Modeling Dynamic Helium Release as a Tracer of Rock Deformation

Use of iiyected helium as a hydrological tracer

Helium has several characteristics which make it attractive for use as a tracer in hydrological studies. These include its inert nature, relatively high solubility in water ( ~ 1 %), low molecular diffusion in water, ready availability in commercial quantities, nontoxic nature, and low background atmospheric concentration. The use of helium as a tracer of water movement has become possible thro...

Modeling Tracer Kinetics in Dynamic GdlDTPA

Three major models (from Tofts, Larsson, and Brix) for collecting and analyzing dynamic MRI gadolinium-diethylenetriamine penta-acetic acid (GI-DTPA) data are examined. All models use compartments representing the blood plasma and the abnormal extravascular extracellular space (EES), and they are intercompatible. All measure combinations of three parameters: (1) kPSp is the influx volume transf...

Dynamic Recrystallization under Hot Deformation of a PH Stainless Steel

Dynamic recrystallization, DRX, behaviour of a precipitation hardened, PH, stainless steel was studied in connection with microstructural developments in a compression test. The experimental results showed that the dominant mechanism of softening is DRX, but at high strain rates and low temperatures, ie, high Zener-Holman parameter, Z, work hardening and dynamic recovery, DRV, produced a pancke...

Development of a New Technique for the Use of Dissolved Helium as an Environmental Groundwater Tracer

Mathematical Modeling of the Release of Active Ingredients from a Contraceptive Patch: Ortho Evra® as a Case StudY

Contraceptive patches have become a frequently used contraceptive method. We present a mathematical model that describes the serum concentration profiles of Norelgestromin (NGMN) and Ethinylestradiol (EE) released from the contraceptive patch Ortho Evra®. We propose a simple one-compartment model based on pharmacokinetics data reported in previous studies. The model assumes a time-dependent rel...