DETERMINANTS OF CONSTRUCTION FIRMS' COMPLIANCE WITH HEALTH AND SAFETY REGULATIONS IN SOUTH AFRICA

The management of health and safety issues is very significant in the construction industry in South Africa in terms of accident rates and cost to contractors. The costs arise from both the cost of compliance with regulations and the cost of accidents and injuries. In spite of the fact that available evidence shows that construction-related accidents and injuries are on the increase in South Africa, many designers and contractors regard the cost of complying with regulations as unnecessary additional financial burdens. It is against this background that this study investigated the statutory regulations relating to health and safety in construction in South Africa and the level of compliance with the regulations and motivation for compliance by contractors. Data obtained from contractors in a questionnaire survey the Western Cape Province of South Africa were analysed using percentage scores and mean score analysis with the aid of the SPSS software. Although the validity of the findings is limited by sample size used in the survey, it is hoped that the findings will provide empirical basis for a more inclusive survey of H&S in the construction industry in South Africa. Keywords: health and safety, regulations, enforcement & compliance, construction industry, South Africa

Hydrogeophysical Study Of The Groundwater Potential Of Ilara-Mokin Southwestern Nigeria

Geoelectric study of the groundwater potential of Ilara-Mokin in Ondo State Southwestern Nigeria was carried out using electrical resistivity (Vertical Electrical Sounding) method with the view to providing adequate information on the different sub-surface geoelectric layers, structural configuration of the concealed basement rocks and the groundwaterpotential of the study area. Forty-one Schlumberger vertical electrical soundings (VES) were conducted across the study area. The computerassisted VES data interpretation enabled generation of geoelectric curves, sections and overburden thickness map which were used in the delineation of key hydrogeologic features like the topsoil, weathered basement, fractured basement and the fresh basement. Resistivity values range from 21 Ω-m to 798 Ω-m in the topsoil, 14 Ω-m to 209 Ω- m in the weathered basement, 51 Ω-m to 209 in the partially weathered/fractured basement and 312 Ω-m to ∞ within the fresh basement. Layer thickness values also vary from 0.3 m to 6.1 m in the topsoil and 0.9 m to 28.6 m in theweathered basement. The depth to the resistive bedrock ranges from 0.3 m to 29.3 m across the study area. The study revealed that greater part of Ilara-Mokin town is underlain by marginally thick overburden thus constituting shallow aquifer units with poor to marginal groundwater potential. Partially weathered/fractured basement were delineated in isolated cases with tendency for low to marginal groundwater yield around central and northeastern areas of the town. The results reasonably provide basic information that is expected to assist in the future development of groundwater resources in Ilara-Mokin

Geophysical study of saline water intrusion in Lagos municipality

Saline water intrusion presently constitutes serious concerns in the Lagos municipality just like many other coastal cities, thus necessitating its intervallic study. The present study involving 52 borehole logs (consisting of natural gamma and electrical resistivity components) was aimed at delineating intruded and vulnerable zones. Saline water columns defined by low resistivity values in the range of 0.1 and 20 Ωm as compared to fresh water (≥ 100 Ωm) were delineated on 22 logs. Four of the geosections generated in this study indicate saline water intrusion at depths varying from surface in Satellite Town, Kirikiri, Ijora, Iganmu, Apapa, Lagos Island, Ikoyi, Victoria Island and Lekki to depths ranging from 40 m at Iganmu to 158 m at Lekki. Intrusions of 47 m (143 - 190 m) and 60 m (56 - 116 m) were delineated at Ajah; 50 m (265 - 315 and 258 - 308) at Lakowe; 57 and 112 m (51 - 108 m and 198 - 308) at Ibeju Lekki, Akodo and 122 m at (233 - 355m) at Awoyaya. The hydrogeologic importance of the Coastal Plain Sand aquifer unit in Lagos is under severe threat of continued sea water intrusion on its southern flank. This study illustrates the current extension of the sea water intrusion. It highlights the depreciation of the water resource due to over pumping at higher rate than the natural recharge and slow sea level rise.Key words: Borehole logs, saline water intrusion/incursion, natural gamma, resistivity, freshwater sand

