bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Concept for the Fatigue Life Prediction of Components from an Aluminum-Steel Compound
Authors: Lamik A. , Leitner H. , Eichlseder W. , Riemelmoser F. 
Published: November 2008

Abstract
The goal of this research project is the development of a simulation model for lifetime estimation of components from AA6016-T4/FeP06 material compound. Since such components are manufactured predominantly by rolling (for manufacturing of the material compound) and deep-drawing, the influence of the plastic deformations during the manufacturing process on the fatigue behavior must be investigated. In particular, the influence of the rolling reduction on the behavior of FeP06 steel has a relevant effect on the fatigue life of this aluminum-steel compound. Simulation models for fatigue life estimation of this material compound must therefore consider the influence of the elastic plastic deformation which occurs during, e.g., rolling and deep-drawing processes. For this purpose, a new model for the generation of yield curve as a function of the rolling reduction of the material FeP06 was determined. The proposed yield curve model shows good results at low and high rolling reduction compared to the models of Voce and Swift. The lifetime estimation shows a substantial improvement of accuracy (600 %) by the consideration of the influence of the rolling reduction.
Study on Antioxidative Synergism of Molybdenum Dialkydithiocarbamate with Alkylated Diphenylamine Antioxidants
Authors: Zhang Yi , Zeng Xian-Jun , Hu Jian-Qiang , Fu Yan , Luo Yan 
Published: November 2008

Abstract
The antioxidation properties of molybdenum dialkyldithiocarbamate, p,p-dioctyldiphenylamine and mixed octylated and butylated diphenylamine additives in poly-α-olefin (PAO) lubricant or mineral oil 150 SN were evaluated by differential scanning calorimetry (DSC) and the Modified Penn State Micro-oxidation Test (PMOT). DSC test measures incipient oxidation temperature and oxidation induction time of the lubricants at high temperatures and the weight loss of oil with deposits formed are measured by the PMOT test. DSC results show that antioxidation properties and of p,p-dioctyldiphenylamine and octylated and butylated diphenylamine were improved significantly by molybdenum dialkyldithiocarbamate addition. PMOT results indicate that when it was combinied with p,p-dioctyldiphenylamine, molybdenum dialkyldithiocarbamate can also effectively reduce the increase in weight loss of oils and deposits formed in oils. These results suggest that the molybdenum dialkyldithiocarbamate shows a good antioxidative synergism with alkylated diphenylamine antioxidants. In addition, FTIR results from the PMOT test confirm that the addition of molybdenum dialkyldithiocarbamate can significantly enhance the oxidation induction time of oils containing p,p-dioctyldiphenylamine and inhibit formation of oxidation products including carbonyl bonds or hydroxyl group. ESR analysis from the PMOT test indicate that molybdenum dialkyldithiocarbamate may form stable radicals with arylamine by the coordination effect. Finally, the proposed mechanism of the inhibition involves a synergy between molybdenum dialkyldithiocarbamate and arylamine antioxidants.
A TRLFS study of Cm(III) hydroxide complexes in alkaline CaCl2solutions
Authors: Rabung Thomas , Altmaier Marcus , Neck Volker , Fanghänel Thomas 
Published: November 2008

AbstractTime-resolved laser fluorescence spectroscopy (TRLFS) is used to study Cm(III) solutions ([Cm]tot=2×10−7 M) in 0.1−3.5 M CaCl2at pHc≈11.7 and in three sets of experiments at constant ionic strength (1.0, 2.5 and 3.5 M CaCl2) with pHcvarying from 10.8 to 11.9. The fluorescence spectra show Cm(III) emission bands in the range 605−620 nm. Increasing the CaCl2concentration strongly enhances the intensity of the observed bands. The concentration of aqueous Cm(III) species determined after 10 kD ultrafiltration increases as well, indicating that the Cm(III) hydroxide complexes are stabilized by a strong interaction with Ca2+ions. In 5 M NaCl-NaOH solutions studied for comparison, the curium is almost completely precipitated as Cm(OH)3colloids which show no fluorescence emission bands.Peak deconvolution and the evaluation of the pH dependence of the spectroscopic data show that three emission bands with λmax=607.5, 609.9 and 614.7 nm come from Cm(III) complexes with three, four and six OH−ligands, respectively. The tri- and tetrahydroxide complexes are dominant in 0.1−1.0 M CaCl2, the hexahydroxide complex dominates at higher CaCl2concentrations and pHc>11.5. As a consequence of the strong dependence on the Ca2+concentration and the absence of these complexes in NaOH-NaCl solutions, thermodynamic modelling of the apparent equilibrium constants for stepwise complex formation and the solubility of colloidal Cm(OH)3(am) requires that the observed species are treated as ternary Ca−Cm(III)−OH complexes: Cax[Cm(OH)3]2x, Cay[Cm(OH)4]2y−1and Caz[Cm(OH)6]2z−3wherexmay be 0 or 1,y=2 andz=3.
Structural investigation of coprecipitation of technetium-99 with iron phases
Authors: Alliot Llorens I. , Deniard Philippe , Gautron E. , Olicard A. , Fattahi Massoud , Jobic Stéphane , Grambow Bernd 
Published: November 2008

