110m Ag Research Articles

Quantitative experiments on the transition between linear to non-linear segregation of Ag in Cu bicrystals studied by radiotracer grain boundary diffusion

Dedicated to Professor Dr. Lasar Shvindlerman on the occasion of his 70th birthday Non-linear segregation of Ag in Cu grain boundaries (GB) was quantitatively studied by radiotracer GB diffusion measurements on Cu bicrystals with non-special near R5 symmetrical ½001� tilt boundaries. Bicrystals were used to guarantee a stable GB during the annealing avoiding in this way disturbing effects like GB motion etc. on the measured diffusion penetration profile. The 110m Ag radioisotope with a well-defined specific activity was applied. This allowed to determine quantitatively the amount of Ag solute atoms in a section as a function of the penetration depth. The controlled variation of the total amount of diffusing Ag atoms along the Cu GB resulted in a fundamental change of the GB penetration profile shape from almost linear to strongly curved. The curvature of the penetration profiles was unambiguously shown to be caused by non-linear segregation of Ag in Cu GB. The full Ag segregation isotherm was calculated from the corresponding GB diffusion penetration profile.

Bulk and grain boundary diffusion of Ag in γ-FeNi alloy

Solute diffusion of Ag in polycrystalline γ-Fe-40 wt.% Ni alloy was studied by means of the radiotracer technique. For bulk and grain boundary diffusion, the following Arrhenius parameters were established: D 0 v = 1.2 × 10 -3 m 2 /s and Q v = 279 kJ/mol and P 0 = 8.1 × 10 -14 m 3 /s and Q gb = 126 kJ/mol, respectively. The diffusion profiles reflect the very low Ag solid solubility which was estimated in the alloy via the specific activity of the applied 110m Ag radiotracer.

Measurement of the Thermal Neutron Capture Cross Section and the Resonance Integral of the 109Ag(n, γ)110m Ag Reaction

In order to develop a neutron flux monitor for long-term neutron irradiation, the thermal neutron(2,200 m/s neutron) capture cross section (≤σ0) and the resonance integral (I 0)of the 109Ag(n,γ)110mAg reaction were measured by the activation and γ-ray spectroscopic methods. Silver foils were irradiated with and without a Cd shield capsule at the Rikkyo Research Reactor. The Co/A1 and Au/A1 alloy wires were irradiated together with silver foils in order to monitor the thermal neutron flux and the fraction of the epi-thermal neutron part (Westcott's index). A high purity Ge detector was used for the γ-ray measurements of the irradiated samples. The σ0 and the I 0 of the 109Ag(n,γ)110mAg reaction are 4.12±0.10 b and 67.9±3.1 b, respectively. The σ0 is 12% smaller than the tabulated one (4.7±0.2 b). On the other hand, the I 0 is in agreement with the tabulated one (72.3±4.0 b) within the limits of error.

The transfer of artificial radioelements contained in seaweed to food transformation products (alginates and carrageenans)

As part of the work of the Groupe Radioecologie Nord Cotentin (the Nord Cotentin Radioecology Group or GRNC), a study has been carried out of potential routes of exposure associated with the industrial extraction of gelling agent from seaweed harvested on the coastline of the English Channel. The main question was whether the seaweed transformation operations tend to eliminate or concentrate the radioactivity in the consumed products. Work carried out in 1989 showed that the extraction of gelling agents from seaweed results in a significant reduction in the artificial radioactivity present in the raw product for radionuclides such as 137 Cs, 125 Sb, 106 Ru-Rh, 60 Co, 99 Tc, 110m Ag, but with the exception of 90 Sr. However, it seemed important to complete this work by studying transfers of 129 I, plutonium isotopes ( 238, 239, 240 Pu), 241 Am and 244 Cm. The seaweed species studied (Laminaria digitata and Chondrus crispus) were collected during February 1999 in the port of Goury, 5 km from the outlet pipe of the La Hague COGEMA nuclear reprocessing plant. This new study confirms that a significant proportion of the artificial radioactivity present in the initial product is eliminated in the end products, including Iodine, Plutonium, Americium and Curium.

