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Dental trauma is a public health problem, accounting for 17% of injuries to the body in those below the age of 6years compared to an average of 5% across all ages. It is more rampant among very young people. The prevalence in Nigeria is increasing. A prevalence of 10.8% was reported in Ibadan about a decade ago. The current study is therefore aimed at finding the prevalence of dental trauma in Ibadan. This was a cross-sectional study carried out among children aged 7 - 15 years in public schools in Ibadan North Local Government Area of Oyo State, Nigeria. Three primary and 3 secondary schools were selected. An interviewer-administered proforma was used to obtain information. Factors assessed were some predisposing factors of dental trauma, among which are Angle's Class II division 1 malocclusion, increased over-jet, anterior open bite and lip competence. Data was analyzed using SPSS version 21 and the level of significance was set at p<0.05. Two hundred and thirty-five children participated in the study. There were 114(48.5%) males and 121(51.5%) females. Prevalence of dental trauma was 11.1%. None of the assessed factors that were statistically significant. The commonest dental trauma was Enamel fracture (Ellis class I), while the most affected teeth were the two upper central incisors. Also, more females and 10 - 12 years old had Enamel-Dentin-Pulp trauma. Dental trauma experience among the children in Ibadan in the last one decade has not significantly changed. Teeth most commonly affected by dental trauma are the upper central incisors. The commonest dental trauma was Ellis class I. [ABSTRACT FROM AUTHOR]

In the current study, the enhancement of the mechanical and tribological behavior of polyimide (PI) composites with varying TiO2 nanoparticles fabricated with spark plasma sintering (SPS) technique was examined. The morphology, mechanical, and tribology of the produced nanocomposites were characterized using scanning electron microscope (SEM), nanoindenter, and tribometer analyzer. The SEM result shows that the TiO2 were diffused uniformly in the polymer matrix. The hardness and modulus of the PI increased with the incorporation of the TiO2 nanoparticles by 314.1% and 76.4%, respectively. Furthermore, the friction coefficient and wear resistance of the nanocomposites was remarkably improved with the TiO2 incorporation. [ABSTRACT FROM AUTHOR]

In this study, the effects of electrical corrosion resistance (ECR) glass fiber on corrosion and mechanical behavior of polyimide (PI) matrix composites prepared using spark plasma sintering (SPS) process were investigated. The morphologies, corrosion properties, and mechanical properties were characterized using scanning electron microscope (SEM), immersion and polarization tests, and nanoindentation tests, respectively. The SEM results revealed that the ECR glass particles were evenly distributed in the PI matrix. The resulting analysis depicts that the introduction of ECR particles contents (5, 10, and 15 wt%) in the PI matrix improved its hardness and elastic modulus both before and after corrosion. The corrosion rate of the pure PI was recorded to be reduced by 61.8%, 50.4%, and 38.9%, respectively, at 5, 10, and 15 wt% loading of ECR particles. This depicts that the ECR glass particles lead to anti-corrosion performance improvement of the pure PI. Finally, the findings suggest the potential of ECR filler materials in the development of novel PI composites for anti-corrosion and mechanical load-bearing applications. [ABSTRACT FROM AUTHOR]

Nile tilapia Oreochromis niloticus is one of the most important fishery resources and a valuable fish species for aquaculture programmes. It is found in almost all waters and is widely dispersed. Several natural populations of this species have been impacted by genetic pollution despite their significant economic relevance. Understanding population structure is a crucial first step in protecting this species in its native habitats as well as in choosing which wild stocks to use in hatchery initiatives. To demonstrate the genetic-population structure of this species, genetic differences among three geographically secluded populations of O. niloticus were investigated utilizing mitochondrial DNA cytochrome b gene sequences. The results were used to estimate the levels of genetic variability within and among the populations. The 56 cyt b (821 bp) sequences analysis revealed 21 haplotypes, with a nucleotide diversity of 0.0510 and a haplotype diversity of 0.881. In each of the populations, seven (7) singleton variable sites and 19 informative-parsimony sites, genetic diversity could be identified and few population haplotypes were found, indicating a minor genetic distinction between them. For the purpose of conservation and/or Nile tilapia breeding programmes, this information would assist in choosing the fish populations that maintain greater genetic variation in O. niloticus.

