The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold C̆erenkov counter (ATC) to separate p̄ from e and e from p, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and report...

Commercial alpha counters are used in science and industry applications to screen materials for surface radon progeny contamination. In this paper, we characterize an XIA UltraLo-1800, ionization drift counter, study the response embedded charge polyethylene sample measurements. We show that modeling such effects is possible a Geant4-based simulation framework attempt derive corrections. This p...

The vulnerability of water bodies to contamination within the neighbourhood of open mine cast environ cannot be overemphasized. Evidence of radioactive trace elements associated with the target minerals in the Plateau State (Nigeria) showed the extent of this vulnerability. In order to address this challenge, the radioactivity levels of water samples from mine ponds, streams, wells, and borehol...

The consistency of proposed burning plasma scenarios with Alfvénic instabilities driven by alpha particles is investigated. If the alpha particle pressure is above the threshold for resonant excitation of Energetic Particle driven Modes (EPMs), significant modification of the alpha particle pressure profile can take place. Model simulations are performed using the Hybrid MHD-Gyrokinetic Code (H...

PURPOSE To determine whether the ability of transforming growth factor-beta (TGF-beta) to influence the contractile activity of corneal fibroblasts depends on their differentiation into myofibroblasts. METHODS Bovine corneal fibroblasts were cultured on collagen gel in MED 5 medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum) with or without TGF-beta 1 (0.01-10 ng/ml). To e...

1. The use of a whole body counter in total body potassium estimations is described. The accuracy and value of the counter in measuring serial changes in total body potassium was assessed. 2. Serial study of twelve normal subjects at varying intervals revealed a normal variability in total body potassium of up to 1.23% (4-weekly measurements over 3 months). The error involved in counting statis...

Background: In this study, the health risk associated with three types of drinking waters (fissure, underground treated and surrounding waters) from two mines in South Africa were assessed. Materials and Methods: The measurement of the radionuclides concentration was carried out by liquid scintillation counter and alpha spectrometer. The estimated radiological risk pose to the people consuming ...