Development of an improved earthing method for power and distribution transformers substations

Engineers and planners have realized that equipment grounding is a necessary part of installation process in Electrical power substations. Over years, grounding or earthing has been carried out primarily through preparation of Earth Mat which is interconnected with several Earth-rods buried around the equipment under consideration. This approach takes several efforts to have an acceptable and reliable result. However, this paper presents a more flexible, economical and results oriented approach. A flow chart which describes the procedures of carrying out the proposed method of earthing is developed. This was applied to two case studies: a proposed Power transformer substation and distribution Transformer substation located within the same geographical domain. On the two cases, the measured earth resistances are presented and discussed. The results from the case study indicates that the earth resistance values obtained from this new approach are reliable and in compliance with IEEE Standards 80,142, 81 and 1100.Keywords: Equipment, Grounding, Earthing, Earth-rod, Flowchart, Earth Mat, Flow Process, Injection Substation, Distribution Substation, Earth Resistance, IEEE Standard

ON EXTREME VALUE THEORY IN MODELING NIGERIA MARINE AND AVIATION INSURANCE CLASS OF BUSINESS

Extreme value theory is applied to model extreme occurrences, and it is applied in business and finance to measure tail risk. Marine and aviation class of insurance business is an important component of non-life business because it insures all risks relating to aviation and marine vessels which play a significant role in the economic development of Nigeria. Recent claims experience has necessitated the investigation of tail risks with a small probability of occurrence but with high potential impact on a company’s survival. The study employs the Extreme Value Theory (EVT) to estimate the minimum expected claims for the marine and aviation insurance business using historical claims data. Diagnostics plot like the mean excess plot suggest the threshold to choose, to fit a Generalized Pareto model based on EVT and the excess distributions were obtained over a chosen threshold. Linear Q-Q plots and tail plots reveal that the parametric model fits the data well. VaR estimate was finally obtained using the extreme value method at a 5% confidence interval and the empirical results show that Extreme VaR is most suitable to calculate VaR as against the Historical and Gaussian methods. This will guide proper underwriting process and loss reserving in this class of business

Unlocking Rural and Remote Coverage with Small Cells and Satellite

According to the Global System for Mobile Alliance (GSMA), in 2017, there were around 3.3 billion people connected to the mobile Internet. This represented an upward surge in global coverage compared to previous years. However, more than one billion people are still not covered by mobile broadband networks, representing what is termed “the coverage gap”. Uncovered populations typically live in rural locations with low population densities, low per-capita income levels and weak or non-existent enabling infrastructure, and thus, closing the mobile coverage gap seems to be more of an economic challenge, than a pure technical one. This paper presents an overview of the need for rural and remote coverage, both from an operator and consumer as well as government perspective. It then presents the major challenges, and necessary actions to be taken by industry, Government and other stake-holders to drive rural and remote coverage by significantly lowering the cost of network roll-out and increase incentives for such deployments. The paper therefore, presents a technical and business case for the use of “Small Cells” in conjunction with satellites with a view to opening up huge markets via collaboration between the mobile operators and satellite system owners, while offering significant improvements in the coverage and capacity needs of remote, rural or underserved end-users in a cost-effective and scalable manner. Detailed insights to these two technologies are presented, including the innovations to overcome technical and regulatory challenges. Lastly, some real-life deployments are given and the paper concludes with some recommendations for Government and network operators presente

Applications of Space Technology for Accelerated Infrastructures Development for Rural Areas Development in Nigeria

