2021
|
Ochieng’ Justus Maurice Juma Ogada, Maina Paul; Ahmed, Hassan Impact of COVID-19 pandemic on African indigenous vegetables value chain in Kenya (Journal Article) In: Agriculture & Food Security, 10 (1), pp. 1-10, 2021. @article{nokey,
title = {Impact of COVID-19 pandemic on African indigenous vegetables value chain in Kenya},
author = {Maurice Juma Ogada, Ochieng’ Justus, Maina Paul, Sikei Geophrey Omondi, Adero Nashon Juma, Evans Taracha and Hassan Ahmed },
url = {https://link.springer.com/content/pdf/10.1186/s40066-021-00328-3.pdf},
doi = {10.1186/s40066-021-00328-3},
year = {2021},
date = {2021-12-06},
journal = {Agriculture & Food Security},
volume = {10},
number = {1},
pages = {1-10},
abstract = {African indigenous vegetables are important for food security and nutrition, and income of the poor farm households. In the era of COVID-19, they are critical for boosting people’s immunity. Unfortunately, both production of and trade in these vegetables is likely to be severely affected by the pandemic},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
African indigenous vegetables are important for food security and nutrition, and income of the poor farm households. In the era of COVID-19, they are critical for boosting people’s immunity. Unfortunately, both production of and trade in these vegetables is likely to be severely affected by the pandemic |
Maren Radeny Maurice Juma Ogada, John Recha; Dawit, Solomon Adoption of complementary climate‑smart agricultural technologies: lessons from Lushoto in Tanzania (Journal Article) In: Agriculture & Food Security, 10 (1), pp. 1-10, 2021. @article{nokey,
title = {Adoption of complementary climate‑smart agricultural technologies: lessons from Lushoto in Tanzania},
author = {Maurice Juma Ogada, Maren Radeny, John Recha and Solomon Dawit},
url = {https://agricultureandfoodsecurity.biomedcentral.com/track/pdf/10.1186/s40066-021-00321-w.pdf},
doi = {10.1186/s40066-021-00321-w},
year = {2021},
date = {2021-11-11},
journal = {Agriculture & Food Security},
volume = {10},
number = {1},
pages = {1-10},
abstract = {Background
Agriculture is important for economic growth and development in many countries in Sub-Saharan Africa, including Tanzania. However, agricultural production and productivity remain relatively low, with significant yield gaps attributed to factors such as limited access to and low adoption of appropriate agricultural technologies, and climate-related risks resulting from climate variability and change. This paper explores the drivers of adoption of climate-smart agricultural (CSA) technologies and practices, taking into account the complementarity among agricultural technologies and heterogeneity of the farm households, using data from Lushoto in Tanzania.
Methods
We use a Multivariate Probit analysis of cross-sectional data collected from 264 smallholder farmers in Lushoto—a climate hotspot in Tanzania—to understand the drivers of household decisions to adopt CSA technologies and practices. The technologies included diversification of multiple stress (drought, floods, pests, diseases)-tolerant crop varieties, use of fertilizers, and application of herbicides and pesticides. The Multivariate Probit model was preferred as it takes into account the inter-relationships of the technologies as well as heterogeneity of the smallholder farmers for more robust estimates. The independent variables used in the analysis included household socio-economic factors such as the relative importance of crop and livestock enterprises, household land size, social capital, access to agricultural credit and weather information, previous experience with fertilizer use and household characteristics (age, education and gender of household head, and household size).
Results
About 63% of the households diversified their crop enterprises, shifting to improved resilient crops and crop varieties. Another 37% adopted fertilizers, while 38% applied pesticides and herbicides. Conditional on the unobservable heterogeneity effects, the results show that household adoption decisions on diversification of multiple stress-tolerant crops and crop varieties, fertilizer, and pesticides and herbicides are complementary. In addition, the results confirm existence of unobserved heterogeneity effects leading to varying impact of the explanatory variables on adoption decisions among farmers with similar observable characteristics.
Conclusions
The findings indicate that any effective CSA technology adoption and diffusion strategies and policies should take into account the complementarity of the technologies and heterogeneity of the smallholder farmers. Therefore, inter-related technologies should be promoted as a package or bundled while taking into consideration household and farm-level constraints to adoption.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Agriculture is important for economic growth and development in many countries in Sub-Saharan Africa, including Tanzania. However, agricultural production and productivity remain relatively low, with significant yield gaps attributed to factors such as limited access to and low adoption of appropriate agricultural technologies, and climate-related risks resulting from climate variability and change. This paper explores the drivers of adoption of climate-smart agricultural (CSA) technologies and practices, taking into account the complementarity among agricultural technologies and heterogeneity of the farm households, using data from Lushoto in Tanzania.
Methods
We use a Multivariate Probit analysis of cross-sectional data collected from 264 smallholder farmers in Lushoto—a climate hotspot in Tanzania—to understand the drivers of household decisions to adopt CSA technologies and practices. The technologies included diversification of multiple stress (drought, floods, pests, diseases)-tolerant crop varieties, use of fertilizers, and application of herbicides and pesticides. The Multivariate Probit model was preferred as it takes into account the inter-relationships of the technologies as well as heterogeneity of the smallholder farmers for more robust estimates. The independent variables used in the analysis included household socio-economic factors such as the relative importance of crop and livestock enterprises, household land size, social capital, access to agricultural credit and weather information, previous experience with fertilizer use and household characteristics (age, education and gender of household head, and household size).
Results
About 63% of the households diversified their crop enterprises, shifting to improved resilient crops and crop varieties. Another 37% adopted fertilizers, while 38% applied pesticides and herbicides. Conditional on the unobservable heterogeneity effects, the results show that household adoption decisions on diversification of multiple stress-tolerant crops and crop varieties, fertilizer, and pesticides and herbicides are complementary. In addition, the results confirm existence of unobserved heterogeneity effects leading to varying impact of the explanatory variables on adoption decisions among farmers with similar observable characteristics.