A mechanistic approach to evaluate the influence of Cd and Zn on57Co,110mAg and134Cs accumulation and depuration by a freshwater mussel (Dreissena polymorpha)

The effects of Cd and Zn on 110m Ag, 57 Co and 134 Cs uptake and depuration in the freshwater mussel Dreissena polymorpha were investigated under laboratory controlled conditions. Differences at the whole body level were identified between groups exposed to radionuclides alone or to radionuclides and metals under different conditions (Cd or Zn alone or a mixture of Cd and Zn). The accumulation of 57 Co was reduced in the presence of Zn, at the whole organism level and in the soft body. On the opposite, 134 Cs increased in the presence of Cd or Zn. Finally, 110m Ag uptake decreased in the presence of both metals in the whole organism but increased in the soft tissues. Two hypotheses related to the major mechanisms governing the influence of metals on radionuclides were tested. First, the uptake was hypothesised to be directly related to the filtration rate, which has been shown to decrease with increasing zinc concentrations. On the other hand, whole organism zinc regulation mechanisms may include the radioactive pollutant as well. None of these two hypotheses could be validated. Consequently, further explanations were provided to link metal exposure to the radionuclide uptake by the bivalves.

Self diffusion of Ag + ions in AgI-Ag 2O-V 2O 5 glassy system

Glassy samples with composition (mole %) 50 AgI-33.33 Ag 2O-16.67V 2O 5 were prepared by rapid quenching from the melt and characterized by X-ray diffraction and differential scanning calorimetry techniques. The glass transition temperature was observed at 343 K. Conductivity of the glassy sample was found to be 2.3 × 10 −3 ohm −1cm −1 at 300 K. The diffusion coefficient at 300 K, estimated by microtome sectioning technique with Ag 110m isotope and self absorption technique with Ag 111 isotope was found to be 1.1 × 10 −8 cm 2/s and 8.9 × 10 −9 cm 2/s respectively. The estimated diffusion coefficient was compared with the diffusion coefficient evaluated from the conductivity data using Nernst-Einstein relation.

Transfer of Chernobyl fallout radionuclides from feed to growing rabbits: cesium-137 balance

Intake, excretion and retention of gamma-emitting radionuclides were assessed in male rabbits fed a radioactive pelleted diet ( 137Cs = 858 Bq kg −1 as fed) containing 40% dehydrated alfalfa meal contaminated by Chernobyl fallout. In order to evaluate radionuclide retention, an experiment was carried out on 33 animals as follows: nine rabbits were slaughtered at the beginning of the trial, six were fed a radioactive diet for 42 days, six a radioactive diet for 21 days, six a radioactive diet for 21 days and a normal diet ( 137Cs = 112 Bq kg −1 as fed) for the following 21 days and six a normal diet for 42 days. All the animals were housed in individual metabolism cages throughout the trial. All faeces and urine were collected and analyzed separately and live weight and feed intake were measured on a weekly basis. At the end of the trial all the animals were slaughtered and the activities of net body and muscles were determined. Cesium-137, 134Cs, 103Ru, 106Ru, 125Sb, 110m Ag, and 40K were measured by gamma spectroscopy. More than 85% of ingested cesium was excreted through faeces and urine (fecal ⪢ urinary) and the retained 137Cs in the carcass of the more contaminated animals was only 3% of the total ingested. The concentration of total cesium in muscle reached a maximum value of 156 Bq kg −1, much lower than the EEC guideline (600 Bq kg −1), and the biological half-life for 137Cs was calculated to be 11 days. The feed-body accumulation factors were determined in net body and muscle.

The impact of chernobyl on the marine environment in Northern Scotland

Accumulations of the radionuclides 137Cs, 134Cs, 106Ru, 103Ru and 110m Ag in seaweed and molluscs have been studied in the months following Chernobyl. The data set ptovides information on the performance of marine organisms as bioindicators for monitoring radioactive contamination. Concentrations of Cs, Ru and Ag radionuclides in Fucus vesiculosus declined with biological half-lives of 57, 80 and 210 days respectively. The biological half-lives of Cs and Ru radioisotopes in Patella were about 40 and 180 days but the decline in levels of 110mAg was less than would have been expected from radioactive decay. Concentrations of 110mAg in marine organisms on the north and east coast have been much higher than those on the west possibly due to differences in enhancement by runoff from nearby land. Radionuclide levels in sea spume were several thousand times greater than in seawater in June 1986.

Precision energy and intensity measurements for γ transitions from 134Cs decay

The precision energies and relative intensities of 11 γ transitions from the decay of 134 Cs have been determined. 192 Ir, 228 Th, 137 Cs, 110m Ag, 60 Co, and 207 Bi served as energy calibration standards, and 152 Eu and 192 Ir as relative intensity calibration standards. Special care was taken in the analysis of data for the weaker transitions. The results are incorporated into a self-consistent decay scheme.

