The determination of radium and/or uranium concentrations in natural waters is useful in a wide range of environmental studies. In this work, a low-background liquid scintillation system (Wallac, Quantulus 1220) was used to determine simultaneously 226Ra and uranium (total) activities in natural water samples. Sample preparation involved filtration and 1 : 10 concentration by evaporation. Then,...

It is most important to assure 4 π−geometry in liquid scintillation counting for accurate results1. Usually this can be assured by dissolution of the sample in an appropriate cocktail. The cocktail does not only contain a solvent but also at least one scintillator and surfactants for aqueous samples because aqueous samples are completely insoluble in the pure organic solvents and scintillators....

The TopCountTM Microplate Scintillation Counter quantitates radioisotopes by liquid scintillation counting in standard microplate formats. Assays that previously had to be transferred from microplates to vials or to non-standard formats for counting can now be quantitated directly in microplates. TopCount can count up to 12 samples simultaneously with performance comparable to that of discrete ...

Kinetic isotope effects (KIEs) are a very powerful tool for investigating enzyme mechanisms. Precision of measurement is the most important factor for KIE determinations, especially for small heavy atom KIEs. Internal competition is commonly used to measure small KIEs on V/K. Several methods, including such as liquid scintillation counting, mass spectrometry, nuclear magnetic resonance spectros...

The use of liquid helium and neon as scintillators for neutrino detection is investigated. Several unique properties of these cryogens make them promising candidates for real-time solar neutrino spectroscopy: large ultraviolet scintillation yields from ionizing radiation, transparency to their own scintillation light, and low levels of radioactive impurities. When neutrinos scatter from electro...

Building on previous research, which indicated that scintillation cells perform differently at different elevations (Burkhart, 2005; Eberline, 1989; George, l983), a pressure chamber has been designed which allows for the simulation of scintillation cell use at different "elevations." The pressure chamber has been constructed in such a way as to accommodate a large flexible bag that is filled w...

Ionospheric scintillation disturbs radio frequency signals affecting navigation based on Global Navigation System (GNSS), especially in Brazil, due to the large magnetic declination. The generation of real-time maps is an important way provide monitoring. This work considers amplitude scintillation, given by S4 index. Some existing and some proposed approaches for generating these are presented...

Ionospheric scintillation originates from the scattering of electromagnetic waves through spatial gradients in the plasma density distribution, drifting across a given propagation direction. Ionospheric scintillation represents a disruptive manifestation of adverse space weather conditions through degradation of the reliability and continuity of satellite telecommunication and navigation system...

Eu- and Li-doped yttrium oxide nanocrystals [Y2-xO3; Eux, Liy], in which Eu and Li dopant ion concentrations were systematically varied, were developed and characterized (TEM, XRD, Raman spectroscopic, UV-excited lifetime, and ICP-AES data) in order to define the most emissive compositions under specific X-ray excitation conditions. These optimized [Y2-xO3; Eux, Liy] compositions display scinti...

Two radiostrontium isotopes, 89Sr and 90Sr, were measured simultaneously by liquid scintillation counter coupling with a full spectrum DPM counting protocol. Strontium was separated from the aqueous media by extraction chromatography using Sr-spec resin. Individual count rates were evaluated from quench correlation curves for 89Sr and 90Sr related with SIS and tSIE quench indicators. The method...