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The quasi-brittle, loading rate dependent behaviour of the concrete, characterized by a fracture process zone (FPZ) ahead of the crack front, can be described through a viscous-cohesive model. In this paper, a viscous cohesive model proposed in a former paper is evaluated for a group of high strength concrete beams loaded at rates from 10-5 mm/s to 10+1 mm/s. A software has been developed to enable the automatic determination of the viscous-cohesive model parameters through inverse analysis on load-versus loading-point displacement (P-d) from threepoint bend tests on notched prismatic specimens. The strategy allowed the sensitivity analysis of the parameters related to viscous behaviour. The analysis of results shows that the formerly proposed model can be improved for a better simulation of the loading rate dependence on the cohesive fracture process. RESUMOO comportamento quase-frágil, dependente da taxa de carregamento do concreto, caracterizado pelo desenvolvimento de uma zona de processos de fratura (ZPF) ao redor do fronte da trinca, pode ser representado por uma lei visco-coesiva. Neste trabalho, um modelo visco-coesivo proposto em um artigo anterior foi avaliado para um grupo de vigas de concreto de alta resistência carregados com taxas variando de 10-5 mm/s a 10+1 mm/s. Desenvolveu-se um software para a determinação automática dos parâmetros do modelo visco-coesivo utilizando-se curvas da relação carga versus deslocamento no ponto de aplicação (P- ) obtidas em ensaios com vigas prismáticas ranhuradas carregadas em três pontos (Three-Point-Bend Test), com taxas de carregamento variadas. A estratégia permitiu a análise de sensibilidade dos parâmetros relacionados com o comportamento viscoso. A análise dos resultados demonstrou que o modelo visco-coesivo proposto no artigo ainda pode ser aperfeiçoado para melhor simular o processo de fraturamento coesivo dependente da taxa de carregamento.

Research publication in the international arena, is crucial for multilingual scholars in mostdisciplinary areas. For many, among them Spanish scholars, it still represents a consider-able hurdle. Thefindings we report here are part of a wider research project involving alarge onlinesurveyof scholars atfive universities and research institutions in Spain. Weaimed to identify the needs of Spanish researchers in terms of research publishing skills inboth English and Spanish, learn about their attitudes, motivations and experiences ofresearch publication and of writing training. The present paper compares the results forscholars in History and Psychology. Through analysis of quantitative and comment data,we show how the motivations of these scholars with regard to research publication in thetwo languages work together with the strategies and resources available to them todetermine language selection. We also review their experience of training in researchwriting and their willingness to pursue further training. Although the two groups ofscholars differ in terms of attitudes to publication in English, they share a willingness tonegotiate the challenges presented by institutional constraints, making strategic decisionsabout the choice of language in which to publish and their own language development., This study is part of a project financed by the Ministry of Science and Innovation (Ref.: FFI2009-08336/FILO), of which Ana I. Moreno is the PI.

The influence of the crystallographic orientation of the surface on ion implantation damage was studied in MgO single crystals. For this purpose, rare gas ions (150 keV-argon) or reactive ions (150 keV-niobium) were implanted at room temperature in (100) and (110) MgO surfaces at a fluence of 5,10 16 ions.cm -2 . With the mean of Rutherford Backscattering Spectroscopy in channeling geometry (RBS-C), it is shown that the damage depends on the crystallographic orientation of the MgO surface. The (100) irradiated surfaces exhibit a localized damage as predicted by TRIM code calculations while in (100) MgO, the defects extend in depth. Chemical effects are also dependent on the crystallographic orientations of the implanted surfaces : the substitutional fraction of the implanted niobium determined by RBS-C and the niobium binding energy estimated by XPS analysis are different in the (110) and (100) MgO irradiated surfaces.

The morphological, plastic, and elastic strains in Na+‐implanted MgO have been determined by measuring the swelling of the surface with a profilometer and in‐plane lattice parameters by x‐ray diffraction at glancing incidence. The high value of the stress (∼9 GPa) is related to a high dislocation density with very low mobility leading to weak plastic flow (∼0.2%).