Abstract
Technetium is a long-lived product of nuclear fission which commonly exhibits two oxidation states (IV and VII). Siderite (FeCO3), suspected to be formed as a container corrosion product in geological radioactive waste repositories, may concentrate by coprecipitation more than 90% of technetium-99, present as Tc(IV) in surrounding aqueous fluids. X-ray diffraction and transmission electron microscopy measurements indicate that technetium can be incorporated within the siderite structure, even if we note that technetium-bearing green rust phase may also be observed. These results suggest that siderite might play a beneficial role in limiting Tc diffusion to the next environment of nuclear waste repositories.
Leaching of a zirconolite ceramic waste-form under proton and He2+ irradiation
Authors: Tribet M. , Toulhoat N. , Moncoffre N. , Jegou Christophe , Leturcq G. , Corbel C. , Toulhoat P. 
Published: November 2008

Abstract
In the hypothesis of a nuclear waste geological disposal, zirconolite is a candidate host material for minor tri- and tetra-valent actinides arising from enhanced nuclear spent fuel reprocessing and partitioning. Its chemical durability has been studied here under charged particle-induced radiolysis (He2+ and proton external beams) to identify possible effects on dissolution rates and mechanisms in pure water. Two experimental geometries have been used to evaluate the influence of the following parameters: solid irradiation and total deposited energy. Results on the evolution of the elemental releases due to the enhanced dissolution of the zirconolite surface during charged particle-induced irradiation of water are presented. Under radiolysis, elemental releases are first kinetically controlled. When the titanium and the zirconium releases reach (or exceed) their corresponding hydroxide solubility limits, the zirconolite dissolution becomes thermodynamically controlled.
Technetium reduction and reoxidation behaviour in Dounreay soils
Authors: Begg James D. C. , Burke Ian T. , Charnock John M. , Morris Katherine 
Published: November 2008

Abstract
Technetium is a radioactive contaminant found in groundwaters at sites where nuclear wastes have been processed or stored. The redox chemistry of technetium is a major control on its environmental mobility. Under oxic conditions, technetium exists as the pertechnetate ion, Tc(VII)O4
−, which is poorly sorbed by minerals across a wide range of environmentally relevant pH values. Under reducing conditions pertechnetate is converted to lower valency species, of which Tc(IV) tends to predominate. Typically, the Tc(IV) oxidation state readily precipitates as insoluble hydrous Tc(IV) oxides or, at low concentrations, is removed from solution by association with mineral surfaces. Here, we present novel X-ray absorption spectroscopy (XAS) data examining Tc associations with reduced Dounreay soils. In reduced unamended microcosms and in microcosms where we added the co-contaminants ethylenediaminetetraacetic acid (EDTA) or bicarbonate to investigate their effect on Tc biogeochemistry, Tc was removed from solution on exposure to the reduced sediments and was present on solids as hydrous Tc(IV)O2-like phases. Furthermore, to investigate the long term stability and remobilization of solid phase associated Tc in reduced soils, we reoxidized reduced, Tc(IV)-labeled soils, in the presence of air and nitrate. The extent of remobilization of Tc to solution was dependent on the oxidant used. After reoxidation with air for 60 d, (42±6)% of the initial soil bound Tc was resolubilized. In the presence of 25 or 100 mmol L−1 nitrate as an oxidant, negligible microcosm reoxidation or remobilization of Tc to solution occurred. XAS analysis of soils treated with the two oxidants showed that in both systems, the remaining soil associated Tc was present as hydrous TcO2-like phases. The recalcitrance of Tc remobilization under reoxidizing conditions has implications for the fate of Tc in contaminated environments.
Effects of hydrogen and bromide on the corrosion of spent nuclear fuel andγ-irradiated UO2(s) in NaCl brine
Authors: Metz Volker , Loida A. , Bohnert E. , Schild D. , Dardenne Kathy 
Published: November 2008

