Camille Rivard

SOLEIL synchrotron · Science Division

The cellulose microfibril realignment of unitary flax fibres with contrasted density of structural defects, which are also known as dislocations and defined as zones of microstructure heterogeneities, was investigated upon tensile testing by means of X-ray diffraction performed on SWING beamline at synchrotron SOLEIL. The in situ continuous tensile...

Wheat is one of the most important crops in the world, mainly used for human consumption and animal feed. To overcome the increasing demand in wheat production, it is necessary to better understand the mechanisms involved in the growth of the wheat grain. X-ray computed tomography is an efficient method for the non-destructive investigation of the...

Hemp-based materials have been recently proposed as adsorbents for metals present in aqueous solutions using adsorption-oriented processes. This study aims to reveal the adsorption mechanism of materials prepared from hemp shives as co-products of the hemp industry, namely sodium carbonate-activated (SHI-C) and polycarboxylic agent-grafted (SHI-BTC...

Flax (Linum usitatissimum) lodging is an issue of great interest for industrial producers due to its economic impact; despite a strong varietal selection over around one century, this plant remains sensitive to lodging which represents a main technico-economic issue. To better understand lodging effects at the cell wall and stem scale, the cell wal...

New Caledonian endemic Mn-hyperaccumulator Grevillea meisneri is useful species for the preparation of ecocatalysts, which contain Mn–Ca oxides that are very difficult to synthesize under laboratory conditions. Mechanisms leading to their formation in the ecocatalysts are unknown. Comparing tissue-level microdistribution of these two elements could...

There is a demand for nanoparticles that are environmentally acceptable, but simultaneously efficient and low cost. We prepared silver nanoparticles (AgNPs) grafted on a native bio-based substrate (cellulose nanocrystals, CNCs) with high biocidal activity and no toxicological impact. AgNPs of 10 nm are nucleated on CNCs in aqueous suspension with c...

Flax lodging is an issue of great interest for producers due to its economic impact. To better understand its effects at the cell wall and stem scale, new knowledge regarding the cell wall composition dynamics during cell wall development and after a 90° tilt bending stress is reported. Deep-Ultra Violet fluorescence emission (DUV) dynamics recorde...

Titanium dioxide is a food additive that has raised some concerns for humans due to the presence of nanoparticles. We were interested in knowing the fate of TiO2 particles in the gastro-intestinal tract and their potential effect on digestive enzymes. For this purpose, we analysed the behaviour of two different food grade TiO2 samples (E171) and on...

Hypothesis Degradation of pollutants using photocatalysts is a surface strategy and their release is generally undesired in nature. Biobased particles with simultaneous activity in aqueous and organic phase could limit their amount for enhanced efficiency. Using photoactive materials as interfacial stabilizer for the preparation of Pickering emulsi...

• Grevillea meisneri, an endemic New Caledonian Mn-hyperaccumulator, is used in rehabilitation of degraded mining sites on the island. Large-scale programs require transplanting nursery-grown seedlings, but effects of the nursery environment on Mn tolerance of transplants and their capacity to hyper-accumulate Mn are unknown, slowing rehabilitation...

Single crystals of synthetic Cr-doped forsterite (Cr:Mg2SiO4) containing both Cr3+ and Cr4+ were partially hydroxylated in piston-cylinder apparatuses at 750–1300 ∘C and pressures from 0.5 to 2.5 GPa, with p(H2O) ≈Ptotal. The oxygen fugacity (fO2) was buffered by graphite-water, Ni–NiO, Re–ReO2, Fe2O3–Fe3O4 or Ag–Ag2O, and the silica activity (aSiO...

Calcareous nannofossils are micrometric calcite platelets secreted by the photosynthetic algae named coccolithophores and incertae sedis. Calcareous nannoplankton inhabit the photic zone from coast to open-ocean and have left an abundant fossil record since the Triassic. Therefore, they constitute an interesting material for geochemical studies alt...

Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradie...

Hybrid nanoparticles involving 10-nm silver nanoparticles (AgNPs) nucleated on unmodified rod-like cellulose nanocrystals (CNCs) were prepared by chemical reduction. H2O2 used as a post-treatment induced a size-shape transition following a redox mechanism, passing from 10-nm spherical AgNPs to 300-nm triangular or prismatic NPs (AgNPrisms), where C...

Iron-organic matter (Fe-OM) aggregates are a key factor in the control of pollutant mobility. Their physical and structural organization depends on the prevailing physicochemical conditions during their formation and on subsequent exposure to variations in porewater goechemistry. Among these conditions, calcium (Ca) could be a major parameter given...

Calcareous nannofossils are micrometric calcite platelets secreted by coccolithophores and incertae sedis photosynthetic algae. Calcareous nannoplankton inhabit the photic zone from coast to open-ocean and have left an abundant fossil record since the Triassic. Therefore, they constitute an interesting material for geochemical studies although it h...

The new ANATOMIX beamline at Synchrotron SOLEIL is dedicated to hard X-ray full-field tomography techniques. Operating in a range of photon energies from approximately 5 to 50 keV, it offers both parallel-beam projection microtomography and nanotomography using a zone-plate transmission X-ray microscope and thus covers a range of spatial resolution...

Metallic ions were quantified and mapped at the tissue and the cell scales in two texture and phenolic content contrasted cider apples by atomic absorption spectroscopy, ion chromatography and synchrotron cryo X-ray fluorescence imaging. Metallic ions content and gradient distribution from the cuticle to the inner tissue significantly varied betwee...

In this study, we investigate the interactions between the cellulose surface and Ag nanoparticles (AgNPs) for the purpose of manufacturing hybrid nanomaterials using bacterial cellulose nanocrystals (BCNs) as a model substrate. We focus on the role of the BCN surface chemistry on the AgNP nucleation obtained by chemical reduction of Ag⁺ ions. Homog...

The main storage components of the maize endosperm are starch, proteins and lipids. Starch and proteins are heterogeneously deposited, leading to the formation of vitreous and floury regions at the periphery and at the centre of the endosperm. The vitreous/floury mass ratio is a key physical parameter of maize end-uses for the food, feed and non-fo...

Sulfur (S) and phosphorus (P) are essential elements for plant growth and physiological functioning. Their deficiency can limit N2 fixation and nodule development in nodulated legumes. The location of S within nodule tissues could provide insights into S metabolism and its little-known relationship with N2 fixation. Determinate and indeterminate no...

Magmatism on Earth mainly occurs at mid-ocean ridges and subduction zones, where it is generated by mantle melting at different redox conditions. This study examines the role of sulfur in redox reactions within subduction zones by determining the sulfur valence state in glass inclusions in mantle minerals.

Background The in vivo observation of diffusible components, such as ions and small phenolic compounds, remains a challenge in turgid plant organs. The analytical techniques used to localize such components in water-rich tissue with a large field of view are lacking. It remains an issue to limit compound diffusion during sample preparation and obse...

Subduction zone magmas are more oxidised on eruption than those at mid-ocean ridges. This is attributed either to oxidising components, derived from subducted lithosphere (slab) and added to the mantle wedge, or to oxidation processes occurring during magma ascent via differentiation. Here we provide direct evidence for contributions of oxidising s...

Supplementary Material

Progress in Microtomography at the ANATOMIX Beamline of Synchrotron Soleil - Volume 24 Supplement - Timm Weitkamp, Mario Scheel, Jonathan Perrin, Vincent Le Roux, Victorien Joyet, Samir Chaouchi, Hernan-Gabriel Pais, Jean-Luc Giorgetta, Alexandre Carcy, Kewin Desjardins, Claude Menneglier, Shu Zhang, Christer Engblom, Matthieu Cerato, Yves-Marie Ab...

