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Papers by Patrick Wafula Kuloba
Acta Amazonica, 2013
Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas con... more Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas concentrações, é tóxico para os seres vivos. A remoção de cobre de efluentes industriais é realizada por diversos processos como a adsorção. Neste trabalho mostrou-se o resultado da adsorção de cobre (II) em carvão ativado de caroço de buriti carbonizado a 400 °C e ativado a 900 °C. O carvão ativado foi caracterizado em termos de área específica, tamanho dos poros, densidades aparente e real, porosidade, microscopia eletrônica de varredura, conteúdo de cinzas, pH, umidade, carbono fixo e grupos funcionais de superfície. O estudo de equilíbrio de adsorção avaliou a influência do diâmetro das partículas do carvão, do tempo de contato adsorvente/adsorbato, do pH e da concentração inicial da solução de cobre (II) sobre a remoção de cobre (II). Com base nos resultados, concluiu-se que há uma maior eficiência de remoção de cobre (II) para diâmetro < 0,595 mm, tempo de contato de 300 minutos, p...
This accomplishment would not have been possible if it wasn't for the dedication of my supervisor... more This accomplishment would not have been possible if it wasn't for the dedication of my supervisors. I wish therefore to express my utmost heartfelt sincere thanks to my supervisors, Prof. Lawrence Gumbe, Prof. Michael Okoth and Dr. Ayub Gitau for their enormous caring guidance and useful suggestions during the period of this study. My sincere appreciation also goes to Prof. Martin Obanda and Mr. Fredrick Munga for helping me with the analysis of the samples respectively. I also wish to express my sincere thanks to the National Council for Science and Technology (NACOSTI) Board and the Chief Executive Officer Prof. Abdirazak Shaukut for providing me with funds that enabled me to carry out the research. My sincere gratitude also goes to KIRDI management for facilitating me to carry out the research in KIRDI's Engineering Development and Service Centre (EDSC).
Open Agriculture, 2022
Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The ob... more Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer's postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R 2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination.
Open Journal of Optimization, 2021
Due to global completion in the automotive industry, productivity improvement is vital in these i... more Due to global completion in the automotive industry, productivity improvement is vital in these industries. In automotive assembly lines, productivity loses are attributed to bottlenecks, long processing time in workstations and underutilization of resources. The purpose of this research is to evaluate the performance of the production system, analyze the bottlenecks in different parts of the workstation, their capacity and constraints. Also, develop different scenarios for improvement. To achieve this objective, a simulation model was developed using Arena Software to analyze bottlenecks in each workstation. The analysis was based on the queue in the system to identify the longest queue in workstations. After analysis of the assembly line, the result showed that the longest waiting time observed is cab preparation and drop, bumper, engine subassembly fitment of soundproof with respective numbers 14.4, 13.97, 13.00, 13.70 minutes, with respective average number waiting of 24.87%, 17.57%, 25.91% and 23.39%. Using different scenarios for the improvement of the production line showed that the waiting time observed in-cab preparation and drop, bumper, engine subassembly, fitment of soundproof has greatly reduced for the two workstations added and three operators respectively from 14.4 to 3.97 and 3.1, from 13.97 to 3.77 and 2.48, from 13.00 to 4.21 and 3.83, from 13.70 to 0.00 and 2.37 minutes, with respective average number waiting from 24.87% to 5% and 2%, from 17.57% to 5% and 0.9%, from 25.91% to 5% and 4%, and from 23.39% to 0.00% and 3%. To conclude the research study was able to demonstrate the modelling approach using simulation for analysis of a production line assembly. The contribution of this research was so enormous, this study has improved the output production up to 144%.
Journal of Engineering in Agriculture and the Environment, 2021
Journal of Engineering in Agriculture and the Environment, 2021
International Journal of Engineering and Advanced Technology, 2019
Augmented Reality (AR) systems present a technological platform that allows a harmonious integrat... more Augmented Reality (AR) systems present a technological platform that allows a harmonious integration of the real and virtual worlds, structured with endless capabilities in its application. With the rise of information technology, AR has made a significant contribution to industrial applications, namely: medicine, aviation, manufacturing, etc. This paper aims to provide dipper insightful on AR technology by investigating the current state-of-the-art of AR technology usage in the manufacturing industry encompassing quality control and maintenance. It describes how AR technology has been integrated into quality control and maintenance, current and available AR devices in use, and future research direction.
