bluuebunny/crossref_metadata_2025_split huggingface dataset:
Desorption of nitramine and nitroaromatic explosive residues from soils detonated under controlled conditions
Authors: Douglas Thomas A , Walsh Marianne E , McGrath Christian J , Weiss Charles A , Jaramillo Ashley Marie , Trainor Thomas P 
Published: October 2010

Abstract
Potentially toxic nitroaromatic and nitramine compounds are introduced onto soils during detonation of explosives. The present study was conducted to investigate the desorption and transformation of explosive compounds loaded onto three soils through controlled detonation. The soils were proximally detonated with Composition B, a commonly used military explosive containing 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). Gas-exchangeable surface areas were measured from pristine and detonated soils. Aqueous batches of detonated soils were prepared by mixing each soil with ultrapure water. Samples were collected for 141 d and concentrations of Composition B compounds and TNT transformation products 2-amino-4,6-dinitrotoluene (2ADNT), 4-amino-2,6-dinitrotoluene (4ADNT), and 1,3,5-trinitrobenzene (1,3,5-TNB) were measured. The RDX, HMX, and TNT concentrations in detonated soil batches exhibited first-order physical desorption for the first, roughly, 10 d and then reached steady state apparent equilibrium within 40 d. An aqueous batch containing powdered Composition B in water was sampled over time to quantify TNT, RDX, and HMX dissolution from undetonated Composition B particles. The TNT, RDX, and HMX concentrations in aqueous batches of pure Composition B reached equilibrium within 6, 11, and 20 d, respectively. Detonated soils exhibited lower gas-exchangeable surface areas than their pristine counterparts. This is likely due to an explosive residue coating on detonated soil surfaces, shock-induced compaction, sintering, and/or partial fusion of soil particles under the intense heat associated with detonation. Our results suggest that explosive compounds loaded to soils through detonation take longer to reach equilibrium concentrations in aqueous batches than soils loaded with explosive residues through aqueous addition. This is likely due to the heterogeneous interactions between explosive residues and soil particle surfaces. Environ. Toxicol. Chem. 2011;30:345–353. © 2010 SETAC
Using meiofauna to assess pollutants in freshwater sediments: A microcosm study with cadmium
Authors: Brinke Marvin , Ristau Kai , Bergtold Matthias , Höss Sebastian , Claus Evelyn , Heininger Peter , Traunspurger Walter 
Published: October 2010

AbstractThe direct and indirect effects of Cd on benthic communities were assessed in a freshwater microcosm study over a period of seven months (218 d). Cadmium was regarded as a model substance to evaluate the usefulness of small-scale laboratory microcosm with microscopic fauna. In particular, effects on the meiofauna community, an ecologically important but rather neglected benthic component, were investigated. In addition, some microfaunal parameters (protozoan abundance and microbial activity) were determined. The sediment was spiked with nominal Cd concentrations of 10, 100, and 1,000 mg/kg dry weight. Because of the strong binding of Cd to sediment particles, measured Cd pore-water concentrations never exceeded 129.5 ± 40.7 µg/L. At 1,000 mg/kg dry weight, the abundances of the two dominant meiofauna taxa, nematodes and oligochaetes, were significantly reduced throughout the present study. Regarding nematodes, species of bacterivorous taxa (Daptonema, Eumonhystera) decreased, whereas species of predacious and omnivorous taxa (Mononchus, Dorylaimus, and Ironus) increased in dominance in microcosms of the highest Cd concentration. Transient effects on microfauna were observed, especially in the first half of the present study, with a reduction in microbial activity and protozoan abundance. However, in microcosms receiving the highest Cd concentration, the abundance of the flagellate Euglena mutabilis increased significantly toward the end of the present study. The results of the present study support the use of small-scale microcosms with natural meiofauna communities as a suitable tool to assess the impact of pollutants in freshwater sediments. Environ. Toxicol. Chem. 2011;30:427–438. © 2010 SETAC
Screening complex effluents for estrogenic activity with the T47D-KBluc cell bioassay: Assay optimization and comparison with in vivo responses in fish
Authors: Wehmas Leah C , Cavallin Jenna E , Durhan Elizabeth J , Kahl Michael D , Martinovic Dalma , Mayasich Joe , Tuominen Tim , Villeneuve Daniel L , Ankley Gerald T 
Published: October 2010