Conclusions
The findings indicate that any effective CSA technology adoption and diffusion strategies and policies should take into account the complementarity of the technologies and heterogeneity of the smallholder farmers. Therefore, inter-related technologies should be promoted as a package or bundled while taking into consideration household and farm-level constraints to adoption. |
Network, Inter Region Economic The Future of Africa in the Post-COVID-19 World (Book) 2021, Inter Region Economic Network, 2021, ISBN: 978-9914-708-80-6. @book{nokey,
title = {The Future of Africa in the Post-COVID-19 World},
author = {Inter Region Economic Network},
editor = {Nashon, Juma Adero and Josephat, Juma},
url = {https://ir.ttu.ac.ke/xmlui/bitstream/handle/123456789/64/The%20Future%20of%20Africa%20in%20the%20Post%20Pandemic%20World%20Final%20Draft%2020210405.pdf?sequence=1&isAllowed=y},
doi = {https://ir.ttu.ac.ke/xmlui/handle/123456789/64},
isbn = {978-9914-708-80-6},
year = {2021},
date = {2021-07-06},
publisher = {Inter Region Economic Network},
edition = {2021},
abstract = {Off the hundreds of pages of this book are key messages from fourteen authors whose revised contributions were accepted for publication after blind peer reviews. The authors represent various universities, research institutes, industries and independent voices from Eastern Africa, Southern Africa, and North America. The chapters are grouped under six matching thematic areas. The themes range from critical lessons at the interface of science and policy that COVID-19 presents African leaders, addressing agri-food systems and climate change, geopolitics and geoeconomics, to the urgency of a new economic order for Africa. The opening section covers disaster-governance lessons from multiscale COVID-19 models. The editor shares key lessons on disaster governance from the COVID-19 experience in the first chapter. The lessons accrued from a year-long study and modelling of COVID-19 trends at scale across thirty-two representative countries, from Africa (16) and the rest of the world (16). These models have been shared at scientific forums and in the public media including Citizen TV, the key emphasis being on ensuring data integrity and efficient testing, tracing, timing, trust building, transparency, training, and transdisciplinary research to effectively contain the pandemic. The chapter advances scientific thinking to give context to the book, challenging African leaders to the new thinking required for improved governance in a post-pandemic world. The author positions human capital and technological development at the core of the systemic change essential to achieving a healthy science-policy interface to propel African countries to higher ranks of global competitiveness. The second section covers post-pandemic agenda for education, skills development and youth. The opening chapter has a compelling message on talent management, borderless engagement of Africa’s highly skilled diaspora in skills transfer, and targeted skilling of the African youth to enhance employability and solve the growing unemployment problem on a continent with a youth bulge. The chapter draws on the diverse cross-country and cross-sector experience gained while mentoring and interacting with African youth on education and skills development, climaxing in a youth-centric education and mentorship project conceived in 2018 under GraFA’s EMPOWER Good Governance and Social Entrepreneurship Programme for doctoral students at Freiberg University of Mining and Technology, Germany. The need to train African youth in ways that can equip them with adaptive resilience for career security as digital transformation and constraints of the pandemic threatened world reshape the labour market stands out. A mind transformation map to promote impactful and sustainable youth-centric innovation ecosystems is shared as well. In the third chapter, Elizabeth Obura draws on a Kenyan example to call the attention of education administrators and other education stakeholders to a transition from “spatial classrooms” to “borderless classrooms” as a post-pandemic coping strategy. She refers to the Diffusion of Innovations Theory to argue for The Future of Africa in the Post-COVID-19 World xiiian informed transition process, rolled out through stages aimed at ensuring an inclusive online learning experience across Africa. The third section addresses geopolitics and geoeconomics. Theo Neethling explores the post-pandemic future of an Africa highly indebted to China due to the more attractive Chinese loans (compared to Western lenders). The loans are used to finance capital-intensive (infrastructure) projects. He notes that China is an emerging world superpower and Africa’s largest bilateral creditor. Sitati Wasilwa then examines the possible trajectory that the Sino-African relations may assume in the post-COVID-19 era. He presents a mutual basis of engagement as the better option for Africa, hence the compelling need for the continent to enhance its bargaining power by implementing new integrated initiatives, such as the African Continental Free Trade Area (AfCFTA). Not to be overlooked under this thematic area is the governance of traditional knowledge systems as embedded in various cultural traditions of regions and local communities. Ethan Mudavanhu explores why traditional knowledge communities have not gained a competitive edge across international markets. He argues that indigenous-knowledge-centred licenses should demonstrate adequate suppleness so that, in a post-COVID-19 Africa, intellectual property standpoints of traditional communities can be effectively assimilated into a more commonly accepted legal charter. The fourth section throws the spotlight on multilateralism, a topic of growing interest especially due to the political philosophy of Trumpism and how it played out in the USA during the pandemic in 2020. Paul O. Odhiambo and Nashon J. Adero together assess the success of Africa’s multilateral and multi-pronged approach to containing COVID-19. The multilateral approach promises the collective bargaining power needed for debt relief arrangements and empowering the continent’s post-pandemic economic recovery. Investment in enabling governance and technologies for collaborative engagements driven by knowledge, quality research, and data is a critical outlook for a thriving Africa in the post-pandemic recovery period, given the foreseeable uncertainties in foreign direct investments (FDI) if the pandemic persists. The subsequent chapter under multilateralism is authored by Cynthia Chigwenya. She shares a different perspective that decries the fragmented approach to COVID-19 witnessed in Africa despite the emergence of multilateral organisations during the pandemic. She cites Tanzania and Madagascar as examples of non-conventional country responses to COVID-19. She further cites pre-existing trade wars between the USA and China among the factors that have worked against multilateralism. Food security, environmental sustainability and natural resources is the theme of the penultimate section of the book. Maurice Juma Ogada, Christine A. Onyango, and Nashon Juma Adero examine post-COVID-19 strategies for revamping agriculture and food systems in sub-Saharan Africa. They observe that the restrictions prompted by COVID-19 would adversely affect agricultural production and trade due to reduced availability of inputs, farm labour and markets. Compromised food xiv The Future of Africa in the Post-COVID-19 Worldsafety standards would also accompany the dwindling demand for food items due to reduced income. The raft of measures they recommend are: enhancing public health surveillance to ensure compliance with public health and food safety protocols; entrenching freer cross-border trade in food staples to enhance transfer from countries of surplus to countries of deficit for the benefit of both producers and consumers; providing economic stimulus to the agriculture sector to facilitate quick recovery; and implementing e-commerce among the smallholders. Ultimately, the post-pandemic future of agriculture and food systems in sub-Saharan Africa owes much to interventions in policy and technology, a fact they have emphasised while calling upon African governments to support agricultural transformation and broad-based food security through joint initiatives, such as the African Continental Free Trade Area (AfCFTA). Climate change has been with us before COVID-19. It remains a major threat to humanity and all other forms of life on the planet. Omondi R. Owino and Nashon J. Adero together discuss climate change in the next chapter as a wicked problem, which exhibits non-linearity, interconnectedness, and complexity. They hence call for a systems approach, with dedicated research and development (R&D), and further critique the efficiency of R&D spending, a critical factor in enhancing research outputs to address climate change and similar complex problems in Africa. The authors state that the observed reduction in carbon dioxide emissions by about 17% by early April 2020, mainly due to the global travel restrictions imposed after COVID-19, is not sustainable without giving climate change the urgency of resolve and gravitas comparable to the response COVID-19 has elicited globally. They assert that climate change remains a key long-term threat to humanity and the planet, hence deserving unwavering attention in Africa’s post-pandemic sustainability agenda. To reinforce their arguments, the authors introduce expanded pillars of sustainability, 7Ps instead of the traditional 3Ps. Tightly woven into the same fabric of environmental sustainability is forest conservation, forests being critical carbon sinks and climate regulators. Charles A. Khamala delves into what he terms “crimes against forestry” using the example of the Mau Forest ecosystem in Kenya. Referring to anthropocentrism and ecocentrism, he discusses the nagging