ABSTRACT The study was aimed at developing mathematical models on the hydraulic performance of Sandbags as Checkdam for erosion control. Pilot studies were carried out at two sites. Site ‘A’ was a natural gully at a location in Ezinihitte-Mbaise, Imo State while site ‘B’ was an artificial channel excavated on the slope of Otamiri River at Federal University of Technology, Owerri. Artificial runoff was simulated into site ‘B’ by pumping water from Otamiri River. Sandbags of ...
ABSTRACT This work investigated the structural characteristics of lime cement concrete using 30 selected mix ratios. The properties studied include, compressive strength, flexural strength, splitting tensile strength, shear strength, poisson ratio, modulus of elasticity, and modulus of rigidity. A total of 360 concrete cube specimen, 360 concrete prototype beam specimen, and 360 concrete cylinder specimen were cast and cured in open water tanks. 3 specimen were cast for each mix proportio...
ABSTRACT The geometric design of highways requires a large number of iterations and repetitive tasks of analysis and drafting in order to prepare plan, profile and cost estimate.
ABSTRACT The existing Ongwediva Waste Stabilization Ponds have had several problems in their operations over the past years. Thus, the treatment performance of the waste stabilization ponds was assessed in terms of the reduction efficiency of some physical, chemical and biological pollutants of importance. Data were collected daily from May to June 2017 and analyzed for both raw and treated wastewater. Results of these investigation showed that the average effluent concentrations of BOD, DO, ...
ABSTRACT Photogrammetric Refraction is one of the major causes of systematic errors affecting the accuracy of maps compiled from aerial images. It has to be eliminated so as to attain the goal of the best results that the technology of photogrammetric mapping is capable of. Many researchers have devoted substantial efforts to develop a number of analytical formulas to remove the effect of refraction. However, these formulas suffer from certain limitations, such as: (i) inconsistent values fo...
ABSTRACT The geometrical design of highways requires a large number of iterations and repetitive tasks of analysis and drafting
ABSTRACT Railway transport in Namibia is one of the most important mode of transport with great importance to the economy of the country. Currently, road networks are the most important because of the low population density of the nation. However, railway lines have been reported to be the most economical, efficient, environmentally friendly, and the safe solution for long distance transportation of heavy goods [1]. The Namibian Railway Network lines linking to the coastal towns and ports, i....
xv ABSTRACT Climate change is affecting global weather patterns, more so by exacerbating the sporadic nature of Namibia’s rainfall patterns. This has negative consequences on urbanization as increased rainfall in certain rainy seasons coupled with increased urban development could lead to dangerous flooding in low-lying areas, as was the case with Acacia residential, Windhoek, in 2004. Increased urban development has the potential to increase runoff and flood peaks by 20% to 50% of those un...
ABSTRACT In this thesis, a methodology for integrated catchment water resources assessment using Bayesian Networks was developed. A custom made software application that combines Bayesian Networks with GIS was used to facilitate data pre-processing and spatial modelling. Dynamic Bayesian Networks were implemented in the software for time-series modelling. The structures of three Bayesian Network models were created automatically using a Hybrid Genetic Algorithm (HGA) which was implemented in ...
ABSTRACT Dual Digestion is a two stage system that combines autotherm·a1 thermophilic aerobic pre-treatment with conventional anaerobic digestion. The practicability of the system using pure oxygen is well proven. Disadvantages are the high cost of the pure oxygen and the absence of a detailed evaluation of anaerobic digester performance. This report discusses the results of a full-scale investigation into the dual digestion system (184m3 aerobic reactor and 1800m3 anaerobic digester), carri...
BACKGROUND Integral to the biological nutrient removal (BNR) activated sludge system is the biologically mediated process of denitrification. Not only does this process reduce the N load to the environment, but it also has the advantages of alkalinity recovery and reducing the oxygen demand. Further, the denitrification protects the biological excess P removal (BEPR), if included, from the deleterious effect of recycling nitrate to the anaerobic reactor (Wentzel et al., 1990). Accordingly, qu...
ABSTRACT Terrorism, with explosions both in and outside buildings, has become a significant problem in the world. There are already several houses of unreinforced masonry, some of which are historical. But under blast loading they do not function well. Retrofitting methods have been developed to protect masonry buildings. Some research work has been carried out in recent years to study the impact of retrofitted URM walls; these experiments require usually significant time and funds. Also, wit...
ABSTRACT Traffic congestion is a common feature on highways in many cities of the world, including Ibadan, Nigeria. Previous studies have shown that several mathematical traffic flow models developed to analyse congestion cannot be easily generalised or adapted to varying situations. In addition, validation errors of some models are as high as 60.0 %. In pursuit of the objective of minimising traffic congestion in parts of the Ibadan metropolis, headway simulation models were developed for th...
ABSTRACT Carbon dioxide (CO2) emissions from solid wastes is a major contributor to the acceleration of global warming. In Nigeria, CO2 capture has been limited to the energy sector only. There is need to explore the reduction of CO2 emissions from solid wastes through appropriate technologies. This study, therefore was designed to assess CO2 extraction by adsorbents in a Municipal Solid Waste (MSW) management facility in Akure, Nigeria. An exploratory study design with an intervention compon...
ABSTRACT This study examined the experimental analysis of sandcrete block production by using different sources of sharp sands in Enugu and Ebonyi State of South-East Geo-Political Zone. As a result of the increasing cost of block production, many manufacturers and builders have resorted to using samples of sharp sand from different locations without appropriate consideration of the material constituents of the samples thereby, resulting in poor and undurable concrete blocks production. In ...