Abstract
Wastewater treatment plant (WWTP) effluents can contain estrogenic chemicals, which potentially disrupt fish reproduction and development. The current study focused on the use of an estrogen-responsive in vitro cell bioassay (T47D-KBluc), to quantify total estrogenicity of WWTP effluents. We tested a novel sample preparation method for the T47D-KBluc assay, using powdered media prepared with direct effluent. Results of the T47D-KBluc assay were compared with the induction of estrogen receptor–regulated gene transcription in male fathead minnows (Pimephales promelas) exposed to the same effluents. Effluent samples for the paired studies were collected over the course of three months. According to the T47D-KBluc assay, the effluent estrogenicity ranged from 1.13 to 2.00 ng 17β-estradiol (E2) equivalents/L. Corresponding in vivo studies exposing male fathead minnows to 0, 10, 50, and 100% effluent dilutions demonstrated that exposure to 100% effluent significantly increased hepatic vitellogenin (VTG) and estrogen receptor α subunit transcripts relative to controls. The induction was also significant in males exposed to 250 ng E2/L or 100 ng E2/L. The in vitro and in vivo results support the conclusion that the effluent contains significant estrogenic activity, but there was a discrepancy between in vitro– and in vivo–based E2 equivalent estimates. Our results suggest that the direct effluent preparation method for the T47D-KBluc assay is a reasonable approach to estimate the estrogenicity of wastewater effluent. Environ. Toxicol. Chem. 2011;30:439–445. © 2010 SETAC
Role of pocket flexibility in the modulation of estrogen receptor alpha by key residue arginine 394
Authors: Mu Yunsong , Peng Sufen , Zhang Aiqian , Wang Liansheng 
Published: October 2010

Abstract
Estradiol derivatives, with similar structures as estradiol (E2) or estradiol metabolites, have been recognized to have detrimental health effects on wildlife and humans. However, data at the molecular level about interactions of these compounds with biological targets are still lacking. Herein, a flexible docking approach was used to characterize the molecular interaction of nine estradiol derivatives with estrogen receptor alpha (ERα) in the ligand-binding domain. All ligands were docked in the buried hydrophobic cavity of the steroid hormone pocket. In addition, the plasticity of an active site was also identified by reversing amino acid arginine 394 for better ligand-receptor binding affinity. Finally, bioassays based on genetically modified yeast strains were used to validate the quality of molecular simulation because of their rapidity and high sensitivity. The experimental findings about logarithm values of the median effective concentration (EC50) value had a linear correlation with computational binding affinity from molecular docking, which described a pattern of interaction between estradiol derivatives and ER. The estrogenic activity of all compounds, although more or less lower than E2, was proved to possess high severe environmental risks. Considering the sidechain flexibility in the ligand binding pocket, 17α-ethylestradiol-3-cyclopentylether was reported to correlate highly significantly with known induced fit conformational changes based upon proof-of-principle calculations on human ERα with the preservation of a strong salt bridge between glutamic acid 353 and arginine 394. Environ. Toxicol. Chem. 2011;30:330–336. © 2010 SETAC
Development of an enzyme-linked immunosorbent assay for quantifying vitellogenin in Pacific salmon and assessment of field exposure to environmental estrogens
Authors: Peck Karen A , Lomax Daniel P , Olson O. Paul , Sol Sean Y , Swanson Penny , Johnson Lyndal L 
Published: October 2010

