pinecone/core-2020-05-10-deduplication huggingface dataset:
Polishing of synthetic electroplating wastewater in microcosm upflow constructed wetlands: Effect of operating conditions

International audienceThis paper addresses the issue of polishing electroplating wastewater in subsurface vertical flow constructed wetland. Electroplating wastewater treatment or polishing in constructed wetlands (CWs) was studied to a very limited degree. Four types of microcosm upflow constructed wetlands were selected for the experiment based on type of bed media and the presence or absence of vegetation (<i>Phragmites australis</i>). The main objective of the system design was to promote metals removal by precipitation as sulfides mediated by sulfate reducing bacteria. The experimental system consisted of eight PVC columns (diameter 20 cm) filled up to. 63.5 cm with either gravel or gravel-peat mixture and was operated for one year, polishing synthetic electroplating wastewater. The wastewater used in this study contained metals (Cu, Ni, Pb and Zn), cyanides and sulfates, which typically occur in electroplating wastewater. During the experiment the effect of the following factors was studied: presence of vegetation, hydraulic loading, wastewater strength, type of bed media, and addition of lactates as external carbon source for the columns with gravel. The results showed that the upflow columns can efficiently remove metals (with the exception of Pb) and cyanides. It was observed that the removal efficiency of Cu, Ni and Zn increases with increasing influent concentration of metals and increasing hydraulic loading rate. The role of plants and bed media was minor. The addition of lactates to the feed of the columns with gravel was found to improve the reduction of metals concentration in the passing wastewater
Mathematical framework for Traction Force Microscopy

International audienceThis paper deals with the Traction Force Microscopy (TFM) problem. It consists in obtaining stresses by solving an inverse problem in an elastic medium, from known experimentally measured displacements. In this article, the application is the determination of the stresses exerted by a living cell at the surface of an elastic gel. We propose an abstract framework which formulates this inverse problem as a constrained minimization problem. The mathematical constraints express the biomechanical conditions that the cell must satisfy. From this framework, two methods currently used can be derived, the adjoint method (AM) and the Fourier Transform Traction Cytometry (FTTC) method. An improvement of the FTTC method is also derived using this framework. The numerical results are compared and show the advantage of the AM, in particular it can capture details more accurately
An adaptive sparse grid semi-lagrangian scheme for first order Hamilton-Jacobi Bellman equations

International audienceWe propose a semi-Lagrangian scheme using a spatially adaptive sparse grid to deal with non-linear time-dependent Hamilton-Jacobi Bellman equations. We focus in particular on front propagation models in higher dimensions which are related to control problems. We test the numerical efficiency of the method on several benchmark problems up to space dimension d = 8, and give evidence of convergence towards the exact viscosity solution. In addition, we study how the complexity and precision scale with the dimension of the problem
An efficient data structure to solve front propagation problems

International audienceIn this paper we develop a general efficient sparse storage technique suitable to coding front evolutions in d>= 2 space dimensions. This technique is mainly applied here to deal with deterministic target problems with constraints, and solve the associated minimal time problems. To this end we consider an Hamilton-Jacobi-Bellman equation and use an adapted anti-diffusive Ultra-Bee scheme. We obtain a general method which is faster than a full storage technique. We show that we can compute problems that are out of reach by full storage techniques (because of memory). Numerical experiments are provided in dimension d=2,3,4
Selective hydrogenation of ethyl-benzoylacetate to 3-hydroxy-3-phenyl-propionate catalyzed by Pd/C in EtOH as a solvent in the presence of KOH: The role of the enolate ion on the reaction mechanism

