93.9% (wb) to 8.3% (wb) within 27 hours with solar greenhouse drying efficiency of 23% while at night the dryer demonstrated desiccant drying efficient of 19.9%. The drying rate for the two-day solar drying was 0.985 kg/h and 0.875 kg/h respectively and that in night drying using desiccants was 0.34 kg/h. The economic analysis of the drying system shows a payback period of less than a year (0.54 year) with benefit-cost ratio of 8.4 implying that the system is economically viable. On the basis of these results, it was concluded that prototype solar greenhouse dryer with Clay-CaCl2 energy storage system has great potential for tomato drying and other high moisture agricultural products in East African countries.
Development of a Biogas to Bio-Methane Upgrading System for Domestic Cooking in Kenya
(Kenyatta University, 2023-06) Reuben, Mugagga Gad; Isaiah B. Omosa; Thomas F.N. Thoruwa
Abstract
Development of Biomass Wastes Briquette Stove for Domestic Use
(Kenyatta University, 2015-11) Mulindi, Humphrey M.
Biomass energy in the form of woodfuel and charcoal contributes close to 68% of the total energy demand in Kenya. The continued depletion of biomass resources has led to the use of agricultural residue to supplement energy needs for domestic cooking. Biomass stoves used to burn these fuels in Kenya are characterized by high inefficiencies and high emissions that pose environmental and health risks to the users. This research aimed to reduce biomass fuels consumption, reduce fuel indoor air pollution and deforestation. The project was carried out in two phases. First, in 2010 there was a survey of the status of bio-waste fuel briquetting technology in Nairobi and peri- urban Nairobi area. Secondly, a semi-gasification stove that uses briquettes derived from solid organic waste material was developed. The survey involved an interview of 63 briquette producers identified from desktop research within Nairobi and its per-urban areas, out of which 40, 15 and 8 were community based groups, NGOs and briquette producing companies respectively. A total 175 briquette users were randomly selected and interviewed from a list of briquette consumers given by briquette producers interviewed. Based on the results of the field survey, a semi- gasifier stove was designed and constructed. The semi-gasifier stove construction took place at Kenyatta University Engineering workshops. Tests were done to determine the thermal efficiency, specific fuel consumption and power of the stove. Standard stove emission test were conducted using KANE 455. About 33% of the briquettes made were from a mixture of charcoal dust and paper. Characterization of briquettes was based on their calorific value, percentage moisture, volatile matter, ash content, fragility of briquettes and burning characteristics. The calorific value of briquettes was between 14.21kJ/g and 24.64kJ/g for water hyacinth based and carbonized baggasse briquettes respectively. Moisture content of the briquettes ranged from 5.8% to 14% for carbonized baggase briquettes and for charcoal with bean stocks plus paper respectively. Carbonized coffee husks with starch binder had the lowest volatile matter of 10.1% while coffee husks with paper had the highest volatile matter of 71.2%. Briquettes made from sawdust and paper had the lowest ash content of 8.8% whereas briquettes from charcoal dust and clay had ash content of 66.8%. The percentage fragility of the briquettes sampled ranged from 0.1% to 80.4% for charcoal with clay and sawdust with paper respectively. The semi-gasifier stove had an average thermal efficiency of 30%±3 and an average fire power of 2.5kW±1.5. The emission testing of the stove using KANE 455 gas analyzer for CO, CO2 and CO/CO2 ratios showed the average values of 0.2067 ± 0.0259ppm, 2.6771 ± 0.13307ppm and 2.31374 ± 0.13184 respectively. Economic analysis show that if a family were to invest in the stove, they would save about Ksh 30($ 0.35), Ksh 1000 ($11.7) and Ksh 2200 ($25.8) ,if their initial cooking stove is open fire, kerosene stove and charcoal stove respectively. If a family claimed carbon credits by using the stove, it would be entitled to up to Ksh 8,000 ($94.1) during its entire life. For mass production the stove would retail at an average of Ksh 800 ($9.4). The prototype stove developed was found to meet the intended need for being used by fuel briquettes.