case of the victims of forest destruction and forcible displacement in light of the law, stated as at February 2021. The pandemic, he avows, has worsened the consequences facing the displaced communities and made more urgent the need to address the intertwined environmental and human-rights problems in the Mau ecosystem. The final section presents free thoughts and informed opinions on COVID-19. Mary Njeri Kinyanjui starts off this section with an incisive piece on why Africa must strive for a new economic order. The COVID-19 pandemic gives Africa an opportunity to rethink its approaches to poverty and development models. She maintains that Africa must rethink its subscription to a skewed global economic order and financial prudence. The flow of thoughts on the urgency of rethinking and reinventing Africa’s approach to solving her own problems proceeds to the next The Future of Africa in the Post-COVID-19 World xvchapter by Sebastiano Rwengabo. He interrogates, at length, the topic of rethinking African security strategy amidst recurrent pandemics. He expounds on complex public health emergencies (CPHE) in the form of recent pandemics such as Ebola, Marburg, and COVID-19, which have exposed Africa’s soft underbelly. He argues that pandemics have acquired the destructive potentiality of conventional security threats and ought to be given as much policy and technical preparedness and attention as conventional security threats. He proposes a deliberate repositioning of Africa’s security calculus to offer solutions to a continent more threatened by pandemics than conventional security threats. In suppliment to Rwengabo’s notion of rethinking Africa’s strategic threats, Charles Mwewa shares a firm message: the post-Covid-19 Africa should be a revolutionary Africa, an Africa ready to harness people’s talents, at home and abroad, to build an Africa ready to fight for its dominant place in the community of nations. His summative message is captured under the title: The Re-Engaged Africa: Ushering in an Equal, Dependence-Free and Economically Self-Sufficient Africa. The respective chapters carry the authors’ contacts and profiles. Welcome to engage the chapters and authors for accelerated delivery on Africa’s development agenda, including Agenda 2063, as we usher in the post-COVID-19 era},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Off the hundreds of pages of this book are key messages from fourteen authors whose revised contributions were accepted for publication after blind peer reviews. The authors represent various universities, research institutes, industries and independent voices from Eastern Africa, Southern Africa, and North America. The chapters are grouped under six matching thematic areas. The themes range from critical lessons at the interface of science and policy that COVID-19 presents African leaders, addressing agri-food systems and climate change, geopolitics and geoeconomics, to the urgency of a new economic order for Africa. The opening section covers disaster-governance lessons from multiscale COVID-19 models. The editor shares key lessons on disaster governance from the COVID-19 experience in the first chapter. The lessons accrued from a year-long study and modelling of COVID-19 trends at scale across thirty-two representative countries, from Africa (16) and the rest of the world (16). These models have been shared at scientific forums and in the public media including Citizen TV, the key emphasis being on ensuring data integrity and efficient testing, tracing, timing, trust building, transparency, training, and transdisciplinary research to effectively contain the pandemic. The chapter advances scientific thinking to give context to the book, challenging African leaders to the new thinking required for improved governance in a post-pandemic world. The author positions human capital and technological development at the core of the systemic change essential to achieving a healthy science-policy interface to propel African countries to higher ranks of global competitiveness. The second section covers post-pandemic agenda for education, skills development and youth. The opening chapter has a compelling message on talent management, borderless engagement of Africa’s highly skilled diaspora in skills transfer, and targeted skilling of the African youth to enhance employability and solve the growing unemployment problem on a continent with a youth bulge. The chapter draws on the diverse cross-country and cross-sector experience gained while mentoring and interacting with African youth on education and skills development, climaxing in a youth-centric education and mentorship project conceived in 2018 under GraFA’s EMPOWER Good Governance and Social Entrepreneurship Programme for doctoral students at Freiberg University of Mining and Technology, Germany. The need to train African youth in ways that can equip them with adaptive resilience for career security as digital transformation and constraints of the pandemic threatened world reshape the labour market stands out. A mind transformation map to promote impactful and sustainable youth-centric innovation ecosystems is shared as well. In the third chapter, Elizabeth Obura draws on a Kenyan example to call the attention of education administrators and other education stakeholders to a transition from “spatial classrooms” to “borderless classrooms” as a post-pandemic coping strategy. She refers to the Diffusion of Innovations Theory to argue for The Future of Africa in the Post-COVID-19 World xiiian informed transition process, rolled out through stages aimed at ensuring an inclusive online learning experience across Africa. The third section addresses geopolitics and geoeconomics. Theo Neethling explores the post-pandemic future of an Africa highly indebted to China due to the more attractive Chinese loans (compared to Western lenders). The loans are used to finance capital-intensive (infrastructure) projects. He notes that China is an emerging world superpower and Africa’s largest bilateral creditor. Sitati Wasilwa then examines the possible trajectory that the Sino-African relations may assume in the post-COVID-19 era. He presents a mutual basis of engagement as the better option for Africa, hence the compelling need for the continent to enhance its bargaining power by implementing new integrated initiatives, such as the African Continental Free Trade Area (AfCFTA). Not to be overlooked under this thematic area is the governance of traditional knowledge systems as embedded in various cultural traditions of regions and local communities. Ethan Mudavanhu explores why traditional knowledge communities have not gained a competitive edge across international markets. He argues that indigenous-knowledge-centred licenses should demonstrate adequate suppleness so that, in a post-COVID-19 Africa, intellectual property standpoints of traditional communities can be effectively assimilated into a more commonly accepted legal charter. The fourth section throws the spotlight on multilateralism, a topic of growing interest especially due to the political philosophy of Trumpism and how it played out in the USA during the pandemic in 2020. Paul O. Odhiambo and Nashon J. Adero together assess the success of Africa’s multilateral and multi-pronged approach to containing COVID-19. The multilateral approach promises the collective bargaining power needed for debt relief arrangements and empowering the continent’s post-pandemic economic recovery. Investment in enabling governance and technologies for collaborative engagements driven by knowledge, quality research, and data is a critical outlook for a thriving Africa in the post-pandemic recovery period, given the foreseeable uncertainties in foreign direct investments (FDI) if the pandemic persists. The subsequent chapter under multilateralism is authored by Cynthia Chigwenya. She shares a different perspective that decries the fragmented approach to COVID-19 witnessed in Africa despite the emergence of multilateral organisations during the pandemic. She cites Tanzania and Madagascar as examples of non-conventional country responses to COVID-19. She further cites pre-existing trade wars between the USA and China among the factors that have worked against multilateralism. Food security, environmental sustainability and natural resources is the theme of the penultimate section of the book. Maurice Juma Ogada, Christine A. Onyango, and Nashon Juma Adero examine post-COVID-19 strategies for revamping agriculture and food systems in sub-Saharan Africa. They observe that the restrictions prompted by COVID-19 would adversely affect agricultural production and trade due to reduced availability of inputs, farm labour and markets. Compromised food xiv The Future of Africa in the Post-COVID-19 Worldsafety standards would also accompany the dwindling demand for food items due to reduced income. The raft of measures they recommend are: enhancing public health surveillance to ensure compliance with public health and food safety protocols; entrenching freer cross-border trade in food staples to enhance transfer from countries of surplus to countries of deficit for the benefit of both producers and consumers; providing economic stimulus to the agriculture sector to facilitate quick recovery; and implementing e-commerce among the smallholders. Ultimately, the post-pandemic future of agriculture and food systems in sub-Saharan Africa owes much to interventions in policy and technology, a fact they have emphasised while calling upon African governments to support agricultural transformation and broad-based food security through joint initiatives, such as the African Continental Free Trade Area (AfCFTA). Climate change has been with us before COVID-19. It remains a major threat to humanity and all other forms of life on the planet. Omondi R. Owino and Nashon J. Adero together discuss climate change in the next chapter as a wicked problem, which