Effect of the Structure of Amido-polynitrogen Molecules on the Complexation of Actinides

AbstractThe complexation and solvent extraction of Eu(III) and actinides in different oxidation states (Am(III), Pu(IV), Np(V)) by bitopic molecules with a dipyridyl-phenanthroline cycle as nitrogen unit and one or two amido functions are described. The complexation has been studied in methanol-water solution with hydrophilic molecules to enhance knowledge about this new family of ligands and to identify the most interesting structural effect. Some extraction tests have been performed with lipophilic molecules of the family to check the possible utility of the new class of ligands under representative fuel reprocessing conditions. These first studies have demonstrated that the presence of a preorganized N-donors unit like dipyridyl-phenanthroline improves the ligand's affinity for actinides and its An/Ln selectivity

Etude du comportement paramagnétique des actinides (IV) (Th, U, Np et Pu) en solution en présence de ligands

International audienceLa spectroscopie RMN est une technique capable de fournir des informations structurales sur des complexes métalliques en solution. Elle peut être appliquée à l’analyse de petites molécules en chimie organique, de protéines (macros molécules) en biologie mais aussi en chimie nucléaire avec la nucléarisation des spectromètres [1]. La présence d’un Actinide (An), avec des électrons 5f non appariés, génère une modification du spectre RMN (un élargissement et/ou une variation du déplacement chimique des pics) caractéristique du paramagnétisme du cation.Dans le cas des complexes paramagnétiques de Ln$^{III}$ (éléments 4$f$), le déplacement chimique total $\Delta _{TOT}$ est modélisé par l’équation de Bleaney (équations (a) et (b)) [2]. Il dépend du déplacement chimique paramagnétique induit $\delta _{para}$ qui peut être décomposé en deux contributions : un terme de contact $\delta _{cont}$ (délocalisation de l’électron $f$ sur l’atome donneur du ligand) et un terme dipolaire $\delta _{dip}$ (interaction entre le spin électronique et nucléaire à travers l’espace). A partir de ce dernier terme, on peut déduire des informations structurales en utilisant les constantes de Bleaney

Head and neck target delineation using a novel PET automatic segmentation algorithm

Purpose To evaluate the feasibility and impact of using a novel advanced PET auto-segmentation method in Head and Neck (H&N) radiotherapy treatment (RT) planning. Methods ATLAAS, Automatic decision Tree-based Learning Algorithm for Advanced Segmentation, previously developed and validated on pre-clinical data, was applied to 18F-FDG-PET/CT scans of 20 H&N patients undergoing Intensity Modulated Radiation Therapy. Primary Gross Tumour Volumes (GTVs) manually delineated on CT/MRI scans (GTVpCT/MRI), together with ATLAAS-generated contours (GTVpATLAAS) were used to derive the RT planning GTV (GTVpfinal). ATLAAS outlines were compared to CT/MRI and final GTVs qualitatively and quantitatively using a conformity metric. Results The ATLAAS contours were found to be reliable and useful. The volume of GTVpATLAAS was smaller than GTVpCT/MRI in 70% of the cases, with an average conformity index of 0.70. The information provided by ATLAAS was used to grow the GTVpCT/MRI in 10 cases (up to 10.6 mL) and to shrink the GTVpCT/MRI in 7 cases (up to 12.3 mL). ATLAAS provided complementary information to CT/MRI and GTVpATLAAS contributed to up to 33% of the final GTV volume across the patient cohort. Conclusions ATLAAS can deliver operator independent PET segmentation to augment clinical outlining using CT and MRI and could have utility in future clinical studies

Numerical simulation of strongly nonlinear and dispersive waves using a Green-Naghdi model

We investigate here the ability of a Green-Naghdi model to reproduce strongly nonlinear and dispersive wave propagation. We test in particular the behavior of the new hybrid finite-volume and finite-difference splitting approach recently developed by the authors and collaborators on the challenging benchmark of waves propagating over a submerged bar. Such a configuration requires a model with very good dispersive properties, because of the high-order harmonics generated by topography-induced nonlinear interactions. We thus depart from the aforementioned work and choose to use a new Green-Naghdi system with improved frequency dispersion characteristics. The absence of dry areas also allows us to improve the treatment of the hyperbolic part of the equations. This leads to very satisfying results for the demanding benchmarks under consideration

A workflow system as an information support to companies operating in the area of sustainable construction

