Conceptions and expectations of mentoring relationships in a teacher education reform context

Peer reviewedPostprin

Root Cause Analysis of a Jet Fuel Tanker Accident

Over the last two decades, economic growth in Nigeria led to a sporadic increase in air transportation, both local and international, and this, in turn, brought about a huge demand for jet fuel to satisfy the aviation needs. In Nigeria, Jet fuel is transported via Bridger Receipt Vehicles (BRV) from shore to airport depots. The presence of the BRVs has increased road activity and this has been associated with a number of accidents. This study is focussed on identifying the root cause of a BRV related accident which happened along the airport road, close to jet fuel storage depots, creating a potential for huge fire disaster. Using the fishbone diagram and a detailed root cause analysis, the study revealed that driving under the influence of alcohol and the prevailing operational challenges played a major role in the series of events that led to the accident. The paper also highlights measures for preventing a recurrence

Digital Deception in the Online Dating Space: A Study of Tinder

As technology continues to impart its worldview, the role of communication in the navigation of dating in online spaces has also evolved. This study examines the relationship between communication and digital deception within a selected population of Tinder users. Tinder is a geo-social, location-aware dating application that is used by millions of people around the world. There are three fundamentally specific objectives of this research, which include: first, examining the ways in which dating apps increase the possibility of digital deception; second, exploring ways in which Tinder\u27s design and functionality contribute to the occurrence of digital deception; and finally, identifying and examining the impacts of online deception, particularly in the context of dating apps, on human communication and relationship formation. To obtain first-hand perceptions of online representation and digital deception on Tinder (and as with other online social platforms), 51 Tinder users from Nigeria and Canada were surveyed through their responses to a questionnaire distributed on June 20 and July 11, 2023. The findings of this study suggest that the use of dating apps among youths has increased, leading to prevalent lying and distrust. In the context of using Tinder among the sampled population, Tinder\u27s design, functionality, and online communication in general facilitate and contribute to instances of digital deception, as its affordances only give room to do little, hence, there is often an attempt to ‘put best foot forward’ and the tendency of lying becomes imminent. Appearance influences deception, but some still trust online dating for meaningful connections; platforms should promote honesty

SUPPLY INSTABILITY INDUCED TORQUE VARIATIONS OF A THREE PHASE ASYNCHRONOUS MOTOR

The torque profile of a three phase asynchronous or induction motor is an indicator of the load handling capacity of the motor. The torque profile of the asynchronous motor is determined by the motor design and by the nature of the voltage supply. The power supply network in Nigeria is unreliable with frequent supply interruptions and outages daily, due to insufficient power generation and supply capacity. These disturbances and recurrent switching on and off may trigger voltage swings below and above the rated line voltage coupled with the tendency for supply frequency variations. In this study, the torque profile of a typical three phase asynchronous motor running under simulated power supply variations is studied in order to reveal the effects of such fluctuations on the motor. Power supply variations, interruptions and low power quality impair motor performance characteristics and these affects the reliability and operational efficiencies of processes where such motors are installed. The result reveals torque variations from the rated value with changing supply conditions which is undesired for a smooth industrial operation

ADOPTION OF INTEGRATED TRANSPORT SYSTEM FOR SUSTAINABLE TRANSPORT PLANNING AND DEVELOPMENT

The importance of addressing urban mobility problems is increasingly being emphasized in the Fourth Industrial Era. This shift towards creating a smart and inclusive cities represents a major milestone towards improving policies and urban mobility processes in both developed and developing cities. One approach to tackle this is the adoption of an integrated active/public transport system for urban mobility. Building on this, the study reviewed the need for an integrated transport system and means to achieve a safe, efficient, accessible, and affordable transport system for all members of society. The study revealed that good modal interchanges are central to creating a better transport network aimed at improving the transportation planning of a country. To achieve this, a well-planned and integrated transport infrastructure and services are needed and should be provided to facilitate and enhance smart mobility for all members of the society irrespective of their status or spatial location. Without planning and investment in better interchanges, the absence of affordable, efficient, and easy to use alternatives will mean those with access to a private car continue to rely on them while those without it will continue to be doubly disadvantaged by the negative social and environmental impacts of over-reliance on private cars. Thus, there is a clear and pressing need for bette