Niobium implantations were performed in α-Al2O3 single crystals to study the chemical interactions between the implanted species and the oxide and to study the microstructural evolution of the implanted layer. The investigation focused on both as-implanted and the oxide and to study the microstructural evolution of the implanted layer. The investigation focused on both as-implanted specimens and specimens that underwent post-implantation anneals in a reducing atmosphere. Ion implantations were performed at 300 K with 150 keV particle energies and fluences ranging from 1016 to 2 × 1017 ions cm-2. Rutherford backscattering spectroscopy (RBS) and X-ray photoemission spectroscopy (XPS) allowed the characterization of the implanted profiles and determination of the chemical state of the implanted ions. X-ray diffraction at glancing incidence and RBS analysis in a channeling geometry were performed to follow the microstructural evolution of the implanted layer. The oxidation state of niobium and the microstructure of the implanted layer were dependent on the atomic concentration of niobium in α-Al2O3. An amorphous phase was observed after a threshold fluence of 5 × 1016 ions cm-2. The amorphous phase contained small metallic precipitates of niobium with a mean diameter of 1 nm. The physical properties of such niobium clusters embedded in an amorphous oxide layer were studied in detail. Electrical conductivity measurements showed that a hopping process between the metallic precipitates was the likely mechanism operating for this system.

150 keV niobium implantations were performed at RT in magnesium oxide single crystals. Fluences ranged from 10 16 to 10 17 ions cm −2 . The RBS and XPS techniques allowed the characterization of the implantation profiles and the chemical states of the implants. A comparison between the experimental profiles and the theoretical predictions obtained with TRIM calculations showed no agreement between the values of projected range R p and ΔR p . A spreading in depth of the ion distribution was observed for Nb implantations. XPS measurements showed that the stable oxidation states of Nh were the 5 + and 4 + states. In order to obtain precise information on the mechanisms of such an anomalous diffusion static lattice calculations of defect parameters are performed for the Nb/MgO system. These calculations allow us to obtain precise information on the stable defects associated with the presence of the metallic impurities in MgO single crystals.

A study of the effects of titanium ion implantation on the structural, mechanical, and tribological properties of single crystal and polycrystalline α-alumina has been carried out. Rutherford Backscattering Spectrometry (RBS) in channeling geometry shows that a great proportion of implanted titanium ions are substitutional at low fluence. This fraction falls to near zero as an amorphous layer is formed. The chemical states for implanted titanium are determined by X-ray Photoelectron Spectroscopy (XPS). Titanium is present in the Ti3+ state near the surface and as metallic Ti0 and as Ti3+ at depths corresponding to higher local concentration of titanium. The same behavior is observed for polycrystalline and single crystal α–alumina. Nanoindentation experiments show that low fluence implantation of titanium results in an increase of mechanical properties whereas high fluence implanted samples exhibit reduced hardness and Young's modulus compared to unimplanted samples. The friction coefficient is not changed by titanium ion implantation. Likewise, the wear characteristics were not changed by low fluence implantation, but amorphization at high fluence leads to a greater disk wear rate.

This paper examines the effects of niobium ion implantation on the surface mechanical properties of single crystal and polycrystalline α-alumina. A structural transformation can be produced in sapphire implanted with a high fluence of niobium ions which leads to the formation of an amorphous layer of alumina containing nanoclusters of metallic niobium. Nanoindentation experiments are carried out to characterize the mechanical properties of the implanted layers. A low fluence implantation increases the Young's modulus but not the hardness. For high fluence, the amorphous transformation softens the material. The tribological behaviour is studied by comparing the friction kinetics in rotating and reciprocating motion. At low fluence, no difference between implanted and unimplanted samples is observed. For high fluence, the implantation increases the friction coefficient and the wear rate. The friction and wear of implanted α-alumina are governed by the behaviour of a transfer film.