Dynamics of flow in river bends

2018 Fall.Includes bibliographical references.Water is indispensable to life and the means by which it is conveyed is equally important. Natural rivers and manmade channels play a critical role in this respect because they are vital for water supply, navigation, transport of sediments, pollutants and nutrients. Most natural rivers typically have meandering (curved) geometries which make a direct study of their flow dynamics cumbersome. In order to reduce this complexity, natural rivers are usually idealized as open channel bends with rigid boundaries in order to gain insights into the flow dynamics. As such, this research examines the dynamics of flow in open channel bends with rigid boundaries, using computational fluid dynamics (CFD). The particular computational fluid dynamics code used in this research, discretizes the equations of fluid motion (i.e. the Navier-Stokes equations) using a finite volume scheme while tracking the free surface with the volume of fluid method. Turbulence was incorporated into the solution of the equations using large eddy simulation techniques. Even though the general aim is to improve current understanding of natural river bend physics, the specific aims of this research are threefold. These are: (1) to study the effects of radius of curvature on the flow physics of an idealized river bend; (2) to study in detail the effect of a variation in curvature length on the flow structure and dynamics of an open channel bend; and (3) examine in detail the effect of inertial forces on the flow dynamics of an idealized river bend by varying the inflow Froude number. While some of the findings in this research confirm some of the results that has already appeared in literature, a significant amount of results highlight new insights into dynamic events in an open channel bend. As a concrete example on the effect of curvature on the flow structure, simulation results show that the maximum bed and wall shear stress are exerted on the inner wall at the entrance to the curve regardless of curvature. However, further into the bend, the maximum shear stress shifts to the outer bend and wall region. Furthermore, the angular distance into the bend at which this occurs is found to depend on the curvature of the channel. Thus, for a mild channel, the maximum shear stress shifts to the outer bend and wall region a short angular distance from the entrance. This distance increases with a decrease in radius of curvature (i.e. as the channel gets tighter) with the maximum shear stress in the tightest channel (that was simulated in this study) always occurring on the inner side of the bend for the entire channel length. Another key finding comes from an investigation of the effect of the variation of curvature length on the flow structure and dynamics of open channel bends. It was found that the flow circulation pattern depends on the curvature length. Simulation results showed that shorter channel bends reached fully developed vortical states faster than similar channels with longer lengths. Furthermore, new results from this study provide a clear explanation for the emergence of a three-cell circulation structure in tight channel bends that occurs as a result of the splitting of the main cell circulation due to the enhanced vorticity in tight bends. Finally, the study on the effects of Froude number on flow structure clearly shows that an increase in the inertia of the fluid does not affect the radial pressure gradient force (a very important force that plays a critical role in shaping the bend channel dynamics) in a mild channel. Remarkably in the tight channels, there seems to be a positive correlation between the magnitudes of the fluid inertia (as measured by the velocity) and the radial pressure gradient force. This finding has important implications for the modeling of river bends since geometric factors are not sufficient to adequately parameterize the flow structure under certain circumstances in reduced order models. These and more results not mentioned in this abstract are detailed in this dissertation. The overall aim of this research is to provide better insights into bend channel flow dynamics so as to enable engineers to carry out more accurate river modeling and training works

Construction Innovation: The Implementation of Lean Construction towards Sustainable Innovation