The Kenyan manufacturing sector mainly comprises of small and medium scale enterprises, whose ori... more The Kenyan manufacturing sector mainly comprises of small and medium scale enterprises, whose orientation for future survival cannot be guaranteed in view of a globalized market. The sector has been envisioned to play a key role in generation of employment opportunities for the Kenyan youths in Vision 2030 strategic plan. For this to succeed, it is necessary for the sector to begin adopting a system that helps them in consistent with the ever changing factors of trade on the world market to achieve success. A known manufacturing system is here proposed to aid the Kenyan manufacturing sector to achieve global competiveness. Next Generation Manufacturing (NGM) is a method of manufacturing that follows a systematic, focused approach and continuously measures the individual results of a manufacturing business against a variety of performance benchmarks. Its objective is principally to prepare manufacturing businesses to stand and carry on in the future generation. Data on performance of...
Abstract Green tealeaf was withered in Low Temperature Nitrogen Plasma (LTNP) environment. The re... more Abstract Green tealeaf was withered in Low Temperature Nitrogen Plasma (LTNP) environment. The result indicated LTNP environment reduced Polyphenols during withering. The reduction was caused by Polyphenol oxidation to other compounds due to the presence of oxygen. The rate of reduction of polyphenols ((dP_c)/dt) decreased with increasing withering time and as the remaining Polyphenol content (Pc) in the green tealeaf decreased. In both cases, ((dP_c)/dt) followed exponential type of function with coefficient of correlations of 0.943 and 0.899 respectively. The relationship of Pc and t followed an inverse proportionality function with coefficient of correlation of 0.843. Statistical analysis using MS-Excel of the experimental data indicated the mean (dP_c)/dt in the green tealeaf during withering in LTNP environment was 7.522mg/h. The mathematical model equations for (dP_c)/dt in green tealeaf against t, (dP_c)/dt against Pc and Pc against t were as follows,(dP_c)/dt = 94.00e^(-0.43...
International Journal of Food Science & Technology, 2013
Low-temperature nitrogen plasma (LTNP) was used to wither green tea leaf to study its effect on t... more Low-temperature nitrogen plasma (LTNP) was used to wither green tea leaf to study its effect on the polyphenol content. Using a dielectric barrier discharge chamber to provide the LTNP environment, green tea leaf was withered at various withering times. Made tea samples indicated that LTNP had an effect on polyphenol content. The highest polyphenol content of 78.56 mg g À1 in made tea was attained in 1 h after which it showed a decreasing trend with increasing retention time. For comparison purposes, green tea leaf was also withered in nonplasma environments. Highest polyphenol content of 133.4 mg g À1 in made tea was attained in a sample withered anaerobically in nitrogen gas at room temperature and atmospheric pressure for 18 h. In another sample, green tea leaf was directly macerated and dried without withering and fermenting and had polyphenol content of 101.91 mg g À1 in made tea. These contents were compared with green tea 4, purple tea and oolong tea that are currently manufactured in Kenya.
This accomplishment would not have been possible if it wasn't for the dedication of my supervisor... more This accomplishment would not have been possible if it wasn't for the dedication of my supervisors. I wish therefore to express my utmost heartfelt sincere thanks to my supervisors, Prof. Lawrence Gumbe, Prof. Michael Okoth and Dr. Ayub Gitau for their enormous caring guidance and useful suggestions during the period of this study. My sincere appreciation also goes to Prof. Martin Obanda and Mr. Fredrick Munga for helping me with the analysis of the samples respectively. I also wish to express my sincere thanks to the National Council for Science and Technology (NACOSTI) Board and the Chief Executive Officer Prof. Abdirazak Shaukut for providing me with funds that enabled me to carry out the research. My sincere gratitude also goes to KIRDI management for facilitating me to carry out the research in KIRDI's Engineering Development and Service Centre (EDSC).
