bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partitioning and Leaching Behavior of Actinides and Rare Earth Elements in a Zirconolite-bearing Hydrothermal Vein System
Authors: Payne Timothy E , Giere Reto , Hart Kaye P , Lumpkin Gregory R , McGlinn Peter J 
Published: October 2011

AbstractChemical extraction techniques and scanning electron microscopy were used to study the distribution and behavior of actinides and rare earth elements (REE) in hydrothermal veins at Adamello, (Italy). The six samples discussed in this paper were from the phlogopite zone, which is one of the major vein zones. The samples were similar in their bulk chemical composition, mineralogy, and leaching behavior of major elements (determined by extraction with 9M HCl). However, there were major differences in the extractability of REE and actinides. The most significant influence on the leaching characteristics appears to be the amounts of U, Th and REE incorporated in resistant host phases. Uranium and Th are very highly enriched in zirconolite grains. Actinides were more readily leached from samples with a higher content of U and Th, relative to the amount of zirconolite. The results show that REE and actinides present in chemically resistant minerals can be retained under aggressive leaching conditions.
Migration Behavior of Plutonium in Compacted Bentonite Under Reducing Condition Using Electromigration
Authors: Idemitsu Kazuya , Yamasaki Yosuke , Nessa Syeda Afsarun , Inagaki Yaohiro , Arima Tatsumi , Mitsugashira Toshiaki , Hara Mitsuo , Suzuki Yoshimitsu 
Published: October 2011

AbstractCarbon steel is one of the candidate overpack materials for high-level waste disposal and is expected to assure complete containment of vitrified waste glass during an initial period of 1000 years in Japan. Carbon steel overpack will be corroded by consuming oxygen introduced by repository construction after closure of repository and then will keep the reducing environment in the vicinity of repository. The migration of iron corrosion products through the buffer material will affect migration of redox-sensitive radionuclides. Therefore the authors have carried out electromigration experiments with source of iron ions supplied by anode corrosion of iron coupons attached to compacted bentonite. Authors tried to use plutonium in this experimental configuration to obtain the knowledge of migration behavior of actinides. Authors also used cesium as reference. The concentrations of iron and sodium showed nearly complementary distributions. It is expected that iron ion could migrate as ferrous ion through the interlayer of montmorillonite replacing exchangeable sodium ions in the interlayer. Concentration profiles of plutonium in bentonite grew as time supplying electric potential as long as 168 h. Plutonium migrated from the iron anode toward cathode as deeper than 1 mm of the interior of bentonite even in 48 h, though plutonium could not diffuse 1 mm for 2 years. On the other hand, profiles of cesium seemed to be controlled by ordinary diffusion because of large diffusion coefficient of cesium in bentonite as large as 10$^{-12}$ m$^{2}$/s. Drift of the cesium profile by electric potential gradient could be observed clearly after 240 h at individual experiment for cesium. Apparent dispersion coefficients of plutonium were calculated from the profiles and were as large as 10$^{-13}$ m$^{2}$/s. Since plutonium migration was accelerated by electric potential, plutonium chemical species would have positive charge and were estimated as PuOH$^{2+}$ or PuCl$^{2+}$ by the thermodynamic calculation. Thus this experiment can provide a diffusion field for cations under a reducing condition with ferrous ions in water-saturated bentonite.
Characterizing Low-Permeable Granitic Rock from Micrometer to Centimeter Scale: X-ray Microcomputed Tomography, Confocal Laser Scanning Microscopy and 14C-PMMA Method
Authors: Siitari-Kauppi Marja , Kelokaski M. , Siitari-Kauppi M. , Voutilainen M. , Myllys M. , Turpeinen T. , Timonen J. , Mateos F. , Montoto M. 
Published: October 2011