In order to better understand the behaviour of Fe³⁺ during partial melting of a mid-ocean-ridge-basalt (MORB) mantle source, we performed partial melting experiments of a spinel peridotite at 1.5 GPa, between 1320 and 1450 °C, and over a range of oxygen fugacities (fO2) varying from FMQ-3.5 to FMQ+6 (log-units relative to FMQ = Fayalite-Magnetite-Q...

Through a mutualistic relationship with woody plant roots, ectomycorrhizal fungi provide growth-limiting nutrients, including inorganic phosphate (Pi), to their host. Reciprocal trades occur at the Hartig net, which is the symbiotic interface of ectomycorrhizas where the two partners are symplasmically isolated. Fungal Pi must be exported to the sy...

A pot experiment was carried out with maize to determine the phosphorus (P) plant-availability of different secondary P-fertilizers derived from wastewater. We analyzed the respective soils by P K-edge X-ray absorption near-edge structure (XANES) spectroscopy to determine the P chemical forms that were present and determine the transformation proce...

Marine sediment records suggest that episodes of major atmospheric CO2 drawdown during the last glacial period were linked to iron (Fe) fertilization of subantarctic surface waters. The principal source of this Fe is thought to be dust transported from southern mid-latitude deserts. However, uncertainty exists over contributions to CO2 sequestratio...

Soils comprise various heterogeneously distributed pools of lithogenic, free organic, occluded, adsorbed, and precipitated phosphorus (P) forms, which differ depending on soil forming factors. Small-scale heterogeneity of element distributions recently has received increased attention in soil science due to its influence on soil functions and soil...

Supplementary Figures, Supplementary Table and Supplementary References

list of Boggs Valley subglacial calcite samples analysed for DNA. Sample BV11, consisting of angular clasts cemented by microsparite, is sterile (see text for details.)

OTU data in .Biom format relative to samples BV8a and BV9b.

OTU .txt file relative to the DNA data for Boggs Valley calcite samples BV8a and BV9b. BV 11 is sterile.

The ID21 beamline (European Synchrotron Radiation facility, France) is a multi micro-analytical platform combining X-ray and infrared micro-probes, for characterization of elements, species, molecular groups and crystalline structures in complex materials. Applications are mainly in the fields of cultural heritage, life science, environmental and e...

Sulfur has been recognized in biogenic calcites for a long time. However, its structural position is matter of debate. For some authors, sulfur is a marker of the organic matrix while it is part of the calcite structure itself for others. To better understand the place of sulfur in calcite, sulfated magnesian calcites (S-MgCalcite) have been synthe...

Phosphorus (P) is an essential element for all forms of life and is applied as fertilizer in agriculture. The P availability for plants may be highly dependents on the chemical state of P in fertilizers and soils; however, the nature of this dependence remains obscure due to the limitations of generally applied wet chemical and instrumental analyti...

The origin(s) and role(s) of metal soaps in paints are a worldwide concern today. These hybrid compounds, containing both fatty acid chains and metals associated with a carboxylate function, are increasingly identified in paints. As reviewed in the first part of this work, the presence of metal soaps in paints is differently interpreted in scientif...

In order to better understand the possible interactions between steel canisters and a claystone host rock, in this case the Callovo-Oxfordian rock (COx), the present study investigated in detail, under conditions relevant to high-level radioactive waste repositories (anoxic conditions, temperature of 90°C), the reactions between metallic iron and:...

Nano-silicon dioxide (SiO2) is used nowadays in several biomedical applications such as drug delivery and cancer therapy, and is produced on an industrial scale as additive to paints and coatings, cosmetics and food. Data regarding the long-term biokinetics of SiO2 engineered nanoparticles (ENPs) is lacking. In this study, the whole-body biodistrib...

