S.J. Ojolo, O. Damisa, J.I. Orisaleye and C. Ogbonnaya
The purpose of this paper is to investigate the physical and mechanical characteristics of the roasted cashew nut during fracture, by subjecting the nut to varying impact load…
Abstract
Purpose
The purpose of this paper is to investigate the physical and mechanical characteristics of the roasted cashew nut during fracture, by subjecting the nut to varying impact load tests at different orientations to ascertain the critical impact load that fractures the shell without damaging the kernel within. This load value was correlated with other parameters; shell/kernel moisture content level, average nut mass, to determine the required projection velocity to achieve this force. This projection velocity is the critical factor in sizing and design of the optimum configurations of the shelling impeller.
Design/methodology/approach
Mechanical properties of roasted cashew nut were first determined to know their fracture points. Each component of the shelling machine was designed. The components were assembled and the machine was tested for performance.
Findings
Machine throughput capacity was determined as 15.57 kg/h; shelling efficiency was 95 per cent; and whole kernel recovery was 70 per cent.
Practical implications
The efficiency in terms of whole kernel recovery could be improved by improving the pretreatment measures on the nuts.
Originality/value
The paper presents a machine which is affordable to peasant farmers and requires little or no training for operation and maintenance. The advantage of reduced unit cost can be derived from large‐scale commercial production of this sheller.
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Sunday Segbenu Nunayon, Emmanuel Abiodun Olanipekun and Ibukun Oluwadara Famakin
University campuses are one of the major consumers of electricity. Therefore, it is important to investigate factors related to electricity saving. This study aims to examine the…
Abstract
Purpose
University campuses are one of the major consumers of electricity. Therefore, it is important to investigate factors related to electricity saving. This study aims to examine the key drivers in achieving efficient electricity management (EEM) practices in public universities.
Design/methodology/approach
To achieve the objective, 23 drivers of EEM practices were identified through a comprehensive literature review and an empirical questionnaire survey was performed with 1,386 electricity end-users of three public universities having staff and students’ halls of residences in Nigeria. The collected data were analyzed using the statistical package for social sciences (SPSS version 21) to identify the number of components that could represent the 23 identified drivers.
Findings
The relative importance index ranking results indicated that 18 drivers were critical. The top five most critical drivers were understanding of the issues, understanding the vision and goal of an energy management programme, knowledge and skill, risk identification and good and effective communication among relevant stakeholders. An exploratory factor analysis revealed that the underlying grouped drivers were raising awareness, top management support and robust energy management team, risk management and stakeholders’ participation. This study also indicates that the most dominant of the four underlying groups was raising awareness, which highlights the role of increasing awareness and public consciousness as a significant catalyst in promoting EEM practices in public universities.
Research limitations/implications
Geographically, this study is limited to the opinion of respondents in public university campuses in Nigeria. Although this study could form the basis for future studies, its limitation must be considered carefully when interpreting and generalizing the results.
Practical implications
This paper has highlighted a few drivers of EEM practices in public universities. The results of this study present scientific evidence that can be used as a basis for formulating public policies that could be incorporated into the energy management regulations of university buildings. It is most important for policymakers to pay adequate attention to the most critical drivers especially those that are related to the “raising awareness” factor to promote sustainable campuses.
Originality/value
This study provides practical knowledge for university management to develop effective methods to implement the identified drivers of efficient and sustainable electricity management on the campus. This study also contributes to the body of knowledge in the field of energy management.
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Lawrance G., P. Sam Paul and Varadarajan A.S.
In the internal turning process, tool life and work piece quality are greatly influenced by the generation of heat in the cutting zone. During machining, cutting fluids are…
Abstract
Purpose
In the internal turning process, tool life and work piece quality are greatly influenced by the generation of heat in the cutting zone. During machining, cutting fluids are applied at the cutting zones to reduce heat generation and enhance tribological properties. However, in the boring process, cutting fluids cannot be applied at cutting zone properly, and wastage of cutting fluid is a threat to the ecology and personnel health. Hence, application of semisolid lubricant in the boring process is considered as an innovative technique for temperature reduction in cutting zone because of its eco-friendly system, which also has a higher ability of biodegradability. This paper aims to study the influence of semisolid lubricants comprising of grease,graphite, aluminium oxide in different composition applied at a tool–chip,tool–work interface using a semisolid lubricant applicator applied with varying pressure.