AbstractFirst results of combining X-ray microcomputer tomography (µCT), confocal laser-scanning microscopy (CLSM) and 14C-polymethylmethacrylate (14C-PMMA) impregnation techniques in the study of granitic rock samples are reported. Combining results of µCT and CLSM with those of the 14C-PMMA technique, the mineral-specific porosity and morphology of the open pore space, as well as its connectivity, could be analyzed from a micrometer up to a decimeter scale.Three different types of granite were studied. In two cases part of the micro-fissure and pore apertures were found to be in a micrometer scale, but in one case all grain-boundary openings were below the detection limit. Micrometer-scale apertures could be analyzed by CLSM and µCT. The benefit of µCT is that it can also provide the heterogeneous distribution of minerals in 3D. The 2D porosity distributions in the mineral phases, consisting of nanometer-scale pores, could be measured by the 14C-PMMA method together with the micro-fissures. This method does not, however, give the exact pore apertures. The limitations and applicability of the methods are discussed.
State of a Bentonite Barrier after 8 Years of Heating and Hydration in the Laboratory
Authors: Villar Maria Victoria , Fernández Ana María , Gómez Roberto , Barrenechea José F. , Luque F. Javier , Martín Pedro Luis , Barcala José Miguel 
Published: October 2011

AbstractThe conditions of the bentonite in an engineered barrier for HLW disposal have been simulated in a laboratory test. Six cylindrical blocks of bentonite compacted at a dry density of 1.64 g/cm3 were piled up in a hermetic Teflon cell. The total length of clay inside the cell was 60 cm. The bottom surface of the bentonite was heated at 100°C while the top surface was injected with granitic water. The duration of the test was 7.6 years. The water intake was measured during the test and, at the end, the cell was dismounted and the dry density, water content, specific surface area, mineralogy, geochemistry and swelling capacity of the clay were measured in different sections along the blocks. The material used in this test is the FEBEX bentonite.
Experimental Approach to Study the Colloid Generation from the Bentonite Barrier to Quantify the Source Term and to Assess its Relevance on the Radionuclide Migration
Authors: Alonso Ursula , Missana Tiziana , García-Gutiérrez Miguel 
Published: October 2011

AbstractA geological repository for high-level radioactive waste (HLWR) consists on a multi-barrier system, emplaced hundred meters deep in a geological medium. In most of the repository concepts, the waste would be located in metal canisters surrounded by a layer of compacted clay, i.e. bentonite. To guarantee the long-term safety of a repository, all mechanisms that could affect the radionuclide (RN) migration rate must be well defined and quantified. The particular interest of this work lies on the possible contribution of bentonite colloids to RN transport. The first parameter necessary to assess the colloid-mediated transport is the quantification of the bentonite colloid source term. Secondly, it is necessary to define if colloids remain stable in the geochemical conditions of the medium.Several mechanisms that are basically related to the hydration of the clay can lead to bentonite colloid generation. In the present work the colloid generation is evaluated at laboratory scale under “realistic” conditions, considering static hydration (no flow). To do so, two experimental set-ups were designed with the aim of quantifying the bentonite colloid generation rates. The experimental cells were designed to study the colloid formation in a confined system by introducing compacted bentonite, at different compactation densities, in stainless steel porous filters. The bentonite hydration is facilitated by immersing the confined cells in different electrolytes, from the most favorable conditions (lowest ionic strength) to different groundwaters of interest as aqueous phase. The concentration of bentonite colloids and the average particle size are evaluated as function of time by Photon Correlation Spectroscopy measurements in the aqueous phase.Preliminary results showed that all the bentonite particles generated have average size in the colloid range, equivalent to that of bentonite colloids prepared in the laboratory, despite the filter porous sizes were hundred times higher. The experimental set up allows performing stability evaluation at the same time and that after months the colloids generated in the lower strength electrolytes remain stable. The configuration allows quantification of the colloid generation rates. The mechanisms responsible of colloid generation are discussed according to the obtained results in different experimental conditions.
Hydrothermal Synthesis and Structure of Neptunium(V) Oxide
Authors: Forbes Tori Z. , Burns Peter C. , Soderholm L. , Skanthakumar S. 
Published: October 2011

