Experimental and Numerical Investigation of Fire Behaviour in Polyurethane Foams

Due to the complex and varying nature of a flame and its products, the scaling of fire behaviour has been a challenge in the area of fire science. The use of small-scale test data to interpret full-scale fire behaviour is an area of ongoing research with potential savings for manufacturers required by code to test products for large-scale fire behaviour. Polyurethane foam was selected as the sample material for the research due to its widespread application in home and office furniture and its potential to act as a fuel source in fires due to a high hydrocarbon content. The heart of the problem lies with predicting how much heat is released by the fire and the rate at which flame spreads across the material. This research builds on previous University of Saskatchewan research and seeks to provide a method to predict full-scale flame spread across a material. Additionally, methodologies such as the Combustion Behavior of Upholstered Furniture (CBUF) Model applied for full-scale heat release rate (HRR) predictions and Alpert’s correlation employed in predicting compartment temperatures are also evaluated. Small-scale cone calorimeter tests which serve as input to the CBUF model were conducted for foam thickness of 2.5, 7.5 and 10 cm at incident heat fluxes of 5, 10, 15, 20, 35 and 50 kW/m2. Separate small-scale tests were conducted on foams instrumented with thermocouples to measure temperatures on the surface and at depth. A numerical model was proposed to predict the surface temperatures and estimate the time to ignition of the small-scale foam specimens. Full-scale compartment fire tests were conducted for centre and edge ignition at the University of Waterloo Live Fire Facility. Compartment temperatures and flame areas were measured. A model was developed to predict flame spread based on the data collected from previous University of Saskatchewan furniture calorimeter test. The results of the flame spread model showed promise in predicting the area spread rates. The model, however, did not capture some of the edge effects that occurred due to the flame reaching the foam boundaries. The area spread model was used within the CBUF model which satisfactorily predicted the full-scale HRR. The HRR predictions were then applied to a modified version of Alpert’s correlation which predicted ceiling jet temperatures accounting for the spread of flame. Predictions of ceiling jet temperatures made using Alpert’s correlation was improved by considering flame spread

Application of Markov Chain Model and ArcGIS in Land Use Projection of Ala River Catchment, Akure, Nigeria

Increase land use change is one of the consequences of rapid population growth of cities in developing countries with its negative consequences on the environment. This study generates previous and present land use of Ala watershed and project the future land use using Markov chain model and ArcGIS software (version 10.2.1). Landsat 7, Enhanced Thematic mapper plus (ETM+) image and Landsat 8 operational land imager (OLI) with path 190 and row 2 used to generate land use (LU) and land cover (LC) images for the years 2000, 2010 and 2019. Six LU/LC classes were considered as follows: developed area (DA), open soil (OS), grass surface (GS), light forest (LF), wetland (WL) and hard rock (HR). Markov chain analysis was used in predicting LU/LC types in the watershed for the years 2029 and 2039. The veracity of the model was tested with Nash Sutcliffe Efficiency index (NSE) and Percent Bias methods. The model results show that the study area is growing rapidly particularly in the recent time. This urban expansion results in significant decrease of WL coverage areas and the significant increase of DA. This implies reduction in the available land for dry season farming and incessant flood occurrence. Keywords: Land cover, land use change, Markov chain, ArcGIS, watershed, urbanizatio

Analysis of Physicochemical and Bacteriological Quality of Surface and Groundwater Samples in Offa, Kwara State, Nigeria