Design/methodology/approach
In the present study, the cutting performance during boring of AISI4340 steel is enhanced through the application of semisolid lubricant with different composition of grease, graphite and aluminium oxide applied at tool-work and tool-chip interface with varying pressure using semisolid lubricant applicator.
Findings
The results show that use of semisolid lubricant like grease, graphite and nano aluminium oxide at tool-chip interface with maximum pressure reduces cutting temperature, tool vibration, cutting force and surface roughness.
Originality/value
Reduce cutting temperature, tool vibration, cutting force and surface roughness.
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Ernestina Mawushie Amewornu and Nnamdi I. Nwulu
This research studies the impact of introducing distributed generators (DGs) into a distribution network. The aim of this paper is to optimally site DGs based on economic…
Abstract
Purpose
This research studies the impact of introducing distributed generators (DGs) into a distribution network. The aim of this paper is to optimally site DGs based on economic, environmental and reliability indices are presented.
Design/methodology/approach
The considered network was modelled by using the network’s line parameters and capacity of the load bus with the help of Power System Analysis Toolbox. The location of the DG is based on voltage stability index and power loss reduction index. The DG energy sources considered are the diesel generator, solar photo-voltaic (PV) and wind generator, and the objectives were to minimize cumulative cost while maximizing reliability of the network. The Advanced Interactive Multidimensional Modelling System was used for the mathematical modelling.
Findings
The obtained results in the cases of introducing renewable energy into a network improves network performance. The benefits of renewable energy on the distribution network measured in terms of electricity production cost, gas emission cost, fuel cost and value of energy not supplied were positive. The research also showed that the total benefit of renewable energy reduces as the price of the renewable generators increases.
Originality/value
This paper introduces a new approach to determining the optimal location of DG for reducing line losses and improved voltage profile. A new cost modelling function based on external grid power transfer cost, technical losses and cost because of the various energies source is also introduced.
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Sunday J. Ojolo, Olatunde Damisa and Oluwatoyin Iyekolo
The main purpose of this paper is to explore the use of solid lubricant during orthogonal machining of carbon steels. This is a pioneer work in Nigeria. Most works have been on…
Abstract
Purpose
The main purpose of this paper is to explore the use of solid lubricant during orthogonal machining of carbon steels. This is a pioneer work in Nigeria. Most works have been on oblique cutting using conventional oil as lubricants.
Design/methodology/approach
Different steels (low, medium and high carbon) were machined at different cutting conditions and tool geometries to determine the effects on surface characteristics while applying solid lubricant.
Findings
The results showed considerable improvement in the surface finish with the use of solid lubricant. There was also a decrease in surface roughness values as compared to wet machining.
Research limitations/implications
Further works on solid lubricant's effects on cutting force and residual stress could be done.
Practical implications
From the findings of this work, solid lubricant use can be advocated as a better alternative to conventional cutting fluid. It is easily recoverable from the chips after machining.
Originality/value
So far, in Nigeria, solid lubricant has not been exploited as coolant during machining. This paper will be a platform for other researches on solid lubricants as coolant during cutting/machining in Nigeria.
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Abiodun Elijah Obayelu, Agatha Osivweneta Ogbe and Sarah E. Edewor
The purpose of this paper is threefold: to assess the gender gaps and the patterns of female workforce in agriculture; to examine the level of household decision making among the…
Abstract
Purpose
The purpose of this paper is threefold: to assess the gender gaps and the patterns of female workforce in agriculture; to examine the level of household decision making among the principal males and females in the household; and to estimate the time spent by the principal males and females in the household by activities in Nigeria.
Design/methodology/approach
The study made use of secondary data obtained from various sources such as published articles, research reports, unpublished discussion paper, policy documents, national and international databases (World Bank World Development Indicators, United Nations Development Programme and the ECOWAS-RAAF-PASANAO survey conducted in Nigeria in 2017), and position papers. The information gathered covers a range of empirical and conceptual issues relating to labour, share of women contributing to agriculture and other gender-related issues. The study covered 1,747 maize and/or rice producing households spread across 141 farming communities in 16 states in Nigeria using a multi-stage sampling technique.