AbstractA competitive enzyme-linked immunosorbent assay was developed to quantitate vitellogenin (VTG) in plasma and serum of coho (Oncorhynchus kisutch) and chinook (O. tshawytscha) salmon. The working range of the assay was 9 to 313 ng/ml (80–20% binding), with 50% binding at 54 ng/ml. The intra-assay and interassay variations at approximately 50% binding were 8.1% (n = 9) and 9.0% (n = 9), respectively. Dilution curves of plasma or serum from coho and chinook females and estrogen-treated males were parallel to the purified coho VTG standard curve. Male plasma samples could be assayed at a minimum dilution of 1:40 (chinook) or 1:75 (coho) without assay interference because of high sample concentration, whereas minimum acceptable dilutions of male serum samples were 1:200 (chinook) or 1:600 (coho). Identification of proper techniques for preserving VTG integrity in plasma and serum samples showed that VTG from both species was robust; both sample types required no protease inhibitor despite subjection to two freeze–thaw cycles. To test its applicability, this assay was used to measure VTG in out-migrating juvenile chinook that were collected from urban and nonurban areas in Puget Sound, Washington, USA. Results showed a small but significant plasma VTG elevation at two urban sites, suggesting that these juveniles may be exposed to environmental estrogens at an early life stage. Also, wild fish tended to have higher plasma VTG levels than hatchery fish collected in the field. Elevation of mean VTG levels was similar to that previously reported in male English sole from the same area, where both males and females exhibited alterations in timing of spawning. Environ. Toxicol. Chem. 2011;30:477–486. © 2010 SETAC
The effect of pH on the uptake and toxicity of the bivalent weak base chloroquine tested onSalix viminalisandDaphnia magna
Authors: Rendal Cecilie , Kusk Kresten Ole , Trapp Stefan 
Published: October 2010

AbstractThe uptake and accumulation of most electrolytes will change with pH because of the different speciation states of these compounds at various pH. Non-ionized compounds will partition into fatty and organic phases (such as cell membranes) more readily than the corresponding charged compounds, and therefore a higher toxicity can be expected. The current study examines the pH-dependent toxicity and bioaccumulation of the bivalent weak base chloroquine (pKa: 10.47 and 6.33, log KOW 4.67) tested on Salix viminalis (basket willow) and Daphnia magna (water flea). The transpiration rates of hydroponically grown willow cuttings were used to determine the toxicity of chloroquine at pH levels of 6, 7, 8, and 9. Root concentration factors were calculated from solution measurements. Results showed more than 10-fold higher toxicity and four to seven times higher root concentration factor at pH 9 than at pH 6. The toxicity of chloroquine was tested on Daphnia magna using the standard Organisation for Economic Co-operation and Development acute toxicity test modified to accommodate testing at pH levels of 7, 8, and 9. Increasing toxicity was seen at higher pH. The results of the current study confirm that the toxicity of weak bases with intermediate pKa values is higher at high pH levels. Environ. Toxicol. Chem. 2011;30:354–359. © 2010 SETAC
Parameter uncertainty in modeling bioaccumulation factors of fish
Authors: Hauck Mara , Hendriks Harrie W.M , Huijbregts Mark A.J , Ragas Ad M.J , van de Meent Dik , Hendriks A. Jan 
Published: October 2010

Abstract
We quantified the uncertainty due to biota-related parameters in estimated bioaccumulation factors (BAFs) of persistent organic pollutants for fish through Monte Carlo simulations. For this purpose, the bioaccumulation model OMEGA (Optimal Modeling for EcotoxicoloGical Applications) was parameterized based on data from the existing literature, analysis of allometric data, and maximum likelihood estimation. Lipid contents, fractions of food assimilated, the allometric rate exponent, normalized food intakes, respiration and growth dilution rates, and partial mass transfer resistances in water and lipid layers were included as uncertain parameters. The uncertainty in partial resistances was particularly important in the estimation of the rate constants for chemical intake from water by fish. Uncertainties in the fractions of food assimilated and partial water layer resistances from and to food were particularly important in the estimation of the rate constants of chemical intake from food. The uncertainty in the model outcomes for the bioaccumulation factors for fish was a factor of 10 (ratio of 95th and fifth percentile estimates), which was mainly caused by the uncertainty in the lipid fraction. For chemicals with a KOW of 103 to 106, the uncertainty in the lipid contents of fish accounted for more than 50% of the uncertainty in the estimated bioaccumulation factor. For chemicals with a high KOW (107 and higher), the fractions of food assimilated and partial resistances also contributed to uncertainty in the estimated bioaccumulation factor (up to 60%). A case study showed that uncertainty in estimated BAF for nonpersistent substances can be dominated by uncertainty in the rate constants for metabolic transformation. Environ. Toxicol. Chem. 2011;30:403–412. © 2010 SETAC
Simultaneous determination of mercury methylation and demethylation capacities of various sulfate-reducing bacteria using species-specific isotopic tracers
Authors: Bridou Romain , Monperrus Mathilde , Gonzalez Pablo Rodriguez , Guyoneaud Rémy , Amouroux David 
Published: October 2010

