Alex Muumbo - Academia.edu (original) (raw)

Papers by Alex Muumbo

Journal of the Reports of the Japan Foundry Engineering Society Meeting, 2001

Journal of the Reports of the Japan Foundry Engineering Society Meeting, 2002

2020 IEEE PES/IAS PowerAfrica, 2020

A country's economic growth is largely dependent on the stability of its energy sector. The g... more A country's economic growth is largely dependent on the stability of its energy sector. The growth of Kenya's power sector is greatly supported by Vision 2030 development blueprint, which is geared at transforming the country into a “middle-income country that is able to provide a high quality of life to all of its citizens by the year 2030”. Though major investments have so far been made in the generation and transmission of power, the distribution sub-sector is yet to reap the full benefits due to a number of challenges ranging from financial to operation and maintenance. Transformers are key components of any power distribution network and despite their specified long operational life, they often fail within a short period of commissioning due to various reasons including vandalism. This has led to great losses to the power distribution sub-sector and consumers alike. This paper proposes an anti-theft system that uses machine learning technique to monitor the pylon's environs against vandals. Results of the study reveals that the system is capable of detecting human images with confidence levels between 68% and 97%.

Accurate prediction of downstream processing performance of a mineral ore is critical to resource... more Accurate prediction of downstream processing performance of a mineral ore is critical to resource evaluation and development decisions, where significant cost and productivity benefits can be realized through early determination of an ore’s properties and processing potential. This study aimed at investigating the chemical, qualitative and quantitative composition of raw iron ore from the deposits in Katse area (Mwingi North Constituency in Kitui County) which lies in the Mozambique mobile belt. The quality of the iron ore was evaluated to establish its suitability as a raw material for iron production in Kenya. Samples were obtained along the perimeter vertices and centre of a land parcel measuring 150m 2 with each excavation being 50cm length, 50 cm width and 500cm depth. Detailed studies were conducted to establish the composition and properties of the 5 samples. X-ray Diffraction (XRD), X-ray Fluorescence (XRF) and Atomic Absorption Spectrometry (AAS) techniques were employed in...

The research in this book aimed at investigating the chemical, qualitative and quantitative compo... more The research in this book aimed at investigating the chemical, qualitative and quantitative composition of raw iron ore from the deposits in Katse area, Mwingi North Constituency in Kitui County, Kenya. The results obtained indicates that Katse iron ores are of a high-grade magnetite and low hematite ore that can be profitably exploited for the production of iron. With other deposits from other parts of the country it can lead to setting up of steel plant in Kenya. This research work was made possible with funding from the National Council for Science and Technology (NACOSTI) Kenya. Lots of gratitude goes to the Ministry of Mining and GDC Co. Ltd for their assistance and allowing me to perform these experiments in their laboratories and not to forget the entire Moi University fraternity for their support and contribution in my research.

Most of the minerals found in Kenya still remain unexploited due to inadequate knowledge on their... more Most of the minerals found in Kenya still remain unexploited due to inadequate knowledge on their status, economic viability and requisite mining technologies. Importing metallic products such as lead, iron, zinc, copper etc. from other countries are very expensive despite Kenya's potential to exploit existing mineral resources. This study aimed at characterizing the selected mineral ore deposit from Katse area in Mwingi North Constituency in Kitui County, Kenya. The quality of the iron ore was evaluated to establish its suitability as a raw material for iron production in Kenya. Samples were obtained along the perimeter vertices and centre of a land parcel measuring 150m 2 with each excavation being 50cm length, 50 cm width and 500cm depth. Detailed studies were conducted to establish the composition and properties of the 5 samples. X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Atomic Absorption Spectrometry (AAS) and Petrography microscopy techniques were employed in the ...

Gears are used in various machines and industries for transportation and transmission of power. O... more Gears are used in various machines and industries for transportation and transmission of power. Other uses are in consumer electronics and many machines used in homes like the washing machines, electric drills and kitchen appliances. Gears come in different sizes ranging from a module of 0.5 to 100 mm. Currently there is a problem of accurately machining gears. This is due to inaccurate positioning of the blank and cutter. The objective of the study was to investigate and determine the appropriate way of producing quality and accurate gears most economically through the use of a circle as a substitute to involute profile in gear cutting. Two different gears of same dimensional characteristics were cut; one using a Computer Numerical Control machine utilizing circle profile and the other using conventional milling machine. Dimensional comparisons were made of the two cut gears against an actual involute profile to determine the margin of error. The circle involute profile made using ...

Kenya being an agricultural based economy produces vast amounts of agricultural bio-wa... more Kenya being an agricultural based economy produces vast amounts of agricultural bio-waste such as maize/corn stalks, rice and wheat straws, tea and coffee waste, sugarcane, banana and barley residues, sisal and cotton wastes as well as other forest residues. Most of these residues are regarded as of no immediate value hence they are wasted in the farms through burning or uncontrolled decay thus leading to nutrient leakage and eutrophication to the surrounding water bodies as well as contributing to odour and green-house gas emission through release of volatile and un-burnt hydrocarbons. The main objective of the researchwas to identify and develop biogas data variables in Kenya through a structured use of anaerobic digestion as a means of producing biogas from agricultural bio-waste including animal manure and crop residues. The short term target of the project was a phased development of well-defined/structured data variables suit...