The selective hydrogenation of ethyl-benzoylacetate to 3-hydroxy-3-phenyl-propionate catalyzed by Pd/C in EtOH in a solution of KOH has been investigated. Mass transfers as well as adsorption and desorption stages do not influence reaction kinetics. A kinetic model is proposed based on the best fitting of the experimental data with Langmuir–Hinshelwood type kinetics equation. The mechanism implies that the enolate of the ethyl-benzoylacetate adsorbs strongly on two sites, thus occupying a large part of the surface Pd atoms without any reaction. The ethyl-benzoylacetate adsorbs also on two sites but with adsorption equilibrium constant almost three order of magnitude lower than that of the enolate anions. Also the hydrogen is poorly adsorbed, however, it forms Pd–H and reacts with the adsorbed keto-ester by a step hydrogenation mechanism in which the first hydride insertion is the rate-determining step. Furthermore, due to the low surface Pd–H availability and the fast desorption of the 3-hydroxy-3-phenyl-propionate the consecutive hydrogenolysis of the C–OH bond of the product is practically suppressed, thus achieving selectivity close to 100%
A procedure to assess local and long-range transport contributions to PM2.5 and secondary inorganic aerosol

All over Europe, low wind speeds and stable atmospheric stratification are meteorological factors leading to air pollution episodes. Discriminating the contribution of the local atmospheric circulation and the regional and long-range transport processes, in determining PM2.5 and pollutants levels, is very important for deciding any effective abatement measure. This is particularly true in the Northeastern part of the Po Valley, one of the most polluted areas in Europe.

This study proposes a method for assessing the relative importance of regional and long-range transport episodes and of local sources on PM2.5 mass and ionic composition.

Air mass back-trajectories were combined with PM chemical composition and local wind data and the relative contributions were estimated.

Air mass histories show that the levels of PM2.5 increased when air masses had arrived from Northern to Central and Northwestern Europe and significantly dropped when the trajectories originated from the Mediterranean area. Furthermore, results reveal that relatively fast winds from quadrant I were associated with clean air and increasing sea-salt components. Diversely, air mass stagnations were closely accompanied by severe pollution events. Heavily polluted episodes were recorded in correspondence of days characterized by low-mobility atmospheric conditions and when air masses had spent most time over the Po Valley region.

These results can help understanding the sources, the chemistry and dynamics of PM2.5 in Northeastern Italy. The proposed approach is easily applicable to other environments
Mobility of major-, minor- and trace elements in solutions of a planosolic soil: Distribution and controlling factors

International audienceSubsurface waters circulating in an unpolluted soil of a planosolic horizon (Massif Central, France) were studied in order to determine their physico-chemical characteristics. Three water sampling sites were chosen along a toposequence. For each site, two piezometers were placed above and in the gravelly and concretion-rich horizon (Fe- and Mn- oxyhydroxides). Concentrations of major-, minor- (cations, anions, Fe, Mn, P and Si) and trace elements (Al, Ba, Cd, Co, Cr, Cu, Ni, Pb, Rb, Sr, Zn and U) were monitored on bulk and filtered water (0.45 μm) to study both the particulate and the dissolved components, from 2004 to 2006, during the soil saturation period (i.e., from November to May). Chemical characteristics of soil solutions provide evidence for various chemical water compositions and for temporal variations of water quality, revealing that the hydrodynamic and chemical reactivity in the solution is different for the three sites. Calculations of pe values indicate a range of redox state of the soil solutions. The pe ranges are different for each piezometer but correspond to anoxic solution. For all piezometers, distribution between the dissolved and the particulate fraction and correlations between the various elements in the soil solutions indicate that: (i) Al and Fe show similar behaviour, (ii) Al is mainly present as oxyhydroxides and (iii) some trace metals are mainly associated with particles which have a mixed nature. The impact of a concretion-rich horizon is noticed both on the nature of particles and on the speciation of trace metals and could be explained by the hydrodynamic and chemical reactivity of the circulating solution. Very few correlations exist between elements in the dissolved phase
Experimental superheating of water and aqueous solutions