Abstract
The use of species-specific isotopic tracers for inorganic and methyl mercury has allowed the simultaneous determination of the methylation and demethylation potentials of pure culture of isolated sulfate-reducing (SR) bacterial strains using low Hg species concentration levels (7 µg/L 199Hg(II), 1 µg/L Me201Hg). A major advantage of the method reported here is that it can be used to follow simultaneously both the degradation of the species added but also the formation of their degradation products and thus the determination during the same incubation of the specific methylation/demethylation yields and rate constants. Methylation/demethylation capacities and extents have been found to differ between the tested strains and the tested conditions. The methylating/demethylating capacities of bacteria appear to be strain specific. All the methylating strains were found to demethylate methylmercury (MeHg). The active mechanism responsible for Hg methylation appears directly dependent on the bacterial activity but is not dependent on the metabolism used by the tested bacteria (sulfate reduction, fermentation, or nitrate respiration). The results provide confirmation that SR strains contribute to MeHg demethylation under anoxic conditions, leading to Hg(II) as the end product, consistent with the oxidative degradation pathway. Kinetic experiments have allowed specific transformation rate constants to be addressed for the two reversible processes and the reactivity of each isotopic tracer to be compared. The differential reactivity highlighted the different steps involved in the two apparent processes (i.e., uptake plus internal transformation of mercury species). Methylation appears as the slowest process, mainly controlled by the assimilation of Hg(II), whereas demethylation is faster and not dependent on the MeHg concentration. Environ. Toxicol. Chem. 2011;30:337–344. © 2010 SETAC
Transfer capacity enhancement by adaptive coordinated control of HVDC‐links based on forecasted load paths
Authors: Eriksson Robert , Perninge Magnus , Söder Lennart 
Published: October 2010

AbstractDue to the intensive use of the transmission networks one of the major issues in electric energy trading is bottlenecks limiting the transfer capacity between different system areas. In this article, a new method for increasing transfer capacity is suggested. The increase in transfer capacity is obtained by an adaptive coordinated modulation control of multiple HVDC‐links in the system. The control method is based on maximizing the distance to the bifurcation surface by adjusting the feedback gain of the HVDC‐links modulation controllers. The system is linearized along the forecasted load path. The feedback gains are then chosen in such a way that system remains stable, in a small signal sense, as long as possible along the forecasted load path. The arising optimization problem is then solved using a particle swarm optimization method. If the load is predicted to increase, instability will eventually occur when the loading reaches a critical limit. Using the proposed control method the point in load‐space where instability occur will be at a significantly higher loading level. The main contribution of this paper is the proposed new method for adaptively coordinating the power modulation of multiple HVDC‐links in a power system, to enhance the total transfer capacity. This in turn will lead to a possibility to increase the traded volumes on the electricity market. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of Steinmetz circuit capacitor degradation on series resonance of networks
Authors: Sainz Luis , Caro M. , Caro E. 
Published: October 2010

AbstractThe Steinmetz circuit is used in AC traction systems to balance consumed currents. In these systems, locating resonances between Steinmetz circuit capacitors and system inductors avoids harmonic problems. In particular, the paper locates analytically the series resonance “observed” from the supply system considering the influence of capacitor degradation with respect to its design value. The study of this resonance is important to avoid problems associated with background voltage distortion. The analytical results are validated with experimental measurements. Copyright © 2010 John Wiley & Sons, Ltd.
A pressure correction method for fluid–particle interaction flow: Direct‐forcing method and sedimentation flow
Authors: Lin San‐Yih , Chin Ya‐Hsien , Hu Jeu‐Jiun , Chen Yi‐Cheng 
Published: October 2010

AbstractA direct‐forcing pressure correction method is developed to simulate fluid–particle interaction problems. In this paper, the sedimentation flow is investigated. This method uses a pressure correction method to solve incompressible flow fields. A direct‐forcing method is introduced to capture the particle motions. It is found that the direct‐forcing method can also be served as a wall‐boundary condition. By applying Gauss's divergence theorem, the formulas for computing the hydrodynamic force and torque acting on the particle from flows are derived from the volume integral of the particle instead of the particle surface. The order of accuracy of the present method is demonstrated by the errors of velocity, pressure, and wall stress. To demonstrate the efficiency and capability of the present method, sedimentations of many spherical particles in an enclosure are simulated. Copyright © 2010 John Wiley & Sons, Ltd.
Toward accurate simulation and analysis of strong acoustic wave phenomena—A review from the experience of our study on rocket problems
Authors: Fujii Kozo , Nonomura Taku , Tsutsumi Seiji 
Published: October 2010