AbstractRadiation induced UO2(s) corrosion is studied at elevated hydrogen pressure in NaCl brine containing traces of bromide. Release of Sr, Cs, Tc and actinides was measured in corrosion experiments with spent nuclear fuel pellets in presence of 10−2 mol H2(kg H2O)−1, and 10−4and 10−3 mol Br−(kg H2O)−1, respectively. For comparison, depleted UO2(s) pellets were γ-irradiated in NaCl brine at 10−3 mol H2(kg H2O)−1and 0−10−4 mol Br−(kg H2O)−1, respectively. In the γ-radiolysis experiments a significant increase in the yield of radiolytic products due to Br−is observed. Both, in the γ-radiolysis experiment with Br−and in that without Br−, the UO2(s) sample was oxidized, and the concentration of dissolved uranium was controlled by precipitation of meta-schoepite and clarkeite. In the spent nuclear fuel corrosion experiment under H2overpressure, aqueous concentrations of Tc and Np were in the range of solubilities of Tc(IV) and Np(IV) hydroxides, whereas measured U concentrations were between solubilities of U(VI) and U(IV) phases. The release rate of Sr was significantly increased in the presence of Br−traces. Results of the complementary spent nuclear fuel corrosion andγ-radiolysis experiments allow the conclusion that Br−traces reduce significantly the protective hydrogen effect with respect to the release of certain radionuclides and the yield of radiolytic products.
Measuring sorption coefficients and BET surface areas on intact drillcore and crushed granite samples
Authors: André Magnus , Neretnieks Ivars , Malmström M. E. 
Published: November 2008

Abstract
In general sorption coefficients, K
d, cat ion exchange capacity, CEC, and BET surface areas are measured on crushed rock samples because it is very time consuming to measure K
d and CEC on larger rock pieces as it takes a long time for the sorbing species to penetrate into and equilibrate a large sample. Also conventional sample holders for BET measurements are too small to hold a large sample.
We have manufactured large sample holders for BET measurements and modified the equipment so that it is possible to measure BET surface areas on samples with 50 mm diameter and up to 100 mm length. Results are presented for intact pieces and compared to results on crushed material from the same drillcore.
For K
d and CEC measurements we have developed a technique and equipment by which ions can be made to rapidly intrude into and equilibrate the internal surfaces of the same size samples as mentioned above. The method is based on electro-migration where the sample is placed between two vessels one with an anode and other with a cathode. The electric potential gradient drives the ions into and through the sample very much faster than molecular diffusion does. With Cs as the sorbing ion a few weeks were sufficient to equilibrate the 50 mm long sample. In previous diffusion experiments it took more than a year to equilibrate a 15 mm thick sample. A special mixing technique eliminates the development of low and high pH in the electrode compartments.

K
d results from measurements on an intact drillcore are presented and comparison is made with results obtained on crushed material from the same bore core. The results from the sorption experiments are compared with the results from the BET surface area determinations in an attempt to evaluate the use of the BET surface area as a proxy for sorption behaviour.
The influence of natural organic matter on the speciation and solubility of Eu in Boom Clay porewater
Authors: Liu D. J. , Bruggeman C. , Maes Norbert 
Published: November 2008