International audienceThe metastable superheated solutions are liquids in transitory thermodynamic equilibrium inside the stability domain of their vapor (whatever the temperature is). Some natural contexts should allow the superheating of natural aqueous solutions, like the soil capillarity (low T superheating), certain continental and submarine geysers (high T superheating), or even the water state in very arid environments like the Mars subsurface (low T) or the deep crustal rocks (high T). The present paper reports experimental measurements on the superheating range of aqueous solutions contained in quartz as fluid inclusions (Synthetic Fluid Inclusion Technique, SFIT) and brought to superheating state by isochoric cooling. About 40 samples were synthetized at 0.75 GPa and 530-700 °C with internally-heated autoclaves. Nine hundred and sixty-seven inclusions were studied by micro-thermometry, including measuring the temperatures of homogenization (Th: L + V → L) and vapor bubbles nucleation (Tn: L → L + V). The Th-Tn difference corresponds to the intensity of superheating that the trapped liquid can undergo and can be translated into liquid pressure (existing just before nucleation occurs at Tn) by an equation of state. Pure water (840-935 kg m−3), dilute NaOH solutions (0.1 and 0.5 mol kg−1), NaCl, CaCl2 and CsCl solutions (1 and 5 mol kg−1) demonstrated a surprising ability to undergo tensile stress. The highest tension ever recorded to the best of our knowledge (−146 MPa, 100 °C) is attained in a 5 m CaCl2 inclusion trapped in quartz matrix, while CsCl solutions qualitatively show still better superheating efficiency. These observations are discussed with regards to the quality of the inner surface of inclusion surfaces (high P-T synthesis conditions) and to the intrinsic cohesion of liquids (thermodynamic and kinetic spinodal). This study demonstrates that natural solutions can reach high levels of superheating, that are accompanied by strong changes of their physico-chemical properties
Parametric resonance-induced time-convolutionless master equation breakdown in finite size exciton-phonon systems

International audienceA detailed analysis is performed to show that the second order time-convolutionless master equation fails to describe the exciton-phonon dynamics in a finite size lattice. To proceed, special attention is paid to characterize the coherences of the exciton reduced density matrix. These specific elements measure the ability of the exciton to develop superimpositions involving the vacuum and the one-exciton states. It is shown that the coherences behave as wave functions whose dynamics is governed by a time-dependent effective Hamiltonian defined in terms of the so-called time-dependent relaxation operator. Due to the confinement, quantum recurrences provide to the relaxation operator an almost periodic nature so that the master equation reduces to a linear system of differential equations with almost periodic coefficients. In accordance with the Floquet theory, we show that unstable solutions emerge due to parametric resonances involving specific frequencies of the relaxation operator and specific excitonic eigenfrequencies. These resonances give rise to an unphysical exponential growth of the coherences indicating the breakdown of the second order master equatio
Growth temperature dependent critical thickness for phase separation in thick (1 um)  InxGa1-xN  (x=0.2?0.4)

This paper reports phase separation in thick (-1 pm) MOVPE In,Gai_xN (x = 0.2-0.4)
films grown by MOVPE at 570-750°C on AIN/Si(111), a-A1203(0001) and
GaN/a-A1203(0001) substrates. Phase separation occurs when InGaN thickness exceeds a
critical value. Critical thickness for phase separation is markedly increased with decreasing
growth temperature. It is around 0.2 pm for a film grown at 750°C, while it is more than 1 pm
for that grown at 570°C. No substrate dependencies are found in critical thickness. The
cross-sectional SEM views of phase-separated films grown at 650°C show that phase
separation is initiated at parts farer more than 0.2 pm from the substrate and extended to the
area near the substrate. SIMS analysis shows a possibility that phase separation is initiated
at a part with relatively large In/Ga ratio fluctuations in InGaN films
A Sensitive New Method for Clinically Monitoring Cytarabine Concentrations at the DNA level in Leukemic Cells

Cytarabine (ara-C), a major antileukemic agent, is phosphorylated in the cell to cytarabine triphosphate (ara-CTP), which then is partly incorporated into DNA.  The drug incorporation into DNA poisons the extending primer against further incorporation of deoxyribonucleotides including dCTP, ultimately inhibiting DNA synthesis.  While intracellular ara-CTP concentration has been found to predict clinical outcome, cytotoxicity in vitro is determined primarily by the extent of drug incorporation into DNA.  However, clinically appropriate quantitation methods for ara-C at the DNA level have not been available.  We developed a sensitive new method for monitoring ara-C incorporated into DNA in vivo.  After DNA from leukemic cells was fractionated using the Schmidt-Thannhauser-Schneider method, it was degraded to constituent nucleosides to release ara-C, which was isolated from the nucleosides using HPLC and then measured by radioimmunoassay.  Recovery for DNA fractionation, ara-C release by degradation, and ara-C isolation were 92.0 ± 6.4%, 90.7 ± 9.4%, and 98.5 ± 1.4%, respectively.  The method was found to determine ara-C incorporation into DNA of ara-C-treated HL60 cells in vitro with minimal interassay variation.  The values determined were compatible with those determined by scintillation counting in parallel experiments using tritiated ara-C.  Our method could be used to monitor DNA-incorporated ara-C concentrations during ara-C therapy, together with plasma ara-C and intracellular ara-CTP concentrations.  ara-C incorporation into DNA appeared to be associated with intracellular retention of ara-CTP or persistence of plasma ara-C.  Thus, the present method is sensitive, accurate, precise, and may permit therapeutic drug monitoring at the DNA level for better individualization of antileukemic regimens
Synthesis and review: tackling the nitrogen management challenge: from global to local scales

