The procedure followed by the Laboratorio de Metrologia Nuclear at the IPEN (Instituto de Pesquisas Energeticas e Nucleares), Sao Paulo - Brazil, for the absolute determination of the (125)I disintegration rate by means of the X-(X,PI) Coincidence and Sum...

The Environmental Science Division at Lawrence Livermore Laboratory has in use a system of absolute Instrumental Neutron Activation Analysis (INAA). Basically, absolute INAA is dependent upon the absolute measurement of the disintegration rates of the nuclides produced by neutron capture. From ...

... were also determined for five types of Convair foils and five types of AGN foils. The absolute disintegration rate of each type foil was determined by ...

A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has

The majority of practical radioactive materials decay by modes that include {gamma}-ray emission. For questions of 'how much' or 'how pure', one must know the absolute intensities of the major radiations. We are using liquid scintillation counting (LSC) to measurements of disintegration rates, ...

A high count rate 4 pi beta - gamma coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond...

A method is described for measuring the absolute disintegration rate of 87.2-day sulfur-35. ( beta -E/sub max/ = 0.167 Mev). The sulfur to be assayed is converted to sulfur dioxide by ignition of barium sulfate with red phosphorus in an atmosphere of oxygen. The sulfur dioxide is then mixed with methane and counted in an ...

The correlation counting method is extended to two-step cascade processes with relatively long-lived intermediate states. Expressions are given for the statistical uncertainties and deadtime effects. The technique is applied to the absolute standardisation of 75Se, 67Ga, 67Cu and 85Sr activities, and to the detection and estimation of afterpulses in liquid scintillation ...

This report is a compilation of fundamental radioanalytical calculations. The units of decay rate of a radioisotope, the curie and the becquerel and their relationship to each other are discussed. Likewise the relationship between the absolute disintegration rate and the counting rate is ...

The relationships between differential and integral cross sections are considered together with their application to the calculation of reaction rates in reactor spectra. A brief review of the measurement of these quantities is given in order to show the importance of chemical analysis in all methods. Particular attention is devoted to the determination of integral ...

Radiochemical purity and the absolute disintegration rate of /sup 32/P preparations are determined. Other ASTM methods are /sup 32/P referred to for the following determinations: /sup 32/P activity by beta counting, 35/sub s/ and other low-energy ..beta.. contamination by aluminum absorption curve, gamma contamination by scintillation ...

The methods cover the determination of the radiochemical purity and the absolute disintegration rate of phosphorus-32 radioisotope preparations. Impurities of interest are those that may be encountered in commercial preparations. Test methods included are: heavy metal spot test, precipitate test, phosphorus-32 concentration, aluminum ...

Methods for radiochemical preparation of meteorite samples for counting of the long-lived nuclides /sup 36/Cl, /sup 26/Al, and /sup 10/Be are given. An anticoincidence arrangement was used for counting. Calibration procedures are described. Absolute disintegration rates for 8 meteorites are given. Four of these have a ...

Gamma spectral analysis of irradiated material can be used to determine absolute disintegration rates for specific radionuclides. These data, together with measured values for the thermal and epithermal neutron fluxes, and irradiation, cooling and counting time values, are all the experimental information required to do ...

The average beta-energy per disintegration has been measured for P32, Y90, I131, and Ca45. An air-filled water-electrode extrapolation ionization chamber was used for measurement of the rate of emission of energy. The absolute disintegration rate was determined by 4?-counting. Good agreement ...

... Title : ABSOLUTE RATE CONSTANTS FOR HYDROCARBON OXIDATION. XII. RATE CONSTANTS FOR SECONDARY PEROXY RADICALS,. ...

Nimbus 2 APT photographs used to determine rate of ice disintegration and dispersion over Hudson Bay

Absolute disintegration rates of specific radioactive products induced by neutron irradition of a sample are determined by spectrometric analysis of gamma-ray emissions. Nuclide identification and quantification is carried out by a complex computer code GAMANAL (described elsewhere). The output of GAMANAL is processed by NADAC, a ...

Stock solutions of (233)Th were produced by the (232)Th(n,gamma) reaction and multiple purifications were used to obtain relative intensities of weak transitions. Liquid scintillation counting (absolute disintegration rates) and gamma-ray spectroscopy with HPGe detectors yielded absolute photon intensities. ...

As an extension of the 4$pi$$beta$-$gamma$ coincidence technique, it is shown that for some radionuclides, the $beta$ count rate should be expressed as a function of at least two observed $beta$ efficiencies, and that the absolute disintegration rate can be obtained by a simultaneous extrapolation to 100% ...