AbstractThe influence of natural organic matter (NOM) on the speciation and solubility of europium (Eu) was studied under geochemical conditions representative for the Boom Clay. Different organic matter types were used, and analysis was performed both after 0.45 μm microfiltration and after 30000 MWCO ultrafiltration to distinguish between larger colloids (assumed to be immobile underin situconditions) and small dissolved species.Equilibrium was approached from undersaturation starting from synthesised Eu(OH)3(s), which, during the experiment, transformed into EuOHCO3(s), in agreement with thermodynamic considerations. In the absence of NOM, the Eu solution concentrations after 0.45 μm filtration exceeded the thermodynamic solubility of EuOHCO3(s) by several orders of magnitude, indicating the presence of inorganic Eu colloids. In the presence of NOM, the Eu solubility increased with increasing NOM concentration as was expected, but, surprisingly, was dependent on the operational size cut-off: at an identical NOM concentration in the filtrate, the Eu solution concentration after 0.45 μm filtration was consistently higher compared to the Eu concentration after 30000 MWCO filtration. This latter observation necessitates detailed knowledge concerning the pore size cut-off of Boom Clay underin situconditions in order to use the correct Eu-NOM complexation constant and/or maximum solubility in transport calculations. At higher NOM concentrations (TOC>30 mg/L) the Eu solubility after 0.45 μm filtration was seemingly independent of the NOM concentration.In contrast, after 30000 MWCO ultrafiltration, the Eu solution increased linearly with increasing DOC, from the expected thermodynamic solubility (∼5×10−7 mol L−1) at 0 mg L−1DOC to ∼3×10−5 mol L−1at 80 mg L−1DOC. All of the data sets were modelled using the Nagra/PSI database [8] for solubility, hydrolysis and inorganic aqueous complexation reactions, and fitted organic complexation reactions between Eu3+and NOM functional groups. Both a free ligand approach (with electrostatic correction) and the humic ion-binding model VI [23], which was for the first time successfully introduced into Phreeqc geochemical code, were tested and provided equally good fits to the data.
Pu(V) reduction and enhancement of particle-water partitioning by exopolymeric substances
Authors: Roberts Kimberly A. , Santschi Peter H. , Honeyman Bruce D. 
Published: November 2008

Abstract
Central to understanding the environmental behavior of Pu in vadose- and saturated-zones, as well as waste streams, is the contribution of colloidal natural organic mater (NOM), e.g. , biopolymeric exopolymeric substances (EPS) from Pseudomonas fluorescens Biovar II and geopolymeric humic acids (HA), to Pu speciation. Because Pu(V) and Pu(IV) are present in aquatic systems at sub-pM concentrations, many established techniques for chemical speciation and oxidation state determination are not available. However, the two redox states of Pu can be distinguished through their tendency to form colloidal species. Controlled laboratory experiments with low-colloid background solutions of 0.1 M NaClO4 with an inert buffer (Tris) and 5 μm silica particles of high specific surface area (500 m2/g) and small (3 nm) pores investigated the ability of NOM compounds for their binding and redox qualities showed that: 1) Pu(V) and Pu(IV) tracers at pM concentrations could be distinguished by their tendency to bind to colloidal species (≥1 kDa), with binding extent being high for Pu(IV), and low for Pu(V); 2) EPS can significantly enhance particle- (or colloid-) water partition coefficients to silica particles (K
d, K
dc), quickly (1 day) for Pu(IV) and slowly (1 month) for Pu(V); 3) Pu(V), in the presence of EPS and silica particles can become associated with particles and colloids over periods of months, likely indicating reduction; 4) K
d values can be affected by the reaction sequence of tracer addition to the solution containing silica particles and NOM compounds ( e.g. , EPS or HA).
Laser ablation microprobe inductively coupled plasma mass spectrometry study on diffusion of uranium into cement materials
Authors: Sugiyama Daisuke , Chida Taiji , Cowper M. M. 
Published: November 2008

Abstract
The diffusion of uranium (U(VI)) in solid cement monoliths of ordinary portland cement (OPC) and low-heat portland cement containing 30[wt.]% fly ash (FAC) was measured by an in-diffusion technique. Detailed sharp depth profiles of uranium in the solid cement matrices were successively and quantitatively measured using laser ablation microprobe inductively coupled plasma mass spectrometry (LAMP-ICP-MS), and the apparent (D
a) and effective (D
e) diffusion coefficient of uranium in cement matrix were calculated as: D
a=∼4×10−16 m2 s−1 and D
e=∼3×10−11 m2 s−1 for OPC, and D
a=∼2×10−17 m2 s−1 and D
e=∼6×10−13 m2 s−1 for FAC.
Binding of Pu(IV) to galacturonic acid and extracellular polymeric substances (EPS) fromShewanella putrefaciens, Clostridium sp. andPseudomonas fluorescens
Authors: Harper Ruth M. , Kantar Cetin , Honeyman Bruce D. 
Published: November 2008