Lightning Protection of Floating Roof Tanks

Prior to export, processed crude oil is stored in Floating Roof Tanks (FRT) to further allow any trapped gas within the crude oil to escape, as this stabilises the crude oil. In the oil and gas industry, FRT’s are vital in the processing of crude oil to the acceptable export specification. In the tropics and other lightning prone regions, lightning induced floating roof tank fire constitutes a major threat to crude oil production. Among others, a single lightning incident could result in the loss of life, product and production time, avoidable incident review time, damaged equipment, wasted repair cost, bad publicity and loss of income. This paper therefore, is aimed at providing an effective solution to the menace of lightning induced tank fire by focussing on the starting process of the lightning induced fire and proposing alternative concepts for breaking the fire triangle before fire ensue

Isomerisation and ring closing metathesis reactions towards benzo-fused heterocyclic compounds

Student Number : 0410864E - MSc dissertation - School of Chemistry - Faculty of ScienceThe aim of the project described in this dissertation is to explore the application of ring closing metathesis (RCM) to the synthesis of 6-, 7-, 8- and 9-membered N,N-, N,O- and O,O-benzo-fused heterocyclic compounds which are interesting structural motifs in medicinal chemistry. In recent times, their structures have been widely used as molecular scaffolds. Some of these heterocycles have been identified as antitumour agents, antibiotics and anti-HIV agents. In our laboratories, a variety of 6-, 7- and 8-membered nitrogen- and oxygen- containing benzo-fused rings have been synthesized through ruthenium-mediated isomerisation and RCM in moderate to good yields. The first step in the present project was N-protection of suitable 2-aminophenols or o-phenylenediamines followed by allylation. Rutheniummediated isomerisation followed by RCM was then used for the synthesis of the 6- membered ring system tert-butyl 4H-1,4-benzoxazine-4-carboxylate 91 and the 7- membered ring system tert-butyl 1,5-benzoxazepine-5(4H)-carboxylate 103 while only RCM was used for the 8-membered ring systems, di(tert-butyl) 2,3,4,5-tetrahydro-1,6- benzodiazocine-1,6-carboxylate 130, di(tert-butyl) 2,5-dihydro-1,6-benzodiazocine-1,6- dicarboxylate 129, 1,6-dibenzoyl-1,2,5,6-tetrahydro-1,6-benzodiazocine 132, 7-methoxy- 2,5-dihydro-1,6-benzodioxocine 137 and the 9-membered ring system 1,6-bis[(4- methylphenyl)sulfonyl]-2,5,6,7-tetrahydro-1H-1,6-benzodiazonine 159. In the synthesis of the 7-membered ring systems, based on established methodology, we encountered problems with the RCM from suitable benzylamine or benzyl alcohol precursors. The reasons for this are not clear but we suspect this could be as a result of electronic and kinetic factors. Nevertheless, we were able to synthesize a 7-membered ring system, tert-butyl 1,5-benzoxazepine-5(4H)-carboxylate 103, from a readily available precursor using a different methodology. Approaches to the synthesis of the 8-membered ring systems, di(tert-butyl) 2,3,4,5- tetrahydro-1,6-benzodiazocine-1,6-carboxylate 130, di(tert-butyl) 2,5-dihydro-1,6- benzodiazocine-1,6-dicarboxylate 129, 1,6-dibenzoyl-1,2,5,6-tetrahydro-1,6- benzodiazocine 132 and 7-methoxy-2,5-dihydro-1,6-benzodioxocine 137, as described in this dissertation, made extensive use of RCM in moderate to good yields, but the deprotection of the Boc group after hydrogenation proved to be a problem. The synthesis of the 9-membered nitrogen containing benzo-fused compounds, 1,6- bis[(4-methylphenyl)sulfonyl]-2,5,6,7-tetrahydro-1H-1,6-benzodiazonine 159 by RCM was successful but in the synthesis of the N,O-benzo-fused compound by RCM, we suspect that polymerization, which is a side reaction in RCM reactions that are slow, occurred. In the synthesis of the 9-membered O,O-benzo-fused compounds, we only isolated the starting material. The final approach in this dissertation involved the use of ruthenium-mediated isomerisation to afford internal isomerisation of the double bond within the heterocyclic rings of the 8-membered and 9-membered benzo-fused compounds previously prepared in our laboratory. This gave a mixture of regioisomers of 10-methoxy-2,3-dihydro-1,6- benzodioxocine 163 and 7-methoxy-2,3-dihydro-1,6-benzodiazocine 164, 1,6-bis[(4- Methylphenyl)sulfonyl]-1,2,3,6-tetrahydro-1,6-benzodiazocine 166, a regioisomeric mixture of 6-[(4-methylphenyl)sulfonyl]-3,6-dihydro-2H-1,6,-benzoxazocine 161 and 6-[(4-methylphenyl)sulfonyl]-5,6-dihydro-4H-1,6,-benzoxazocine 162, and the 9- membered benzo-fused ring system, 1,6-bis[(4-methylphenyl)sulfonyl]-2,3,6,7- tetrahydro-1H-1,6-benzodiazonine 170. The yields were good and the solid state structures of these isomerised compounds were examined by X-ray crystallography. Xray diffraction was also performed on the solid state 8- and 9-membered benzo-fused ring systems. We also compared the crystal structures of the 8- and 9-membered benzo-fused compounds with their isomerised compounds