AbstractThis paper gives an overview of the numerical simulations for the analysis of strong nonlinear acoustic waves during rocket development, with the emphasis on recent ones carried out using large‐scale supercomputers. After the discussion on the difficulties encountered in such simulations, a computational study of blast wave propagation conducted for estimating the safety distance of a rocket is presented. The study was conducted about 20 years ago and the result showed the advantages of the moving grid method as well as the importance of grid resolution studies. A recent study on rocket plume acoustics is then presented. The result shows that the generation and propagation of Mach waves from the plume shear layers are key features to be captured. Direct simulations of such flows have now become feasible owing to the developments in computers and numerical schemes. Then, problems that still remain unsolved are discussed. Our study so far has been limited to simulations using structured grids of high spatial resolution although direct simulations of strongly nonlinear acoustic waves are becoming feasible. More studies have to be carried out for developing highly accurate schemes for unstructured grid systems for the applications to flow configurations over complex geometries. With such improvements, computational fluid dynamics (CFD) would become a still better effective tool for the analysis and estimation of nonlinear acoustic phenomena, especially in aerospace applications. Copyright © 2010 John Wiley & Sons, Ltd.
Stabilized finite element computation of NOx emission in aero‐engine combustors
Authors: Corsini A. , Rispoli F. , Tezduyar T. E. 
Published: October 2010

AbstractA stabilized finite element formulation for the computation of turbulent reacting flows and NOx emission is presented. The method is based on the Streamline‐Upwind/Petrov–Galerkin (SUPG) and Pressure‐Stabilizing/Petrov‐Galerkin (PSPG) formulations, complemented with directionally formulated diffusion for reaction‐dominated flows (‘DRDJ’ stabilization). The stabilized formulation is applied to the advection–diffusion–reaction equations governing the turbulent combustion and the NOx emission equations based on the thermal and the N2O pathways. The simulation is carried out for a co‐axial burner, with a non‐premixed swirling flame. The burner is operated at high pressure to represent the take‐off conditions for an aero‐engine. The vortical patterns of the swirling flame are analyzed together with the temperature field and flame position. The NOx formation processes are discussed, providing insight into the features of thermal and N2O mechanisms. Copyright © 2010 John Wiley & Sons, Ltd.
A numerical scheme for Euler–Lagrange simulation of bubbly flows in complex systems
Authors: Shams E. , Finn J. , Apte S. V. 
Published: October 2010

AbstractAn Eulerian–Lagrangian approach is developed for the simulation of turbulent bubbly flows in complex systems. The liquid phase is treated as a continuum and the Navier–Stokes equations are solved in an unstructured grid, finite volume framework for turbulent flows. The dynamics of the disperse phase is modeled in a Lagrangian frame and includes models for the motion of each individual bubble, bubble size variations due to the local pressure changes, and interactions among the bubbles and with boundaries. The bubble growth/collapse is modeled by the Rayleigh–Plesset (RP) equation. Three modeling approaches are considered: (a) one‐way coupling, where the influence of the bubble on the fluid flow is neglected, (b) two‐way coupling, where the momentum‐exchange between the fluid and the bubbles is modeled, and (c) volumetric coupling, where the volumetric displacement of the fluid by the bubble motion and the momentum‐exchange are modeled. A novel adaptive time‐stepping scheme based on stability‐analysis of the non‐linear bubble dynamics equations is developed. The numerical approach is verified for various single bubble test cases to show second‐order accuracy. Interactions of multiple bubbles with vortical flows are simulated to study the effectiveness of the volumetric coupling approach in predicting the flow features observed experimentally. Finally, the numerical approach is used to perform a large‐eddy simulation in two configurations: (i) flow over a cavity to predict small‐scale cavitation and inception and (ii) a rising dense bubble plume in a stationary water column. The results show good predictive capability of the numerical algorithm in capturing complex flow features. Copyright © 2010 John Wiley & Sons, Ltd.