Rural to urban migration still persists in Nigeria despite government’s claim of rural development programs. This situation if not checked portends negative signal for the already over-populated urban areas, particularly in areas of food security, sanitation, housing, crimes, etc. The development of rural areas is measured by the availability of infrastructures and economic opportunities that are available to the people. These infrastructures include: transportation infrastructure, educational infrastructure, healthcare infrastructure, energy infrastructure, water supply/sanitation infrastructure, information and communication technology (ICT) infrastructure and so on. Rural areas in Nigeria urgently require accelerated infrastructure development to alleviate poverty. When this is done rapid growth is ensured and poverty is drastically reduced. The world today has become increasingly reliant on information and communication technologies (ICT) and with it comes the need for societies and communities to stay connected and be integrated into the global information super highway. Space technology today has also become an integral part of global information infrastructure, connecting people across the world and serving communications needs of governments, businesses and individuals. For Nigeria to be technologically developed, the “digital divide” (that is the imbalance between urban and rural dwellers in which the rural dwellers have far lesser access to the same quality of knowledge), information, and education resources that are more readily available to urban areas because of the absence of required communication infrastructure need to be removed. The digital divide brings a virtual, but real impediment to the advancement of the society and individuals in remote rural settlements. This paper seeks to discuss the applications of space technology for accelerated rural infrastructures development in rural areas in Nigeri

Computational Dynamics of Anti-Corrosion Performance of Laser Alloyed Metallic Materials

Laser surface alloying (LSA) is a material processing technique that utilizes the high power density available from defocused laser beam to melt both reinforcement powders and a part of the underlying substrate. Because melting occurs solitary at the surface, large temperature gradients exist across the boundary between the underlying solid substrate and the melted surface region, which results in rapid self-quenching and resolidifications. Reinforcement powders are deposited in the molten pool of the substrate to produce corrosion-resistant coatings. These processes influence the structure and properties of the alloyed region. A 3D mathematical model is developed to obtain insights on the behavior of laser melted pools subjected to various process parameters. It is expected that the melt pool flow, thermal and solidification characteristics will have a profound effect on the microstructure of the solidified region

A novel superfamily containing the β-grasp fold involved in binding diverse soluble ligands

BACKGROUND: Domains containing the β-grasp fold are utilized in a great diversity of physiological functions but their role, if any, in soluble or small molecule ligand recognition is poorly studied. RESULTS: Using sensitive sequence and structure similarity searches we identify a novel superfamily containing the β-grasp fold. They are found in a diverse set of proteins that include the animal vitamin B12 uptake proteins transcobalamin and intrinsic factor, the bacterial polysaccharide export proteins, the competence DNA receptor ComEA, the cob(I)alamin generating enzyme PduS and the Nqo1 subunit of the respiratory electron transport chain. We present evidence that members of this superfamily are likely to bind a range of soluble ligands, including B12. There are two major clades within this superfamily, namely the transcobalamin-like clade and the Nqo1-like clade. The former clade is typified by an insert of a β-hairpin after the helix of the β-grasp fold, whereas the latter clade is characterized by an insert between strands 4 and 5 of the core fold. CONCLUSION: Members of both clades within this superfamily are predicted to interact with ligands in a similar spatial location, with their specific inserts playing a role in the process. Both clades are widely represented in bacteria suggesting that this superfamily was derived early in bacterial evolution. The animal lineage appears to have acquired the transcobalamin-like proteins from low GC Gram-positive bacteria, and this might be correlated with the emergence of the ability to utilize B12 produced by gut bacteria. REVIEWERS: This article was reviewed by Andrei Osterman, Igor Zhulin, and Arcady Mushegian

Antimicrobial Susceptibility Profile of Bacterial Pathogens Isolated From Pregnant Women with Asymptomatic Bacteriuria at Tertiary Hospital in Northeastern Nigeria