exhibits non-linearity, interconnectedness, and complexity. They hence call for a systems approach, with dedicated research and development (R&D), and further critique the efficiency of R&D spending, a critical factor in enhancing research outputs to address climate change and similar complex problems in Africa. The authors state that the observed reduction in carbon dioxide emissions by about 17% by early April 2020, mainly due to the global travel restrictions imposed after COVID-19, is not sustainable without giving climate change the urgency of resolve and gravitas comparable to the response COVID-19 has elicited globally. They assert that climate change remains a key long-term threat to humanity and the planet, hence deserving unwavering attention in Africa’s post-pandemic sustainability agenda. To reinforce their arguments, the authors introduce expanded pillars of sustainability, 7Ps instead of the traditional 3Ps. Tightly woven into the same fabric of environmental sustainability is forest conservation, forests being critical carbon sinks and climate regulators. Charles A. Khamala delves into what he terms “crimes against forestry” using the example of the Mau Forest ecosystem in Kenya. Referring to anthropocentrism and ecocentrism, he discusses the nagging case of the victims of forest destruction and forcible displacement in light of the law, stated as at February 2021. The pandemic, he avows, has worsened the consequences facing the displaced communities and made more urgent the need to address the intertwined environmental and human-rights problems in the Mau ecosystem. The final section presents free thoughts and informed opinions on COVID-19. Mary Njeri Kinyanjui starts off this section with an incisive piece on why Africa must strive for a new economic order. The COVID-19 pandemic gives Africa an opportunity to rethink its approaches to poverty and development models. She maintains that Africa must rethink its subscription to a skewed global economic order and financial prudence. The flow of thoughts on the urgency of rethinking and reinventing Africa’s approach to solving her own problems proceeds to the next The Future of Africa in the Post-COVID-19 World xvchapter by Sebastiano Rwengabo. He interrogates, at length, the topic of rethinking African security strategy amidst recurrent pandemics. He expounds on complex public health emergencies (CPHE) in the form of recent pandemics such as Ebola, Marburg, and COVID-19, which have exposed Africa’s soft underbelly. He argues that pandemics have acquired the destructive potentiality of conventional security threats and ought to be given as much policy and technical preparedness and attention as conventional security threats. He proposes a deliberate repositioning of Africa’s security calculus to offer solutions to a continent more threatened by pandemics than conventional security threats. In suppliment to Rwengabo’s notion of rethinking Africa’s strategic threats, Charles Mwewa shares a firm message: the post-Covid-19 Africa should be a revolutionary Africa, an Africa ready to harness people’s talents, at home and abroad, to build an Africa ready to fight for its dominant place in the community of nations. His summative message is captured under the title: The Re-Engaged Africa: Ushering in an Equal, Dependence-Free and Economically Self-Sufficient Africa. The respective chapters carry the authors’ contacts and profiles. Welcome to engage the chapters and authors for accelerated delivery on Africa’s development agenda, including Agenda 2063, as we usher in the post-COVID-19 era |
Adero, Nashon Juma Lessons from Modelling COVID-19 Scenarios in Kenya and Implications for Policy and Planning (Journal Article) In: Academia Letters, 2021. @article{nokey,
title = {Lessons from Modelling COVID-19 Scenarios in Kenya and Implications for Policy and Planning},
author = {Nashon Juma Adero},
url = {https://www.academia.edu/49919679/Lessons_from_Modelling_COVID_19_Scenarios_in_Kenya_and_Implications_for_Policy_and_Planning},
doi = {10.20935/al1862},
year = {2021},
date = {2021-07-01},
journal = {Academia Letters},
abstract = {This study examined and modelled the cross-country spread of the novel coronavirus diseaseof 2019 (COVID-19) in Africa and outside Africa, nally converging on Kenya as the coun-try of interest. A review of the models widely used to calibrate policy and strategic responsesconrmed the suitability of statistical models for predicting the spread of COVID-19, within a10%marginoferror. ThemainobjectivewastoprovideinsightsintothespreadofCOVID-19and present “what-if” scenarios in aid of policy simulations within a compact bandwidth of future scenarios, as required for policy and planning. The models proved resourceful in pre-dictingtheend-monthcaseswithin10%andthelikelihoodofsubsequentwaves, bothintermsof the magnitudes and the time of starting and attening. In the case of Kenya, the period of the waves tended to be approximately four months within the study period presented here,from April 2020 to May 2021. The key lessons imply a greater role of modelling, digitalisa-tion, geospatial and mapping technologies, and transdisciplinary research in the aspirationalfuture of disease and disaster governance},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study examined and modelled the cross-country spread of the novel coronavirus diseaseof 2019 (COVID-19) in Africa and outside Africa, nally converging on Kenya as the coun-try of interest. A review of the models widely used to calibrate policy and strategic responsesconrmed the suitability of statistical models for predicting the spread of COVID-19, within a10%marginoferror. ThemainobjectivewastoprovideinsightsintothespreadofCOVID-19and present “what-if” scenarios in aid of policy simulations within a compact bandwidth of future scenarios, as required for policy and planning. The models proved resourceful in pre-dictingtheend-monthcaseswithin10%andthelikelihoodofsubsequentwaves, bothintermsof the magnitudes and the time of starting and attening. In the case of Kenya, the period of the waves tended to be approximately four months within the study period presented here,from April 2020 to May 2021. The key lessons imply a greater role of modelling, digitalisa-tion, geospatial and mapping technologies, and transdisciplinary research in the aspirationalfuture of disease and disaster governance |
Ibrahim Ondicho, Bernard Alunda; Park, Nokeun Effect of Fe on the Hall-Petch relationship of (CoCrMnNi)100-x Fex medium-and high-entropy alloys (Journal Article) In: Intermetallics, 133 , pp. 107239, 2021. @article{nokey,
title = {Effect of Fe on the Hall-Petch relationship of (CoCrMnNi)100-x Fex medium-and high-entropy alloys},
author = {Ibrahim Ondicho, Bernard Alunda and Nokeun Park},
url = {https://ir.ttu.ac.ke/xmlui/bitstream/handle/123456789/56/Effect%20of%20Fe%20on%20the%20Hall-Petch%20relationship%20of%20%28CoCrMnNi%29100-x%20Fex%20medium-and%20high-entropy%20alloys.pdf?sequence=1&isAllowed=y},
doi = {http://ir.ttu.ac.ke/xmlui/handle/123456789/56},
year = {2021},
date = {2021-06-22},
urldate = {2021-06-22},
journal = {Intermetallics},
volume = {133},
pages = {107239},
abstract = {In the present study, a systematic investigation on the effect of Fe content on the Hall-Petch coefficient of (CoCrMnNi)100-x Fex (x =20, 40, 50, and 60) medium- and high-entropy alloys (M/HEAs) was carried out. The cold-rolled alloys were annealed at 900 ◦C and 1000 ◦C between 3 min and 10 h for recrystallization. Scanning electron microscope with a backscattered detector was used to obtain micrographs of recrystallized specimens for grain size calculation. Tensile testing was used to evaluate the mechanical properties of the alloys. The micro- structure showed that regardless of the alloy composition, the grain size was approximately similar when sub- jected to the same heat treatment condition. Moreover, all the alloys obeyed the classical Hall-Petch relationship. Friction stress (solid solution, SS strengthening) decreased with an increase of Fe content, which was attributed to weak lattice distortion caused by the reduction of the atomic size misfit. The Hall-Petch coefficient, which represents grain boundary (GB) strengthening, also decreases as the Fe content increases. A linear relationship between intrinsic stacking fault energy and Hall-Petch coefficient was found not to exist. However, it is proposed that the monotonic decrease of the Hall-Petch coefficient is directly related to the unstable stacking fault energy (γUSFE). As a result, an increase of Fe content in (CoCrMnNi)100-x Fex alloy system leads to an increase of γUSFE, which in turn weakens GB strengthening (Hall-Petch coefficient). Moreover, HEAs and MEAs with higher Fe content tend to have low yield strength due to weak contributions from both SS and GB strengthening. Therefore, to design superior MEAs and HEAs with enhanced strength, the choice of principal elements and their respective contents is imperative for an optimized contribution from both SS and GB strengthening mechanisms.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the present study, a systematic investigation on the effect of Fe content on the Hall-Petch coefficient of (CoCrMnNi)100-x Fex (x =20, 40, 50, and 60) medium- and high-entropy alloys (M/HEAs) was carried out. The cold-rolled alloys were annealed at 900 ◦C and 1000 ◦C between 3 min and 10 h for recrystallization. Scanning electron microscope with a backscattered detector was used to obtain micrographs of recrystallized specimens for grain size calculation. Tensile testing was used to evaluate the mechanical properties of the alloys. The micro- structure showed that regardless of the alloy composition, the grain size was approximately similar when sub- jected to the same heat treatment condition. Moreover, all the alloys obeyed the classical Hall-Petch relationship. Friction stress (solid solution, SS strengthening) decreased with an increase of Fe content, which was attributed to weak lattice distortion caused by the reduction of the atomic size misfit. The Hall-Petch coefficient, which represents grain boundary (GB) strengthening, also decreases as the Fe content increases. A linear relationship between intrinsic stacking fault energy and Hall-Petch coefficient was found not to exist. However, it is proposed that the monotonic decrease of the Hall-Petch coefficient is directly related to the unstable stacking fault energy (γUSFE). As a result, an increase of Fe content in (CoCrMnNi)100-x Fex alloy system leads to an increase of γUSFE, which in turn weakens GB strengthening (Hall-Petch coefficient). Moreover, HEAs and MEAs with higher Fe content tend to have low yield strength due to weak contributions from both SS and GB strengthening. Therefore, to design superior MEAs and HEAs with enhanced strength, the choice of principal elements and their respective contents is imperative for an optimized contribution from both SS and GB strengthening mechanisms. |
