8. Introduction Critical points of distance functions Toponogov's theorem; first application:a Background on finiteness theorems Homotopy Finiteness Appendix. Some volume estimates Betti numbers and rank Appendix: The generalized Mayer-Vietoris estimate Rank, curvature and diameter Ricci curvature, volume and the Laplacian Appendix. The maximum principle Ricci curvature, diameter growth and fin...

The present study analyzed 5785 vegetables for concentrations of As, Cd, Cr, Pb, Ni and Hg, and estimated the health risk to local consumers by deterministic (point estimates) approaches. Levels of elements varied in different vegetables. Average levels of As, Cd, Cr, Ni, Hg and Pb were 0.013, 0.017, 0.057, 0.002, 0.094 and 0.034 mg/kg (fresh weight), respectively. The samples with 0.25% for Cd...

Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to ...

Tetranitromethane (T.N.M.) occurs in the production of T.N.T. as a byproduct of toluene nitration. It is a highly toxic substance, and its toxic properties have been recently investigated by Sievers, Rushing, Gay, and Monaco (1947). According to them, the maximum allowable concentration of T.N.M. is less than 5 p.p.m. Elkins (1950) recommends 0-5 p.p.m. or 4 mg./m.3 of air as the safe maximum a...

Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This can lead to an incorrect estimation of formation elastic properties measured from sonic logs. Previous work has focused on estimating the elastic properties of the formation surrounding a borehole under anisotropic stress loading. We studied the effect ...

Generation–recombination noise associated with bulk defect levels in silicon is modeled in a partial differential equation-based device simulator to study the maximum allowable defect density that guarantees generation-recombination (g–r) noise-free operation in the presence of hotcarrier effects and space-charge injection.

Rock mass description and characterisation is a basic task for exploration, mining work-flows and ground-water studies. Rock analysis can be performed using borehole logs that are created using a televiewer. Planar discontinuities in the rock appear as sinusoidal curves in borehole logs. The aim of this project is to develop a fast algorithm to analyse borehole imagery using image processing te...

The elastodynamic body-wave field outside a fluid-filled open borehole due to a monopole source in the fluid, is reduced to the radiation-field due to a suitable equivalent force system (EFS) in the absence of the borehole, consisting of a monopole plus a vertical dipole. Theoretical seismograms of the EFS displacements in the solid are shown to be in excellent agreement with those obtained fro...

Asymptotic hyperstability is achievable under certain switching laws if at least one of the feed-forward parameterization: 1) possesses a strictly positive real transfer function, 2) a minimum residence time interval is respected for each activation time interval of such a parameterization, and 3) a maximum allowable residence time interval is guaranteed for all active parameterization which is...