The effects of niobium and rubidium ion implantation on monocrystalline (100) MgO slices have been investigated using Rutherford backscattering spectrometry in channeling geometry (RBS), electron spectroscopy for chemical analysis (ESCA) and optical absorption measurements. Analysis of the implantation profiles have been performed on samples implanted at 300 K with energies of 150 and 320 keV and doses ranging from 2 × 10 15 to 2 × 10 17 ionscm −2 . For doses above 10 16 ionscm −2 , the implantation profiles differ significantly from theoretical predictions of the “TRIM” code and exhibit a marked depth diffusion effect of implanted particles. Moreover, a particularly high fraction (between 60 and 95%) of implanted atoms in substitutional sites is evidenced. It has to be noticed that even for the highest doses the amorphization of the implanted layer does not occur. The different chemical states of atoms in the implanted layers investigated by ESCA and optical measurements have been correlated with RBS results in order to precise the anomalous diffusion effects of implanted species.

We have investigated the influence of chemical bonding and structure of different oxides on niobium implantation effects. For this purpose, single crystals of α-Al 2 O 3 , TiO 2 , MgO and amorphous SiO 2 have been implanted with 150 keV Nb + ions and fluences ranging from 10 16 up to 10 17 ionscm −2 . Two different behaviours have been observed depending on ionicity of the studied materials. For more covalent oxides such as α-Al 2 O 3 , TiO 2 and SiO 2 implanted with low fluences, the implantation profiles are in good agreement with theoretical predictions (TRIM). For high doses (> 5 × 10 16 ions/cm −2 ) the formation of an amorphous layer has been observed in sapphire and rutile. For a typical ionic oxide such as MgO an anomalous depth distribution profile of implanted particles is observed and the major part of implanted niobium is in substitutional sites. The amorphization is not observed even for the highest implantation doses. These results suggest that different chemical effects occur and they could be correlated with the ability to deform octahedral sites in these oxides and space charge effects.

International audience; The lack of male pedigree control is the major limitation of an otherwise very useful and cost effective mating design, namely, the polycross. This study was conducted to investigate the relative contribution of different pollen parents to the sound-seeds stage, and also in a field progeny trial. Pollen from 15 radiata pine (Pinus radiata D. Don) parents was mixed in equal volume and applied to the same 15 parents, potentially allowing selfing. Samples of 8-year-old offspring were genotyped from five polycross families, and available seed from three of these five families was tested for unequal paternal contributions. The total paternal exclusion probability of five chloroplast markers and four microsatellite markers in our study was 99.1%. Overall, 81% of the offspring (both seeds and 8-year-old offspring) were assigned to 1 out of the 15 potential male parents, but a surprisingly high proportion (about 13%) was evidently fathered by pollen not included in the pollen-mix. Inconclusive evidence of unequal paternal contribution was observed in some families, but it did not influence the general combining ability (GCA) estimates appreciably, as evident from a high degree of correspondence between GCA estimates obtained from polycross and female-tester mating designs. A non-significant negative correlation was observed between the relative reproductive success (across polycross families) and predicted breeding values for diameter growth

summary Mycorrhizas formed on Prinus pinaster by an IAA-overproducer mutant strain (h1 FIR 4 h1 F1 331) of Hebeloma cylindrosporum are described. The wild strain (hl) was used as reference. The wild type mycorrhiza had a thin mantle and a uniseriate Hartig net, which reached the second layer of cortical cells, as generally described. Conversely, the mutant type mycorrhiza had special features; a large mantle and a highly developed Hartig net (up en seven layers of hyphae in width) which reached the endodermis. Even when the Hartig net was formed of several layers of hyphae, the cortical cells remained alive, indicating that the fungus may aid survival of the host cells. Intracellular hyphae surrounded by invaginated host plasmalemma and by interfacial material, were frequently seen in cortical cells, In this case, both fungal and host cells were alive. Even if the mutant strain is more invasive, the IAA overproduction dries not seem to modify its symbiotic status. It is possible that IAA plays a role in cell wall loosening, allowing the fungus to overcome barriers which normally prevent the invasion of living cortical cells.

