31 results about "Liquid scintillation counting" patented technology

A liquid scintillation counting system employs a guard detector efficiency compensation system to adjust sample event counts to compensate for a non-ideal guard which may not detect all cosmic and environmental gamma background noise events. The system and method determines counts of events detected coincidently by a guard detector subsystem and a sample detector subsystem in one or more energy regions as well as counts of events that are detected by the sample detector subsystem and not coincidently detected by the guard detector subsystem for the respective energy regions. The system and method calculates correction values for the respective energy regions based on the counts of coincident and non-coincident events and the guard efficiency values associated with the respective energy regions, using, for example, a quenched or unquenched sample. The system then applies the calculated correction values to counts for the respective energy regions, to produce corrected sample event counts.

The present invention relates to a method for testing the activity concentrations of strontium-89 and strontium-90 in a liquid effluent of a nuclear power plant. The method includes the following steps that: (a) a strontium carrier is added into the liquid effluent, the strontium carrier and the liquid effluent are mixed, an obtained mixture is made to pass through a cationic resin column, so that a first eluent can be collected; (b) the first eluent is evaporated until the first eluent is dried, an obtained product is dissolved by a first nitric acid solution, an obtained mixture is made to pass through a strontium specific resin column, the first nitric acid solution is used to elute the strontium specific resin column, so that a second eluent can be collected; (c) the second eluent is arranged in a constant-weight liquid scintillation counting vial, and the second eluent is weighed after being dried, and the recovery rate Y of strontium is calculated; (d) the total radioactivity activity concentration A of the strontium-89 and strontium-90 in the liquid effluent is calculated; and (e) the strontium-89 and strontium-90 are generated based on fission in a nuclear facility and are released for testing time, the proportions of the strontium-89 and strontium-90 in the liquid effluent are calculated according to a formula (2), and the activity concentrations of the strontium-89 and strontium-90 in the liquid effluent are calculated. With the method adopted, work efficiency can be greatly improved, and radiation impact on workers caused by the liquid effluent can be reduced.

The object of the invention is a multifunction instrument (10 ) for measuring biochemical and medical samples, which are preferably placed into the wells (13) of the sample plates (12) and measured by a detector (20). The detector is movable with slide (26, 27) and guide (22, 23) elements so that a rotating device (14) can turn the detector into vertical position for liquid scintillation counting and / or luminescence counting. The second horizontal position and light path (30) is provided for fluorescence measuring with a light source (40) for excitation. Also an absorbance detector (50) is included.

Presented herein are systems and methods that provide for calibration and / or testing of liquid scintillation counters (LSCs) using an electronic test source. In certain embodiments, the electronic test source described herein provides for emission of emulated radioactive event test pulses that emulate light pulses produced by a scintillator as a result of radioactive decay of a variety of different kinds of radioactive emitters (e.g., beta, alpha, and gamma emitters). Additionally, in certain embodiments, the systems and methods described herein provide for the emission of emulated background light (e.g., luminescence and after-pulses) from the electronic test source. The emulated radioactive event test pulses and, optionally, emulated background light can be used for the calibration and / or testing of LSCs, in place of hazardous radioactive material and / or volatile chemicals. Accordingly, the systems and methods described herein dramatically improve the calibration and / or testing of liquid scintillation counters.

The invention belongs to the technical field of nuclear facility decommisioning treatment, and particularly relates to a method for leaching plutonium in waste resin. The method comprises the steps ofweighing a waste resin sample, putting into a porcelain crucible, covering with a crucible cover, ashing in a muffle furnace, taking out, and placing to room temperature; adding HNO3+HF into a waterbath kettle for leaching, taking out, and placing to room temperature; filtering the leaching solution, fixing the volume to 10mL, accurately transferring the supernatant, adding a scintillation solution, fully shaking up, and measuring on a liquid scintillation counter; respectively weighing three groups of plutonium-containing waste resin samples in a porcelain crucible, requiring that upper-layer resin is weighed for first group, middle-layer resin is weighed for the second group and lower-layer resin is weighed for the third group, and covering a crucible cover; after ashing in a muffle furnace, transferring ash into a high-pressure digestion tank by using a nitric acid solution; and adding hydrofluoric acid and perchloric acid into the high-pressure digestion tank for high-pressure digestion. According to the invention, 90% or above of plutonium in the waste resin is transferred to an aqueous phase.