Doktorska disertacija obravnava področje dostopnosti informacij, pomembnih za odločanje o izbiri storitev in proizvodov pri prenovi stavbe. Te so pogosto neurejene in razpršene po celotnem spletu ter zapisane v različnih formatih. Posledično je lahko iskanje želenih informacij zelo zamudno in nepregledno. Informacije lahko zajamemo v delotoku, ki predstavlja zaporedje povezanih storitev, izvajanih v primerno orkestriranih korakih. Osnovna hipoteza trdi, da lahko model informacijskega sistema delotokov zajame visoko stopnjo ključnih informacij in znanj na področju trajnostne gradnje in načrtovanja ter kot tak predstavlja primerno informacijsko podporo gradbenim podjetjem in investitorjem. Potrebe po informacijski podpori ugotavljamo s pomočjo raziskave med ključnimi deležniki na področju gradbeništva. Rezultati izvedene raziskave razkrivajo velike potrebe po dostopu do urejenih informacij in kažejo na veliko pripravljenosti deležnikov za sodelovanje ter medsebojno deljenje informacij. Izdelan je pregled obstoječih rešitev in dognanj na omenjenem področju. Predstavljen je trajnosten pogled na stavbe s pregledom najbolj razširjenih in aktualnih pristopov trajnostnega ocenjevanja stavb, ki razkriva razlike pri pripisovanju teže posameznim trajnostnim vidikom. V nadaljevanju izdelamo pregled stanja slovenskega stavbnega fonda, ki razkriva, da je velika večina stavb potencialno potrebnih prenove. Predstavljene so tudi semantične tehnologije, ki omogočajo izdelavo naprednih informacijskih sistemov in ki jih zato uporabimo v nadaljnjem delu. V nadaljevanju dela je predstavljen razvoj prototipa informacijskega sistema, ki temelji na delotokih. Opisana je zasnova arhitekture informacijskega sistema, model sprejemanja odločitev in razvita ontologija, ki podpira zapis informacij v delotoke in hrambo informacij v pripadajoči podatkovni bazi OWL/RDF. V zaključnem delu je predstavljena validacija prototipa informacijskega sistema, ki kaže, da smo uspeli zadostiti opredeljenim zahtevam. Postavljena hipoteza je torej potrjena.The research presented in this thesis is concerned with the accessibility of information on the world web, crucial for the decision making process regarding products and services required for building refurbishment. This information is often dispersed, poorly structured and written in various formats. As a consequence, information search on the web can be extremely time-consuming and difficult to carry out. The information can be sequenced in a workflow consisting of a series of interconnected services which are executed in orchestrated steps. The research hypothesis postulates that the workflow information system model is able to encompass a large proportion of key information and knowledge from the sustainable construction field. As such, it represents efficient information support to potential clients and construction contracting companies. Information support requirements of various stakeholders from the construction sector were identified by using a survey. The obtained results exhibit a clear need for structured information, as well as a significant willingness of stakeholders to share the information. An overview of the existing solutions and accomplishments in sustainable construction is presented. The concept of sustainability assessment is presented, along with an overview of the most frequently employed approaches for the sustainability assessment of buildings, which reveals differences in assigning relative importance to individual sustainability aspects. An overview of the Slovenian residential building fund is carried out. It shows that the majority of residential building stock is in need of refurbishment. Further, semantic technologies that enable the establishment of advanced information systems are presented. The second part presents the development of a workflow-based prototype information system. The design of the information system architecture is presented, together with the decision making model and the ontology that supports information recording into workflows and data storage into the OWL/RDF database. The validation of the information system is presented in the concluding part. It is shown that the system requirements defined in the beginning of the research were achievedthe initial hypothesis is therefore confirmed

Considerations for the design and conduct of human gut microbiota intervention studies relating to foods

With the growing appreciation for the influence of the intestinal microbiota on human health, there is increasing motivation to design and refine interventions to promote favorable shifts in the microbiota and their interactions with the host. Technological advances have improved our understanding and ability to measure this indigenous population and the impact of such interventions. However, the rapid growth and evolution of the field, as well as the diversity of methods used, parameters measured and populations studied, make it difficult to interpret the significance of the findings and translate their outcomes to the wider population. This can prevent comparisons across studies and hinder the drawing of appropriate conclusions. This review outlines considerations to facilitate the design, implementation and interpretation of human gut microbiota intervention studies relating to foods based upon our current understanding of the intestinal microbiota, its functionality and interactions with the human host. This includes parameters associated with study design, eligibility criteria, statistical considerations, characterization of products and the measurement of compliance. Methodologies and markers to assess compositional and functional changes in the microbiota, following interventions are discussed in addition to approaches to assess changes in microbiota-host interactions and host responses. Last, EU legislative aspects in relation to foods and health claims are presented. While it is appreciated that the field of gastrointestinal microbiology is rapidly evolving, such guidance will assist in the design and interpretation of human gut microbiota interventional studies relating to foods.Peer reviewe

Analyse préliminaire de la valeur verte pour les logements

Analyse préliminaire de la valeur verte pour les logement