Enhancing Asset Security by Integrating Internet of Things on Non-Powered Assets
(Kenyatta University, 2023) Mwema, Joshua Mueke; John Kandiri
Advancements in the field of asset security have emerged as a result of the Internet of Things (IoT)’s explosive expansion. Several innovations have featured systems ranging from smart home automation to asset tracking and monitoring. The systems use different technologies such as Radio Frequency Identification (RFID), Global System for Mobile communications (GSM), General Packet Radio Services (GPRS), Wireless Fidelity (Wi-Fi) among others to secure the assets. As technology improve, intruders also update themselves with intrusion skills and knowledge, and this has led to the emergence of more sophisticated challenges in terms of asset security. To curb these challenges, this project proposes an asset security system that will be comprised of IoT integration, real-time alerts, and power autonomy for remote monitoring of the non-powered assets. Besides, a tamper-proof unit will be used to detect when the asset has been broken into, which will prevent intruders from compromising the security system inside the asset. In that case, a notification will be sent to the asset owner through the GSM SMS functionality. Further, based on the distance from the pre-set distance, the device will map the value to asset security states namely; zero to 0.5, 0.5 to 1 and greater than 1 where they will be interpreted as low, medium, and high-level security threat states respectively. This research project will bring on-board geofencing and remote-control capabilities to asset security systems so that the location of a device can be tracked when it is relocated.
Enhancing efficiency of biomass carbonization for high Quality and quantity charcoal production by using Metallic clay insulated kiln
(Kenyatta University, 2014) Mulei, Fredrick Mwange; Laichena, Justus K.; Okwach, Silvester
The main objective of this study was to construct a metallic clay insulated kiln to enhance charcoal yield in quality and quantity. This research project aims at improving the charcoal quality in terms of calorific value and smoke - free, and maximum yield of charcoal (per kilogram of biomass substrate loaded). The quantity of charcoal harvested per kilogram of primary four biomass materials loaded as substrates was determined in four tests in each substrate. The main objective was to develop metallic clay insulated kiln with high efficiency, economical and environmentally friendly. metallic clay insulated kiln would offer solution to the problems of low efficiencies of existing charcoal kilns, for example, Traditional Earth Mould Kiln, Mark V. Kiln, Beehive kiln, and Half Orange kiln, among others. These kilns have efficiency of 10%, 31%, 32% and 28.8%, respectively, compared to the achieved 40.85 ± 5.04 % for this metallic clay insulated kiln. In this research a metallic clay insulated kiln was constructed and tested. The major aspect is that a proto type 0.15 m' drum was used to provide feedstock housing. This was tightly covered such that no fraction of feedstock was burned to provide carbonization heat. Clay insulation housing was constructed while the drum was provided with metallic stands and each of the substrates was loaded in the drum. Insulation wall made of clay/mud was constructed to prevent heat loss from the drums and combustion area. The quantity of charcoal produced from the metallic clay insulated kiln was compared with the quantity of wood substrate used. To determine the quality of the charcoal (in terms of calorific value and smoke), universal standard charcoal testing method was used that is Water Boiling test. The quality of charcoal produced from the kiln was then compared with charcoal produced from other different existing kilns in the literature. The data analysis was done by the help of statistical package for social science (SPSS) and Microsoft Excel. In conclusion, efficiency of charcoal production should be emphasized so as to make the practice of charcoal production sustainable by use of metallic clay insulated kiln. It was also found that metallic clay insulated improved kiln had higher efficiency (40.85 ± 5.04 %) than existing kilns such as Beehive, Mark V, Half Orange, Traditional Earth Mould, drum kilns adopted by FAO and others. Adoption! utilization of the metallic clay insulated kiln (with high efficiency as obtained in this research project (40.85 ± 5.04 %)) will reduce/cut-off the problems experienced in use of the _existing low - efficiency kilns. It is both an economical benefit, and environmental friendly. Charcoal production using improved charcoal kilns with high efficiency would give much higher yields of charcoal of excellent quality (in sense of HHV and smoke-free). This can make the practice very profitable, and users will have motivation for sustainable production of charcoal.