Findings
It was interesting to note that an average male was older and had more educational qualification than their female counterparts. In the same vein, he owned more assets (virgin lands, other plots and buildings) when compared with their female counterparts and earned higher incomes from farming and other labour activities with the exception of trading. Furthermore, the result revealed females spent more time taking care of children, cooking and schooling than their male counterparts. It can therefore be concluded that a gender gap exists in agricultural labour participation with the males playing dominant roles as compared with their female counterparts. Analysis of women’s agricultural should not neglect the structural bases of their inequality.
Research limitations/implications
The study is limited by lack of enough data base on women’s and men’s engagement in labour force and on agricultural activities which can be analysed for policy formulation and implementation.
Social implications
The paper elucidates some of the possible social, economic and biological implications of changes in women’s work and their participation in agriculture in Nigeria.
Originality/value
The paper is original in nature and will add value to the integration of women into the development process in Nigeria.
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Women cross-border traders face impediments in their entrepreneurial work from time-to-time. To overcome these impediments, females need to take on self-concept (self-esteem…
Abstract
Purpose
Women cross-border traders face impediments in their entrepreneurial work from time-to-time. To overcome these impediments, females need to take on self-concept (self-esteem, self-confidence, social roles) mediated by self-organization (adaptability, interaction, team working) in order to thrive in cross-border trading (CBT), using evidence from Uganda. So, in this paper the authors explain the behavior of a female who succeeds in CBT with interest of scaling it up to empower more female entrepreneurs.
Design/methodology/approach
This study is a correlational and cross-sectional type. A questionnaire survey of 288 females was used. The data collected were analyzed through SPSS.
Findings
The results reveal that self-concept, mediated by self-organization, controlled by tenure in business and the age of a female in CBT significantly influences CBT behavior among females in Uganda.
Research limitations/implications
This study focused on females who are involved in CBT in Uganda. Therefore, it is likely that the results may not be generalized to other settings. The results show that for females to succeed in CBT, self-concept and self-organization affect CBT behavior once they are controlled by tenure in business and the age of a female in CBT at more than 30 years of age and longer than 5 years.
Originality/value
This study provides initial evidence that self-concept, mediated by self-organization, controlled by tenure in business and age of a CBT directly affects CBT behavior, using evidence from an African developing country – Uganda.
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Ariel Mutegi Mbae and Nnamdi I. Nwulu
In the daily energy dispatch process in a power system, accurate short-term electricity load forecasting is a very important tool used by spot market players. It is a critical…
Abstract
Purpose
In the daily energy dispatch process in a power system, accurate short-term electricity load forecasting is a very important tool used by spot market players. It is a critical requirement for optimal generator unit commitment, economic dispatch, system security and stability assessment, contingency and ancillary services management, reserve setting, demand side management, system maintenance and financial planning in power systems. The purpose of this study is to present an improved grey Verhulst electricity load forecasting model.
Design/methodology/approach
To test the effectiveness of the proposed model for short-term load forecast, studies made use of Kenya’s load demand data for the period from January 2014 to June 2019.
Findings
The convectional grey Verhulst forecasting model yielded a mean absolute percentage error of 7.82 per cent, whereas the improved model yielded much better results with an error of 2.96 per cent.
Practical implications
In the daily energy dispatch process in a power system, accurate short-term load forecasting is a very important tool used by spot market players. It is a critical ingredient for optimal generator unit commitment, economic dispatch, system security and stability assessment, contingency and ancillary services management, reserve setting, demand side management, system maintenance and financial planning in power systems. The fact that the model uses actual Kenya’s utility data confirms its usefulness in the practical world for both economic planning and policy matters.
Social implications
In terms of generation and transmission investments, proper load forecasting will enable utilities to make economically viable decisions. It forms a critical cog of the strategic plans for power utilities and other market players to avoid a situation of heavy stranded investment that adversely impact the final electricity prices and the other extreme scenario of expensive power shortages.
Originality/value
This research combined the use of natural logarithm and the exponential weighted moving average to improve the forecast accuracy of the grey Verhulst forecasting model.