AbstractThe conditional stability constants for trace-level concentrations of Pu(IV) complexing with galacturonic acid and EPS, isolated from axenicClostridiumsp.,P. fluorescensandShewanella putrefaciensCN32 cultures, were determined at pH 4 and an ionic strength of 0.1 M NaCl using an ion-exchange technique. The analysis of ion-exchange data with Schubert´s technique indicates that the Pu binding by galacturonic acid and EPS fromClostridiumsp. andS. putrefacienscan be described based on the formation of 1:1 Pu(IV)-ligand complexes. However, the accurate description of Pu binding by EPS fromP. fluorescensrequires postulation of a mixture of 1:1/1:2 complexes between Pu(IV) and ligands under the experimental conditions studied.The results from the ion-exchange experiments were also modeled based on a non-electrostatic, discrete ligand approach in which bacterial EPS is conceptualized as being composed of a suite of monoprotic acids, HLi, of arbitrarily-assigned pKa(i) values (e.g., 4, 6 and 8). The examination of ion-exchange data in a chemical model suggested that only the pKa4 (L1) and 6 (L2) ligands are sufficient to accurately simulate the Pu(IV)/EPS binding, implying that carboxylic groups in EPS are the primary binding sites for complexing with Pu(IV) under the experimental conditions examined. The affinity of EPS for complexing Pu(IV) decreases in the order ofClostridiumsp.>S. putrefaciens>P. fluorescensalthough the concentrations of carboxylic groups in EPS decrease in the order ofP. fluorescens>S. putrefaciens>Clostridiumsp. This discrepancy may be due to differences in binding affinities between Na+ion in solution and EPS ligands. AtI=0.1 M, models demonstrated that the EPS fromP. fluorescensexhibits a much stronger affinity for the Na+ion compared to ligands from other EPS; therefore, the deprotonated carboxylic sites of EPS fromP. fluorescensare hypothesized to be mostly bound by Na+in solution.
The Classical Nuclear Localization Signal Receptor, Importin-α, Is Required for Efficient Transition Through the G1/S Stage of the Cell Cycle inSaccharomyces cerevisiae
Authors: Pulliam Kanika F , Fasken Milo B , McLane Laura M , Pulliam John V , Corbett Anita H 
Published: November 2008

AbstractThere is significant evidence linking nucleocytoplasmic transport to cell cycle control. The budding yeast, Saccharomyces cerevisiae, serves as an ideal model system for studying transport events critical to cell cycle progression because the nuclear envelope remains intact throughout the cell cycle. Previous studies linked the classical nuclear localization signal (cNLS) receptor, importin-α/Srp1, to the G2/M transition of the cell cycle. Here, we utilize two engineered mutants of importin-α/Srp1 with specific molecular defects to explore how protein import affects cell cycle progression. One mutant, Srp1-E402Q, is defective in binding to cNLS cargoes that contain two clusters of basic residues termed a bipartite cNLS. The other mutant, Srp1-55, has defects in release of cNLS cargoes into the nucleus. Consistent with distinct in vivo functional consequences for each of the Srp1 mutants analyzed, we find that overexpression of different nuclear transport factors can suppress the temperature-sensitive growth defects of each mutant. Studies aimed at understanding how each of these mutants affects cell cycle progression reveal a profound defect at the G1 to S phase transition in both srp1-E402Q and srp1-55 mutants as well as a modest G1/S defect in the temperature-sensitive srp1-31 mutant, which was previously implicated in G2/M. We take advantage of the characterized defects in the srp1-E402Q and srp1-55 mutants to predict candidate cargo proteins likely to be affected in these mutants and provide evidence that three of these cargoes, Cdc45, Yox1, and Mcm10, are not efficiently localized to the nucleus in importin-α mutants. These results reveal that the classical nuclear protein import pathway makes important contributions to the G1/S cell cycle transition.
The Joint Effects of Selection and Dominance on the QST − FST Contrast
Authors: Santure Anna W , Wang Jinliang 
Published: November 2008

Abstract
Q ST measures the differentiation of quantitative traits between populations. It is often compared to FST, which measures population differentiation at neutral marker loci due to drift, migration, and mutation. When QST is different from FST, it is usually taken as evidence that selection has either restrained or accelerated the differentiation of the quantitative trait relative to neutral markers. However, a number of other factors such as inbreeding, dominance, and epistasis may also affect the QST − FST contrast. In this study, we examine the effects of dominance, selection, and inbreeding on QST − FST. We compare QST with FST at selected and neutral loci for populations at equilibrium between selection, drift, mutation, and migration using both analytic and simulation approaches. Interestingly, when divergent selection is acting on a locus, inbreeding and dominance generally inflate QST relative to FST when they are both measured at the quantitative locus at equilibrium. As a consequence, dominance is unlikely to hide the signature of divergent selection on the QST − FST contrast. However, although in theory dominance and inbreeding affect the expectation for QST − FST, of most concern is the very large variance in both QST and FST, suggesting that we should be cautious in attributing small differences between QST and FST to selection.