A Hybrid Model for Text Summarization using Natural Language Processing
(Kenyatta University, 2022) Karanja, James Mugi; Eliud E.O. Obere
Small and medium sized businesses are key aspects of economic progress in every country and their internationalization is thought to be essential to the growth of the economy and firm growth. Micro, small, and medium-sized businesses have endured a great deal of failure and death in Kenya, despite the fact that they are crucial for increasing employment, capital base, and revenue. The performance of the small and medium sized enterprises in Kenya’s internationalization remains dismal because more focus by the government has been on foreign investors. This study sought to establish the key internationalization strategies that impact Micro and SMEs performance in Nairobi City County. The general objective of the study was to investigate effects of internationalization strategies and performance of micro, small and medium sized manufacturing enterprises in Nairobi City County. The specific objectives of this study therefore were to determine the effect of managerial competence, network structure, operating network and international market knowledge on performance of Micro, Small and Medium size Manufacturing Enterprises in Nairobi City County, Kenya. The study was anchored on study: Stakeholders’ Theory, Tradition Foreign Direct Investment Theory, Stage Model Theory and The Network Approach. This study used a descriptive survey design. The target population was 262 exporting micro small and medium sized manufacturing enterprises that are located in Nairobi City, County. A sample size of 53 potential respondents were randomly selected representing 20% of the total population as justified under sampling technique. The key source of data was primary, obtained using structured questionnaires whose reliability and validity were ascertained. Descriptive and inferential analysis were the two methods that were utilized. The study found that managerial competence, operating environment and international marketing knowledge had significant effect on MSMEs performance. Managerial competence is thought to be an important determinant of internationalization for MSMEs. The study recommended global partnership to enhance global experience and innovation capability on SMEs' export success.
Impact of Integrated Mandatory E – Government on Public Service Kenya; Case of Siaya County Government
(Kenyatta University, 2023-08) Miganda, Gloria Amondi
Kenyan citizens have always needed and demanded better service in terms of service provision from their government. Through its ministries and agencies, the government has listened and adopted an integrated e-government system to aid technocrats in providing efficient and effective services. The Government of Kenya adopted and implemented IFMIS (Integrated Financial Management Information System), GHRIS (Government Human Resource Information System), plus IPPD (Integrated Payroll and Personnel Database), which are, Integrated e-government systems that have been in use in government agencies, parastatals, and ministries. These information systems amalgamated different government activities into single units, making the work of public servants easier. Adopting the e-government mentioned above is intended to cure the problems of maladministration, corruption, inefficiency, and ineffective service delivery to the people. The issues discussed above persist to date, necessitating this study. This research sought to examine the Impact of Integrated mandatory e-government in public service; Case of the Siaya County Government. It intended to establish the impact of IFMIS, GHRIS, and IPPD and outline the benefits and challenges of the software systems and how to mitigate them. This study adopted a descriptive survey design, in addition to a sample size of 108 drawn from the population. Seventy-one (71) individuals answered the questions in the questionnaire, representing a reaction frequency of sixty-six (66) percent. Data collection was done using a structured questionnaire, and SPSS software aided in data analysis. Outcomes of the research indicated that the dependent variables of this research had a substantial positive influence on adoption of e-government services in Kenya’s devolved system of governance. However, statistical modelling using the regression analysis while controlling for confounding variable presented that the dependent variables had a positive influence on the adoption of the e-Government. Given the outcomes of this research, it is recommended that County Government of Siaya need to enhance the dependant variables areas in the workplace in order to improve the adoption of e-Government by its staff.

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