A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has <100% counting efficiency owing to two factors: (1) ''end effect,'' due to ...

A paddle method for measurement of the disintegrating time of orally disintegrating tablets with rizatriptan benzoate as a model drug was evaluated. The paddle method employed a dissolution test assembly with tablets immersed in disintegrating medium through a fastened sinker. Paddle stirring rate, opening of the ...

This multinational, randomized, double-blind study was specifically designed to prospectively compare the onset of antidepressant efficacy of mirtazapine orally disintegrating tablets and sertraline at dosages commonly used in clinical practice. A total of 345 patients with major depressive episode (DSM-IV) received mirtazapine (30-45 mg/d) or sertraline (50-150 mg/d) for 8 ...

tron capture itself; the photo-disintegration commences at the center of a star ... *On the other hand, the rate of photo-disintegration is quite sensitive ...

The continuous gamma-ray spectrum (inner bremsstrahlung), accompanying orbital electron capture in Cs131, has been observed by the method of scintillation spectrometry. The absolute intensity of the gamma radiation has been measured and compared with the total disintegration rate. The end point of the gammaray distribution was found to ...

A method of data collection for the determination of absolute disintegration rates by the 4$pi$$beta$-$gamma$ coincidence technique is described, which gives nearly an order of magnitude smaller variance, for a given total counting time, than conventional methods. It is applicable when the $beta$ counter output is proportional ...

Absolute cross sections were determined for several (d, alpha ) reactions. Thin targets were bombarded by a beam of 7.8-Mev deuterons which were collected iii a Faraday cup and measured by a current integrator. Product nuclei were separated chemically from extrancous activities. Absolute disintegration ...

In the ? disintegration 224Ac-->?220Fr two new ?-rays were observed and values of absolute ?-intensities measured. By ??, ?? coincidence methods, the different modes of disintegration of 220Fr nuclear levels are studied; many ?-transitions were observed and analysed. A disintegration scheme is presented.

A high count rate 4..pi.. ..beta..-..gamma.. coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence ...

The results of absolute determination of the specific radioactivity of tritiated water on the basis of the measured disintegration rate of tritium by the internal gas counting method are presented. Two reducing agents, uraniurm and zinc, were used to convert the water into the gaseous state. The absolute ...

A convenient way of measuring relative fast fluxes in a small reactor core using foils of phosphorus-Polythene mixture is described. Determination of the disintegration rate of these foils involves the measurement of the BETA -ray self-absorption of the foils as a function of thickness. Accurate disintegration ...

The purpose of the study was to examine the disintegration of tablets in media designed to simulate conditions pertaining in the stomach. Although many studies have been performed to determine dissolution rates in these media, little work has been undertaken on the preliminary step in dissolution, namely disintegration. Two tablet ...

A model stomach system was used to investigate disintegration of various foods in simulated gastric environment. Food disintegration modes and typical disintegration profiles are summarized in this paper. Mechanisms contributing to the disintegration kinetics of different foods were investigated as related to ...

The conclusion is drawn that the change in the rate of the established creep in the oriented fibers is brought about by the change in the rate of the breakdown of the chemical bonds, i.e., connected with the processes of disintegration.

We calculate the rate of both neutral- and charged-current neutrino and antineutrino disintegration of deuterium. These rates are of interest for solar {sup 8}B and hep ({sup 3}He + p) spectra and supernovae neutrinos, and are relevant for the Sudbury Neutrino Observatory (SNO).

We calculate the rate of both neutral- and charged-current neutrino and antineutrino disintegration of deuterium. These rates are of interest for solar (sup 8)B and hep ((sup 3)He + p) spectra and supernovae neutrinos, and are relevant for the Sudbury Neu...

The effects of ultraviolet light and Co/sup 60/ gamma radiation on the rate of thermal disintegration of silver oxalate with 5 mole% Cd admixture were investigated. (R.V.J.)

A method involving liquid scintillation counting is described for the accurate measurement of disintegration rate of exp 55 Fe. The method is based on the use of calculated efficiency functions together with either of the nuclides exp 54 Mn and exp 51 Cr ...

...applicable, content uniformity, disintegration times, and/or dissolution rates. (d) Pharmaceutical alternatives means...applicable, content uniformity, disintegration times and/or dissolution rates. (e) Bioequivalence means the...

... Title : ABSOLUTE CHEMILUMINESCENT REACTION RATES FOR EMISSION OF THE O2 HERZBERG BANDS IN OXYGEN AND OXYGEN-INERT ...

) Since the disintegration rate of polonium-210 (210 Po) equals that of lead-210 after several years, and since it is easier to measure the disintegration rate of polonium-210, we substitute these values 150 11 . The disintegration rates of polonium-210 and radium-226 were ...