Fredrick LALA, NDINYA Perception of Gemba Kaizen's upper management commitment principle on employee performance in Kenya Wildlife service, Tsavo East National Park, Kenya (Journal Article) In: International Journal of Development and Management Review, 16 (1), pp. 18-38, 2021, ISSN: 1597-9482. @article{nokey,
title = {Perception of Gemba Kaizen's upper management commitment principle on employee performance in Kenya Wildlife service, Tsavo East National Park, Kenya},
author = {LALA, Fredrick, NDINYA, Amina, OGADA, Maurice, CHEPKULEI, Bellah, APOLLO, Florence, MSINGA, Stephen, MOHAMMED, Mariam},
url = {https://www.ajol.info/index.php/ijdmr/article/view/208107/196161},
doi = {https://www.ajol.info/index.php/ijdmr/article/view/208107/196161},
issn = {1597-9482},
year = {2021},
date = {2021-06-03},
urldate = {2021-06-03},
journal = {International Journal of Development and Management Review},
volume = {16},
number = {1},
pages = {18-38},
abstract = {Harnessing human capital and converting it into useful industrial processes can best be realized through competent management systems. However, without significant commitment from the upper management as espoused in the Gemba Kaizen principles, strategies to improve employee performance may fall short of their objectives. Gemba Kaizen principles have been adopted in several private and public sector organizations globally, and the upper management commitment principle is being subsequently practiced in the organizations. However, the influence of the application of the Gemba Kaizen upper management commitment principle on employee performance has not received significant research attention previously. Therefore, the objective of this study was to examine the application of GembaKaizen’supper management commitment principle on employee performance in Kenya Wildlife Service, Tsavo East National Park, Kenya. The study adopted a descriptive research design targeting employees of Kenya Wildlife Service, Tsavo East National Park. Data collected through pre-tested copies of questionnaire from 202 respondentsrevealed that the Gemba Kaizenupper management commitment principlesignificantly influenced employee performance in the Kenya Wildlife Service. There was a significant linear relationship between the Kaizen Principle of upper management commitment and employees’ understanding the contribution of their role in performance of the organization. Employees increase their outputs if the top management is committed by communicating the importance of meeting regulatory requirements, establishing the quality policy, ensuring that quality objectives are established, conducting management reviews and ensuring the availability of resources. It is, therefore, recommended that the upper management in the Kenya Wildlife Service begin inculcating the need for team effort and customer satisfaction among employees for the achievement of organizational objectives.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Harnessing human capital and converting it into useful industrial processes can best be realized through competent management systems. However, without significant commitment from the upper management as espoused in the Gemba Kaizen principles, strategies to improve employee performance may fall short of their objectives. Gemba Kaizen principles have been adopted in several private and public sector organizations globally, and the upper management commitment principle is being subsequently practiced in the organizations. However, the influence of the application of the Gemba Kaizen upper management commitment principle on employee performance has not received significant research attention previously. Therefore, the objective of this study was to examine the application of GembaKaizen’supper management commitment principle on employee performance in Kenya Wildlife Service, Tsavo East National Park, Kenya. The study adopted a descriptive research design targeting employees of Kenya Wildlife Service, Tsavo East National Park. Data collected through pre-tested copies of questionnaire from 202 respondentsrevealed that the Gemba Kaizenupper management commitment principlesignificantly influenced employee performance in the Kenya Wildlife Service. There was a significant linear relationship between the Kaizen Principle of upper management commitment and employees’ understanding the contribution of their role in performance of the organization. Employees increase their outputs if the top management is committed by communicating the importance of meeting regulatory requirements, establishing the quality policy, ensuring that quality objectives are established, conducting management reviews and ensuring the availability of resources. It is, therefore, recommended that the upper management in the Kenya Wildlife Service begin inculcating the need for team effort and customer satisfaction among employees for the achievement of organizational objectives. |
Justus Ochieng2 Teresa Sequeros1, Pepijn Schreinemachers3*; Suebpongsang18, Pornsiri Mungbean in Southeast Asia and East Africa: varieties, practices and constraints (Journal Article) In: Agriculture & Food Security, 10 (1), pp. 1-13, 2021. @article{nokey,
title = {Mungbean in Southeast Asia and East Africa: varieties, practices and constraints},
author = {Teresa Sequeros1, Justus Ochieng2 , Pepijn Schreinemachers3* , Papias H. Binagwa4
, Zenaida M. Huelgas5, Ratri Tri Hapsari6, Maurice Ogada Juma7, Joseph Rajabu Kangile8, Rael Karimi9,
Nur Khaririyatun10, Emmanuel K. Mbeyagala11, Henry Mvungi12, Ramakrishnan Madhavan Nair13,
Losira Nasirumbi Sanya14 , Thi Tan Loc Nguyen15, Siviengkhek Phommalath16, Thira Pinn17, Esther Simfukwe12
and Pornsiri Suebpongsang18},
url = {https://agricultureandfoodsecurity.biomedcentral.com/track/pdf/10.1186/s40066-020-00273-7.pdf},
doi = {10.1186/s40066-020-00273-7},
year = {2021},
date = {2021-01-21},
journal = {Agriculture & Food Security},
volume = {10},
number = {1},
pages = {1-13},
abstract = {Background
Improving the productivity of grain legumes is important to address global challenges of food security and soil degradation. This study’s objective was to quantify the adoption of improved mungbean (Vigna radiata L.) varieties and agricultural practices and to identify production constraints for six countries in Southeast Asia and three countries in East Africa.
Methods
A Delphi method using expert elicitation was applied at subnational levels and then aggregated to national levels. Each panel employed repetitive and independent questioning of experts. The study organized 31 expert panels involving 387 experts across 9 countries.
Results
The share of improved varieties in the planted area, as estimated by the expert panels, was 92% for the Philippines, 91% for Vietnam, 99% for Thailand, 84% for Cambodia, 60% for Indonesia, 35% for Laos, 91% for Kenya, 30% for Uganda and 25% for Tanzania. The average age of improved varieties was 19 years in Asia and 12 years in East Africa. Of the mungbean area in Southeast Asia, 61% was planted to varieties developed by the World Vegetable Center, but this was only 2% in East Africa. Production constraints generally included insect pests and plant diseases, unstable markets with low price and low market demand, and the lack of quality seed of suitable varieties.
Conclusions
There are ample opportunities to improve mungbean productivity through wider use of improved varieties and practices, which is important to meet the contemporary challenges of improving human nutrition and agricultural sustainability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Improving the productivity of grain legumes is important to address global challenges of food security and soil degradation. This study’s objective was to quantify the adoption of improved mungbean (Vigna radiata L.) varieties and agricultural practices and to identify production constraints for six countries in Southeast Asia and three countries in East Africa.
Methods
A Delphi method using expert elicitation was applied at subnational levels and then aggregated to national levels. Each panel employed repetitive and independent questioning of experts. The study organized 31 expert panels involving 387 experts across 9 countries.
Results
The share of improved varieties in the planted area, as estimated by the expert panels, was 92% for the Philippines, 91% for Vietnam, 99% for Thailand, 84% for Cambodia, 60% for Indonesia, 35% for Laos, 91% for Kenya, 30% for Uganda and 25% for Tanzania. The average age of improved varieties was 19 years in Asia and 12 years in East Africa. Of the mungbean area in Southeast Asia, 61% was planted to varieties developed by the World Vegetable Center, but this was only 2% in East Africa. Production constraints generally included insect pests and plant diseases, unstable markets with low price and low market demand, and the lack of quality seed of suitable varieties.