Asymptomatic urinary tract infection among pregnant women is a common clinical episode that is frequently undiagnosed. A total of 200 clean-catch mid-stream urine (150 pregnant women and 50 non-pregnant women)were examined by microscopy and culture methods. Overall, the  prevalence of asymptomatic bacteriuria was 59.0% (118/200) and was significantly higher among pregnant (63.3%, 95/150) than non-pregnant (46.0%, 23/50) subjects (÷2 = 4.66, df = 1, p = 0.03). Tertiary education (72.6%, OR = 1.45, p = 0.014), third trimester (77.6%, OR = 1.39, p = 0.042), multi-gravidity (79.0%, OR = 1.41, p = 0.0017) and multiparity (75.9%, OR = 1.49, p = 0.03) were factors associated with asymptomatic bacteriuria in studied pregnant subjects. Of the 118 bacterial isolates, Klebsiella spp accounted for 39.8% (47/118), followed by S. aureus 22.9% (27/118), E.coli 19.5% (23/118), Proteus spp 9.3% (11/118) and P. aeruginosa 8.5% (10/118) (p < 0.0001). Antibacterial susceptibility test revealed that all bacterial isolates were susceptible to quinolones (ciprofloxacin, pefloxacin and ofloxacin). In addition to this, S. aureus was also susceptible to erythromycin. However, all bacterial isolates were resistant to readily available antibacterial drugs including augmentin®, cotrimoxazole, penicillin and cephalexin. In conclusion, prevalence of asymptomatic bacteriuria among pregnant women in this study isconsidered to be high and the bacterial isolates were quinolones sensitive and resistant to other commonly used antibacterial drugs. Considering the clinical implications of untreated urinary tract infection, it is therefore advisable that routine urine culture may be adopted as part of antenatal care.Keywords: Asymptomatic bacteriuria, urinary tract infection, antimicrobial susceptibility, tertiary hospita

ADOPTING INDIGENOUS LANGUAGES IN TEACHING COMMUNICATION AND ENGINEERING EDUCATION IN TERTIARY INSTITUTIONS: LESSONS FROM SOUTH AFRICAN UNIVERSITIES

This study sought to determine the potential place of Afrikaans and IsiXhosa as indigenous languages to promote communication education in South African Universities. This study examined the approaches and curriculum development of the use of Afrikaans and IsiXhosa to teach journalism trainees in Rhodes and North-West Universities. For the purpose of this study, uses and gratification theory was employed to examine how communication and engineering instructors have adopted Afrikaans and IsiXhosa to teach and train students in the field of engineering and journalism. The method adopted for this study was a mixed method approach combining qualitative content analysis, observation and interviews. Furthermore, a review of previous studies on the adoption of Afrikaans and IsiXhosa for communication and engineering education was examined. The result showed that many of communication and engineering trainers believed that the use of Afrikaans for communication and engineering education aids socio-cultural development among white South Africans. From the findings, it was observed that the idea of integrating Afrikaans and IsiXhosa to teach journalism was premised on promoting local identities. Interestingly, the result indicated that Rhodes School of Journalism has a course focused on IsiXhosa for Journalism, which is a compulsory course for first year undergraduate students to understand the application of IsiXhosa in journalism practice for creating community based solutions. The study, therefore, recommends that communication educators can adopt indigenous languages for teaching communication and engineering education in Nigeria and other African countries. The adoption of indigenous languages in teaching communication education would facilitate social integration and multicultural development

Menace of Waste Dumping Along Median Strips and Drainage in Ogun State: a Development Communication Approach

Waste dumping along the median strips and drainages is fast becoming a norm among residents of Ogun State. This study sought to investigate the reasons why residents dump refuse along the median strips ; to what extent are they aware of the statutory provisions against the menace as well as find how their knowledge of the health and environmental consequences of Waste Dumping along the median Strip and Drainages. Theory of planned behaviour connected to the research area was reviewed thereby clarifying the main topic and aiding the data collection. The research methodology of survey and in-depth interview were used in the study. An interview was conducted with the Permanent Secretary Cabinet Matter in the Ogun State Government. A structured designed questionnaire was administered to a randomly selected sample of 300 respondents. 150 respondents each in Idiroko Expresss Road Ota, Ogun State and the Adatan/Lafenwa Road, Abeokuta, Ogun State. The result of the study revealed that Government, believes that the practice of the people is unjustifiable, describing it as an act of total indiscipline. Although residents of Ogun State are aware of the wrongness of dumping waste along the median strips and drainages, results from the findings of the survey revealed that 54% of the respondents attributed illicit waste dumping act to the long distance of waste containers, 56.3% related their actions to non-availability of waste dump site. The study further shows that 80.2% of the sampled population expressed knowledge of the existence of laws against dumping of waste along median strips and drainages. The study therefore concluded that on the need for an urgent shift from Mongolic to Dialogic communication in curbing the deepening behavioural pattern of dumping waste along the median strips and drainages by residents of Ogun Stat