Effect of PH on Geotechnical Properties of Laterite Soil Used in Highway Pavement Construction

Laterite is one of the major materials used in highway pavement construction in Nigeria. Its properties are affected by some environmental factors which may make it unsuitable for highway pavement construction. This research was aimed of investigating the effect of pH on geotechnical properties of Laterite soil used in highway construction. Laterite soil sample was collected from a burrow pit at LAUTECH and it was sun dried for about 24 hours and then soaked in different pH solutions (pH =3.0, pH=5.0, pH = 7.0 and pH= 9.0) using diluted tetraoxosulphate (vi) acid (H2SO4) and ammonia. The container was perforated at the bottom in order simulate the actual field condition. The soil samples were taken from soaked sample at 14, 28, 42, 56, 70 and 84 days for sun drying and subsequent laboratory tests. The original and treated samples were subjected to the following laboratory tests: Sieve analysis, Liquid and Plastic limits, Plasticity index, British standard compaction and California bearing ratio. The results showed that the pH of the solution has strong influence on the geotechnical characteristics of the Laterite soil when compared with the original soil sample. This influence caused reduction on the strength properties of the soil and thereby rending it unsuitable for highway construction. Keywords: Laterite, pH, consistency limits, California bearing ratio

Molecular Detection of Hepatitis B Virus Among HBsAg Non-Reactive Blood of Donors

Despite all blood donations being tested routinely for HBsAg as a clinical marker of transmissible HBV, cases of post-transfusion hepatitis B virus infection are still being reported because molecular studies using Polymerase Chain Reaction (PCR) are not routinely available for Transfusion Transmissible Infection (TTIs) testing. In this study, we sought to use the PCR technique to re-screen donated blood that had already been proven to be HBsAg non-reactive with rapid diagnostic testing and ELISA. One hundred and eighty-five samples were obtained from a proportion of the blood deposited at the blood bank of the Federal Medical Center, Birnin-Kebbi, Nigeria. Socio-demographic parameters such as age group, status, ethnicity, occupation, and group PCV were obtained from donors' records. Nested PCR was employed to detect HBV DNA. Furthermore, genotyping was performed to determine HBV genotypes in the positive samples using PCR with genotype-specific primers. Of the 185 donors, it was observed that five (2.7%) of the population were positive for HBV. HBV is more common among people aged 18–30, singles, Hausa, and self-employed. In addition, the five positive samples were of genotype E. This study suggests the need to complement antibody-based tests with DNA testing for effective HBV screening and consequent safe transfusion. Keywords: Hepatitis B Virus; HBsAg; PCR; DNA testin