15288 research outputs found
Sort by
Development of a solar system for charging mobile phones with customized DC chargers for rural areas in Nigeria
Get PDFThe introduction of mobile phones has redefined the world of communication in that it has turned the world into a
global village as people can now make contact through phone calls within and across countries at affordable rates.
Nowadays, almost every home has a functional mobile phone, be it a conventional, android, or iPhone, among others.
These phones use non-self-charging rechargeable batteries that need to be recharged from time to time to meet the
demands of the users. However, access to a reliable source of power to meet the energy demand, including mobile
phone charging needs, of off-grid rural dwellers remains a global challenge. As a result, this study designed and implemented
a solar-powered mobile phone charging system with customized DC chargers for use in remote off-grid
areas. The test results showed that the system is very effective for charging mobile phones
Circular Economy Based Model for End-of- Life Tire Management in Emerging Economies
Get PDFEnd-of-life tires (EOLTs) are challenging waste sources belonging to a solid
waste type, called “bulky” in the management of waste. It presents a variety of
eco-friendly problems ranging from fire hazards to health and hygiene risks.
Nonetheless, most developing countries are having heaps of EOLT loitering
on their streets and dumping sites. An evolution to the circular-based
economy suggests the opportunity to provide quality and resource-efficient
services and improved material recovery along the value chain. The authors
conducted a systemic analysis to ascertain the need for sustainable EOLT
management for developing countries, based on literature review and
observational data. A group of waste management specialists from six
developing countries were semi-structurally interviewed to examine the
applicability of the established EOLT waste management strategies in the
developed states to the developing countries. The analysis indicated that a
“new” model is necessary to promote sustainable EOLT management toward
the circular economy. The authors proposed an EOLT management system
designed to accommodate the specificities of socioeconomic disadvantages of
an emerging economy. The model would be beneficial for the government and
other stakeholders in the waste management sector
Corrosion Behavior of AA70 Reinforced Zea mays Husk Particle in NaCl/H2SO4 Concentrations
Get PDFThe effects of Zea mays husk particle and heat treatment on the corrosion behavior of AA70 matrix composite
in 1.5 wt.% NaCl/0.0125 M H2SO4 concentrations were studied using an electrochemical technique and optical
microscopy. Results showed that the samples had similar anodic-cathodic polarization behavior after heat treatment,
with no passivation. However, the heat-treated AA70 matrix composites were more corrosion-resistant than the
untreated AA70 matrix composite material in 1.5 wt.% NaCl/0.0125 M H2SO4 concentrations. The composite
with 15 wt.% Zea mays husk and a particle size of 300 μm reinforced AA70 matrix revealed the least corrosive
tendency and is the most thermodynamically stable in chloride and sulphate ions conditions. Therefore, the
corrosion behavior of heat-treated AA70 matrix composites was better compared to that of AA70 material in
1.5 wt.% NaCl/0.0125 M H2SO4 solution. Furthermore, the presence of a high concentration of aggressive
chloride ions increases the corrosion susceptibility, and the Zea mays husk particle breaks down the stable oxide
film, resulting in increased chloride ion adsorption. The optical microscopy examination suggested the presence
of localized corrosion on the material surfac
Analysis of the morphological and mechanical characterization of aluminium matrix composite reinforced with chitosan
Get PDFRecent studies acknowledge that convectional ceramic particulate could be replaced by
several agricultural by-products in the development of aluminium matrix
composites because of its selected for their low cost and relative ubiquity. This study
explores the development of aluminium matrix composite from AA6061 alloy reinforced
with chitosan particulates at weight proportions (3, 6, 9, and 12 wt%). The study further
characterizes the developed composites using Scanning Electron Microscopy (SEM),
Energy Dispersive Spectroscopy (EDS), X-ray Diffractometer (XRD), hardness, tensile
and thermal and electrical conductivity test techniques. Results indicated that increasing
chitosan content up to 10 wt% enhanced the hardness performance, while tensile
strength of the composites increased sporadically, as SEM images observed
reinforcement links embedded in grain boundaries. However, the thermal and electrical
conductivity diminished due to the addition of chitosan particulates to the alloy matrix.
The overall study showed the great potential of chitosan polymer as reinforcement
to aluminium alloy
An Overview of Value Engineering in Component Fabrication and Assembly
Get PDFThe growing emphasis on sustainability and efficiency in industrial processes has led to the
adoption of waste reduction strategies. Fabrication and assembly as a form of
manufacturing technology requires waste elimination in the fabrication throughput.
However, extensive studies that address the use of VE in component fabrication and
assembly are lacking. This paper aims to examine the role of Value Engineering (VE) in
component fabrication, particularly in engineering applications. VE is a systematic approach
that optimises product value by eliminating unnecessary costs and improving performance.
The strategy focuses on functionality, cost-effectiveness, and stakeholder collaboration. VE
is applied at various stages of component fabrication throughput, such as material selection,
design optimisation, process streamlining, raw material, and finished components supply
chain management. The literature assessment established that significant waste reduction
potential and economic benefits could be achieved through VE implementation in
engineering component fabrication and assembly, such as eliminating overproduction,
excessive inventory, faults, transportation, waiting time, and superfluous processing.
However, the challenges and limitations of the approach include resistance to change,
resource constraints, and interdisciplinary collaboration. Emerging trends and future
research directions for implementing VE in waste reduction efforts within the components
fabrication industry are also discussed
CLASSIFICATION OF THE BASEMENT COMPLEX USING AEROMAGNETIC AND REMOTE SENSING DATA ANALYSES: CASE STUDY OF EKITI STATE, SOUTH-WEST NIGERIA.