AbstractSingle crystals of Np2O5 have been synthesized by low-temperature hydrothermal reaction of a Np5+ stock solution with natural calcite crystals. The structure of Np2O5 was solved by direct methods and refined on the basis of F2 for all unique data collected on a Bruker X-ray diffractometer equipped with an APEX II CCD detector. Np2O5 is monoclinic, space group P2/c, with a = 8.168(2) Å, b = 6.584(1) Å, c = 9.3130(2) Å, &#946; = 116.01(1)&#730;, V = 449.8(2) Å3, and Z = 1. The structure contains chains of edge-sharing neptunyl pentagonal bipyramids linked into sheets through cation-cation interactions with distorted neptunyl square bipyramids. Additional cation-cation interactions connect the sheets into a three-dimensional framework. The formation of Np2O5 on the surface of calcite crystals has important implications for the precipitation of isolated neptunyl phases in natural aqueous systems.
New Synthesis Route and Characterization of Siderite (FeCO3) and Coprecipitation of 99Tc
Authors: Llorens Isabelle , Fattahi Massoud , Grambow Bernd 
Published: October 2011

AbstractTechnetium-99 is a long-lived product of nuclear fission. In the ground-waters of European disposal sites Tc is expected to be in the tetravalent state since the geochemical conditions are reducing due to the presence of redox couples such as Fe(II)/Fe(III), and the presence of reducing minerals such as pyrite and siderite (FeCO3). Siderite is expected to be formed as well as container corrosion product. Experiments of coprecipitation of Fe2+ and Tc(IV) were conducted in the laboratory under an inert atmosphere at room temperature. High resolution transmission electron microscopy shows that the coprecipitate is around 3 nm sized particles. Analytical electron microscopy indicates that the precipitate contains 30 atom % of Tc and 70 atom % Fe. The Tc was homogeneously distributed. Selected Area Electron Diffraction doesn't reveal the formation of siderite, which suggests that the presence of technetium in high concentration inhibit the formation of this phase.
The geological research in France - The Dosssier 2005 Argile
Authors: Plas Frederic , WENDLING Jacques 
Published: October 2011

AbstractAt the end of fifteen years of researchs defined by the French act of December 30, 1991 on radwaste management, Andra gave a report, “Dossier Argile 2005”, which concluded with the feasibility of a reversible disposal in the argillaceous Callovo-Oxfordien formation studied by means of an underground research laboratory at Meuse/Haute-Marne site. Starting from source data like the characteristics of the geological medium and the waste inventory, the process followed by Andra to achieve at this conclusion is of type sequential and iterative between concept design, scientific knowledge, in particular that of the phenomenological evolution of the reposiroty and its geological environment from operating period to long term, and Safety assessment. The “Dossier Argile 2005” covers a broad radwaste inventory, ILLW, HLW and Spent Fuel, so that it makes it possible to cover whole of the technological, scientific and safety topics. This article will give an overview of the geological disposal studies in France and draw the main conclusion of the Dossier 2005 Argile. It will be focused on the near field (Engineering components and near field host rock), while considering if necessary its integration within the whole system. After a short description of the concepts (incl. waste inventory and the characteristics of the Meuse/Haute the Marne site) and the functions of the components of repository and geological medium, one will describe successively the broad outline of the phenomenological evolution of repository and the geological medium in near field, by in particular releasing the time scales of processes and uncertainties of knowledge. On this basis, one will indicate the safety scenarios which were considered and the broad outline of performance and dose calculations. Lessons learn from the Dossier 2005 Argile will be discussed and perspective and priority for future will be indicated.
The Effects of Dry Density and Porewater Salinity on the Physical and Microbiological Characteristics of Compacted 100% Bentonite
Authors: Stroes-Gascoyne Simcha , Hamon C.J. , Dixon D.A. , Kohle C.L. , Maak P. 
Published: October 2011

AbstractThis study examined the conditions required to suppress microbial activity in compacted bentonite, such that microbially influenced corrosion (MIC) of copper waste containers, surrounded by compacted bentonite in a future deep geologic repository, would become insignificant. Experiments were carried out to determine the effects of dry density and porewater salinity on swelling pressure, water activity (aw) and the culturable microbial community in compacted bentonite. A dry density ³ 1.6 g/cm3 ensures that aw is < 0.96 and the swelling pressure > 2 MPa. Both conditions suppress microbial culturability below background levels (2.1 x 102 Colony-Forming Units/g) in as-purchased bentonite. Under such conditions, cells likely survive as dormant cells or inactive spores, which greatly reduces the possibility of significant MIC. Observations in natural clay-rich environments support these findings.
Measurements of Eh and pH in Compacted MX-80 Bentonite
Authors: Carlsson Torbjörn , Muurinen Arto 
Published: October 2011