A method is described for directly determining the absolute abundanees of gamma-emitting radionuclides in complex mixtures without manipulation of data. A pure standard of known disintegration rate is subtracted direetly from pulse height data stored in the Argonnetype 256-channel analyzer. Abundance is determined by ...

The method covers the measurement of alpha particle activity of water. It is applicable to alpha emitters having energies above 3.9 MeV and at activity levels above 0.5 pCi/ml of radioactively homogeneous water. The method is not applicable to samples containing alpha-emitting radioelements that are volatile under conditions of the analysis. The method can be used for either ...

Methods are described for the determination of the radiochemical purity and the absolute disintegration rate of /sup 32/P radioisotope preparations. The /sup 32/P activity is determined by ..beta.. counting, and other low-energy ..beta.. radioactive contaminants are determined by aluminum-absorption curve data. Any ...

The purpose of this study was to investigate the efficiency of superdisintegrants in promoting tablet disintegration and drug dissolution under varied media pH. Significant reductions in the rate and extent of water uptake and swelling were observed for both sodium starch glycolate (Primojel) and croscarmellose sodium (Ac-Di-Sol) in an acidic medium (0.1 N ...

It has been general to assume that the emission of ?-rays in radioactive disintegration is an effect subsidiary to the ejection of the ? or ? particle from the nucleus. Recently, however, the general experimental proof that the time interval concerned in this nuclear process is considerably greater than the time of relaxation of the inner extra-nuclear electrons-and, more ...

Ultrasonic energy can be applied as pre-treatment to disintegrate sludge flocs and disrupt bacterial cells' walls, and the hydrolysis can be improved, so that the rate of sludge digestion and methane production is improved. In this paper, by adding NaHCO3 to mask the oxidizing effect of OH, the mechanisms of disintegration are ...

It is believed that acute pain suppresses nervus vagus, thereby, influencing gastrointestinal secretion and motility, which are the two factors that are necessary for disintegration and dissolution of solid dosage forms. We studied the pharmacokinetics of meloxicam and the effect of vagal suppression on the oral bioavailability and bioequivalence using a marketed (Brand) and a ...

Gamma scintilation spectrometry was used as a basis for the quantitative determination of absolute disintegration rate values for I/sup 131/, I/sup 132/, I/sup 133/, I/sup 13/ s/sup 4/, I/sup 135/ Ba/sup 139/, Ba/sup 140/, Sr/sup 91/ and Sr/sup 92/ collected from reactor effluert air on activated coconut charcoal. After ...

Hydrodynamic disintegration of activated sludge resulted in organic matter and polymers transfer from the solid phase into the liquid phase. Disintegration by hydrodynamic cavitation had a positive effect on the degree and rate of excess sludge anaerobic digestion. Also, addition of a part of anaerobic digested sludge containing ...

The present work was aimed at formulation development, evaluation and comparative study of the effects of superdisintegrants in Cefixime 50 mg oral disintegrating tablets. The superdisintegrants used for the present study were sodium starch glycolate and crosscarmellose sodium. The formulated tablets were evaluated for various tableting properties, like hardness, thickness, ...

The present work was aimed at formulation development, evaluation and comparative study of the effects of superdisintegrants in Cefixime 50 mg oral disintegrating tablets. The superdisintegrants used for the present study were sodium starch glycolate and crosscarmellose sodium. The formulated tablets were evaluated for various tableting properties, like hardness, thickness, ...

Measurements of the rate of photosynthesis of phytoplankton are frequently based on a sample disintegration rate determined from a count rate and counting efficiency of a single aliquot, which may vary considerably in volume. In view of the data presented herein, it is evident that, if such a procedure is followed ...

A method for the production of t-butoxy radicals by the photolysis of t-butyl hypochlorite was employed to determine the absolute rate of combination of t-butoxy radicals at room temperature and to determine the absolute rate of hydrogen atom abstraction ...

The reaction of tert-butoxy radicals with diphenylmethanol and with cumene was examined using nanosecond laser flash photolysis techniques in order to determine the absolute values of the rates of reaction of the radicals. The absolute rate measured for both substrates compare favorably with the values for the ...

The Np/sup 237/ specific activity has been determined to be 1562 sintering time 7 disintegrations per minute per microgram which corresponds to a half-life value of 2.14 sintering time 0.01 x 10/sup 6/ years. The previously reported value was 2.2 sintering time 0.1 x 10/sup 6/ years. The new value was obtained by the absolute alpha counting ...