The water quality assessment in First Baptist Church, Offa, Kwara State Nigeria was carried out by examining nine samples in and around the church premises. One surface water sample, five borehole water samples and three well water samples were examined. The result obtained from the physicochemical analysis showed a turbidity range of (2-6NTU), electrical conductivity EC (693-893 μs/cm), total dissolved solids TDS (346-542mg/L), pH (6.83-7.62), magnesium Mg (17-53mg/L), manganese Mn (0.02-0.1), aluminium Al (0.02-0.13mg/L), iron Fe (0.10-0.44mg/L), zinc Zn (0.8-3.60mg/L), chromium Cr (0.02-0.13mg/L), lead Pb (0.01-0.04), Sulphate SO4 (3- 20mg/L), Nitrate NO3 (3-18mg/L), phosphate PO4 (1.5-14mg/L), chlorine Cl (14-42mg/L), copper Cu (0.04- 0.7mg/L), chemical oxygen demand COD (62-120mg/L), total hardness TH (80-160mg/L) and total alkalinity TA (80-136mg/L). These results, together with that of the microbial analysis were compared with the standard provided by the World Health Organization WHO. Hence, it is crucial that the water supplies are regularly assessed and properly treated to provide the consumers with safe and healthy water

Extent of Information and Communication Technology Skills Possessed by Librarians in University Libraries in Anambra State, Nigeria

Persistent innovations and advances in Information and Communication Technology have substantially modified the way information is acquired, processed, stored, retrieved, and communicated. This has consequently changed the ways the library, which is visibly and significantly placed in the profession of information management operates, hence creating the need for library and information professionals to be sufficiently skilled in ICT operations which are now necessary for effective information services delivery. However, users are seemingly starved with services which the library professionals are expected to deliver through the use of ICTs. This implies that librarians are possibly not conversant with ICTs that they might be unable to respond to users’ needs promptly and render excellent library service to users as well. This is an ugly situation and may likely bring discredit to librarians and library profession in this 21st Century. This study therefore surveyed extent of Information and Communication Technology skills possessed by librarians in the universities in Anambra State, Nigeria. The research design adopted for this study is descriptive survey. The population consists of thirty-three (33) librarians in the five universities in Anambra State. Population was small hence, the whole subjects were studied. Two instruments - achievement test and questionnaire were used for data collection. Data obtained were analyzed using simple percentages, frequencies, and mean rating. Findings of the study include: Librarians in the universities in Anambra State are weakly skilled in ICTs hence their overall average percentage score in ICT skills was 58.3%. Their average percentage scores in dimensions of ICT are as follows: Basic Computing 83%, File Management 71%, Word Processing, 76%, E-mail operations 54%, Automated Cataloguing and Classification/use of OPAC 42%, use of Library Automation Software 56%,  use of the Internet/WWW 61%, Information Search and Retrieval 62%, Presentation using Microsoft Power Point, 40%, Database Creation/Management 38%. Average percentage scores showed that librarians are highly-skilled in Basic Computing, Word Processing, and File Management and are moderately-skilled in Information Search and Retrieval, Internet and World Wide Web. They are weakly-skilled in Library Automation, E-mail operations, and are not skilled in Automated Cataloguing and Classification/use of OPAC, presentation using Microsoft Power Point, Database Creation/Management. Challenges militating against librarians’ ICT skills acquisition were identified and solutions were proffered. Keywords: Information and Communications Technologies, skill, Information and Communications Technologies Skills, University Library

Physico-thermal properties of TiO2 nanoparticles using molecular dynamics simulations with relevance to thermal conductance of nanofluids