Conclusions
There are ample opportunities to improve mungbean productivity through wider use of improved varieties and practices, which is important to meet the contemporary challenges of improving human nutrition and agricultural sustainability. |
Bernard Ouma Alunda 2 Luke Oduor Otieno 1, Jaehyun Kim 3; 1, Yong Joong Lee Design and Fabrication of a High-Speed Atomic Force Microscope Scan-Head (Journal Article) In: Sensors, 21 (2), pp. 362, 2021. @article{nokey,
title = {Design and Fabrication of a High-Speed Atomic Force Microscope Scan-Head},
author = {Luke Oduor Otieno 1 , Bernard Ouma Alunda 2 , Jaehyun Kim 3 and Yong Joong Lee 1},
url = {https://www.mdpi.com/1424-8220/21/2/362/pdf},
doi = {10.3390/s21020362},
year = {2021},
date = {2021-01-07},
journal = {Sensors},
volume = {21},
number = {2},
pages = {362},
abstract = {A high-speed atomic force microscope (HS-AFM) requires a specialized set of hardware and software and therefore improving video-rate HS-AFMs for general applications is an ongoing process. To improve the imaging rate of an AFM, all components have to be carefully redesigned since the slowest component determines the overall bandwidth of the instrument. In this work, we present a design of a compact HS-AFM scan-head featuring minimal loading on the Z-scanner. Using a custom-programmed controller and a high-speed lateral scanner, we demonstrate its working by obtaining topographic images of Blu-ray disk data tracks in contact- and tapping-modes. Images acquired using a contact-mode cantilever with a natural frequency of 60 kHz in constant deflection mode show good tracking of topography at 400 Hz. In constant height mode, tracking of topography is demonstrated at rates up to 1.9 kHz for the scan size of 1μm×1μm with 100×100 pixels},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A high-speed atomic force microscope (HS-AFM) requires a specialized set of hardware and software and therefore improving video-rate HS-AFMs for general applications is an ongoing process. To improve the imaging rate of an AFM, all components have to be carefully redesigned since the slowest component determines the overall bandwidth of the instrument. In this work, we present a design of a compact HS-AFM scan-head featuring minimal loading on the Z-scanner. Using a custom-programmed controller and a high-speed lateral scanner, we demonstrate its working by obtaining topographic images of Blu-ray disk data tracks in contact- and tapping-modes. Images acquired using a contact-mode cantilever with a natural frequency of 60 kHz in constant deflection mode show good tracking of topography at 400 Hz. In constant height mode, tracking of topography is demonstrated at rates up to 1.9 kHz for the scan size of 1μm×1μm with 100×100 pixels |
Bernard Alunda Ibrahim Ondicho, Fredrick Madaraka Effect of Bimodal Grain Size Distribution on the Strain Hardening Behavior of a Medium‑Entropy Alloy (Journal Article) In: Acta Metallurgica Sinica, 34 (4), pp. 465-475, 2021. @article{nokey,
title = {Effect of Bimodal Grain Size Distribution on the Strain Hardening Behavior of a Medium‑Entropy Alloy},
author = {Ibrahim Ondicho, Bernard Alunda, Fredrick Madaraka, Melody Chepkoech},
url = {https://cemerem.ttu.ac.ke/wp-content/uploads/2022/01/Effect-of-Bimodal-Grain-Size-Distribution-on-the-Strain-Hardening-Behavior-of-a-Medium-Entropy-Alloy.pdf},
doi = {10.1007/s40195-020-01173-2},
year = {2021},
date = {2021-01-03},
journal = {Acta Metallurgica Sinica},
volume = {34},
number = {4},
pages = {465-475},
abstract = {The evolution of strain hardening behavior of the Fe50(CoCrMnNi)50 medium-entropy alloy as a function of the fraction of recrystallized microstructure and the grain size was studied using the Hollomon and Ludwigson equations. The specimens under study were partially recrystallized, fully recrystallized with ultrafine-grained microstructure, and fully recrystallized with coarse grains. The yield strength decreases steadily as the fraction of recrystallized microstructure and grain size increases due to the recovery process and the Hall–Petch effect. Interestingly, the bimodal grain distribution was found to have a significant impact on strain hardening during plastic deformation. For instance, the highest ultimate tensile strength was exhibited by a 0.97 μm specimen, which was observed to contain a bimodal grain distribution. Furthermore, using the Ludwigson equation, the effect of the bimodal grain distribution was established from the behavior of K2 and n1 curves. These curves tend to show very high values in the specimens with a bimodal grain distribution compared to those that show a homogenous grain distribution. Additionally, the bimodal grain distribution contributes to the extensive Lüders strain observed in the 0.97 μm specimen, which induces a significant deviation of the Hollomon equation at lower strains.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The evolution of strain hardening behavior of the Fe50(CoCrMnNi)50 medium-entropy alloy as a function of the fraction of recrystallized microstructure and the grain size was studied using the Hollomon and Ludwigson equations. The specimens under study were partially recrystallized, fully recrystallized with ultrafine-grained microstructure, and fully recrystallized with coarse grains. The yield strength decreases steadily as the fraction of recrystallized microstructure and grain size increases due to the recovery process and the Hall–Petch effect. Interestingly, the bimodal grain distribution was found to have a significant impact on strain hardening during plastic deformation. For instance, the highest ultimate tensile strength was exhibited by a 0.97 μm specimen, which was observed to contain a bimodal grain distribution. Furthermore, using the Ludwigson equation, the effect of the bimodal grain distribution was established from the behavior of K2 and n1 curves. These curves tend to show very high values in the specimens with a bimodal grain distribution compared to those that show a homogenous grain distribution. Additionally, the bimodal grain distribution contributes to the extensive Lüders strain observed in the 0.97 μm specimen, which induces a significant deviation of the Hollomon equation at lower strains. |
2020
|
D.O. Agumba B.O. Alunda, I. O. Ondicho Investigating the performance of square ring under uniform squeeze rate and internal pressure (Journal Article) In: Materialwissenschaft und Werkstofftechnik, 51 (12), pp. 1653-1661, 2020. @article{nokey,
title = {Investigating the performance of square ring under uniform squeeze rate and internal pressure},
author = {B.O. Alunda, D.O. Agumba, I.O. Ondicho, L.O. Otieno, M. Chepkoech, N.A. Mutua5, J.S. Hawong},
url = {https://www.researchgate.net/profile/Dickens-Agumba/publication/347844001_Investigating_the_performance_of_square_ring_under_uniform_squeeze_rate_and_internal_pressure/links/61489c7c519a1a381f717b16/Investigating-the-performance-of-square-ring-under-uniform-squeeze-rate-and-internal-pressure.pdf},
doi = {10.1002/mawe.201900236},
year = {2020},
date = {2020-12-17},
journal = {Materialwissenschaft und Werkstofftechnik},
volume = {51},
number = {12},
pages = {1653-1661},
abstract = {Transportation and controlling fluid flow under high pressures in pumps, valves, boilers and heat exchangers is a common exercise in the industries. The main challenge, however that has confronted designers and manufacturers of pumps and valves along with those responsible for the maintenance and upkeep of such types of machinery is managing leakages at the positions where the seals are used. One fundamental feature of seal packing is the ability of the seal to ′flow′ into the groove spaces and effectively block fluid from passing through them. The square ring has shown good ‘flow’ behavior in addition to offering low contact stresses. This research seeks to investigate the performance of the square ring. The Hertz contact theory and photoelastic experimental hybrid method are used in the study of the performance of the square ring under a squeeze rate of 20 % and varying internal pressure. It was observed that while increasing the applied internal pressure, the deformation length and angle increased due to the high stresses produced by the applied pressure. Additionally, was initiated at an internal pressure of 0.98 MPa.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Transportation and controlling fluid flow under high pressures in pumps, valves, boilers and heat exchangers is a common exercise in the industries. The main challenge, however that has confronted designers and manufacturers of pumps and valves along with those responsible for the maintenance and upkeep of such types of machinery is managing leakages at the positions where the seals are used. One fundamental feature of seal packing is the ability of the seal to ′flow′ into the groove spaces and effectively block fluid from passing through them. The square ring has shown good ‘flow’ behavior in addition to offering low contact stresses. This research seeks to investigate the performance of the square ring. The Hertz contact theory and photoelastic experimental hybrid method are used in the study of the performance of the square ring under a squeeze rate of 20 % and varying internal pressure. It was observed that while increasing the applied internal pressure, the deformation length and angle increased due to the high stresses produced by the applied pressure. Additionally, was initiated at an internal pressure of 0.98 MPa. |