Acta Amazonica, 2013
Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas con... more Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas concentrações, é tóxico para os seres vivos. A remoção de cobre de efluentes industriais é realizada por diversos processos como a adsorção. Neste trabalho mostrou-se o resultado da adsorção de cobre (II) em carvão ativado de caroço de buriti carbonizado a 400 °C e ativado a 900 °C. O carvão ativado foi caracterizado em termos de área específica, tamanho dos poros, densidades aparente e real, porosidade, microscopia eletrônica de varredura, conteúdo de cinzas, pH, umidade, carbono fixo e grupos funcionais de superfície. O estudo de equilíbrio de adsorção avaliou a influência do diâmetro das partículas do carvão, do tempo de contato adsorvente/adsorbato, do pH e da concentração inicial da solução de cobre (II) sobre a remoção de cobre (II). Com base nos resultados, concluiu-se que há uma maior eficiência de remoção de cobre (II) para diâmetro < 0,595 mm, tempo de contato de 300 minutos, p...
This accomplishment would not have been possible if it wasn't for the dedication of my supervisor... more This accomplishment would not have been possible if it wasn't for the dedication of my supervisors. I wish therefore to express my utmost heartfelt sincere thanks to my supervisors, Prof. Lawrence Gumbe, Prof. Michael Okoth and Dr. Ayub Gitau for their enormous caring guidance and useful suggestions during the period of this study. My sincere appreciation also goes to Prof. Martin Obanda and Mr. Fredrick Munga for helping me with the analysis of the samples respectively. I also wish to express my sincere thanks to the National Council for Science and Technology (NACOSTI) Board and the Chief Executive Officer Prof. Abdirazak Shaukut for providing me with funds that enabled me to carry out the research. My sincere gratitude also goes to KIRDI management for facilitating me to carry out the research in KIRDI's Engineering Development and Service Centre (EDSC).
Open Agriculture, 2022
Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The ob... more Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer's postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R 2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination.
Open Journal of Optimization, 2021
Due to global completion in the automotive industry, productivity improvement is vital in these i... more Due to global completion in the automotive industry, productivity improvement is vital in these industries. In automotive assembly lines, productivity loses are attributed to bottlenecks, long processing time in workstations and underutilization of resources. The purpose of this research is to evaluate the performance of the production system, analyze the bottlenecks in different parts of the workstation, their capacity and constraints. Also, develop different scenarios for improvement. To achieve this objective, a simulation model was developed using Arena Software to analyze bottlenecks in each workstation. The analysis was based on the queue in the system to identify the longest queue in workstations. After analysis of the assembly line, the result showed that the longest waiting time observed is cab preparation and drop, bumper, engine subassembly fitment of soundproof with respective numbers 14.4, 13.97, 13.00, 13.70 minutes, with respective average number waiting of 24.87%, 17.57%, 25.91% and 23.39%. Using different scenarios for the improvement of the production line showed that the waiting time observed in-cab preparation and drop, bumper, engine subassembly, fitment of soundproof has greatly reduced for the two workstations added and three operators respectively from 14.4 to 3.97 and 3.1, from 13.97 to 3.77 and 2.48, from 13.00 to 4.21 and 3.83, from 13.70 to 0.00 and 2.37 minutes, with respective average number waiting from 24.87% to 5% and 2%, from 17.57% to 5% and 0.9%, from 25.91% to 5% and 4%, and from 23.39% to 0.00% and 3%. To conclude the research study was able to demonstrate the modelling approach using simulation for analysis of a production line assembly. The contribution of this research was so enormous, this study has improved the output production up to 144%.
Journal of Engineering in Agriculture and the Environment, 2021
Journal of Engineering in Agriculture and the Environment, 2021
International Journal of Engineering and Advanced Technology, 2019
Augmented Reality (AR) systems present a technological platform that allows a harmonious integrat... more Augmented Reality (AR) systems present a technological platform that allows a harmonious integration of the real and virtual worlds, structured with endless capabilities in its application. With the rise of information technology, AR has made a significant contribution to industrial applications, namely: medicine, aviation, manufacturing, etc. This paper aims to provide dipper insightful on AR technology by investigating the current state-of-the-art of AR technology usage in the manufacturing industry encompassing quality control and maintenance. It describes how AR technology has been integrated into quality control and maintenance, current and available AR devices in use, and future research direction.