Nanoparticles have attracted the attention of researchers in a number of multidisciplinary fields as they possess enhanced structural and physical properties, which make them desirable to a wide range of industries. These enhancements have mostly been attributed to nanoparticles possessing large surface area-to-volume ratio. The concept of engineered nanofluids refers to making stable suspension of nanoparticles in base fluids to provide more efficient and thermally enhanced effective thermal conductance in a number of engineering applications involving heat transfer processes. Although experimental and computational studies have shown significant enhancement of thermal conductivity of nanofluids compared to the conventional heat transfer fluids, the underlying mechanism behind this enhancement is still not well understood. Out of the several mechanisms which have been proposed in the literature to be behind this enhancement of thermal conductivity, nanoparticle clustering seems to evolve as a relatively more significant factor for the enhancement of effective conductance of nanofluids and hence requires more detailed investigation in the future. In this study, initially, numerical investigations are conducted to study the effect of particle clustering on thermal conductivity of nanofluids. The degree of thermal enhancement is analysed for different factors that capture particle clustering, such as aggregate size, particle concentration, interfacial thermal resistance, and fractal and chemical dimensions. This analysis is conducted for three model water-based nanofluids of aluminium oxide (Al2O3), copper oxide (CuO) and titanium dioxide (TiO2) nanoparticles in which particle concentrations are varied up to 4 volume %. Results from the numerical work are validated using available experimental data. Studies showed that predicted and experimental data for thermal conductivity enhancement are in good agreement as particle clustering is seen to influence effective thermal conductance of the model nanofluids. Considering this observation and to further understand the mechanism behind particle clustering, particle scale properties such as thermodynamic, structural, surface and interaction force properties are investigated in vacuum and liquid environments at different temperatures, using Molecular Dynamics (MD) simulations. These simulations are carried out on TiO2 nanoparticles (with particle sizes ranging between 2 – 6nm) as a model system owing to their wide industrial applications, with a particular focus on two mostly encountered forms of TiO2 namely; anatase and rutile. From MD simulations, the Radial Distribution Function (RDF) plots of the particles in vacuum revealed much higher crystallinity with peaks of almost an order higher than that of the nanoparticles in water. For anatase, surface energy of the particles in vacuum is seen to be higher than that of the particles in water by about 100% for the smaller size particles (especially for 2 and 3nm), and about 60% for relatively larger particles (especially for 4 to 6 nm). In both environments, surface energy of anatase nanoparticles is also seen to increase with particle size to a maximum value of critical particle size (i.e. 4 nm) after which no further significant increase in surface energy is observed. Finally, force – displacement analysis which captures interaction force relations is conducted for different particle sizes in vacuum and water environments, using MD simulations. This analysis provides interaction force information which is vital in studying particle interactions. In this study, the nanoparticles are seen to be more attractive at a smaller size and the attraction increases as the particle size increases. Particles are also seen to become repulsive at initial contact. Overall, this thesis presents vital information on particle scale properties of TiO2 nanoparticles (as a model system) under different environments. These properties are known to influence clustering of nanoparticles which in turn influence thermal enhancement of nanofluids. In the near future, knowledge of these particle scale properties will aid in the development of more enhanced nano and bulk systems with better physico-thermal properties, to meet the ever growing requirement for technological advancement

Extent of Information and Communication Technology Skills Possessed by Librarians in University Libraries in Anambra State, Nigeria

Persistent innovations and advances in Information and Communication Technology have substantially modified the way information is acquired, processed, stored, retrieved, and communicated. This has consequently changed the ways the library, which is visibly and significantly placed in the profession of information management operates, hence creating the need for library and information professionals to be sufficiently skilled in ICT operations which are now necessary for effective information services delivery. However, users are seemingly starved with services which the library professionals are expected to deliver through the use of ICTs. This implies that librarians are possibly not conversant with ICTs that they might be unable to respond to users’ needs promptly and render excellent library service to users as well. This is an ugly situation and may likely bring discredit to librarians and library profession in this 21st Century. This study therefore surveyed extent of Information and Communication Technology skills possessed by librarians in the universities in Anambra State, Nigeria. The research design adopted for this study is descriptive survey. The population consists of thirty-three (33) librarians in the five universities in Anambra State. Population was small hence, the whole subjects were studied. Two instruments - achievement test and questionnaire were used for data collection. Data obtained were analyzed using simple percentages, frequencies, and mean rating. Findings of the study include: Librarians in the universities in Anambra State are weakly skilled in ICTs hence their overall average percentage score in ICT skills was 58.3%. Their average percentage scores in dimensions of ICT are as follows: Basic Computing 83%, File Management 71%, Word Processing, 76%, E-mail operations 54%, Automated Cataloguing and Classification/use of OPAC 42%, use of Library Automation Software 56%, use of the Internet/WWW 61%, Information Search and Retrieval 62%, Presentation using Microsoft Power Point, 40%, Database Creation/Management 38%. Average percentage scores showed that librarians are highly-skilled in Basic Computing, Word Processing, and File Management and are moderately-skilled in Information Search and Retrieval, Internet and World Wide Web. They are weakly-skilled in Library Automation, E-mail operations, and are not skilled in Automated Cataloguing and Classification/use of OPAC, presentation using Microsoft Power Point, Database Creation/Management. Challenges militating against librarians’ ICT skills acquisition were identified and solutions were proffered