Studies of authigenic phosphorus (P) minerals in marine sediments typically focus on authigenic carbonate fluorapatite, which is considered to be the major sink for P in marine sediments and can easily be semi-quantitatively extracted with the SEDEX sequential extraction method. The role of other potentially important authigenic P phases, such as t...

The Morrow Plots were established at the U. of Illinois in 1876 to answer agricultural questions. They are the oldest agronomic experiment fields in the US with a recorded history of cropping practices. The exceptional series of samples thus represent a unique opportunity to investigate both short- and long-term influence of cropping practices on t...

Background and Aims Phosphorus (P) is an essential nutrient for plants but its low availability often necessitates amendments for agronomical issues. Objectives were to determine P spatial distribution and speciation that remain poorly understood in cultivated soils. Methods Aquic Argiudoll soil samples developed on a calcareous loam glacial till w...

To better understand the reaction mechanisms involved at the Fe(0)/clay minerals interface, we investigate in the present study the reaction between an Fe(0) surface and a clay suspension extracted from the Callovo-Oxfordian claystone (COx). Batch experiments were carried out under anoxic conditions in sealed autoclave, at 90°C to mimic predicted r...

This study was conducted to determine phosphorus (P) species captured in a vertical-flow constructed wetland (VFCW) system combining a trickling filter followed by FeCl3 injection for phosphate coagulation. Suspended solids (SS) thus formed accumulated over time at the VFCW surface and transformed into a sludge deposit layer which was shown to conc...

Studies of authigenic phosphorus (P) minerals in marine sediments typically focus on authigenic carbonate fluorapatite, which is considered to be the major sink for P in marine sediments and can easily be semi-quantitatively extracted with the SEDEX sequential extraction method. The role of other potentially important authigenic P phases, such as t...

The Morrow Plots were established at the Urbana campus of the University of Illinois in 1876 to answer agricultural questions. They are the oldest agronomic experiment fields in the United States with a recorded history of cropping practices (systematic monoculture, crop rotations, and fertilization, etc…). The exceptional series of samples availab...

The aim of this study is to investigate phosphorus (P) species modifications triggered by soil genesis and mountain ecosystem development after glacial retreat using a lake sediment archive (Lake Anterne, North French Alps). Five lake sediment samples, representative of different stages of soil and ecosystem development, were selected for P speciat...

We investigate the relationship between sulfur and oxygen fugacity at Erta Ale and Masaya volcanoes. Oxygen fugacity was assessed utilizing Fe3+/∑Fe and major element compositions measured in olivine-hosted melt inclusions and matrix glasses. Erta Ale melts have Fe3+/∑Fe of 0.15-0.16, reflecting fO2 of ΔQFM 0.0 ± 0.3, which is indistinguishable fro...

The ID21 Scanning X-ray Microscope (SXM) is optimized for micro-spectroscopy with submicron resolution in the 2 to 9.5 keV energy range. After a brief description of the microscope setup, we present here recent developments, in particular, the latest version of the compact Wavelength Dispersive Spectrometer and the refurbished cryo-stage.

The interaction between metallic iron and kaolinite was studied in conditions relevant to those that may be encountered in a high-level radioactive waste disposal facility in geological formation. Experiments were carried out under anoxic atmosphere at 90 °C and in chloride solutions to simulate conditions close to disposal facilities. KGa-2 kaolin...

In the context of radioactive waste repository in geological formation, kaolinite-metallic iron interaction in chlorine solution was conducted in batch experiments, under anoxic conditions at 90 °C during 9 months. After a mineralogical characterization at a global scale, products were analyzed at the micrometer and nanometer scales by X-ray absorp...

Dans le contexte de stockage des déchets radioactifs en profondeur, des interactions entre le fer métal d'une part et la roche du Callovo-Oxfordien (COx), sa fraction argileuse purifiée (SCOx) ou des phases argileuses pures (kaolinite, illite, smectites) d'autre part, sont réalisées à 90°C sous atmosphère anoxique en solution chlorurée-salée. Le rô...