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The purpose of this paper is to identify the factors responsible for road traffic accidents among commercial commuter drivers in Lagos, Nigeria.

A total of 188 commercial drivers, driving 18‐seater mass transit buses in inter‐city highways were studied. Their accident records for the previous three years collected from Police records, Federal Road Safety Commission records, self‐administered questionnaires and observation of driving habits of the drivers. Their eye status were measured and data also collected from the Driver Union's Insurance Agency. A total of 25 human factor variables, identified as possible contributors to road traffic accidents were studied.

Six variables were found as possible significant contributors to road traffic accidents. They are old age, overtaking, overspeeding, religious affiliation, bad brake conditions and use of bad tyres. When the variables were subjected to two‐way interactions, 44 variable combinations were significant (p < 0.05) with R² of 0.994 and residual error of 1.165.

Accidents are not usually caused by single variables but by a combination of variables.

Apart from variables commonly found in the literature as possible causes of road traffic accidents, there may be some factors that may be peculiar to some countries like religious affiliation, belief in use of charms to protect drivers from accident and eye problems that are not identified because of lack of regular tests among others.

The purpose of this study was to obtain some anthropometric dimensions of students in secondary schools necessary for the design of school furniture and use them to establish the models that best determine the relationships among the anthropometric dimensions and standing height.

A total of 480 students aged 10 to 18 years (n = 480, SD = ± 2.3 years) were randomly selected from eight public and eight private secondary schools in Ibadan, South West Nigeria. All the dimensions were subjected to curve estimation using Statistical Products and Services Solution 16.0 Statistical Package. The models with p < 0.005 and highest coefficient of determinations were selected as the best models to predict the relationships among the standing height and other variables.

The study proposes 11 models using standing height to estimate necessary anthropometric dimensions for the design of school furniture. The results of the study show that all anthropometric dimensions correlate more non-linearly with standing height than linearly.

The proposed models will have wide applications for the estimation of anthropometric data necessary for the design and construction of school furniture for use in secondary schools in South Western Nigeria.

Product verification and validation are integral to quality management. Product verification means verifying the conformity between a product’s actual and planned characteristics whereas validation means determining whether and to what extent it satisfies customers’ requirements. One of the key forms of product validation is testing with a group of customers. The purpose of this paper is to introduce a graphical method of product validation based on the Kano model.

The approach is based on a proposed method for categorising requirements based on a Kano questionnaire and then applies this method for the validation of a product – a website. The proposed method is based on three steps: graphical determination of requirements in a Kano model; determination of requirement fulfilment degree and prioritisation of corrective measures and improvements.

The study opens space for discussion of the potential for improving a product and methods for identifying critical faults in products. The proposed method also permits an assessment of the potential effectiveness of an improvement because it is able to quantify the effect of the product on the consumer resulting from a given quantity of effort. A case study demonstrated that the resulting priority of corrective measures and improvements was affected not only by the level of fulfilment of the requirements but also by the type, the most critical being non-fulfilment of must-be requirements.

The requirement curves are based on a verbal assessment of satisfaction in two states – if the requirement were fulfilled and if it were not fulfilled. The values of the start and end points may not be precise and could be affected by the natural character of subjective variables.

The proposed method is particularly suited to the initial testing of a product that is intended to lead to measures to eliminate customer dissatisfaction or increase their satisfaction – that is, to improve the product. The method also permits an assessment of the extent to which customers feel that their expectations have been satisfied and the effect that will be felt if the organisation decides to increase fulfilment.

The Kano model has not yet been applied to product validation, although it contains all the information necessary for this task. Knowing how satisfied customers are is an important part of product validation. At the same time, knowing a mechanism for “creating” this satisfaction is also very valuable information.

There is the need to focus on humans while designing engineering facilities for users. The need to focus on Nigerians when designing for them is presented in this paper. The paper aims to discuss these issues.

Relevant literatures were consulted on the history of ergonomics and its importance was stressed. Some instances where ergonomics should be applied in the country were identified.

The paper observed that the application of ergonomics in Nigeria is low and some constraints that are militating against the use of ergonomics in Nigeria are discussed.

The paper suggested ways to fully imbibe the use of human-centered engineering (ergonomics) in Nigeria.

The topic of Lean Six Sigma (LSS) implementation in a supply chain context is an emerging research stream comprising of diverse objectives and complex processes thereby presenting opportunities for further exploration and organizational process improvement. Thus, this study proposes an integrated multi-criteria decision-making methodology to determine what can facilitate the successful implementation of LSS as an organizational change strategy in the manufacturing supply chain.

The proposed methodology based on Decision-Making Trial and Evaluation Laboratory and hierarchical Evaluation Based on Distance to Average Solution is employed to ascertain the relative importance and priorities of an identified framework of factors with the aid of opinions of managers in the Nigerian plastics industry.

The results show a high significance of institution-based factors (e.g. government regulations) and present relevant implications to the policymakers as well as the managers and practitioners of the plastics manufacturing industry.

This study indicates a possible pathway to accurately evaluate a framework of critical factors to integrate and institutionalize LSS in the manufacturing supply chain for organizational performance improvement.

After a long observation of the high rate of rice importation and low productivity in Côte d’Ivoire, the certified rice seed was introduced and encouraged to be used by the local farmers. This study evaluates the profitability of rice production and the impact of certified seed usage on the yield and income of farmers in Côte d’Ivoire.

Data were collected from 265 rice farmers. Descriptive statistics were used to identify the challenges faced in using certified seeds. Profitability analysis was used to examine the profitability of rice production. To eliminate bias due to the counterfactuals, the endogenous switching regression was employed to investigate the impact of the certified seeds on income and yield.

