Authors:N. Mann, T. Todd, T. Tranter, and F. Šebesta
A novel approach to preparing granular sorbents for the separation of actinides has been developed, where the extractant is directly immobilized in an inert matrix. This allows substantially higher extractant loadings in the sorbent than for conventional extraction chromatography resins. This approach utilizes polyacrylonitrile (PAN) as the inert matrix material. The well-known actinide extractant octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) has been loaded into sorbent granules at extractant loadings from 20 to 33 wt.% CMPO. The porosity of the PAN matrix allows the active material to have rapid and complete access to the solution containing the impurities, resulting in improved kinetics and higher sorption capacities. Sorbents containing CMPO were prepared using PAN as a binding matrix, and tested against commercially available actinide extraction chromatography resins. Direct comparative batch contact tests performed with TRU-ResinÒ and CMPO-PAN using an INEEL tank waste simulant, resulting in distribution coefficient (Kd) values for Am approximately 2-90 times higher for CMPO-PAN than for TRU-Resin. Batch distribution coefficient (Kd) values for Pu were approximately 60-150 times higher for CMPO-PAN than for the TRU-Resin. Acid dependency curves were generated for Am and Pu with CMPO-PAN over a concentration range of 1 mM to 5M HNO3.
Authors:T. Todd, N. Mann, T. Tranter, F. Šebesta, J. John, and A. Motl
Ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) composite sorbents have been evaluated for the removal of cesium from Idaho National Engineering and Environmental Laboratory (INEEL) concentrated acidic tank waste. Batch contacts were performed to qualitatively evaluate the effects of increased nitric acid, sodium and potassium. An equilibrium isotherm was generated with simulated concentrated tank waste solutions and fit to the Langmuir equation. Additional batch contact experiments were performed to determine if mercury, plutonium and americium would sorb onto AMP-PAN. Dynamic sorption was evaluated in column tests employing 1.5 cm3 columns operating at 5, 10 and 20 bed volumes of flow per hour. Results indicate, as expected, that dynamic cesium sorption capacity is reduced as the flowrate is increased. Calculated dynamic capacities for cesium were 22.5, 19.8 and 19.6 mg Cs/g sorbent, for 5, 10 and 20 bed volume per hour flows, respectively. The thermal stability of loaded AMP-PAN was evaluated by performing thermogrovimetric analysis (TGA) on samples of AMP, PAN (polymer), and AMP-PAN. Results indicate that AMP-PAN is stable to 400 °C, with less than a 10% loss of weight, which is at least partially due to loss of water of hydration. The evaluation of AMP-PAN indicates that it will effectively remove cesium from concentrated acidic tank waste solutions.
Authors:Matthias Brand, Hans-JÜrgen Rumpf, Zsolt Demetrovics, Astrid MÜller, Rudolf Stark, Daniel L. King, Anna E. Goudriaan, Karl Mann, Patrick Trotzke, Naomi A. Fineberg, Samuel R. Chamberlain, Shane W. Kraus, Elisa Wegmann, JoËl Billieux, and Marc N. Potenza
Gambling and gaming disorders have been included as “disorders due to addictive behaviors” in the International Classification of Diseases (ICD-11). Other problematic behaviors may be considered as “other specified disorders due to addictive behaviors (6C5Y).”
Narrative review, experts' opinions.
We suggest the following meta-level criteria for considering potential addictive behaviors as fulfilling the category of “other specified disorders due to addictive behaviors”:
1. Clinical relevance: Empirical evidence from multiple scientific studies demonstrates that the specific potential addictive behavior is clinically relevant and individuals experience negative consequences and functional impairments in daily life due to the problematic and potentially addictive behavior.
2. Theoretical embedding: Current theories and theoretical models belonging to the field of research on addictive behaviors describe and explain most appropriately the candidate phenomenon of a potential addictive behavior.
3. Empirical evidence: Data based on self-reports, clinical interviews, surveys, behavioral experiments, and, if available, biological investigations (neural, physiological, genetic) suggest that psychological (and neurobiological) mechanisms involved in other addictive behaviors are also valid for the candidate phenomenon. Varying degrees of support for problematic forms of pornography use, buying and shopping, and use of social networks are available. These conditions may fit the category of “other specified disorders due to addictive behaviors”.
It is important not to over-pathologize everyday-life behavior while concurrently not trivializing conditions that are of clinical importance and that deserve public health considerations. The proposed meta-level-criteria may help guide both research efforts and clinical practice.