Background: Most of the murder victims in Nigeria are concealed in shallow graves or clandestine paths or bushes. Knowledge of post-mortem interval (PMI) of buried carcasses is useful in estimating time since death for buried homicide scenarios. The PMI of buried remains is different from that of remains on the soil surface. Aims and Objectives: The study aimed at investigating the PMI of buried remains in a tropical rainforest vegetation of Nigeria using matured domestic pigs as human analogs. Materials and Methods: Four animals were used for this study. Animals were sacrificed and buried in one-foot-depth graves. A flat wood was placed on top of the animals before it was covered with sand so that the visible changes can be monitored during the study period. The study was carried out during the rainy and dry seasons. Soil analysis was carried out to ensure that there was no chemical substance inhibiting decomposition. Results: Animals did not completely skeletonize within the study period (168 days). However, four stages of decomposition were identified within the study period - Fresh, bloat, active decay, and advanced decay stages. Conclusions: The PMI was influenced by fungi activities and rain infusion. On the last day of the study, the decomposition was at the advanced decay stage and only few bones of the head, neck, trunk, and limbs were visible with greyish discoloration of the skin and other visceral structures. The visible post-mortem changes of the buried carrions noted in this study may be used to estimate the time of death of buried humans in a tropical rainforest vegetation of Nigeria.
Darlington Nnamdi OnyejikeUgochukwu Godfrey EsomonuVictor Adolf FischerIfeoma Miracle Onyejike
The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment.In this study,computational fluid dynamics(CFD)method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment.Based on cloud chart,concentration at the monitoring site and hazard range of lower explosion limit(LEL)and upper explosion limit(UEL),the influences of leakage hole direction and shape,soil property,burial depth,obstacle type on the diffusion law and hazard range are analyzed.Results show that the leakage gas is not radially diffused until it reaches the ground,and the velocity of gas diffusion to the ground and the hazard range decrease as the angle between the leaking direction and the buoyancy direction increases.Triangular and square leak holes have a faster diffusion rate and a wider hazard range than circular.The diffusion rate of leakage gas in soil rises as soil granularity and porosity increase.The time of leakage gas diffusion to the ground increases significantly with the increase of burial depth,and the hazard range reduces as burial depth increases.Boulder-type obstacles will alter the diffusion path of the leakage gas and accelerate the expansion of the hazard distance,while trench-type obstacles will cause the natural gas to accumulate in the trench and form a high concentration region slowing the expansion of the surface gas concentration.