Excitation functions for production of the radioactive isotopes Na24 (14.8 hr.), Br82 (34 hr.), and Kr (34 hr.) were obtained by bombardment of a stack of NaBr films obtained by evaporation in high vacuum onto aluminum foil. Deuteron energy determinations were made by measurement of range in aluminum; the maximum deuteron energy used in these experiments was 13.5 Mev. The activities of each ...

... of the reaction rate (defined as the absolute difference between the two reaction rates divided by the rate of photocatalysis alone) imparted by the ...

... o fast heart rate ... Use immediately upon opening individual tablet blister ... Keep REMERONSolTab � Orally Disintegrating Tablets and all medicines out of the reach ...

The displacement of three sizes of liquid jets breaking up in a ... model of jet displacement which includes the rate of mass removal also led to a correla- ...

... by equation (6). To establish a kinetic law of initial ... Such a disintegration rate was observed for pure ... of different kinetic equations, constitute 29-33 ...

... Accession Number : AD0751310. Title : The Absolute Measurement of Rate Constants for Some Kay Reactions Involving Free Radicals. ...

The absolute rate constants for the reaction between the NH2 free radical and acetylene and ethylene

In evaluating the hazards from indoor {sup 222}Rn, it is imperative that the behavior of the four short-lived particulate progeny are fully understood since they are the radioisotopes that deliver most of the radiobiological damage to occupants. One known characteristic of these radon progeny is that they deposit (plate out) onto macroscopic surfaces. Some of these plated-out atoms become ...

The principle of laminar impact disintegration of layers of great width was proven on frozen ground and coals. Studies were made on coal sections form the Kuzbass, seasonally frozen ground in Moscow, Novsibirsk and Ust'Kamenogorsk, and long-term frozen rock from the Zapolyar' mines. The tests were made on special full-scale test beds, developed for specific ...

Investigations have proved that in the case of po preparations disintegration time, dissolution rate and in vivo absorption rate are closely interrelated. These correlations described by adequate mathematical formulas are valid in the case of papaverine, drotaverine and Depogen--compounds with benzyl-isoquinoline structure. ...

Mathematical models were developed to elucidate the relationships among process control parameters and the effect of these parameters on the performance of anoxic/oxic biological wastewater processes combined with sludge disintegrators (A/O-SD). The model equations were also applied for analyses of activated sludge processes hybrid with sludge ...

The disintegration rates of 222Rn and its daughters in natural water were determined successfully by the use of the integral counting method with a liquid scintillation spectrometer. A significant advantage of this method is its freedom from the quenching effect. Moreover, when plural alpha-, and beta-emitters are present, their total amounts can be ...

Data on the ages of 63 nearby star clusters are used to study the formation and disintegration rates of open clusters. The present cluster formation rate near the sun is found to be about 0.0000005/sq kpc-year.

As the well-known 4 pi X- gamma -coincidence method cannot be used directly to find the disintegration rate of exp 55 Fe, another method was developed in which a tracer nuclide, possessing coincident gamma radiation, was used. It was now possible to deter...

... rate. The compressibility of the ambient gas, as well as the surface tension, tends to promote absolute instability. The precise ...

The purpose of this research was the determination of the cross sections of various (d, alpha ) reactions induced by the 7.78 plus or minus 0.05 Mev deuterons from the University of Michigan cyclotron. Special emphasis was given to reactions involving closed-shell nuclei as target isotopes. Experimental techniques were refined to permit precision measurement of the cross section ...

Absolute cross sections for 7.8-Mev deuterons were measured for the following reactions: Zr/sup 94/(d alpha )Y/sup 92*/. Zr/sup 92/(d, alpha )Y/sup 90*/; Zr/sup 90/(d, alpha )Y/sup 88*/; Mo/sup 9/ s/sup 7/(d, alpha )Nb/sup 95*/: Mo/sup 97/(d alpha )Nb/sup 95/m; Mo/sup 98/(d, alpha )Nb/sup 96/; Mo/sup 92/(d, alpha )Nb/sup 90/; Ti/sup 46/(d , alpha )Sc/sup 44/; Ti/sup ...

The authors propose a multistage stochastic model to explain data on the kinetics of target cell lysis by cytotoxic T lymphocytes in multicellular conjugates. A novel feature of this model is that the authors explicitly consider both the lethal hitting stage and the target cell disintegration stage of the cytolytic process. Further, the authors allow for the possibility that ...

The aim of this study is to investigate the factors affecting the characteristics of rapidly disintegrating tablets containing an amorphous ingredient prepared by crystalline transition method (CTM) under various storage conditions. Effect of storage conditions and formulating ratio of amorphous sucrose on the characteristic changes (tensile strength, porosity, and ...