AbstractThe low-content free water and high swelling pressure in compacted bentonite, planned to be used as a buffer in nuclear waste repositories, create adverse conditions for direct measurements of the chemical conditions. This paper presents laboratory results from online measurements with Eh and pH electrodes in water-saturated compacted MX-80 bentonite. The Eh was measured with Au and Pt wires as electrodes, while the pH was determined with IrOx electrodes. The latter were prepared in accordance with the method by Yao et al. [1]. The measurements were carried out in two types of cells: 'squeezing cells' and 'diffusion cells'. The squeezing cell excludes almost completely all chemical interactions between the sample and the surrounding environment outside the cell. The diffusion cell, on the other hand, contains a sample that stays in contact with an external solution and therefore allows following of the physico-chemical interaction between the sample and the external solution. The measuring electrodes were positioned inside the cell in the compacted bentonite, while the reference electrode was positioned outside the cell.
Do Debt Constraints Influence Firms' Sensitivity to a Temporary Tax Holiday on Repatriations?
Authors: Albring Susan M. , Mills Lillian F. , Newberry Kaye J. 
Published: October 2011

ABSTRACT
We examine whether U.S. multinationals' private and public debt constraints influence their responses to a temporary reduction in repatriation taxes (tax holiday). Using a sample of 421 U.S. multinationals with permanently reinvested earnings, we find that external debt constraints played an important role in determining their responses to the tax holiday. Specifically, we find that firms subject to fewer financial covenants in their private debt agreements or with greater access to public bond markets repatriated significantly more of their eligible funds. Our results suggest that U.S. multinationals with greater access to external debt markets have more flexibility to time their repatriations around a tax holiday and, as such, they are the primary beneficiaries of any tax savings. It is unlikely that these firms were the intended target of the American Jobs Creation Act (AJCA) 2004, given the stated legislative goals of directing repatriated funds toward financial stabilization and previously unfunded positive return investments.
JEL Classifications: M4; H2; L1.
Rester psychanalyste face au chaos des nouvelles filiations
Authors: Faure-Pragier Sylvie 
Published: October 2011

Résumé Les progrès dans les techniques de procréation bouleversent la filiation et modifient la structure familiale. Comment rester psychanalyste devant une évolution où la femme récupère un pouvoir grandissant tandis que l’homme perd son autorité ? L’auteure étudie la conception hors sexualité, les dons de gamètes et l’homoparentalité. Elle se livre enfin à quelques considérations éthiques.
A Lexicon for User Driven Healthcare
Authors: Ross Susan 
Published: October 2011

What do the terms Learning Healthcare Systems, Participatory Medicine, Evidence-based Medicine, Narrative Medicine, Patient-centered Medicine, and Health 2.0 mean? What is their connection to each other, to User-Driven Healthcare, and, most importantly, to real people—healthcare providers and healthcare consumers? In this paper, the author presents current definitions of these abstractions to begin to compile a glossary of terms, a lexicon of sorts, for all stakeholders in the emerging field of User-Driven Healthcare.
Clytemnestra at the Mall: A Plea for More Improvisational Pedagogy in the Arts
Authors: SPITZ ELLEN HANDLER 
Published: October 2011

Abstract
A work of art no matter how old and classic is actually, not just potentially, a work of art only when it lives in some individualized experience…. It cannot be asserted too strongly that what is not immediate is not aesthetic.
—John Dewey, Art as Experience
Anticoagulation for venous thromboembolism
Authors: Palareti G. 
Published: October 2011