Get PDFThis study investigates the basement rocks in Ekiti State for the purpose of geophysical classification so as to delineate prospective area of mineralization within the State. Aeromagnetic data and satellite imagery covering the entire state were analysed using appropriate software. Reduction to equator geophysical transformation was first carried out on the residual magnetic intensity data before the application of Fast Fourier Transform filters to generate some derivative maps such as the analytic signal and tilt derivative maps which amplified lineament and enhanced both weak and strong magnetic anomalies. The Shuttle Radar Topography Mission (SRTM) data were processed to produce lineament density map, which was analysed for various linear and curvilinear features. The study area was classified into magnetic-high anomalous zone (HMA), magnetic-intermediate anomalous zone (IMA) and magnetic-low anomalous zone (LMA) based on the analytical signal analysis. Analysis of the structures showed the dominance of northeast-southwest and northwest-southeast trends. Evaluation of Lineament density showed high value of 0.5203 km-2 around the centre and the western part of the study area, which are also HMA and IMA zones, an indication of concentration of more faults, joints and line of weaknesses which may serve as favourable tracts for mineralisation in the study area
Capital flight, institutional quality and real sector in sub-Saharan African countries
Get PDFPurpose
This study aims to provide an empirical investigation into rising capital flight and the role of
institutional quality to mitigate its effect on the real sector in sub-Saharan Africa (SSA).
Design/methodology/approach
The study uses the system generalized method of moments and uses data spanning from 1989 to
2020 from 26 SSA countries.
Findings
The findings show that capital flight has no direct impact on the real sector while institutional
quality adversely impacted the agricultural and industrial sectors. The study also found that
institutional quality is unable to mitigate the effect of capital flight on the industrial sector.
Originality/value
This study investigates if institutional quality mitigates the impact of capital flight on the real
sector proxied by industrial value-added and agriculture value-added
Organisational Compliance and Corporate Reputation: Moderating Role of the Scorecard Implementation Strategy
Get PDFCompliance is considered a critical factor in improving the corporate reputation of publicly
traded corporations in Nigeria. This study, therefore, examines the roles of organisational
compliance in fostering corporate reputation with the moderating role of the scorecard
implementation strategy. The study used a descriptive research design. Based on the sample
size of four hundred and thirty (430) respondents that participated in the study. Smart partial
least squared (3.0) was adopted to show the degree of relationships between organisational
compliance, scorecard implementation strategy, and corporate reputation. The statistical
results show that there are direct significant relationships between organisational compliance
and corporate reputation. The findings also revealed that scorecard implementation strategy
moderates the relationship between organisational compliance and corporate reputation. The
study recommends that firms should endeavour to evaluate and regularly review corporate
governance‐related principles to be sure of compliance with the laid down standards that
depict best practices. In addition, a scorecard implementation strategy should be implemented
in enforcing acceptable standards and sanctions for non‐compliance
Personality-Traits Taxonomy and Operational and Environmental Performance: A Cross-Sectional Analysis of Small and Medium Scale Manufacturing Enterprises
Get PDFThis research aimed to assess the operational and environmental performance of smalland
medium-sized enterprises (SMEs) in Nigeria in relation to their adoption of personality-traits
taxonomy (i.e., conscientiousness, openness to experience, extraversion, neuroticism or emotional
resilience and agreeableness). The survey-based study involved the entire population of SME operators
in South West Nigeria, totaling 1842 individuals (i.e., entrepreneurs). Through the use of
stratified random-selection methods, a sample size of 420 was chosen. Data was collected, and both
structural and measurement models were used to assess it. The results of the study demonstrate
that personality traits have a significant influence on how successful SMEs function. The results
also demonstrate that personality traits have a positive impact on SMEs’ environmental performance.
These findings suggest that sustaining operational and environmental performance may be
accomplished by resource allocation, promoting diversity and inclusion, and employing trustworthy
assessment methods. To enhance both their overall operational performance and their environmental
performance in particular, the study advises SME operators in Nigeria to undertake proper management
of personality traits for sustainability. The paper recommends for greater research on this
subject and emphasises the necessity of understanding how personality factors impact operational
and environmental performance in Nigerian SMEs
Nasal Carriage, Antimicrobial Susceptibility Profile, and Enterotoxin Genes of Staphylococcus aureus Isolated from Children with Asthma
Get PDFsuggests that Staphylococcus aureus contributes to the pathology of asthma. The aim of this
study was to evaluate the nasal carriage, antimicrobial susceptibility profile, and presence of
enterotoxin genes from S. aureus isolated from children with asthma. Nasal swab samples were
collected from 158 children, including 98 children with asthma and 60 healthy controls. S.
aureus isolates were identified using phenotypic methods and the presence of the nuc gene.
Antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method.
Polymerase chain reaction (PCR) confirmed the presence of the mecA gene and enterotoxin
genes. The nuc gene was confirmed in 83 isolates, resulting in a nasal carriage of 52.5%
(83/158). The nasal carriage of S. aureus was higher among asthma cases (72.4%), with a
significant association of S. aureus nasal carriage observed among asthma cases (OR 0.201, 95%
CI 0.063–0.645, p = 0.007). Methicillin-resistant S. aureus (MRSA) nasal carriage was 11.4%.
The S. aureus isolates showed high resistance to cefoxitin (99%) and penicillin (92%) but were
sensitive to gentamicin (25%). Furthermore, 67.5% of the isolates were multi-drug resistant. The
staphylococcal enterotoxin c gene (sec) was the most prevalent enterotoxin (19.7%) among cases
and controls. These findings highlight the need for improved antibiotic stewardship in paediatric
medicine and implementation of infection control policie