This study sought to establish the challenges that the Reproductive Health Division (High Risk Pr... more This study sought to establish the challenges that the Reproductive Health Division (High Risk Pregnancy Clinic) at Moi Teaching and Referral Hospital based in Eldoret city, one of the two referral hospitals in Kenya, faces in adopting e-medical consultation as a way of improving maternal healthcare for patients with hypertension in pregnancy and reducing maternal deaths. In this paper, an outline of the strategies and pillars that the Clinic needs to adopt to embrace the use of e-medical consultation for the diagnosis, treatment and management of hypertension in pregnancy is presented. The survey conducted established that the division is still lagging behind and has not adopted the use of e-health, especially in the consultation sessions between the doctors and patients. The outlined strategies when implemented will help steer the Reproductive Health Division (High Risk Pregnancy Clinic) towards making healthcare services available in an efficient and effective way to expectant wo...

International Journal of Composite Materials, 2017

Plant fibre reinforced polymer composites, of which rice husks fibre reinforced polypropylene com... more Plant fibre reinforced polymer composites, of which rice husks fibre reinforced polypropylene composite is an example, are gaining prominence in engineering applications. Rice husks fibre reinforced polypropylene composite is ecofriendly, affordable and it is commonly used for light load structural and non structural components as well as structures. When fractured by rapidly or gradually applied loads, the rice husks fibre reinforced polypropylene composite cannot be economically repaired using traditional repair methods such as patch, bolted or scarf repair which would be applicable for leaf based as well as seed hair based fibre reinforced polymer composites. In this research, repair by refilling the damaged volume by injection of healing agents has been investigated. The repair helps in recovering part of initial impact strength lost during destructive testing. The composite test pieces were produced by injection moulding, cooled and tested for impact strengths. Impact strength ...

Africa is facing a serious crisis, due to serious environmental degradation arising from the econ... more Africa is facing a serious crisis, due to serious environmental degradation arising from the economic exploitation of its forests. A possible mitigating measure would be the development and provision of alternative cheap structural materials to replace timber. A good cheap alternative material is plant fibre reinforced polymer composite. Use of rice husk fiber reinforced polymer composite minimizes environmental pollution due to characteristic biodegradability [1]. Engineering materials fail when loaded beyond their elastic limit by fracture or plastic deformation. Structures made from healable materials have significantly prolonged service life [2]. A rice husk fibre reinforced polypropylene composite will undergo failure that involves crack initiation, propagation, and complete fracture [3]. Rice husk fibre reinforced polypropylene composite forms a chemical or frictional bond, whose strength largely depends on strength of the interface [4]. In this research, rice husk fibres were...

International Journal of Cast Metals Research, 2003

Attempts to develop appropriate semi-solid processing techniques to manufacture iron castings hav... more Attempts to develop appropriate semi-solid processing techniques to manufacture iron castings have not been successful despite extensive laboratory studies done in the past. This research aimed at producing equiaxed primary phase structure in gray cast iron slurry using a cooling plate under a mechanism explained by the crystal separation theory, and casting the slurry into moulds made from different materials to form cylindrical components. A boron nitride coating was applied onto the surface of the cooling plate to improve melt-flow and prevent the melt from sticking along the flow path. Primary particle size, number, volume fraction and hardness for cast components were investigated with respect to radial and longitudinal position along sectioned surfaces. Results on size, shape and grain count of graphite precipitated in the matrix are also discussed, comparing resulting component microstructure with that of castings made through conventional sand casting. Pouring of melt onto the cooling plate was done at a temperature a little higher than liquidus to initiate nucleation of primary phase along the flow path. The casting technique enhanced nucleation rate, leading to finer and higher volume fraction of the primary particles before the slurry flowed into the mould. The nature of flow along the cooling plate ensured that agglomeration of primary particles was minimized, resulting in highly globular grains hence better mechanical properties.

International Journal of Cast Metals Research, 2002

The International Review of Research in Open and Distributed Learning, 2015

In this paper, we discuss the challenges experienced by Kenyan public universities in implementat... more In this paper, we discuss the challenges experienced by Kenyan public universities in implementation of e-learning and recommend possible solutions towards its successful implementation. In the last few years, most Kenyan public universities have adopted e-learning as a new approach to teaching and learning. However, the implementation challenges faced by these universities have continued to impact negatively on its effective utilization. This paper presents the findings from a survey of 148 staff of three Kenyan public universities who are currently using e-learning in blended mode approach. The purpose of this study was to investigate the challenges hindering the implementation of e-learning in Kenyan public universities. Data was collected through questionnaires, in-depth interviews and document analysis. The findings reveal that e-learning comes with some challenges that must be addressed by Kenyan public universities before successful implementation can be realized. However, th...

Journal of Energy Technologies and Policy, 2014

International Journal of Bioscience, Biochemistry and Bioinformatics, 2012

Minerals Engineering, 2012

MATERIALS TRANSACTIONS, 2003

International Journal of Cast Metals Research, 2004