Convective-Reactive CO2 Dissolution in Aquifers with Mass Transfer with Immobile Water

The objective of this paper is to study the impact of immobile water, its fraction and its mass transfer with the flowing region on efficiency of CO2 dissolution in aquifers with an immobile water zone. A continuum scale code is developed with underlying assumptions of spatially homogeneous and temporally invariable partitioning fraction of the porous media, first-order mass transfer between the mobile and immobile zones, and simplified reaction of CO2 aqueous solution with calcium carbonate rock. Using ranges of values for Damköhler number (Da), fraction of the total pore volume and mass transfer coefficient rate (α), 96 simulations are conducted. It is shown that, due to a lower intensity of reaction in the mobile region, intermediate values of α serve as a threshold below which the mass transfer coefficient is not affecting the overall CO2 storage and above which overall CO2 storage increases as a function of mass transfer coefficient. Additionally we found that (i) when α is high and geochemistry is intensive (high Da), the overall CO2 storage decreases with increase in fraction of mobile water. This is because CO2 storage through consumption of rock in immobile water with higher geochemistry is reduced. (ii) When α is high but Da is low, the system is effectively a single porosity medium with no chemistry-influenced discrimination between mobile and immobile zones, and therefore overall CO2 storage increases with fraction of mobile water. (iii) When α is low, the magnitude of Da does not influence the overall CO2 storage

Comparative efficacy of experimentally prepared washed cell and formalin killed fowl cholera vaccines

An experiment was conducted to determine the comparative efficacy of experimentally prepared washed cell (WC) and formalin killed (FK) fowl cholera vaccines with virulent avian Pasteurella multocida (PM38) serotype 1 (X-73). Primary vaccination was given through IM route in each birds of groups A (immunized with washed cell fowl cholera vaccine) and B (immunized with formalin killed fowl cholera vaccine). Booster dose was given through SC route after 15 days of primary vaccination. Sera were collected from the birds at 15, 21, 28 and 42 days post-vaccination. The degree of antibody levels of pre-vaccination and post vaccination sera were determined by passive haemagglutination test (PHA). Sera mean PHA titres at 15, 21, 28 and 42 days post-vaccination ingroups A and B were 30.4±4.43 -and 43.2±5.87, 46.4±6.06 and 60.8±8.86, 67.2±11.14 and 96.00±10.67 and 134.4±22.28 and 204.8±20.90 respectively. The present results revealed that both FKFC vaccine and WCFC vaccine worked satisfactory in terms of protection rate against Avian pasteurellosis. It was also demonstrated that experimental FKFC vaccine conferred 100% protection against challenge infection when WCFC vaccine protected 80% vaccinated birds