SummaryAcute venous thromboembolism (VTE) is treated with parenteral administration of heparin or derivatives, in conjunction with oral vitamin K antagonists (VKAs) to reach and maintain INR values between 2.0 and 3.0 for at least 3 months; the duration of a further period of treatment for secondary prevention of recurrences is still matter of debate. If bleeding occurs during treatment the decision will be based on: a) type of bleeding (major or minor), and b) thrombotic risk if anticoagulation is withheld (characteristics of patients and time elapsed from the index VTE). In case of major bleeding anticoagulation should be stopped and reversed. A first but insufficient measure is i.v. vitamin K administration. Fresh frozen plasma is widely used; however, large volumes are needed (at least 15 mL/kg body weight) with risk for fluid overload. Prothrombin complex concentrate infusion, with 3 or (better) the 4 pro-coagulant factors, is a more efficient (fast and safe) measure. In patients at high thrombotic risk (first month or other conditions) and absolute contraindication for anticoagulation a caval filter is recommended, to avoid as much as possible lifethreatening pulmonary embolism.
Comparing MTA and Ketac Molar Easymix for Furcation Perforation Repair using a Volumetric Method
Authors: KAYA Sadullah , GANİDAĞLI AYAZ Selengül , DOĞAN Mehmet Sinan , AYDIN Haluk 
Published: October 2011

Aim: We compared the ability of mineral trioxide aggregate (MTA) and Ketac Molar Easymix (KM) to repair furcal perforations in extracted human molars, based on the volume of methylene blue dye penetration.
Methodology: In total, 44 human mandibular molars were divided randomly into two (n = 20 each) experimental groups, with two teeth used as positive controls and two teeth without perforations used as negative controls. Group 1 was repaired with MTA and group 2 with Ketac Molar Easymix. The volumetric determination of dye penetration was based on the molecular characteristics of methylene blue. The standard area of a methylene blue particle is known and the surface area can be calculated. We converted the dye penetration area into a volume and performed quantitative analyses.
Results: Volume measurement using the dye penetration method showed that KM resulted in more microleakage than MTA (p < 0.05).
Conclusions: Mineral trioxide aggregate resulted in significantly less dye leakage than Ketac Molar Easymix using a volumetric measurement method.

How to cite this article: Kaya S, Ganidağlı Ayaz S, Doğan MS, Aydın H. Comparing MTA and Ketac Molar Easymix for furcation perforation repair using a volumetric method. Int Dent Res 2011;1:13-17.
Fabrication of structural composites from waste carpet
Authors: Jain Abhishek , Pandey Gajendra , SINGH Abhishek K. , Rajagopalan Vasudevan , Vaidyanathan Ranji , Singh Raman P. 
Published: October 2011

AbstractVacuum‐assisted resin transfer molding (VARTM) has been used to fabricate engineered composite materials from postconsumer carpet waste. The process is unique and applicable to any type of carpet. This method utilizes the three‐dimensional material architecture of carpet to result in composites with improved mechanical properties, as compared to other recycled carpet‐based materials. The technique can be used to make laminated structures for load‐bearing applications. As a result, this can lead to the recycling of waste carpet with the potential of reduced environmental impact. The potential applications of these composites include low‐cost containers, civil infrastructure components, and materials for impact protection. Moreover, the simplicity of the fabrication technique makes it attractive for commercialization. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 380–389, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20261
Processing and Properties of a Polymer/Composite Double‐Layer Laminate
Authors: Salomi A. , Greco A. , Pacifico T. , Rametta R. , Maffezzoli A. 
Published: October 2011

AbstractCoupled polymer/composite parts were obtained for adapting a bladder‐molding technique previously developed for the production of hollow components with continuous fiber‐reinforced thermoplastic matrix composites. The internal layer (bladder side) is made up of an unreinforced thermoplastic polymer, linear low‐density polyethylene (LLDPE), and the external one (mold side) is made up of a thermoplastic matrix composite based on isotactic polypropylene (PP) and E‐glass fabric. The adhesion between the two layers is achieved by applying pressure (<1 bar) through a silicone bladder. The composite/polymer interface was characterized by the evaluation of the interfacial shear strength (IFSS) (between composite and unreinforced polymer), flexural stiffness, and short‐beam strength analysis. The experimental mechanical properties were compared with model results, derived on the assumption that perfect adhesion exists between the two layers. A good agreement between the predicted and experimental mechanical properties was observed. As indicated by double notch shear tests used for the IFSS evaluation, good adhesion between LLDPE and PP matrix composite was achieved during processing. The results reported confirm the suitability of the method for a double‐layer structure fabrication. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: E32–E43, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20267