One of the 'grand challenges' of this age is the anthropogenic impact exerted on the nitrogen cycle. Issues of concern range from an excess of fixed nitrogen resulting in environmental pressures for some regions, while for other regions insufficient fixed nitrogen affects food security and may lead to health risks. To address these issues, nitrogen needs to be managed in an integrated fashion, at a variety of scales (from global to local). Such management has to be based on a thorough understanding of the sources of reactive nitrogen released into the environment, its deposition and effects. This requires a comprehensive assessment of the key drivers of changes in the nitrogen cycle both spatially, at the field, regional and global scale and over time. In this focus issue, we address the challenges of managing reactive nitrogen in the context of food production and its impacts on human and ecosystem health. In addition, we discuss the scope for and design of management approaches in regions with too much and too little nitrogen. This focus issue includes several contributions from authors who participated at the N2013 conference in Kampala in November 2013, where delegates compiled and agreed upon the 'Kampala Statement-for-Action on Reactive Nitrogen in Africa and Globally'. These contributions further underline scientifically the claims of the 'Kampala Statement', that simultaneously reducing pollution and increasing nitrogen available in the food system, by improved nitrogen management offers win-wins for environment, health and food security in both developing and developed economies. The specific messages conveyed in the Kampala Statement focus on improving nitrogen management (I), including the reduction of nitrogen losses from agriculture, industry, transport and energy sectors, as well as improving waste treatment and informing individuals and institutions (II). Highlighting the need for innovation and increased awareness among stakeholders (III) and the identification of policy and technology solutions to tackle global nitrogen management issues (IV), this will enable countries to fulfil their regional and global commitments
Finite-key analysis for time-energy high-dimensional quantum key distribution

Time-energy high-dimensional quantum key distribution (HD-QKD) leverages the high-dimensional nature of time-energy entangled biphotons and the loss tolerance of single-photon detection to achieve long-distance key distribution with high photon information efficiency. To date, the general-attack security of HD-QKD has only been proven in the asymptotic regime, while HD-QKD's finite-key security has only been established for a limited set of attacks. Here we fill this gap by providing a rigorous HD-QKD security proof for general attacks in the finite-key regime. Our proof relies on an entropic uncertainty relation that we derive for time and conjugate-time measurements that use dispersive optics, and our analysis includes an efficient decoy-state protocol in its parameter estimation. We present numerically evaluated secret-key rates illustrating the feasibility of secure and composable HD-QKD over metropolitan-area distances when the system is subjected to the most powerful eavesdropping attack.United States. Office of Naval Research (Grant N00014- 13-1-0774)United States. Air Force Office of Scientific Research (Grant FA9550-14-1-0052)Natural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship
Synthesis, antimicrobial evaluation and hemolytic activity of 2-[[5-alkyl/aralkyl substituted-1,3,4-oxadiazol-2-yl]thio]-N-[4-(4-morpholinyl)phenyl]acetamide derivatives