Gedischte aus Biafra (Poetry from Biafra)

An illustrated color brochure, featuring my poem Rituals eines Angriffs [Rituals of Raids] about the uncanny resemblance of the ubiquituous air raids of the day and the raids on chicken by hawks ritually reenacted in the routines of the hawk mask Ojionu on festive occasions (plus poetry by five other Biafran poets

Evaluation of groundwater repositories in parts of Enugu, Eastern Nigeria via electrical resistivity technique

Abstract Resistivity survey was carried out in Enugu North, Southeastern Nigeria, in order to evaluate the groundwater condition of the area. The inadequacy of surface water, proper knowledge of the aquifer and increasing population has affected the extraction and development of groundwater in the area. Resistivity, thickness, depth, curve frequencies and protection level were determined. The result revealed a total of 5–6 geoelectric layers with model curves exhibiting the following curve types: KHK taking about 10%; AAKQ, KHAK, KHAA, HKQ, HKQQ and HAA taking 12%, AAA, AKH, HAK and KHKQ taking 24% while AKQ and AAK take 20 and 34%, respectively. The aquifer is within the fourth and fifth layer considering the layer with the largest thickness with the fourth layer taking up to 84% of the aquifers in the study area. The overburden layer resistivity and thickness ranged from 589.8 to 85,094.8 Ωm and 8.9 to 99.5 m with mean values of 42,642.3 Ωm and 54.2 m, respectively. The contour maps were generated using Surfer software package version 15 which show the variation of overburden parameters. The study area was generally considered as having a high protective level as a result of the low values of geophysically based protection index of the aquifer layers and weak to fair GPI rating implying that the aquifer can be protected from infiltrating contaminants. However, high hydraulic conductivity and porosity suggest high groundwater potential and high infiltration of polluted geofluids

CORPORATE GOVERNANCE MECHANISM AND STOCK PRICE PERFORMANCE: INSIGHTS FROM NIGERIA

Over the years, firms from financial, real estate and construction sectors in Nigeria have been challenged heavily by corporate governance lapses. This seems to have affected major spheres of performance and specifically market stock price of the firms, thereby necessitating investigation into its level of influence. This study assessed how corporate governance practices affected listed businesses in Nigeria's firm performance. The study's goal is to assess the impact of board diversity, independence, size, and ownership on the stock price performance of a sample of Nigerian public companies. In order to achieve this, the study used secondary data, which was based on an ex post facto research strategy and used a pooled data set gathered from sixteen (16) quoted businesses during the period between the 2006 and 2019 financial period. Descriptive statistics, correlation matrices, and robust least squares regression analysis techniques were used to analyze the data that had been gathered. The Agency theory and entrenchment hypothesis served as the study's pillars. The results support the entrenchment hypothesis, which contends that large board ownership percentages have a negative impact on stock price performance. In particular, we discover that the stock price performance of listed companies in Nigeria throughout the study period was negatively impacted by the corporate governance variables of board size and board ownership, both of which are statistically significant at1%, 5%, and 10%. The entrenchment effect, which is already at work among our sample companies, leads us to urge, among other things, that consideration be given to the review of board ownership and size in light of the study's findings