The Kenyan manufacturing sector mainly comprises of small and medium scale enterprises, whose ori... more The Kenyan manufacturing sector mainly comprises of small and medium scale enterprises, whose orientation for future survival cannot be guaranteed in view of a globalized market. The sector has been envisioned to play a key role in generation of employment opportunities for the Kenyan youths in Vision 2030 strategic plan. For this to succeed, it is necessary for the sector to begin adopting a system that helps them in consistent with the ever changing factors of trade on the world market to achieve success. A known manufacturing system is here proposed to aid the Kenyan manufacturing sector to achieve global competiveness. Next Generation Manufacturing (NGM) is a method of manufacturing that follows a systematic, focused approach and continuously measures the individual results of a manufacturing business against a variety of performance benchmarks. Its objective is principally to prepare manufacturing businesses to stand and carry on in the future generation. Data on performance of...
Abstract Green tealeaf was withered in Low Temperature Nitrogen Plasma (LTNP) environment. The re... more Abstract Green tealeaf was withered in Low Temperature Nitrogen Plasma (LTNP) environment. The result indicated LTNP environment reduced Polyphenols during withering. The reduction was caused by Polyphenol oxidation to other compounds due to the presence of oxygen. The rate of reduction of polyphenols ((dP_c)/dt) decreased with increasing withering time and as the remaining Polyphenol content (Pc) in the green tealeaf decreased. In both cases, ((dP_c)/dt) followed exponential type of function with coefficient of correlations of 0.943 and 0.899 respectively. The relationship of Pc and t followed an inverse proportionality function with coefficient of correlation of 0.843. Statistical analysis using MS-Excel of the experimental data indicated the mean (dP_c)/dt in the green tealeaf during withering in LTNP environment was 7.522mg/h. The mathematical model equations for (dP_c)/dt in green tealeaf against t, (dP_c)/dt against Pc and Pc against t were as follows,(dP_c)/dt = 94.00e^(-0.43...
International Journal of Food Science & Technology, 2013
Low-temperature nitrogen plasma (LTNP) was used to wither green tea leaf to study its effect on t... more Low-temperature nitrogen plasma (LTNP) was used to wither green tea leaf to study its effect on the polyphenol content. Using a dielectric barrier discharge chamber to provide the LTNP environment, green tea leaf was withered at various withering times. Made tea samples indicated that LTNP had an effect on polyphenol content. The highest polyphenol content of 78.56 mg g À1 in made tea was attained in 1 h after which it showed a decreasing trend with increasing retention time. For comparison purposes, green tea leaf was also withered in nonplasma environments. Highest polyphenol content of 133.4 mg g À1 in made tea was attained in a sample withered anaerobically in nitrogen gas at room temperature and atmospheric pressure for 18 h. In another sample, green tea leaf was directly macerated and dried without withering and fermenting and had polyphenol content of 101.91 mg g À1 in made tea. These contents were compared with green tea 4, purple tea and oolong tea that are currently manufactured in Kenya.
This accomplishment would not have been possible if it wasn't for the dedication of my supervisor... more This accomplishment would not have been possible if it wasn't for the dedication of my supervisors. I wish therefore to express my utmost heartfelt sincere thanks to my supervisors, Prof. Lawrence Gumbe, Prof. Michael Okoth and Dr. Ayub Gitau for their enormous caring guidance and useful suggestions during the period of this study. My sincere appreciation also goes to Prof. Martin Obanda and Mr. Fredrick Munga for helping me with the analysis of the samples respectively. I also wish to express my sincere thanks to the National Council for Science and Technology (NACOSTI) Board and the Chief Executive Officer Prof. Abdirazak Shaukut for providing me with funds that enabled me to carry out the research. My sincere gratitude also goes to KIRDI management for facilitating me to carry out the research in KIRDI's Engineering Development and Service Centre (EDSC).