Abstract2,5-Disubstituted 1,3,4-oxadiazole compounds are one of the most attractive classes for researchers due to their pharmacological activities. In the current research, a new series of 2-[[5-alkyl/aralkyl-1,3,4-oxadiazol-2-yl]thio]-N-[4-(4-morpholinyl)phenyl]acetamides (6a–m) were prepared by converting different aryl/aralkyl organic acids (1a–m) successively into corresponding esters (2a–m), hydrazides (3a–m) and 5-aryl/aralkyl-1,3,4-oxadiazol-2-thiols (4a–m). Finally, the target compounds 6a–m were synthesized by stirring 5-aryl/aralkyl-1,3,4-oxadiazol-2-thiols (4a–m) with 2-bromo-N-[4-(4-morpholinyl)phenyl]acetamide (5) in the presence of N,N-dimethylformamide (DMF) and sodium hydride (NaH). The structures of the synthesized compounds were elucidated through IR, 1H-NMR, 13C-NMR and mass spectral data. The compounds were also screened for antimicrobial and hemolytic activity and most of them were found to be active against the selected microbial species at variable extent relative to reference standards. The compounds, 6d and 6f were active against the selected panel of microbes and the former was the most potent one. This series showed less toxicity and may be considered for further biological screening and application trial except 6h and 6l, possessing higher cytotoxicity
Ovaries and Female Phenotype in a Girl with 46,XY Karyotype and Mutations in the CBX2 Gene

A girl with a prenatal 46,XY karyotype was born with a completely normal female phenotype, including uterus and histologically normal ovaries. In mice with a similar phenotype, the ablation of M33, an ortholog of Drosophila Polycomb, causes male-to-female sex reversal. The analysis of the human homolog of M33, Chromobox homolog 2 (CBX2), in this girl revealed loss-of-function mutations that allowed us, by placing CBX2 upstream of SRY, to add an additional component to the still incomplete cascade of human sex development
Apples, oranges, and consistent comparisons of the temporal dynamics of energy transitions

Benjamin Sovacool (2016) has provided interesting food for thought in asking “how long will it take?” for the unfolding of energy transitions. Historical evidence of “grand” or global energy system transitions taking decades to centuries to unfold contrasted with highly selective recent and rapid examples of mostly incremental technological change make for an engaging argument. But the observed contrasts are due to the apples-and-oranges comparison between transitions that are measured differently, defined differently, characterized by different processes, and explained differently
Frequency-tunable microwave field detection in an atomic vapor cell

We use an atomic vapor cell as a frequency tunable microwave field detector operating at frequencies from GHz to tens of GHz. We detect microwave magnetic fields from 2.3 GHz to 26.4 GHz, and measure the amplitude of the sigma+ component of an 18 GHz microwave field. Our proof-of-principle demonstration represents a four orders of magnitude extension of the frequency tunable range of atomic magnetometers from their previous dc to several MHz range. When integrated with a high resolution microwave imaging system, this will allow for the complete reconstruction of the vector components of a microwave magnetic field and the relative phase between them. Potential applications include near-field characterisation of microwave circuitry and devices, and medical microwave sensing and imaging
Entangled optical vortex links

Optical vortices are lines of phase singularity which percolate through all optical fields. We report the entanglement of linked optical vortex loops in the light produced by spontaneous parametric down-conversion. As measured by using a Bell inequality, this entanglement between topological features extends over macroscopic and finite volumes. The entanglement of photons in complex three-dimensional topological states suggests the possibility of entanglement of similar features in other quantum systems describable by complex scalar functions, such as superconductors, superfluids, and Bose-Einstein condensates
Kinetic properties of particle-in-cell simulations compromised by Monte Carlo collisions

he particle-in-cell method with Monte Carlo collisions is frequently used when a detailed kinetic simulation of a weakly collisional plasma is required. In such cases, one usually desires, inter alia, an accurate calculation of the particle distribution functions in velocity space. However, velocity space diffusion affects most, perhaps all, kinetic simulations to some degree, leading to numerical thermalization (i.e., relaxation of the velocity distribution toward a Maxwellian), and consequently distortion of the true velocity distribution functions, among other undesirable effects. The rate of such thermalization can be considered a figure of merit for kinetic simulations. This article shows that, contrary to previous assumption, the addition of Monte Carlo collisions to a one-dimensional particle-in-cell simulation seriously degrades certain properties of the simulation. In particular, the thermalization time can be reduced by as much as three orders of magnitude. This effect makes obtaining strictly converged simulation results difficult in many cases of practical interest