The prevalent theory of construction has been seen as a hindrance to construction innovation. The concept of lean construction is concerned with the application of lean thinking to the construction industry. However, in lean construction there are many arguments supporting the view that ‘the prevalent theory of production (or specifically, theory of construction) is counterproductive, and leads to added costs and reduced overall performance through the deficient production control principles based on the theory’. Presently, the construction industry and all other organisations face various problems as a result of the uncertainties of the global economic climate; including labour redundancies, delayed projects and zero margin contract bids. The construction industry is seen as one of the worst performing industry as regards innovation. This calls for concern about the poor state of construction innovation. The emergence of lean construction is to bring significant reform to the construction industry to achieve the objectives of sustainability within the built environment in the critical social, economic and environmental aspects. Increasingly, lean construction offers new techniques of constructing sustainable projects. It is about reducing costs by cutting waste, innovating by engaging people and organising the work-place to be more efficient. Hence, the aim of this paper is to highlight the cost and benefits of the potential contribution of lean construction to the attainment of sustainable innovation in construction. An exploratory method of investigation is adopted in achieving the aim of this paper by critically reviewing, exploring, and synthesising literature and industry case studies related to the subject matter. Evidence from the literature reveals that innovation through lean improvement in construction processes has provided proof of sustainability outcomes in terms of reduced waste, effort and time. Hence, lean construction impacts significantly on innovation by enhancing competitiveness, innovativeness, and resource efficiency within the construction industry. Keywords: Construction industry, Construction innovation, Lean construction, Sustainabilit

Integrating Lean with CMMI using VBS

Student research poste

Redesign of Johar: a framework for developing accessible applications

As the population of disabled people continues to grow, designing accessible applications is still a challenge, since most applications are incompatible with assistive technologies used by disabled people to interact with the computer. This accessibility issue is usually caused by the reluctance of software engineers or developers to include complete accessibility features in their applications, which in turn is often due to the extra cost and development effort required to dynamically adapt applications to a wide range of disabilities. Our aim to resolve accessibility issues led to the design and implementation of the Johar framework, which facilitates the development of applications accessible to both disabled and non-disabled users. In the Johar architectural model, the ability-based front-end user interfaces are called interface interpreters, while the application-specific logic or functionality implemented by application developers are called applications or apps. The seamless interaction between each interface interpreter and app is made possible by Johar. In this thesis, we assure the quality of Johar by detecting and resolving many inconsistencies, omissions, irrelevancies, and other anomalies that can trigger unexpected or abnormal behaviour in Johar, and/or alter the smooth operation of interface interpreters and apps. Our approach to conducting the quality assurance involved reviewing the two components of Johar, johar.gem and johar.idf, by critically examining the functionality of classes in each component, including how classes interrelate and how functions are allocated or distributed among the classes. We also performed an exhaustive comparative review of four documents - IDF Format Specification document, XML Schema Document or XSD, the Interface Interpreter Specification document, and the johar.idf package - which are vital to the smooth running of all interface interpreters and apps. We also developed an automated testing tool in order to determine whether all errors or violations in an IDF (Interface Description File) are detected and reported. As part of this thesis, we designed and implemented an interface interpreter, called Star that presents WIMP (Windows, Icons, Menus, and Pointers) graphical user interfaces to users, which is based on the new version of Johar. This new version evolved as a result of the redesign activities carried out on the Johar components and the various modifications effected during the quality assurance process. We also demonstrated the usage of Star on two apps to prove Johar’s ability to guarantee smooth interaction between interface interpreters and apps. Finally, in this thesis, we designed two other interface interpreters which will be implemented in the near future

Review of flexible energy harvesting for bioengineering in alignment with SDG

To cater to the extensive body movements and deformations necessitated by biomedical equipment flexible piezoelectrics emerge as a promising solution for energy harvesting. This review research delves into the potential of Flexible Piezoelectric Materials (FPM) as a sustainable solution for clean and affordable energy, aligning with the United Nations' Sustainable Development Goals (SDGs). By systematically examining the secondary functions of stretchability, hybrid energy harvesting, and self-healing, the study aims to comprehensively understand these materials' mechanisms, strategies, and relationships between structural characteristics and properties. The research highlights the significance of designing piezoelectric materials that can conform to the curvilinear shape of the human body, enabling sustainable and efficient mechanical energy capture for various applications, such as biosensors and actuators. The study identifies critical areas for future investigation, including the commercialization of stretchable piezoelectric systems, prevention of unintended interference in hybrid energy harvesters, development of consistent wearability metrics, and enhancement of the elastic piezoelectric material, electrode circuit, and substrate for improved stretchability and comfort. In conclusion, this review research offers valuable insights into developing and implementing FPM as a promising and innovative approach to harnessing clean, affordable energy in line with the SDGs.</p