MODELING AND SIMULATION OF MECHANICAL PROPERTIES OF PULVERIZED COW BONE AND LATERITIC PAVING TILES

This study included the experimental production and investigation of the mechanicalproperties of paving tiles produced from a mixture of laterite, silica sand, pulverized cow bones,and cement. Empirical models of compressive and flexural strength were also developed andherein presented for the paving tiles. The maximum compressive strength of the paving tiles wereobtained for 20, 15, and 10% cement content as 5.05, 5.05 and 3.08 MPa, while the maximumflexural strength for similar values of cement content were obtained as 1.83, 1.21 and 0.26 MParespectively. The results indicate that there was no noticeable difference in the values of thecompressive strength at 20 and 15% cement content, while a sharp reduction of the mechanicalproperties was experienced as the cement content reduces from 15 to 10%. Recommendedcomposition for paving tiles with pulverized cow bones composite is cement, 15%; pulverized cowbones, 30%; laterite 35% and silica sand, 20% respectively. Sustainable production of paving tilesand a sustainable environment can, therefore, be enhanced by replacing granite constituent withwaste cow bones, which can easily be replicated by the empirical models herein developed

An Overview of TIG Welding of Ti6Al4V : Recent Developments

Abstract: Titanium is a commonly used non-ferrous metal in the aerospace, chemical and nuclear industry, due to its unique structural and mechanical properties. Selection of suitable welding techniques and understanding of the effects of parameters corroboration to achieve a quality joint necessitated this article. The article presents recent researches in process parameters optimization done on Tungsten Inert Gas (TIG) welding of Ti6Al4V alloy. Furthermore, it discusses the effects of the parameters used in TIG welding technique on the weld quality, mechanical properties, and microstructure of joined plates. Pulsed TIG welding was found to be the most suitable type of welding for Ti6Al4V alloys based on its ease of use and reduced heat input compared to the conventional TIG welding

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates

Cooling potential of formulated bio-quenchant oils on cast Aluminium alloy material

The biodegradable vegetable oil based quenchants can serve as cooling media alternative to that of the toxic non-biodegradable petroleum based mineral oil in a heat treatment of aluminium and its alloy. 70 vol. % of edible vegetable oil are blended with 30 vol. % of Jatropha oil to form bio-quenchant oils for Aluminium (Al)-alloy probe treated at 500oC and soaked for 15 min in a mue furnace. The cooling potential properties such as the cooling rate, the heat transfer coecient, the Grossman quench severity and the biot number are investigated. The results obtained show that the blended bleached (BB) melon oil provides the highest cooling rate of 49.30oC s-1, while the blended raw (BR) palm oil ensures the lowest cooling rate of 18.45oCs-1. Heat transfer coecients of 704.6 Wm-2K-1, 432.3 Wm-2K-1, and 394.4 Wm-2K-1 are exhibited by the blended bleached melon oil, the blended raw melon oil and the blended bleached groundnut oil, respectively. They are found higher than that of a petroleum based mineral oil, which amounts to 68.7 Wm-2K-1. The lowest heat transfer coecient of 272.11 Wm-2K-1 is obtained in case of using a blended raw palm oil. The quench severity of the blended bleached melon oil, the blended raw melon oil and the blended raw groundnut oil refers to a Grossman H-factor of 1.01 m-1, 0.78 m-1, and 0.67 m-1, respectively. The lat-ter values are higher than that obtained in case of a blended raw palm oil, which is equal to 0.37 m-1. However, the heat ow parameters obtained reveal that the blended bleached and the blended raw melon and groundnut oil can be characterized as fast quenching oils, while the blended bleached and the blended raw palm oil can be characterized as medium quenching oils of results comparable to and even better than those of the industrial petroleum based mineral oil

Perceptions and Use of Antimicrobials Among Staff of a University Community in Southwestern Nigeria

Public attitude and knowledge of antibiotics are determinants of rational use of antibiotics and prevention of antimicrobial drug resistance. This study assessed perception and use of antimicrobials among staff members of a University in Southwestern Nigeria. Descriptive cross-sectional study among 450 staff members of Osun State University in Southwestern Nigeria using multistage sampling method was carried out. Semi-structured self-administered and pre-tested questionnaires were used in data collection. Data were analyzed using the SPSS software Version 17.0. Binary logistic regression models for the outcome variable of composite knowledge and attitude scores toward antimicrobials and their possible predictors were done and level of significance was set at p values ≤ .05 and confidence interval of 95% for all inferential analyses. Mean age of respondents was 26.8 (±11.1) years, and 331 (73.6%) had up to tertiary-level education. One hundred eighty-three (40.7%) and 267 (59.3%) had good and poor knowledge scores, respectively; 175 (38.9%) had positive attitude whereas 275 (61.1%) had negative attitude toward the use of antibiotics. About 279 (62.0%) were informed about judicious use of antibiotics, 398 (88.4%) had ever used antibiotics in the past 1 year with the Ampicillin and Cloxacillin combinations being the most commonly used. Eighty-eight (22.1%) used antibiotics for more than 10 days as at the last use. Predictors for having good knowledge and attitude include age, educational status, and ever having used antibiotics. Inadequate knowledge and attitude toward antibiotics were observed, and this necessitates sustained health education campaign to stakeholders on rational use of antibiotics, especially toward prevention of antimicrobial resistance