Fe-Al multilayers have been mixed with Xe + ions at high temperatures. The composition depth profiles have been analyzed by secondary ion mass spectroscopy (SIMS). It is shown that SIMS reveals the Al-rich compound formation inside the initial Al layers, and that this point cannot be questioned by exaltation effect on Fe + or Al + ion intensities. Phase formation has been proved by X-ray diffraction at grazing incidence

Single crystals of TiO2 rutile were implanted at 300 K with niobium ions at fluences in the range 5×1013 to 2.5×1017 ions cm−2, corresponding to a mean local concentration of 6×1018 to 3×1022 Nbcm−3, respectively. Rutherford backscattering spectroscopy (RBS) in channeling geometry and X-ray photoemission spectroscopy (XPS) have been performed to determine the Nb substitutional fraction and the Nb oxidation state as a function of fluence. The microstructural evolution has been followed by X-ray diffraction at glancing incidence. The dc conductivity measurements were performed using the four probes technique in the temperature range of 150 to 850 K. The conductivity as a function of the Nb fluence exhibits two different behaviours: (i) at low fluence, between 5×1013 and 5×1014 Nbcm−2, the conductivity increases by four orders of magnitude, (ii) while at high fluence, between 5×1015 and 2.5×1017 Nbcm−2, it varies slowly from 102 to 2×103 Ω−1cm−1. The conductivity is thermally activated and the activation energy deduced from Arrhenius plots (σ α(1/T)) depends on the local concentration of implanted niobium. It decreases from 0.12 eV (5×1014 Nbcm−2) to 0.01 eV (2.5×1017 Nbcm−2). A high oxidation state of niobium was observed at low fluences and the conductivity could be described by a polaron process. At high fluences the niobium oxidation state vanishes and then a hopping process between metallic clusters is superimposed on the polaron mechanism.

The atomic redistribution and the structural change have been determined in an amorphous Fe-Ti alloy submitted to Xe + bombardment. It is shown that the region of peak damage becomes enriched with Ti whereas the subsurface region is Ti depleted and partially recrystallizedat the fluence of 1.8×10 16 Xe + cm -2 . The consequences of this phenomenon of radiation-induced segregation on our understanding of the diffusion mechanisms in metallic glasses are discussed

A comparison of the structural and surface mechanical properties of α - Al 2 O 3 implanted with titanium and niobium ions were carried out. For this purpose, single crystal samples were implanted with Ti + and Nb + ions at 150 keV with fluences ranging from 10 16 to 10 17 ions cm −2 . For fluences above 10 16 ions cm −2 , the substitutional fraction of titanium is two times that of niobium. For high fluences (10 17 ions cm −2 ) the formation of an amorphous layer is evidenced. The different chemical states of atoms in the implanted layers were determined by X-ray photoelectron spectroscopy (XPS). Nanoindentation experiments showed that low fluence implantations of titanium and niobium resulted in the increase of elastic modulus. For high fluences the amorphous transformation softens the implanted material and significant decreases of the hardness and Young's modulus were observed.

The quasi-brittle, loading rate dependent behaviour of the concrete, characterized by a fracture process zone (FPZ) ahead of the crack front, can be described through a viscous-cohesive model. In this paper, a viscous cohesive model proposed in a former paper is evaluated for a group of high strength concrete beams loaded at rates from 10-5 mm/s to 10+1 mm/s. A software has been developed to enable the automatic determination of the viscous-cohesive model parameters through inverse analysis on load-versus loading-point displacement (P-d) from threepoint bend tests on notched prismatic specimens. The strategy allowed the sensitivity analysis of the parameters related to viscous behaviour. The analysis of results shows that the formerly proposed model can be improved for a better simulation of the loading rate dependence on the cohesive fracture process.