The difficulties faced by the rice farmers in the procurement of certified seeds were the unavailability of seeds, the high cost of seeds and poor credit access. Furthermore, rice farmers using certified seeds get a higher net income (USD 263.74/ha) than those using farmers' seeds (USD 212.31/ha). The average treatment on the treated was 1.61 for the yield and 574.75 for the income. The average treatment on the untreated was 1.20 for the yield and 422.59 for the income. These indicate a higher yield and income among adopters of certified rice seed.

Certified rice seed usage is profitable and enhances the output and income of rice farmers. The study advocates the creation of a stronger relationship between the farmers and the extension agents to encourage the use of certified seeds and increase the profit of the farmers.

There is scant information on the profitability of certified rice seed usage and how it affect yield and income. Therefore, this study serves as empirical evidence for policymakers to develop strategies that are required to enhance certified seed usage, boost rice productivity and achieve food security.

This study aims to investigate the literature related to the use of digital technologies for promoting circular economy (CE) in the construction industry.

A comprehensive approach was adopted, involving bibliometric analysis, text-mining analysis and content analysis to meet three objectives (1) to unveil the evolutionary progress of the field, (2) to identify the key research themes in the field and (3) to identify challenges hindering the implementation of digital technologies for CE.

A total of 365 publications was analysed. The results revealed eight key digital technologies categorised into two main clusters including “digitalisation and advanced technologies” and “sustainable construction technologies”. The former involved technologies, namely machine learning, artificial intelligence, deep learning, big data analytics and object detection and computer vision that were used for (1) forecasting construction and demolition (C&D) waste generation, (2) waste identification and classification and (3) computer vision for waste management. The latter included technologies such as Internet of Things (IoT), blockchain and building information modelling (BIM) that help optimise resource use, enhance transparency and sustainability practices in the industry. Overall, these technologies show great potential for improving waste management and enabling CE in construction.

This research employs a holistic approach to provide a status-quo understanding of the digital technologies that can be utilised to support the implementation of CE in construction. Further, this study underlines the key challenges associated with adopting digital technologies, whilst also offering opportunities for future improvement of the field.

The purpose of this study was to compare the physico-chemical properties and amino acid profile of three maize hybrid cultivars grown in Nigeria.

Two normal maize endosperm varieties, yellow SUWAN-ISR (YNM) and white ART/98/SW05-OB-WC (WNM), and one yellow QPM variety, TZE-POP-DT-STR-QPM (YQPM), were selected for the study. Physico-chemical properties, physical tests, proximate composition analysis, functional properties and characteristics and amino acid profile tests were carried out on the grains using standard methods.

Protein was significantly higher (p < 0.05) in YQPM (10.49 per cent) than in normal endosperm, YNM (8.83 per cent) and WNM (8.50 per cent). Amino acid profile of the grains revealed that total amino acid of YQPM (94.67 g/100 g of protein) and essential amino acid of YQPM (39.070) were the highest among the three, with highest significantly different value of tryptophan (0.388 g/100 g of protein) at p < 0.05. The cooking quality of YQPM was found to be better than the other two, with highest hydration capacity and increase in volume after cooking (90.8 ± 0.01 g/1000 grains and 147.53 ± 0.02 per cent).

YQPM will be highly beneficial in the tropics, where maize is grown as the major staple food to reduce hunger and malnutrition because of its amino acid balance and its better cooking quality.

This paper aims to explore the intellectual structure shaping the circular economy (CE) discourse within the built environment in Africa.

The study adopted a bibliometric analysis approach to explore the intellectual structure of CE in the built environment in Africa. The authors collected 31 papers published between 2005 and 2021 from the Scopus database and used VOSviewer for data analysis.

The findings show that there are six clusters shaping the intellectual structure: demolition, material recovery and reuse; waste as a resource; cellulose and agro-based materials; resilience and low-carbon footprint; recycling materials; and the fourth industrial revolution. The two most cited scholars had three publications each, while the top journal was Resources, Conservation and Recycling. The dominant concepts included CE, sustainability, alternative materials, waste management, lifecycle, demolition and climate change. The study concludes that there is low CE research output in Africa, which implies that the concept is either novel or facing resistance.

The data were drawn from one database, Scopus; hence, adoption of alternative databases such as Web of Science, Google Scholar and Dimensions could potentially have yielded a higher number of articles for analysis which potentially would result in different conclusions on the subject understudy.

This study made a significant contribution by articulating the CE intellectual structure in the built environment, identified prominent scholars and academic platforms responsible for promoting circularity in Africa.

In a circular economy, the goal is to keep materials values in the economy for as long as possible. For the construction industry to support the goal of the circular economy, there is the need for materials reuse. However, there is little or no information about the amount and quality of reusable materials obtainable when buildings are deconstructed. The purpose of this paper, therefore, is to develop a reusability analytics tool for assessing end-of-life status of building materials.

A review of the extant literature was carried out to identify the best approach to modelling end-of-life reusability assessment tool. The reliability analysis principle and materials properties were used to develop the predictive mathematical model for assessing building materials performance. The model was tested using the case study of a building design and materials take-off quantities as specified in the bill of quantity of the building design.

The results of analytics show that the quality of the building materials varies with the building component. For example, from the case study, at the 80th year of the building, the qualities of the obtainable concrete from the building are 0.9865, 0.9835, 0.9728 and 0.9799, respectively, from the foundation, first floor, frame and stair components of the building.

As a contribution to the concept of circular economy in the built environment, the tool provides a foundation for estimating the quality of obtainable building materials at the end-of-life based on the life expectancy of the building materials.