The invention provides a method and apparatus for preparing samples of carbon dioxide with a 14C content for analysis in liquid scintillation counting equipment, the sample being of a known mass and being introduced into and substantially wholly absorbed into an absorption “cocktail”, absorption being completed at a stage before saturation of the absorbent occurs. The absorbent is contained in a vial which, when absorption has been completed, is transferred into the scintillation counting equipment without intermediate transfer of the contents.

The invention relates to a measurement 231 The liquid scintillation counting method of Pa nuclide activity is characterized in that, described method step comprises at least: calculating 231 The kinetic equation of the Pa decay chain; establishing the 231 The atomic concentration of neutron nuclides in the Pa decay chain and 231 The relationship of Pa atomic concentration; based on the measured total count data and the described 231 The relationship between the atomic concentration of the neutron nuclide in the Pa decay chain and the detection efficiency of the radionuclide establishes a measurement equation; based on the measured sample count and the detection efficiency calculation of the radionuclide 231 Pa nuclide activity. Measurements of the invention 231 The liquid scintillation counting method of Pa nuclide activity is calculated by 231 The solution of the kinetic equation for the Pa decay chain to establish 231 The atomic concentration of neutron nuclides in the Pa decay chain and 231 The relationship between Pa atomic concentration can be solved 231 Pa radioactivity imbalance, and the difficulty of measuring branch decay, also further improved the accuracy of the results.

The invention relates to a high-flux evaluation method for a cholesterol and aliphatic acid metabolism inhibition medicament. The method comprises the following steps that (1) cells are cultured and marked; (2) cholesterol is extracted in the alkaline environment via petroleum ether, a Microbeta liquid scintillation counting instrument is used for counting, and an cholesterol metabolism inhibitioneffect of the inhibition medicament to be evaluated is obtained; and (3) aliphatic acid is extracted in the acidic environment via the petroleum ether, the Microbeta liquid scintillation counting instrument is used for counting, and an aliphatic acid metabolism inhibition effect of the inhibition medicament to be evaluated is obtained. Compared with the prior art, a simple, rapid, high-efficiencyand high-flux cholesterol and aliphatic acid extraction technology is established, the cost of instrument is reduced, convenience is provided for operation, the product extraction efficiency is higher, and the method is much more competitive in the market.

The invention discloses a method for measuring the activity of beta-glucan synthase. The method disclosed by the invention has the advantage that the activity of the beta-glucan synthase is determined by detecting the amount of glucan consumed by synthesizing the beta-glucan synthase into beta-glucan with the glucan as an enzymatic reaction substrate and 3,5-dinitrosalicylic acid as a color developing agent under visible light. Compared with a traditional method for measuring the activity of the beta-glucan synthase by measuring the change of radioactive activity of UDP (Uridine Diphosphate)-[14C] glucan through a liquid scintillation counting instrument by using the UDP-[14C] glucan as a substrate, and the experiment cost is greatly reduced. In addition, no radioactive glucan is used as the substrate in the method, thus the safety of the experiment is high. The method has the advantages of high sensitivity, simpleness and safety in operation, convenience, quickness and convenience for large-scale popularization and application. The method disclosed by the invention can be widely used for researching and developing saccharide and enzyme products.

The invention discloses a 63 The Ni activity concentration measuring method comprises the following steps: 1), preparing sample Y1 to be tested into sample Y2 and sample Y3 respectively; 2), adopting atomic emission spectrometry to measure the nickel mass concentration in sample Y2: 3), adopting inductance Measure the nickel isotope abundance ratio of sample Y3 by coupled plasma mass spectrometry: 4), calculate the nickel mass concentration C' and nickel isotope abundance ratio R' of the sample Y1 to be tested i8 , Ni isotopic abundance N i , N 8 , 63 Ni mass concentration C 3 , 63 Ni activity concentration A 3 , The invention solves the problems of low measurement accuracy, unfriendly environment and incomplete measurement indicators caused by the existing liquid scintillation counter method.

A method for determinating radioactive intensity of plant and soil includes adding oxidant in a closed system, heating and digesting sample of plant and soil, leading oxygen in to oxidate sample thoroughly, absorbing generated CO2 with sodium hydroxide after it being purified and using liquid scintillation counter to analyse C-14 radioactive intensity of absorption liquid.