Distribution of fission products in dust samples from the region of Thessaloniki, Greece, after the Chernobyl nuclear accident.

The distribution of the fission products (95)Zr, (95)Nb, (103)Ru, (106)Ru (determined through (106)Rh), (125)Sb, (129m)Te, (134)Cs, (137)Cs, (140)Ba, (140)La, (141)Ce and (144)Ce has been determined in dust samples from the region of Thessaloniki, Greece, after the nuclear accident at Chernobyl. The samples studied also included (110m)Ag, not belonging to the products of (235)U fission. Samples showing higher concentrations of radionuclides also show a higher content in clay minerals, whereas samples having low concentrations of radionuclides usually contain large amounts of quartz and feldspars. Desorption and leaching experiments using solutions of chlorides of sodium, potassium, calcium and magnesium (0.5 N), as well as distilled and tap water, were also performed. Sodium and potassium chloride solutions were found to be efficient in desorbing and/or leaching of caesium and ruthenium isotopes to an extent of about 30%.

Release of metal fission products from UO 2 kernel of coated fuel particle

Release behaviors of Cs 137, Cs 134, Sb 125, Ce 144, Ru 106 and Ag 110m during irradiation from the high-density UO 2 kernel of Triso-coated fuel particle were studied. The intact coated fuel particles were carefully cracked after irradiation; the amounts of fission products remaining in the UO 2 and their partition between the UO 2 and the coating were measured hv gamma-ray spectrometry. The results are discussed in view of the high-temperature chemistry of the fission products within the coated fuel particles.

Solvent diffusion in α-silver-tin alloys

Coefficients for diffusion of Ag 110m in α- Ag-Sn alloys were measured as a function of temperature and concentration over the temperature range 950–1150 K and 0 to 9 at.% tin.The standard sectioning technique and the method developed by Kriukov and Shukovitzky were applied. The latter involves less experimental effort and, as for relative measurements, even proved to be the more accurate. A strong non-linear increase in the solvent diffusion upon alloying was observed in agreement with results on similar alloys, such as Ag-Cd, Ag-In and Ag-Sb. This is very much in contrast to recent data on solvent diffusion in Ag-Sn, published by Gas and Bernardini, who found a linear enhancement up to 6 at.% tin. The marked dependence of solvent diffusion on temperature and impurity concentration is discussed in terms of the complex model proposed by Hehenkamp, Schielt and Sander to describe the solvent and solute diffusion beyond the limit of infinite dilution. Changes in the solvent correlation factor upon alloying are taken into account by introducing effective jump frequencies. It is shown, how the experimentally observed proportionality of the normalized solvent diffusion coefficient to the normalized vacancy concentration serves to get useful information about the diffusion behaviour such as the linear enhancement factor, average effective jump frequencies, activation energies and free binding enthalpies of impurity-vacancy-associates. According to Lidiard the impurity correlation factor in the case of infinite dilution is calculated, combining the linear enhancement factor with data on solute diffusion. The results are in good agreement with values from measurements of the isotope effect.

Analyse du fonctionnement du spectrometre a coincidence et addition; Application a l'etude de 207Bi ET 110mAg

Improvements in the determination of the energy levels of radioisotopes by the sum-peak technique of coincidence counting have been achieved by the utilisation of two Ge(Li) detectors. The performances of the spectrometer, and the validity of the method of interpretation of the γ-ray spectrum and of the shape of the continuum have been tested from the decay of 207 Bi and 110m Ag.

Study of the Radioacitve Decay of Ag110m

The decay of Ag 110m to the levels of Cd 110 has been investigated to verify the existence of some weak gamma transitions reported earlier. The energy and relative intensity measurements for all the gamma transitions have been done. Previously reported γ-transitions of energy 264.25, 341.19, 356.24, 409.32, 572.7, 603.0, 630.61, 676.6, 708.115, 774.8, 1186.7, 1572.3, 1629.65 and 2004.7 keV have not been observed while the 360.7, 466.9, 493.8, 544.8, 957.3, 1125.7, 1163.5, 1165.6, 1251.2, 1300.0, 1592.8, 1775.6 and 1783.4 keV transitions have been confirmed. As a consequence of these measurements, levels at 2078.804, 2287.41 and 2662.51 keV have been discarded. Gamma-gamma directional correlation measurements have been done on 24 cascades and the multipole admixtures for 12 gamma transitions have been evaluated. Large M1 admixture is found in 2 2 + →2 1 + and 4 2 + →4 1 + transitions.

