Investigation of Gamma Ray Shielding and Compressive Strength of Concrete Containing Barite and Ferrophosphorous

This work emphasizes on the improvement of the gamma shielding ability of concrete using heavyweight materials of barite and ferrophosphorous. The physical properties and chemical composition of the selected aggregate materials were also studied. The specific gravity test results suggested barite and ferrophosphorous show excellent characteristics for improving shielding ability due to their high specific gravity of 4.21 and 5.35, respectively. The samples which applied barite and ferrophosphorous as aggregates, show high densities of 3,233 kg/m3 and 4,288 kg/m3, respectively. The sample applied ferrophosphorus material as an aggregate, had the highest linear attenuation coefficients with the highest density. The computed linear attenuation coefficients indicated higher values when compared with measured values due to low homogeneity of samples.

SUNKEN OIL AND THE REMOVAL OF OIL FROM SUNKEN WRECKS

ABSTRACT Following the technical triumph of removing most of the oil from the sunken wreck of the PRESTIGE, interest and expectations have been raised in equal measure. Since 2005 there have been a number of incidents worldwide involving sunken wrecks containing oil, as well as a smaller number of pollution cases in which oil spilled from ships has sunk due to its high specific gravity. The response to such incidents poses unique challenges and reference is made to ITOPF'S database of historical spills in order to demonstrate how attitudes and the policies for dealing with these cases have changed. The problems posed by oil in wrecks or on the seabed straddle the disciplines of ship salvage and conventional spill clean-up. Whilst the technology used in recovering such oil differs, the rationale for determining whether or not certain measures have merit is in large part based on an assessment of what is technically reasonable. These principles are reflected in the development of the IOPC Funds’ technical guidelines for the removal of oil from sunken wrecks. This paper explores the evolution of response policy with reference to key shipping incidents involving sunken wrecks and sunken oil. In the course of this review, the conflicts between public expectations and technical limitations are highlighted.