Oduor Otieno Luke, Yong; Bernard, Ouma Alunda Implementation of a Sinusoidal Raster Scan for High-Speed Atomic Force Microscopy (Journal Article) In: Journal of the Korean Physical Society, 77 (7), pp. 605-612, 2020. @article{nokey,
title = {Implementation of a Sinusoidal Raster Scan for High-Speed Atomic Force Microscopy},
author = {Luke, Oduor Otieno, Yong, Joong Lee and Bernard, Ouma Alunda},
url = {http://ir.ttu.ac.ke:8080/xmlui/bitstream/handle/123456789/59/Implementation%20of%20a%20Sinusoidal%20Raster%20Scan%20for%20High-Speed%20Atomic%20Force%20Microscopy.pdf?sequence=1&isAllowed=y},
doi = {10.3938/jkps.77.605},
year = {2020},
date = {2020-10-13},
journal = {Journal of the Korean Physical Society},
volume = {77},
number = {7},
pages = {605-612},
abstract = {To improve the speed of an atomic force microscope (AFM), one must improve the bandwidth of its components, and the lateral XY scanner is no exception. Sinusoidal raster scans provide a simple way of improving lateral scan rates without the need for additional hardware and/or complex control algorithms. However, a raster scan using a sinusoidal waveform leads to a non-uniform probesample velocity. Uniform spatial sampling of scan data can be achieved in this case by varying the sampling rate as the probe sample velocity varies. In this work, we present a field-programmable gate array (FPGA)-based implementation of a sinusoidal raster scan with uniform spatial sampling for a high-speed atomic force microscope (HS-AFM). Using a home-made HS-AFM scanner and a custom controller, we demonstrate the performance of our approach by imaging Blu-ray disk data tracks in the contact mode. While the results show images comparable to those acquired using the traditional triangular raster scans, mirroring effects are better suppressed in high-speed imaging with sinusoidal scan signals.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
To improve the speed of an atomic force microscope (AFM), one must improve the bandwidth of its components, and the lateral XY scanner is no exception. Sinusoidal raster scans provide a simple way of improving lateral scan rates without the need for additional hardware and/or complex control algorithms. However, a raster scan using a sinusoidal waveform leads to a non-uniform probesample velocity. Uniform spatial sampling of scan data can be achieved in this case by varying the sampling rate as the probe sample velocity varies. In this work, we present a field-programmable gate array (FPGA)-based implementation of a sinusoidal raster scan with uniform spatial sampling for a high-speed atomic force microscope (HS-AFM). Using a home-made HS-AFM scanner and a custom controller, we demonstrate the performance of our approach by imaging Blu-ray disk data tracks in the contact mode. While the results show images comparable to those acquired using the traditional triangular raster scans, mirroring effects are better suppressed in high-speed imaging with sinusoidal scan signals. |
Bernard O. Alunda,; Lee, Yong J. Review: Cantilever-Based Sensors for High Speed Atomic Force Microscopy (Journal Article) In: Sensors, 20 (17), pp. 4784, 2020. @article{nokey,
title = {Review: Cantilever-Based Sensors for High Speed Atomic Force Microscopy},
author = {Alunda, Bernard O., and Yong J. Lee},
url = {https://www.mdpi.com/1424-8220/20/17/4784/pdf},
doi = {10.3390/s20174784},
year = {2020},
date = {2020-08-25},
journal = {Sensors},
volume = {20},
number = {17},
pages = {4784},
abstract = {This review critically summarizes the recent advances of the microcantilever-based force sensors for atomic force microscope (AFM) applications. They are one the most common mechanical spring–mass systems and are extremely sensitive to changes in the resonant frequency, thus finding numerous applications especially for molecular sensing. Specifically, we comment on the latest progress in research on the deflection detection systems, fabrication, coating and functionalization of the microcantilevers and their application as bio- and chemical sensors. A trend on the recent breakthroughs on the study of biological samples using high-speed atomic force microscope is also reported in this review.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This review critically summarizes the recent advances of the microcantilever-based force sensors for atomic force microscope (AFM) applications. They are one the most common mechanical spring–mass systems and are extremely sensitive to changes in the resonant frequency, thus finding numerous applications especially for molecular sensing. Specifically, we comment on the latest progress in research on the deflection detection systems, fabrication, coating and functionalization of the microcantilevers and their application as bio- and chemical sensors. A trend on the recent breakthroughs on the study of biological samples using high-speed atomic force microscope is also reported in this review. |
Bernard Alunda Ibrahim Ondicho, Dicken Owino Revealing a Transformation‑Induced Plasticity (TRIP) Phenomenon in a Medium‑Entropy Alloy (Journal Article) In: Acta Metallurgica Sinica (English Letters), 33 (8), pp. 1159-1165, 2020. @article{nokey,
title = {Revealing a Transformation‑Induced Plasticity (TRIP) Phenomenon in a Medium‑Entropy Alloy},
author = {Ibrahim Ondicho, Bernard Alunda, Dicken Owino, Luke Otieno, Melody Chepkoech},
url = {http://ir.ttu.ac.ke:8080/xmlui/bitstream/handle/123456789/61/Brics%20Project%20Programme%20Updates%20October%202016%20.pdf?sequence=1&isAllowed=y},
doi = {10.1007/s40195-020-01088-y},
year = {2020},
date = {2020-06-18},
journal = {Acta Metallurgica Sinica (English Letters)},
volume = {33},
number = {8},
pages = {1159-1165},
abstract = {A transformation-induced plasticity phenomenon in Fe65(CoCrMnNi)35 medium-entropy alloy was investigated. According to the X-ray diffraction patterns, the as-cast specimen contains a single-phase face-centered cubic (fcc), while low-temperature annealing at 500 °C and 600 °C leads to the introduction of a body-centered cubic (bcc) phase as a secondary phase. Further increment of the annealing temperature to above 700 °C eliminates the bcc phase, and the microstructure was found to contain a single-phase fcc. At 20% true strain, an fcc-to-bcc phase transformation is observed; whereas, at 28% true strain, an fcc-to-hcp phase transformation takes place as an additional deformation mechanism. This strain-induced phase transformation phenomenon leads to improved tensile properties of this alloy},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A transformation-induced plasticity phenomenon in Fe65(CoCrMnNi)35 medium-entropy alloy was investigated. According to the X-ray diffraction patterns, the as-cast specimen contains a single-phase face-centered cubic (fcc), while low-temperature annealing at 500 °C and 600 °C leads to the introduction of a body-centered cubic (bcc) phase as a secondary phase. Further increment of the annealing temperature to above 700 °C eliminates the bcc phase, and the microstructure was found to contain a single-phase fcc. At 20% true strain, an fcc-to-bcc phase transformation is observed; whereas, at 28% true strain, an fcc-to-hcp phase transformation takes place as an additional deformation mechanism. This strain-induced phase transformation phenomenon leads to improved tensile properties of this alloy |
Drebenstedt C. Adero N. J., Prokofeva E. N.; V, Vostrikov A. Spatial data and technologies for geomonitoring of land use under aspect of mineral resource sector development (Journal Article) In: Eurasian Mining, 2020 (1), pp. 69-74, 2020, ISSN: 2072-0823. @article{nokey,
title = {Spatial data and technologies for geomonitoring of land use under aspect of mineral resource sector development},
author = {Adero N. J., Drebenstedt C., Prokofeva E. N. and Vostrikov A. V},
url = {https://elibrary.ru/item.asp?id=45492577},
doi = {10.17580/em.2020.01.14},
issn = {2072-0823},
year = {2020},
date = {2020-06-02},
journal = {Eurasian Mining},
volume = {2020},
number = {1},
pages = {69-74},
abstract = {The main efforts of modern geoecology focus on various aspects of monitoring the state of the natural environment within the sphere of anthropogenic impacts on raw materials complexes and on determining the irreversible level of adverse impacts and consequences of natural disasters in the absence of effective tools and systems for early forecasting and detection of hazards and environmental risks (erosion, oil spills, oil and gas leaks and contamination of surface and groundwater, landslides, collapses, subsidence, mining, fire, among others). As a result, even with the highest methodological and technical level of modern research, there remains trivial conclusion on the need to protect nature. This leaves open the main question of effective methods of nature protection and the necessary changes in technologies and methods of data management. The improvement of the methodological basis for the design of mining systems to achieve integrated development of subsoil is aimed at advancing the innovative energy and resource-saving geotechnologies, which ensure the required efficiency and safety of work, including early detection of potential hazards and risks. In this study, an integrated approach to the processing of remotely sensed data is being developed, which is envisaged to share the results of the measurements obtained in Russia and Kenya by various satellite-based technologies in both optical and radar bands.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The main efforts of modern geoecology focus on various aspects of monitoring the state of the natural environment within the sphere of anthropogenic impacts on raw materials complexes and on determining the irreversible level of adverse impacts and consequences of natural disasters in the absence of effective tools and systems for early forecasting and detection of hazards and environmental risks (erosion, oil spills, oil and gas leaks and contamination of surface and groundwater, landslides, collapses, subsidence, mining, fire, among others). As a result, even with the highest methodological and technical level of modern research, there remains trivial conclusion on the need to protect nature. This leaves open the main question of effective methods of nature protection and the necessary changes in technologies and methods of data management. The improvement of the methodological basis for the design of mining systems to achieve integrated development of subsoil is aimed at advancing the innovative energy and resource-saving geotechnologies, which ensure the required efficiency and safety of work, including early detection of potential hazards and risks. In this study, an integrated approach to the processing of remotely sensed data is being developed, which is envisaged to share the results of the measurements obtained in Russia and Kenya by various satellite-based technologies in both optical and radar bands. |