Impurity diffusion of 110m Ag in Cu

physica status solidi (a)Volume 49, Issue 2 p. K125-K128 Short Note Impurity diffusion of 110m Ag in Cu G. Krautheim, G. Krautheim Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this authorA. Neidhardt, A. Neidhardt Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this authorU. Reinhold, U. Reinhold Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this author G. Krautheim, G. Krautheim Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this authorA. Neidhardt, A. Neidhardt Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this authorU. Reinhold, U. Reinhold Ingenieurhochschule Zwickau, Abteilung Mathematik und NaturwissenschaftenSearch for more papers by this author First published: 16 October 1978 https://doi.org/10.1002/pssa.2210490254Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume49, Issue216 October 1978Pages K125-K128 RelatedInformation

Mobility and ionic form of silver as related to longevity of cut carnations

The mobility of different ionic forms of silver ((110m)Ag) has been studied using semiconductor radiation detectors. Silver, applied as silvernitrate (2mM), moves upward in the stems of cut carnations (Dianthus caryophyllus L.) at about 3 cm day(-1). This transport has the characteristics of a chromatographic exchange transport, but is not promoted by the addition of other cations (K(+) or Ca(2+)). The silverthiosulphate anionic complex is transported at the same speed as [(32)P]phosphate (about 2 m h(-1)); orders of magnitude faster than Ag(+). The antiethylene action of silver is preserved in this complex, as shown by a significant improvement of the longevity of carnation flowers in the presence or absence of ethephon, even after a short treatment with the silverthiosulphate complex. Analysis of the silver content of different flower parts after a silverthiosulphate treatment shows a distinct accumulation in the receptacle, possibly associated with the antiethylene action.

Deviation from the Einstein Relation in Average Crystals. II. Self-Diffusion of Ag+Ions in α-Ag2Te

The self-diffusion coefficient D of silver ions in α-Ag 2 Te has been measured by the tracer technique using Ag 110m and the mobility µ of cations is estimated from the ionic conductivity σ. The ratio µ/ D is slightly deviated from the Einstein relation. This deviation is discussed in comparison with a theory appropriated to the average crystals proposed by Yokota.

Deviation from the Einstein Relation in Average Crystals Self-Diffusion of Ag+ Ions in α-Ag2S and α-Ag2Se

The mobility µ and the diffusion coefficient D of silver ions in Ag 2 S, Ag 2 Se and alloys Ag 2 S 1- x Se x have been measured by the aid of tracer technique using Ag 110m . The ratio µ/ D is found to deviate from the Einstein relation remarkably. Although such deviation is usually attributed to the existence of correlation between successive jumps of a diffusing ion, the present substances are so much disordered that the correlation effect theory cannot be applied. Recently Yokota has proposed a new model appropriate to our substances. The experimental results are compared with his theory with a minor modification. It is proved that the theory is applicable to our substances.

The multipolarity of the 116 keV isomeric transition in Ag 110

The internal conversion lines of the 116 keV isomeric transition in the Ag 110m decay have been studied using the Chalk River π 2 β-spectrometer. The measured conversion line intensity ratios are K/ ΣL/ ΣM/ Σ(N+O) = 2.04±0.06/1/0.214±0.008/0.036±0.003, L I/L II = 4.81±0.45 and L I/L III = 1.02±0.02. The transition energy is 116.410±0.015 keV. The K/ΣL ratio is in agreement with published values and supports the M4 multipolarity assignment to this transition. The measured L line intensity ratios agree with the corresponding theoretical ratios from Sliv and Band for M4 radiation and confirm the multipolarity assignment. The problem presented by the inconsistency of this multipolarity assignment with the spins of Ag 110m and Ag 110 is discussed.

The isomeric decays of Ag 108m and Ag 110m

The electron spectrum in the range 1 to 29 keV and 48 to 120 keV from the decay of Ag 110m has been studied in an iron-free, double focussing spectrometer. The K/L ratio of the 116 keV isomeric transition in the decay of Ag 110m to Ag 110 was measured to be 1.95±0.10 and the L/(M+N+O) ratio to be 4.0±1.0. These data help to confirm the M4 character of the 116 keV transition. No evidence for the proposed E1 transition of 20–30 keV which should follow the 116 keV transition was found. An upper limit of 4 keV was placed for the energy of this proposed transition. The 30.2 keV transition from the decay of Ag 108m was observed. The K/L ratio is less than 0.3 which is consistent with an E3 or higher multipole transition.