The study assessed the contamination status of a fish pond with the view of offering insight on the accumulative features of polycyclic aromatic hydrocarbons (PAHs) in the sediments and fish parts. The PAHs were extracted and cleaned up on activated alumina adsorbent. A gas chromatograph coupled with flame ionization detector (FID) was used to quantify the compounds. In general, the sediments were more concentrated in the analyzed PAHs than the water samples. Low (3.51–24.7%) spatial distribution existed in the PAHs level as revealed in the calculated CV%. Fluoranthene, pyrene and anthracene were most concentrated compounds in the fish. The PAHs percentage load ratio of 34.9:34.2:30.9 were observed in the muscle, head and liver, respectively. Acenaphtylene, acenaphthene, indeno(1,2,3-cd)pyrene and dibenzo(a,h)anthracene were highly accumulated in the sediments as compared to other samples, while fluorene and benzo(k)fluoranthene showed the least and highest accumulated PAHs respectively in all the fish parts. [ABSTRACT FROM AUTHOR]

Though the trilateral cycle (TLC) is a promising heat recovery-to-power cycle, its application has not been widely accepted or commercialised due to some thermodynamic feasibility concerns. This study examined the performance analysis and sensitivity of the system parameters on the thermodynamic performance of the TLC power generator systems for waste heat recovery-to-power generation. Thermodynamic models of the simple, recuperative, reheat and regenerative TLCs were established. Performance analysis and sensitivity of the system parameters on the cycles' performance were conducted at the expander inlet temperature of 453 to 473 K, expander pressure of 2 to 3 MPa and expander isentropic efficiency of 50% to 100%. The expander inlet temperatures, pressures, and its isentropic efficiencies have significant effects on the thermodynamic efficiencies and net work output of the cycles. At 473 K cycle high temperature, the thermal efficiencies of the cycles increase from 20.13% to 21.97%, 23.29% to 23.91%, 20.62% to 22.07% and 20.66% to 22.9% for the simple, recuperative, reheat and regenerative TLCs, respectively. Their corresponding net power outputs varied from 131.6 to 134.1 kW, 145.9 to 152.2 kW, 113.8 to 124.1 kW and 124.9 to 130.5 kW, respectively. The cycles' thermodynamic performance increased with an increase in expander inlet temperature, expander pressure and expander isentropic efficiencies. [ABSTRACT FROM AUTHOR]

Ti6Al4V is one of the most useful alloys because of its high strength, low weight, high oxidation resistance and low CTE. However, it is weak in shear strength which has affected its performance. This research was aimed at developing high-entropy alloy of Ti20-Al16-V16-Fe16-Ni16-Cr16 at near equi-molar level via spark plasma sintering technique which would possess better mechanical and oxidation characteristics than Ti64. The powders were blended, sintered at varying temperatures from 700 to 1100 °C and characterized. Results showed that HEA sintered at 1000 °C possessed the best mechanical, oxidative and microstructural properties, while that sintered at 700 °C had the least mechanical and thermal properties. The developed HEA had elastic modulus improvement of about 336% over Ti6Al4V and about 277% over Ti6Al4V-0.55B alloys. It had creep resistance of 2.47% at loading of 300 mN and 4.38% at loading of 500 mN, densification of 98.86%, porosity of 1.14% and a parabolic oxidation profile. It was concluded that the developed alloy has superior mechanical and oxidation properties than Ti64 and so can perform better in applications where high strength at high temperature is required. [ABSTRACT FROM AUTHOR]

High-entropy alloy (HEA) has gained considerable interest in the research community because of its essential properties over conventional alloys. Hence, this work was aimed at development of Ti20–Al20–V20–Fe20–Ni20 HEA with the objective of determining its suitability in high-strength applications. Spark plasma sintering (SPS) was the fabrication technique used. SEM–EDS and XRD were used in the characterization, while nanoindenter and tribometer were used in the Vickers hardness and wear testing, respectively. Results obtained showed that sintering temperature of 1100 ℃ was the optimal temperature. The developed HEA had Vickers hardness improvement of 130% over Ti6Al4V alloy, wear rate improvement of 130% over Inconel 718 alloy and 666% over TiAl alloy. It was concluded that the developed HEA can perform much better than the famous Ti6Al4V superalloy in high-temperature/strength applications. [ABSTRACT FROM AUTHOR]

A high level of recognition has been given to high-entropy alloys (HEAs) in recent years because of their excellent properties over conventional superalloys. Consequently, research focus has shifted to the development and characterization of high-performing HEAs. The objective of this work was to develop and characterize Ti36-Al16-V16-Fe16-Cr16 HEA with the aim of determining its performance over conventional superalloys in engineering applications. Spark plasma sintering was the fabrication technique used. SEM–EDS and XRD were used in the characterization while a nano indenter and tribometer were used in the Vickers hardness and wear testing, respectively. Results obtained showed that a sintering temperature of 1000°C was optimal. The developed HEA had a Vickers hardness improvement of 136% over the Ti6Al4V alloy; and a wear rate improvement of 157% over Inconel 718 alloy, and 614% over TiAl alloy. It was concluded that the developed HEA can perform much better than conventional Ti6Al4V and other superalloys in engineering applications. [ABSTRACT FROM AUTHOR]