2019
|
Mika; Adero Siljander, Nashon Juma; Gitau Land use/land cover classification for the iron mining site of Kishushe, Kenya: A feasibility study of traditional and machine learning algorithms (Journal Article) In: African Journal of Mining, Entrepreneurship and Natural Resource Management (AJMENRM), 2019, ISSN: 2706-6002. @article{nokey,
title = {Land use/land cover classification for the iron mining site of Kishushe, Kenya: A feasibility study of traditional and machine learning algorithms},
author = {Siljander, Mika; Adero, Nashon Juma; Gitau, Francis; Nyambu, Emmanuel},
url = {https://helda.helsinki.fi/handle/10138/326921},
issn = {2706-6002},
year = {2019},
date = {2019-12-01},
journal = {African Journal of Mining, Entrepreneurship and Natural Resource Management (AJMENRM)},
abstract = { Motivated by the need to enhance the precision of land use/land cover classification for mining
environments challenged by rapid anthropogenic and natural changes, we analysed multispectral Sentinel 2A
satellite data using four different classifiers: Maximum Likelihood Classifier (MLC), Support Vector Machine
(SVM), Random Tree (RT) and Random Forest (RF). Using adjusted training sample sizes drawn from the
Kishushe iron ore mining site in Taita Taveta, Kenya, we conducted image analysis and compared the
classification accuracies of the four methods, confirmed further by ground truthing. The study met the main
objective of evaluating and comparing the performance of the traditional Maximum Likelihood classifier with
the three machine learning algorithms of Support Vector Machine (SVM), Random Trees (RT), and Random
Forest (RF). Eight land use/land cover classes were generated from each of the four classifications performed
in R statistics software for RF and in ArcGIS 10.7 for RT, MLC and SVM methods. Random Forest (RF) method
delivered the best overall accuracy at 74.63 % with a Kappa value of 0.67. Random Trees (RT) method came
second at 72.64 % with a Kappa value of 0.64. The overall accuracy of the SVM method was 58.21 % with a
Kappa value of 0.46 and for the MLC method, the overall accuracy was 57.21 % with a Kappa value of 0.45.
These results confirmed that machine learning classifiers outperform traditional classifiers. The study also
confirmed that for robust land use/land cover classification, it is essential to have quality training data as the
quality can have large and considerable effects on classification results. Since the reliability of land use/land
cover (LULC) maps derived from remotely sensed data for mining sites depends on accurate classification, this
study gives evidence-based recommendation for adopting machine learning algorithms in satellite image
analysis and classification to support environmentally sustainable decisions and informed policy direction for
sound mine planning and monitoring},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Motivated by the need to enhance the precision of land use/land cover classification for mining
environments challenged by rapid anthropogenic and natural changes, we analysed multispectral Sentinel 2A
satellite data using four different classifiers: Maximum Likelihood Classifier (MLC), Support Vector Machine
(SVM), Random Tree (RT) and Random Forest (RF). Using adjusted training sample sizes drawn from the
Kishushe iron ore mining site in Taita Taveta, Kenya, we conducted image analysis and compared the
classification accuracies of the four methods, confirmed further by ground truthing. The study met the main
objective of evaluating and comparing the performance of the traditional Maximum Likelihood classifier with
the three machine learning algorithms of Support Vector Machine (SVM), Random Trees (RT), and Random
Forest (RF). Eight land use/land cover classes were generated from each of the four classifications performed
in R statistics software for RF and in ArcGIS 10.7 for RT, MLC and SVM methods. Random Forest (RF) method
delivered the best overall accuracy at 74.63 % with a Kappa value of 0.67. Random Trees (RT) method came
second at 72.64 % with a Kappa value of 0.64. The overall accuracy of the SVM method was 58.21 % with a
Kappa value of 0.46 and for the MLC method, the overall accuracy was 57.21 % with a Kappa value of 0.45.
These results confirmed that machine learning classifiers outperform traditional classifiers. The study also
confirmed that for robust land use/land cover classification, it is essential to have quality training data as the
quality can have large and considerable effects on classification results. Since the reliability of land use/land
cover (LULC) maps derived from remotely sensed data for mining sites depends on accurate classification, this
study gives evidence-based recommendation for adopting machine learning algorithms in satellite image
analysis and classification to support environmentally sustainable decisions and informed policy direction for
sound mine planning and monitoring |
2017
|
Alunda Benard Ouma Nzioka Antony Mutua, Odero Shirley Atieno Kinetic Study of the Thermal Decomposition for Mixed Municipal Solid Waste Using Thermogravimetric Analysis (Journal Article) In: Periodicals of Engineering and Natural Sciences (PEN), 5 (3), pp. 355-363, 2017, ISSN: 2303-4521. @article{nokey,
title = {Kinetic Study of the Thermal Decomposition for Mixed Municipal Solid Waste Using Thermogravimetric Analysis},
author = {Nzioka Antony Mutua, Alunda Benard Ouma, Odero Shirley Atieno},
url = {http://pen.ius.edu.ba/index.php/pen/article/download/123/151},
doi = {10.21533/pen.v5i3.123},
issn = {2303-4521},
year = {2017},
date = {2017-10-18},
journal = { Periodicals of Engineering and Natural Sciences (PEN)},
volume = {5},
number = {3},
pages = {355-363},
abstract = {Thermal conversion of wastes is one of the perspective solution to ‘municipal solid waste’ problem. Thermal conversion process entails thermal decomposition of material with an increase in temperature. This experimental analysis investigated thermal decomposition of municipal solid waste using the thermogravimetric technique. The objective of the analysis was to analyze the changes in kinetic characteristics with changes in the composition of content in sample waste and temperature. Sample waste analyzed consisted of plant organic waste, paper, plastics, wood and inert substance. Proximate and elemental analyses were determined and calorific values determined experimentally using bomb calorimeter. Thermogravimetric curves were derived using thermogravimetric analyzer (TGA) at different temperature rates. Activation energy and pre¬exponential factor were derived using Flynn¬Wall¬Ozawa, Kissinger¬Akahira¬Sunose and Kissinger model equations. Additional statistical analyses of variance using ANOVA was conducted for the different sets of composition analyzed. Results showed kinetic parameter values for different model¬free models used in analysis as well as the level of variance in activation energies for different composition of waste and temperature rates used},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thermal conversion of wastes is one of the perspective solution to ‘municipal solid waste’ problem. Thermal conversion process entails thermal decomposition of material with an increase in temperature. This experimental analysis investigated thermal decomposition of municipal solid waste using the thermogravimetric technique. The objective of the analysis was to analyze the changes in kinetic characteristics with changes in the composition of content in sample waste and temperature. Sample waste analyzed consisted of plant organic waste, paper, plastics, wood and inert substance. Proximate and elemental analyses were determined and calorific values determined experimentally using bomb calorimeter. Thermogravimetric curves were derived using thermogravimetric analyzer (TGA) at different temperature rates. Activation energy and pre¬exponential factor were derived using Flynn¬Wall¬Ozawa, Kissinger¬Akahira¬Sunose and Kissinger model equations. Additional statistical analyses of variance using ANOVA was conducted for the different sets of composition analyzed. Results showed kinetic parameter values for different model¬free models used in analysis as well as the level of variance in activation energies for different composition of waste and temperature rates used |