RISK ASSESSMENT AND SAFETY ANALYSIS FOR A JET FUEL TANK CORROSION RECERTIFICATION OPERATION

Aviation Turbine Kerosene (ATK) or jet fuel is stored in stainless steel tanks or in epoxy coated tanks to prevent contamination through reaction with the tank sheets. Epoxy coated tanks overtime may develop cracks and coating defects which exposes the jet fuel to the steel surface. This is not optimal and it is an aberration to global best practices. Coating defects are corrected after surface preparation through blasting, and grit blasting is one of the common methods. Grit blasting is a hot work that may generate sparks which can be ignited by jet fuel fumes. In the oil and gas industry, personnel are moved via choppers to and from oil platforms and rigs, and this requires ready availability of jet fuel in storage tanks on oil platforms. Jet fuel tank repairs and recertification on offshore facilities where flammable crude oil and gas vapours may be present, coupled with jet fuel fumes is a high risk operation. This study presents a detailed job safety analysis and risk assessment that identifies potential hazards and the necessary safeguards and controls needed to safely manage tank recertification on offshore facilities toward preventing explosion and accidents

Macromolecular 4-aminoquinoline compounds as potential antimalarial drugs

4-Aminoquinolines have a long and successful history as antimalarials as they have provided a number of useful antimalarials. P. falciparum, a causative organism of the most deadly form of human malaria, is generally slow to develop resistance to these drugs. 4-Aminoquinoline derivatives appear to bind to nucleoproteins and interfere with protein synthesis in susceptible organisms; the drugs intercalate readily into double-stranded DNA and inhibit both DNA and RNA polymerase. In addition, 4-aminoquinolines are found to concentrate in parasites’ digestive vacuoles, thereby increasing the pH of the vacuoles, and thus interfere with the parasites’ ability to metabolize. 4-Aminoquinolines on the other hand have raised considerable interest because of their anti-carcinogenic properties and their ability to inhibit tumor development and presently are being used in combination therapy with anti-cancer drugs to inhibit development of drug resistance in cancer cells caused by anti-cancer drugs. 8-Aminoquinoline mechanism is quite different from that of 4-aminoquinoline in that the 8-aminoquinolines are converted in the liver to an active quinone metabolite creating oxygen free radicals that interfere with the plasmodial electron chain transport chain during respiration. Anti-cancer drugs are often toxic when delivered straight, but the bioreversible drug conjugation of anticancer drugs to water-soluble macromolecular carriers has proved to enhance the therapeutic effectiveness of anticancer drugs. Following facilitated pharmacokinetics pathways, the conjugates, acting as prodrugs, will release the active drug species in the transformed target cells and their designs are geared towards reducing pharmacological barriers of toxicity, drug resistance and poor bioavailability encountered with currently used anti-cancer drugs. In order to demonstrate the multidrug binding capacity of polyaspartamide, the co-conjugation of 4- and 8-aminoquinoline derivatives with anti-cancer agents was achieved, and the co-conjugates are expected to serve as resistance-reducing agents. This present project aimed at the anchoring of 4-aminoquinoline to various amine functionalized polymeric carriers, and selected macromolecular 4-aminoquinoline compounds were screened for in vitro antiplasmodial activity