Characterizing small-scale migration behavior of sequestered CO2 in a realistic geological fabric

For typical reservoir conditions, buoyancy and capillary forces grow dominant over viscous forces within a few hundred meters of the injection wells as the pressure gradient due to injection decreases, resulting in qualitatively different plume migration regimes. The migration regime depends on two factors: the capillary pressure of the leading edge of the plume and the range of threshold entry pressures within the rock at the leading edge of the plume. A capillary channel regime arises when these two factors have the same magnitude. Flow patterns within this regime vary from finger-like structures with minimal rock contact to back-filling structures with compact volumes of saturation distributed between fingers. Reservoir heterogeneity is one of the principal factors influencing CO2 migration pathway in the capillary channel regime. Here we characterize buoyancy-driven migration in a natural 2D geologic domain (1 m × 0.5 m peel from an alluvium) in which sedimentologic heterogeneity has been resolved at sub-millimeter (depositional) resolution. The relevant features of the heterogeneity are grain size distribution, which determines the mean and range of threshold pressures and correlation lengths of threshold pressures in horizontal and vertical directions. The relevant physics for this migration regime is invasion percolation, and simulations indicate that CO2 migrates through the peel in a few narrow pathways which cannot be captured by conventional coarse-grid simulations. The storage efficiency of the capillary channel regime would be low and consequently CO2 would also migrate greater distances than expected from models or simulations that neglect the capillary channel flow regime.Bureau of Economic Geolog

The Effectiveness of Mandala Colouring Therapy in Increasing Year 3 Pupils’ Focus During the Initial Lesson

Focus is a very important element in the world of education to increase the effectiveness of other learning skills such as reading writing and calculating The lack of focus issue existed as the pupils were uninterested and unmotivated to learn This has caused disruptive behaviours in the classroom which affected both teachers and pupils An intervention was essential in curbing this problem Hence this study was embarked to identify the effectiveness of the Mandala Colouring Therapy in increasing Year 3 pupils focus during the initial lesson of the day A mixed method study was conducted at 5 national schools in Temerloh Pahang The participants were 100 Year 3 low average pupils and 20 teachers who taught initial lesson periods The data was collected through interviews and questionnaires These quantitative data was analysed using frequency counts on SPSS while the qualitative data was analysed using Burnard s method The overall findings revealed that pupils interest and focus has been increased with Mandala Colouring Therap

Unbiased estimates of galaxy scaling relations from photometric redshift surveys

Many physical properties of galaxies correlate with one another, and these correlations are often used to constrain galaxy formation models. Such correlations include the color-magnitude relation, the luminosity-size relation, the Fundamental Plane, etc. However, the transformation from observable (e.g. angular size, apparent brightness) to physical quantity (physical size, luminosity), is often distance-dependent. Noise in the distance estimate will lead to biased estimates of these correlations, thus compromising the ability of photometric redshift surveys to constrain galaxy formation models. We describe two methods which can remove this bias. One is a generalization of the V_max method, and the other is a maximum likelihood approach. We illustrate their effectiveness by studying the size-luminosity relation in a mock catalog, although both methods can be applied to other scaling relations as well. We show that if one simply uses photometric redshifts one obtains a biased relation; our methods correct for this bias and recover the true relation

Emission Spectra from Internal Shocks in Gamma-Ray-Burst Sources

Unsteady activity of gamma-ray burst sources leads to internal shocks in their emergent relativistic wind. We study the emission spectra from such shocks, assuming that they produce a power-law distribution of relativistic electrons and posses strong magnetic fields. The synchrotron radiation emitted by the accelerated electrons is Compton up-scattered multiple times by the same electrons. A substantial component of the scattered photons acquires high energies and produces e+e- pairs. The pairs transfer back their kinetic energy to the radiation through Compton scattering. The generic spectral signature from pair creation and multiple Compton scattering is highly sensitive to the radius at which the shock dissipation takes place and to the Lorentz factor of the wind. The entire emission spectrum extends over a wide range of photon energies, from the optical regime up to TeV energies. For reasonable values of the wind parameters, the calculated spectrum is found to be in good agreement with the burst spectra observed by BATSE.Comment: 12 pages, latex, 2 figures, submitted to ApJ