This research evaluates the influence of process parameters of the spark plasma sintering (SPS) technique on the densification and hardness properties of ECR/TiO2/PI nanocomposite. Taguchi's design of experiment was employed for designing the sintering process, while analysis of variance (ANOVA) was adopted to evaluate the contribution of the factor variables to the response variable of hardness and density. 10 wt% ECR-glass and 4 wt% TiO2 were used as reinforcements in the polyimide matrix at varying pressure and temperature for the physical experiment. The sintered samples were examined using a scanning electron microscope, nanoindentation tests, and an Archimedes-based density tester. The optimization was performed on total 9 numbers of runs of experiments. The most desirable SPS processing parameters were recorded at 320 °C and a pressure of 30 MPa. Under this processing condition, a density of 1.49 g/cm3 (relative density of 98.7%), Vickers hardness, and nanoindentation hardness value of 33.46 HV and 361.30 MPa, respectively, were obtained. This research work suggests a facile way to produce high-performance PI nanocomposite for various engineering applications, such as mechanical load-bearing and insulation applications. [ABSTRACT FROM AUTHOR]

Background: The importance of accurate diagnosis of infectious diseases is central and crucial to the effectiveness of treatment and prevention of the associated long-term complications of such infections. The objective of this study was therefore to determine the accuracy of the Widal antibody titre test in the diagnosis of typhoid fever relative to the gold standard blood culture technique. Methodology: A total of 40 students attending the Olabisi Onabanjo University Health Services, Ago-Iwoye, Ogun State, Nigeria on account of suspected typhoid fever by positive Widal test (= 1/80) and not on antibiotic therapy, were recruited for the study. Stool and blood samples were collected from each participant and analysed at the medical laboratory of the health center using conventional culture techniques and confirmation of isolates by simplex and multiplex polymerase chain reaction (PCR) amplification assays of hilA (Salmonella enterica), ipaH (Shigella spp), rfc (Shigella flexneri) and wbgZ (Shigella sonnei) genes. Antibiotic susceptibility testing (AST) of isolated bacteria to 10 panel of antibiotics was done using the Kirby Bauer disk diffusion test and interpreted according to the Clinical and Laboratory Standards Institute (CSLI) guideline. Results: Of the 40 patients with suspected typhoid fever by the Widal test, 9 yielded Salmonella enterica giving a 22.5% isolation rate, with Salmonella enterica serovar Typhi (Salmonella Typhi) confirmed as sole bacterium from blood cultures in 5 (12.5%) patients and co-infection of Salmonella and Shigella from stool samples in 4 (10.0%) patients. A total of 52 enteric bacteria isolates were recovered from blood and stool samples of the 40 patients made of Salmonella enterica 9 (17.3%), Shigella spp 20 (38.5%), S. flexneri 9 (17.3%) and S. sonnei 14 (26.9%). All the enteric isolates were multi-drug resistant (MDR), with resistance rates to the antibiotic panel ranging from 33.3%-100%, and all the isolates were resistant to ceftriaxone and pefloxacin. Salmonella isolates were also 100% resistant to nitrofurantoin, ofloxacin and ciprofloxacin; S. flexneri were 100% resistant to nitrofurantoin, amoxicillin, cotrimoxazole, ofloxacin and ciprofloxacin; and S. sonnei were 100% resistant to nitrofurantoin and cotrimoxazole. Conclusion: These results showed that only 12.5% of typhoid fever diagnosis by Widal test had Salmonella Typhi isolated from their blood cultures while Salmonella enterica and Shigella spp were isolated from stool samples of other cases. There is need to adopt culture techniques for laboratory diagnosis of febrile illnesses in order to improve treatment regimen. The fact that AST can also be performed with culture technique could further guide antibiotic prescription and reduce the risk of emergence of resistant bacteria. [ABSTRACT FROM AUTHOR]

This paper assessed the status of climate smart agriculture (CSA) among VADI farmers in North-central Nigeria using qualitative and quantitative methods in data collection. Two hundred and forty-seven farmers were randomly selected from the study area. Also, focus group discussions were conducted. Data collected were subjected to qualitative analysis and logit regression. The study identified five broad and important practices relevant to CSA in North-central Nigeria, which include: mobility and social networks, adjusting agricultural production systems, diversification on and beyond the farm, farm financial management, and knowledge management and regulations. The determinants of CSA in north-central Nigeria include: farming experience, education, extension, livestock ownership, income, land ownership, household size, credit, land area cultivated, distance to the market and water resources, leadership position, risk orientation, gender, and mass media exposure. Government policies need to support research and development that develops and diffuses the climate-smart technologies to help farmers respond to changes in climatic conditions. [ABSTRACT FROM AUTHOR]