The most precise timepiece ever created, a strontium atomic clock, won't lose or gain a second over the next 15 billion years.
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Diffusion experiments with cesium and strontium in biotite gneiss samples have been performed. Both the transport of strontium and cesium through rock samples and the concentration profiles of cesium and strontium inside rock samples have been determined. The result shows that diffusion of cesium and strontium occurs in the rock material.
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Radionuclide Basics: Cesium-137. Cesium (chemical symbol Cs) is a soft, flexible, silvery-white metal that becomes liquid near room temperature, but easily bonds …
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Transport of Strontium and Cesium in Simulated Hanford Tank Waste Leachate through Quartz Sand under Saturated and Unsaturated Flow. ... The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric with …
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Cesium-134 10 Iodine-131 1 Strontium-89 10 Strontium-90 2 Tritium 1,000 Other radionuclides 0.1 times the applicable limit a The ability to achieve detection limits depends on proper consideration of the counting geometry, the photon energy, the sample size, and the actual counting time of detection.
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In all cases, a compromise is required between cesium and strontium removal performance, with most studies showing greater cesium removal. In comparison, the current core-shell composites achieve superior efficiency for Sr 2+ ions while achieving desirable Cs + removal in a single system.
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The concentrations of cesium and strontium were determined by measuring their activity in the water samples using a gamma counter (Perkin Elmer 1480 Wizard). After the measurement, the water samples were brought back into the experimental system in order to maintain the total activity of the solution.
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A flow-through column test setup was developed to measure the breakthrough curves of 133 cesium (Cs) and 88 strontium (Sr) cations in a natural silty sand.
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Many modern atomic clocks use oscillations of strontium atoms rather than cesium to measure time; the most precise of these is accurate to within 1/15,000,000,000 of a second.
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An ytterbium clock measurement would be a good candidate for a new definition, but optical lattice clocks using mercury and strontium have also produced promising …
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Fallout radioactivity in soil and food samples in the Ukraine: measurements of iodine, plutonium, cesium, and strontium isotopes
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Why are the similarities of cesium to potassium and strontium to calcium important? A. Cesium and strontium are easily converted into potassium and calcium, respectively, INCREASING their half-life.
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The NIST team measured frequency ratios, the quantitative relationships between the frequencies of the atoms as measured in three pairs (ytterbium-strontium, ytterbium-aluminum, aluminum-strontium). The results are the three most accurate measurements ever made of natural constants.
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cesium and strontium ions from aqueous media by using a batch technique. It was found that cesium and strontium exhibits a physical adsorption mechanism onto the natural attapulgite with a good adsorption efficiency. The adsorp-tion thermodynamic parameters of cesium and strontium referred to an exothermic nature for strontium ion and an
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Crucial to the accuracy of an atomic clock is the width of the resonance used. Current cesium atomic clocks already use a very narrow resonance, and even more accurate results are being obtained using lattices of strontium.
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AbstractA flow-through column test setup was developed to measure the breakthrough curves of cesium133 (Cs) and strontium88 (Sr) cations in a natural silty sand. Advantages of this column setup inc...
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The influence of chemical activation–natrification of bentonites on adsorption of Cs and Sr was studied with regards to utilization of bentonites for depositing high-level radioactive waste and spent nuclear fuel. Bentonite samples from three Slovak deposits in three different grain-size (15, 45 and 250 μm), natural and natrified forms (Na …
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This measurement can be achieved by decreasing the absorption of the radioactive element from the gastrointestinal tract or by enhancing excretion in urine or feces, or by blocking the incorporation into specific organs. ... The duration of therapy is guided by the amount of radioactive cesium that is removed. (b) For strontium, the …
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Research groups around the world are racing to make the most stable and accurate optical clocks. A team at JILA and the University of Delaware, USA, has now …
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Atomic clocks typically work by measuring the vibrational frequency of atoms, such as strontium or cesium, as the atoms jump between different energy levels. Every atom naturally oscillates at ...
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Read chapter 5 Cesium-137 and Strontium-90 Capsules: The production of nuclear materials for the national defense was an intense, nationwide effort that b...
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Cesium, strontium, and barium fractions were obtained by successive elutions with 0,7M HCl, 1.5M ammonium lactate pH 7.0, and 4M HCl. The cesium fraction was further radiochemically purified, the carrier recovery for cesium determined by flame photometry, and the activity counted in a gamma spectrometer.
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1985, the cesium carbonate and strontium nitrate were converted into cesium chloride and strontium fluoride, respectively, and sealed within double-walled capsules at the Waste Encapsulation and Storage Facility (WESF). The loaded capsules were then transferred to water-filled pools at the facility for storage. There are 1,335 …
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We can measure time intervals — the duration between two events — most accurately with atomic clocks. ... A cloud of strontium atoms inside an optical lattice atomic clock at JILA, which is jointly operated by NIST and the University of Colorado Boulder. ... Because cesium atoms react to microwave radiation with a frequency of 9,192,631,770 ...
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Frequency ratios offer an important advantage as a metric for evaluating optical atomic clocks. A direct measurement of an optical clock frequency in the usual units of hertz (one cycle per second) is …
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Radioactive cesium, strontium, and iodine in river water could be removed by the adsorbents that are investigated here, whereas these same elements in seawater were removed by the adsorbents to a small or negligible degree. These results confirm the concept that an increase in salt concentration suppresses adsorption .
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The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents.
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The aim of this work is sorptive removal of cesium and strontium ions from aqueous solution using natural zeolite and management of produced secondary…
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These constitute the rst radiation-enhanced di usion measurements of strontium, cesium and europium in SiC. Keywords: Di usion, SIMS, Fission Product, SiC, TRISO, Radiation Enhanced Di usion, Cesium, Strontium, Europium 1. Introduction 10 Tristructural-isotropic (TRISO) coated fuel is the fuel form of choice for the Next
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The authors compared the aluminium-ion and ytterbium clocks at NIST and the strontium clock at JILA over several months to check reproducibility and reduce statistical uncertainties.
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This study was conducted to confirm the Cs-137 and Sr-90 adsorption properties of illite. In the experimental method, illite was added to Cs-137 and Sr-90 solutions and stirred. And Following the completion of the adsorption reaction, the solid/liquid phase was separated using a centrifuge, and the adsorption rate was …
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In this paper results of systematic measurements on the diffusion of radionuclides through samples of various sedimentary rocks of Konrad, Asse and Gorleben sites are presented.
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In contrast, optical atomic clocks measure the oscillation of atoms that "tick" much faster than cesium atoms when pulsed with light in the visible range of the …
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