Minimization of Volumetric Errors in CAD Medical Models Using 64 Slice Spiral CT Scanner

Sixty four slice spiral Computed Tomography (CT) scanner is one of the advanced CT scanners to capture the large volume of tissues and improved longitudinal resolution. The CT images are used to develop a 3-Dimensional (3D) Computer Aided Design (CAD) medical model. While developing a 3D CAD medical model volumetric errors occur due to partial volume or volume averaging effect. In order to study, various CT image construction parameters were considered to minimize the volumetric errors in 3D CAD medical models, a human dry mandible has been selected as a phantom. A Taguchi technique was used to find optimal CT image construction parameters. A L9 orthogonal array was used to optimize the CT image construction parameters constituting slice thickness, slice increment and Field of View (FOV) while performing CT image construction. The resultant optimal parameters are scrutinized using analysis of variance (ANOVA) method for its influence on the CT image construction. In this work, it has been found that there is a volumetric error of a 3D CAD medical model (STL file) from CT images of a dry mandible was 1978 mm3 (6.11%).Mechanical Engineerin

Experimental Investigation of Process Parameters on 64 Slice Spiral CT Scanner of Medical Models

Rapid Prototyping (RP) is one of the advanced manufacturing methods to develop medical models. These models are generated by 3-Dimensional (3D) Computer Aided Design (CAD) model using Computed Tomography (CT) images. One of the advanced CT scanners to capture the large volume of tissues in shorter scan time is 64 slice spiral CT scanner. While developing these medical models, dimensional and volumetric errors occur due to Beam Hardening (BH) effect. This work has led to explore the influence of various CT Image acquisition parameters on the dimensional and volumetric errors, which are evaluated experimentally. A L9 orthogonal array and signal to noise ratio are applied to study performance characteristics of CT image acquisition parameters like tube voltage, tube current and pitch. The experimental results are analyzed by using the analysis of variance (ANOVA) method and significant factors are identified. In this work, it has been concluded that there is a reduction of dimensional error from 1.43 mm to 0.52 mm and volumetric error from 6793 mm3 to 3892 mm3.Mechanical Engineerin

HEPATOPROTECTIVE ACTIVITY OF ALSTONIA SCHOLARIS FRUITS AGAINST CARBON TETRACHLORIDE-INDUCED HEPATOTOXICITY IN RATS

The hepatoprotective activity of ethanolic extract of fruits of Alstonia scholaris was evaluated by carbon tetrachloride (CCL4)-induced hepatotoxicity in rats. The toxicant CCL4 was used to induce hepatotoxicity at a dose of 2 ml/kg as 1:1 mixture with olive oil. The ethanolic extract of fruits of Alstonia scholaris was administered in the dose of 150 and 300 mg/kg/day orally for 5 days. Silymarin (50 mg/kg) was used as standard drug. The hepatoprotective effect of the ethanolic extract was evaluated by the assessment of biochemical parameters such as SGOT, SGPT, SALKP, total bilirubin and histopathological studies of the liver. Treatment of animals with the ethanolic extract significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver as indicated by lower levels of serum bilirubin as compared with the normal and silymarin treated groups

Dynamic crossover scaling in polymer solutions

The crossover region in the phase diagram of polymer solutions, in the regime above the overlap concentration, is explored by Brownian Dynamics simulations, to map out the universal crossover scaling functions for the gyration radius and the single-chain diffusion constant. Scaling considerations, our simulation results, and recently reported data on the polymer contribution to the viscosity obtained from rheological measurements on DNA systems, support the assumption that there are simple relations between these functions, such that they can be inferred from one another.Comment: 4 pages, 6 figures, 1 Table. Revised version to appear in Physical Review Letters. Includes supplemental material