1,640 research outputs found

    Chaotic enhancement of dark matter density in binary systems

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    We study the capture of galactic dark matter particles (DMP) in two-body and few-body systems with a symplectic map description. This approach allows modeling the scattering of 101610^{16} DMPs after following the time evolution of the captured particle on about 10910^9 orbital periods of the binary system. We obtain the DMP density distribution inside such systems and determine the enhancement factor of their density in a center vicinity compared to its galactic value as a function of the mass ratio of the bodies and the ratio of the body velocity to the velocity of the galactic DMP wind. We find that the enhancement factor can be on the order of tens of thousands.Comment: 6 pages, 9 figure

    Research and training in the Olifants and Limpopo basins of southern Africa

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    L'article décrit la participation des chercheurs français, détachés à l'Institut international de la gestion des ressources en eau (IWMI) par le ministère français de l'Agriculture, aux travaux concernant les bassins hydrographiques de référence Olifants et Limpopo, entrepris dans le cadre du Programme pour relever les défis « Eau et alimentation ». Les scientifiques français mis à la disposition de l'IWMI ne sont pas seulement investis dans les dimensions économiques, géographiques et agronomiques de ces programmes de recherche et de formation, ils contribuent également à la coordination des différents programmes dans les bassins hydrographiques et à l'amélioration de leur coordination. / This paper describes the contribution of the French researchers seconded to International Water Management Institute (IWMI) by the French Ministry of Agriculture in the Olifants and Limpopo benchmark basins of the Challenge Program on Water and Food. The French researchers made available to IWMI are not only involved in the economic, geographic and agronomic aspects of these projects, but also participate in coordinating and developing synergy between different projects in the basins.GESTION DE L'EAU;RECHERCHE;FORMATION PROFESSIONNELLE;AFRIQUE DU SUD;RESEARCH;TRAINING;WATER MANAGEMENT;SOUTHERN AFRICA

    Safer Streets: Cutting Repeat Crimes by Juvenile Offenders.

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    FIGHT CRIME: INVEST IN KIDS is an anti-crime organization led by more than 3,500 law enforcement leaders -- chiefs, sheriffs and prosecutors -- and survivors of crime. Most of the survivors are parents of murdered children. Crime requires punishment. Punishment may be placing a young offender in custody, or, depending on the crime, imposing a range of other tough sanctions. The bottom line is that residents must be safe walking the streets. Research shows, however, that punishment alone will often not be enough; troubled teens will need help to stop their aggression, substance abuse, or other anti-social behaviors. It is usually not too late to change anti-social patterns of behavior. Sanctions that include strict and effective interventions can direct anti-social and dangerous juveniles onto a different path that will make Americans safer

    Research and training in the Olifants and Limpopo basins of southern Africa

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    This paper describes the contribution of the French researchers seconded to International Water Management Institute (IWMI) by the French Ministry of Agriculture in the Olifants and Limpopo benchmark basins of the Challenge Program on Water and Food. The French researchers made available to IWMI are not only involved in the economic, geographic and agronomic aspects of these projects, but also participate in coordinating and developing synergy between different projects in the basins.L'article décrit la participation des chercheurs français, détachés à l'Institut international de la gestion des ressources en eau (IWMI) par le ministère français de l'Agriculture, aux travaux concernant les bassins hydrographiques de référence Olifants et Limpopo, entrepris dans le cadre du Programme pour relever les défis « Eau et alimentation ». Les scientifiques français mis à la disposition de l'IWMI ne sont pas seulement investis dans les dimensions économiques, géographiques et agronomiques de ces programmes de recherche et de formation, ils contribuent également à la coordination des différents programmes dans les bassins hydrographiques et à l'amélioration de leur coordination. / This paper describes the contribution of the French researchers seconded to International Water Management Institute (IWMI) by the French Ministry of Agriculture in the Olifants and Limpopo benchmark basins of the Challenge Program on Water and Food. The French researchers made available to IWMI are not only involved in the economic, geographic and agronomic aspects of these projects, but also participate in coordinating and developing synergy between different projects in the basins

    Stratabound arsenic and vein antimony mineralisation in Silurian greywackes at Glendinning, south Scotland

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    Stratiform and disseminated pyrite-arsenopyrite concentrations are overprinted by fracturecontrolled polymetallic mineralisation including stibnite through at least tens of metres of Silurian sediments at Glendinning, near Langholm. Three shallow boreholes were drilled on an anomaly defined by VLF-EM and II? surveys and by antimony values X0 ppm in thin B-C horizon soils. A parallel conductive zone with an accompanying soil anomaly but lacking an IP response was investigated by a fourth hole. The stratabound sulphides form disseminations and bands parallel to the bedding and are particularly concentrated in intraformational breccia units regarded as debris flows, which, together with the presence of smaIl scale slump folds in the greywackes, testify to the existence of an unstable slope during sedimentation. The thickest such unit has a true thickness of 4 m and together with 8 m of adjoining greywackes grades 0.7% As. Phases of fracture-controlled Fe-As-Sb-Pb- Zn-Cu-(?)Hg mineralisation associated with widespread dolomite and quartz veinlets and narrow breccia veins are superimposed on the stratabound mineralisation. Their spatial association with the stratabound mineralisation, the presence of up to 0.33% Sb in the stratiform arsenopyrite and as much as 5% As in the stratiform pyrite, favour a common source for the arsenic and antimony. This source was probably a synsedimentary metal accumulation in a mid or lower fan environment where euxinic conditions periodically developed

    Avec leur statut original, quels rôles pour les sociétés d'aménagement régional dans les politiques de l'eau et de l’irrigation ?

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    Les sociétés d’aménagement régional (SAR) opérateurs régionaux de la gestion de l’eau avec un mandat d’aménagement du territoire ont un statut original de sociétés commerciales. Elles jouent un rôle majeur dans la réalisation des investissements nécessaires à l’irrigation dans le Sud de la France. Une interview de trois cadres de ces sociétés permet de cerner comment elles peuvent jouer ce rôle. La relation avec les irrigants se fait par des contrats de droit privé impliquant généralement un comptage des quantités d’eau distribuée et une attention particulière au prix de l’eau. La vente d’eau à différents usagers agricole, urbain ou industriel permet d’équilibrer les comptes. Ces sociétés apportant à l’État la garantie d’organisations structurées, la répartition de l’eau, la création de ressource avant l’équipement des exploitations irrigantes, le conseil d’État recommande de leur donner plus de poids. / Regional development companies (SAR), regional organizations of water management with a role of regional planning and development have, in France, an original status of corporations. They play a major role in making the necessary investments in irrigation in the South of France. An interview with three managers of these companies can identify how they can play this role. Relationship with irrigators is done by private contracts generally involving water measurement and special attention to water price. The sale of water to different users agricultural, urban or industrial balances the accounts. As these companies bring to the state the guaranty of structured organizations, balanced distribution of water, creating resource before farm equipment, the State Council recommends to give them more weight

    Relationship between tillering and grain yield of Kansas wheat varieties

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