191 research outputs found

    Measurement and Control of the Beam Energy for the SPIRAL2 Accelerator

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    WEPF32, http://accelconf.web.cern.ch/AccelConf/ibic2013/International audienceThe first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, will be composed of an ion source, a deuteron/proton source, a RFQ and a superconducting linear accelerator delivering high intensities, up to 5 mA and 40MeV for the deuteron beams. As part of theMEBT commissioning, the beam energy will be measured on the BTI (Bench of Intermediate Test) at the exit of the RFQ. At the exit of the LINAC, the system has to measure but also control the beam energy. The control consists in ensuring that the beam energy is under a limit by taking account of the measurement uncertainty. The energy is measured by a method of time of flight, the signal is captured by non-intercepting capacitive pick-ups. This paper presents also the results obtained in terms of uncertainties and dynamics of measures

    Hodge polynomials of some moduli spaces of Coherent Systems

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    When k<nk<n, we study the coherent systems that come from a BGN extension in which the quotient bundle is strictly semistable. In this case we describe a stratification of the moduli space of coherent systems. We also describe the strata as complements of determinantal varieties and we prove that these are irreducible and smooth. These descriptions allow us to compute the Hodge polynomials of this moduli space in some cases. In particular, we give explicit computations for the cases in which (n,d,k)=(3,d,1)(n,d,k)=(3,d,1) and dd is even, obtaining from them the usual Poincar\'e polynomials.Comment: Formerly entitled: "A stratification of some moduli spaces of coherent systems on algebraic curves and their Hodge--Poincar\'e polynomials". The paper has been substantially shorten. Theorem 8.20 has been revised and corrected. Final version accepted for publication in International Journal of Mathematics. arXiv admin note: text overlap with arXiv:math/0407523 by other author

    Progress on the Beam Energy Monitor for the SPIRAL2 Accelerator.

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    WEPF29, posterInternational audienceThe first part of the SPIRAL2 project entered last year in the end of the construction phase at GANIL in France. The facility will be composed by an ion source, a deuteron/proton source, a RFQ and a superconducting linear accelerator. The driver is planned to accelerate high intensities, up to 5 mA and 40 MeV for the deuteron beams. A monitoring system was built to measure the beam energy on the BTI line (Bench of Intermediate Test) at the exit of the RFQ. As part of theMEBT commissioning, the beamenergy will be measured on the BTI with an Epics monitoring application. At the exit of the LINAC, another system will have to measure and control the beam energy. The control consists in ensuring that the beam energy stays under a limit by taking account of the measurement uncertainty. The energy is measured by a method of time of flight; the signal is captured by non-intercepting capacitive pick-ups. This paper describes the BTI monitor interface and presents the system evolution following the design review

    Intensity Control in GANIL's Experimental Rooms

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    TUPF31International audienceThe safety re-examination of existing GANIL facilities requires the implementation of a safety system which makes a control of the beam intensity sent to the experimental rooms possible. The aim is to demonstrate that beam intensities stay below the authorized limits defined by the safety GANIL group. The challenge is to be able to measure by a non-interceptive method a wide range of beam intensities from 5nA to 5 A with a maximum uncertainty of 5%, independently of the frequency (from 7 to 14.5MHz) and the beam energy (from 1.2 to 95MeV.A). After a comparative study, two types of high frequency diagnostics were selected, the capacitive pick-up and the fast current transformer. This paper presents the signal simulations from diagnostics with different beam energies, the uncertainty calculations and the results of the first tests with beam

    Comparison of systemic, compartmental and CFD modelling approaches: Application to the simulation of a biological reactor of wastewater treatment

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    Nowadays there exist two main approaches to simulate the hydrodynamics of chemical reactors: the systemic method, based on the description of a given reactor as a limited number of elementary reactors, and the more theoretical CFD approach, based on the resolution of the Navier-Stokes equations in a large number of computing cells. This work describes another recent modelling approach based on the description of the reactor as a network of both structural and functional compartments. The complete methodology to build such a model, using CFD simulations, tracer experiments, mass transfer and chemical processes, is described. The simulation results with such a model are then compared to those obtained with the systemic and CFD models in the case of a biological gas-liquid reactor for wastewater treatment, involving oxygen transfer and complex biological kinetics. This work shows that the compartmental model gives results very similar to those of a full CFD simulation but with lower calculation time (10 times in most cases) with the advantage of remaining almost as simple to manipulate as the systemic approach

    Characterization of nanomedicines’ surface coverage using molecular probes and capillary electrophoresis

