ABSTRACT Wellbore instabilities are responsible for 10-20% of the total drilling cost. It has been estimated that wellbore instability causes an annual economic loss of US$ 500 - 1000 million in the oil industry across the world. Hence, the maintenance of wellbore stability is of major concern to drilling engineers in the oil and gas industry. Hence, several models have been developed for the assessment or prediction of wellbore instabilities. However, these models do have some limitations. ...
ABSTRACT This study presents the results of a combined experimental and theoretical study of the strength, fracture toughness and interfacial properties of natural fiber-reinforced earth-based composite materials. The composites, which consist of mixtures of laterite, clay and straw, are stabilized with controlled levels of Portland cement. The compositional dependence of compressive, flexural/bend strength and fracture toughness are explored for different proportions of the constituent mate...
ABSTRACT This paper presents the use of multilayered chitosan films incorporated with antimicrobial agent, potassium sorbate to enhance effective food packaging. In this study, potassium sorbate was incorporated into multilayer chitosan films for antimicrobial food packaging applications. The effectiveness of the films was tested through measurement of release kinetics and antimicrobial activity on a selected microorganism, Aspergillus niger. All the films prepared with potassium sorbate sho...
ABSTRACT Chemical and physical methods for the synthesis of magnetic nanoparticles for cancer detection and treatment often involve toxic chemicals, high cost and the formation of non-stable nanoparticles. This prompted the development of fundamental understanding of the synthesis of magnetic nanoparticles, which are biocompatible, cost effective, stable, localized and environmentally friendly in the presence of magnetotactic bacteria. In this work, fundamental understanding of the underlyin...
Abstract This dissertation shows the use of material science and engineering approaches in developing solutions to problems in the life science with focus in nano and micro-particles for the detection and treatment of cancer. It presents the results of experimental and theoretical studies of magnetite, gold nanoparticles and injectable multi-functional biodegradable polymer-loaded microparticles. Biocompatible magnetite nanoparticles (BMNPs) were produced from Magnetospirillum magneticum (M....
ABSTRACT One of the unintended impacts of crude oil exploration is the pollution of agricultural land and aquatic resources when there is accidental oil spillage. The environmental effect of this has resulted in untold hardship to communities within oil producing regions all over the world and has been the main reason for conflicts in the regions. Nigerian Niger Delta region has been devastated by oil pollution and gas flaring, and both the government of Nigeria and the multinational oil pro...
ABSTRACT Laterite is an eco-friendly construction material that has the ability of being re-cycled indefinitely. The research is aimed at achieving the effective utilization of laterite as a sustainable construction material by attempting to identify the best percentage of the soil stabilizers needed to improve the laterite. In this study, hydrated lime and bone ash were used as soil stabilizers to improve the strength of Nigerian laterite (obtained from Gosa and Sauka in Abuja, Nigeria). Co...
ABSTRACT The corrosion behavior of uncoated and cut-back bitumen coated X65 Steel samples are being investigated in environments of different pH (2, 3, 4 and 7). Immersion tests were carried out on the samples at 25ºC. The comparison of the corrosion behavior of uncoated, spray-coated and brush-coated X65 steel samples in the different pH media and temperature were observed using the weight measurements approach and visual examination. With 72 hours intervals in the weight measurement of th...
ABSTRACT This work studies the adsorption capacity of laterite and iron oxide nanoparticles for dissolved ions in solution and therefore its ability to reduce conductivity of mine waste effluent. Three laterite samples were prepared and used as adsorbents. The first laterite adsorbent was used without any treatment, the second was heat treated and the third was mixed with 15 % iron oxide nanoparticles of particle size 100 nm. Laterite and nanoparticle characterization, pH and adsorption test...
ABSTRACT This research presents the design, construction, and analysis of the performance of a mixed-mode solar dryer for crops. A mixed-mode solar dryer utilizes direct solar radiation from the sun as well as input heat ducted from the solar collector inlet which is directly connected to the dryer. Such dryers have been shown to outperform passive solar dryers as it was also shown in this work using drying kinetics. Tomatoes were dried in the drying chamber under the mixed-mode condition. T...
ABSTRACT Failure of offshore oil and gas pipelines occurs under certain conditions due to some applied mechanical forces. These conditions constitute a potential threat to the integrity of in-service life span of the pipelines which can lead to loss of resources and environmental pollution. Several studies have shown that pipelines fail as a result of Welding, Fatigue Crack Growth, Corrosion Fatigue, Stress Corrosion Cracking, and Erosion due to fluid flow. This paper presents a model by usi...
ABSTRACT Organic-inorganic perovskite photovoltaics (PVs) have attracted a lot of attention as highefficiency thin film PVs which are relatively cheap and easy to fabricate. Lead halide perovskites have shown a rapid rise in power conversion efficiency by 3.8 % in 2009 to 21.02 % in 2016. One major problem is that lead is toxic and poses a serious concern to health and the environment. The most likely substitute for lead is tin. Tin-based perovskite solar cells have shown good semiconducting...
Abstract The study explores the investigation of the chemical composition, microstructure and mechanical properties of steel and cement mortar used in reinforced concrete. The compositions and mechanical properties of the locally produced steel were analyzed to ascertain their potential for applications for construction. Two samples of construction steels produced and used in Nigeria were studied along. The chemical compositions of these steels were determined using Solaris CCD techniques. Th...
ABSTRACT Metals in service often give a superficial impression of permanence, but all except gold are chemically unstable in air and air-saturated water at ambient temperatures and most are also unstable in air-free water. Corrosion can be defined in general terms as the degradation of a material, usually a metal, or its properties because of a reaction with its environment. It results to damage cost between 1 – 5 % GNP as reported from different countries. Corrosion can be initiated by di...
Abstract Many building collapsed cases have been reported throughout the West African regions. It is recorded that during some of these subsidences, many lives are lost and the vast majority end up in hospitals and clinics with huge loss in investments also. This poses a major challenge to the health and wellbeing of the human race. Overwhelming facts of poor workmanship, engineering fault and poor maintenance have been highlighted as major factors. On the other hand, most research has shown...