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    International audienceA faithful characterization of nanomedicine (NM) is needed for a better understanding of their in vivo outcomes. Size and surface charge are studied with well-established methods. However, other relevant parameters for the understanding of NM behavior in vivo remain largely inaccessible. For instance, the reactive surface of nanomedicines, which are often grafted with macromolecules to decrease their recognition by the immune system, is excluded from a systematic characterization. Yet, it is known that a subtle modification of NMs' surface characteristics (grafting density, molecular architecture and conformation of macromolecules) is at the root of major changes in the presence of biological components. In this work, a method that investigates the steric hindrance properties of the NMs’ surface coverage based on its capacity to exclude or allow adsorption of well-defined proteins was developed based on capillary electrophoresis. A series of proteins with different molecular weights (MW) were used as molecular probes to screen their adsorption behavior on nanoparticles bearing different molecular architectures at their surface. This novel strategy evaluating to some degree a functionality of NMs can bring additional information about their shell property and might allow for a better perception of their behavior in the presence of biological components. The developed method could discriminate nanoparticles with a high surface coverage excluding high MW proteins from nanoparticles with a low surface coverage that allowed high MW proteins to adsorb on their surface. The method has the potential for further standardization and automation for a routine use. It can be applied in quality control of NMs and to investigate interactions between proteins and NM in different situations

    Selection of oligonucleotides for whole-genome microarrays with semi-automatic update

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    Summary: Oligonucleotide microarray probes are designed to match specific transcripts present in databases that are regularly updated. As a consequence probes should be checked every new database release. We thus developed an informatics tool allowing the semi-automatic update of probe collections of long oligonucleotides and applied it to the mouse RefSeq database

    Curve counting via stable pairs in the derived category

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    For a nonsingular projective 3-fold XX, we define integer invariants virtually enumerating pairs (C,D)(C,D) where C⊂XC\subset X is an embedded curve and D⊂CD\subset C is a divisor. A virtual class is constructed on the associated moduli space by viewing a pair as an object in the derived category of XX. The resulting invariants are conjecturally equivalent, after universal transformations, to both the Gromov-Witten and DT theories of XX. For Calabi-Yau 3-folds, the latter equivalence should be viewed as a wall-crossing formula in the derived category. Several calculations of the new invariants are carried out. In the Fano case, the local contributions of nonsingular embedded curves are found. In the local toric Calabi-Yau case, a completely new form of the topological vertex is described. The virtual enumeration of pairs is closely related to the geometry underlying the BPS state counts of Gopakumar and Vafa. We prove that our integrality predictions for Gromov-Witten invariants agree with the BPS integrality. Conversely, the BPS geometry imposes strong conditions on the enumeration of pairs.Comment: Corrected typos and duality error in Proposition 4.6. 47 page

    Comparative analysis of the fecal microbiota from different species of domesticated and wild suids

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    This study was supported by the Ministry of Economy and Competitiveness (MINECO) from the Spanish Government (grant number AGL2016-78160-C2-1-R). The authors are also grateful to the Centres de Recerca de Catalunya (CERCA) Programme and Global Alliance for Research on African swine fever (GARA). The authors thank Frederic Paboeuf and Audrey Fougeroux for providing SPF and domestic pig samples.Most of the microorganisms living in a symbiotic relationship in different animal body sites (microbiota) reside in the gastrointestinal tract (GIT). Several studies have shown that the microbiota is involved in host susceptibilities to pathogens. The fecal microbiota of domestic and wild suids was analyzed. Bacterial communities were determined from feces obtained from domestic pigs (Sus scrofa) raised under different conditions: specific-pathogen-free (SPF) pigs and domestic pigs from the same bred, and indigenous domestic pigs from a backyard farm in Kenya. Secondly, the fecal microbiota composition of the African swine fever (ASF) resistant warthogs (Phacochoerus africanus) from Africa and a European zoo was determined. African swine fever (ASF) is a devastating disease for domestic pigs. African animals showed the highest microbial diversity while the SPF pigs the lowest. Analysis of the core microbiota from warthogs (resistant to ASF) and pigs (susceptible to ASF) showed 45 shared OTUs, while 6 OTUs were exclusively present in resistant animals. These six OTUs were members of the Moraxellaceae family, Pseudomonadales order and Paludibacter, Anaeroplasma, Petrimonas, and Moraxella genera. Further characterization of these microbial communities should be performed to determine the potential involvement in ASF resistance
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