All-Optical Production of Chromium Bose-Einstein Condensates

We report on the production of ^52Cr Bose Einstein Condensates (BEC) with an all-optical method. We first load 5.10^6 metastable chromium atoms in a 1D far-off-resonance optical trap (FORT) from a Magneto Optical Trap (MOT), by combining the use of Radio Frequency (RF) frequency sweeps and depumping towards the ^5S_2 state. The atoms are then pumped to the absolute ground state, and transferred into a crossed FORT in which they are evaporated. The fast loading of the 1D FORT (35 ms 1/e time), and the use of relatively fast evaporative ramps allow us to obtain in 20 s about 15000 atoms in an almost pure condensate.Comment: 4 pages, 4 figure

Development of probabilistic models for quantitative pathway analysis of plant pest introduction for the EU territory

This report demonstrates a probabilistic quantitative pathway analysis model that can be used in risk assessment for plant pest introduction into EU territory on a range of edible commodities (apples, oranges, stone fruits and wheat). Two types of model were developed: a general commodity model that simulates distribution of an imported infested/infected commodity to and within the EU from source countries by month; and a consignment model that simulates the movement and distribution of individual consignments from source countries to destinations in the EU. The general pathway model has two modules. Module 1 is a trade pathway model, with a Eurostat database of five years of monthly trade volumes for each specific commodity into the EU28 from all source countries and territories. Infestation levels based on interception records, commercial quality standards or other information determine volume of infested commodity entering and transhipped within the EU. Module 2 allocates commodity volumes to processing, retail use and waste streams and overlays the distribution onto EU NUTS2 regions based on population densities and processing unit locations. Transfer potential to domestic host crops is a function of distribution of imported infested product and area of domestic production in NUTS2 regions, pest dispersal potential, and phenology of susceptibility in domestic crops. The consignment model covers the several routes on supply chains for processing and retail use. The output of the general pathway model is a distribution of estimated volumes of infested produce by NUTS2 region across the EU28, by month or annually; this is then related to the accessible susceptible domestic crop. Risk is expressed as a potential volume of infested fruit in potential contact with an area of susceptible domestic host crop. The output of the consignment model is a volume of infested produce retained at each stage along the specific consignment trade chain

Accumulation and thermalization of cold atoms in a finite-depth magnetic trap

We experimentally and theoretically study the continuous accumulation of cold atoms from a magneto-optical trap (MOT) into a finite depth trap, consisting in a magnetic quadrupole trap dressed by a radiofrequency (RF) field. Chromium atoms (52 isotope) in a MOT are continuously optically pumped by the MOT lasers to metastable dark states. In presence of a RF field, the temperature of the metastable atoms that remain magnetically trapped can be as low as 25 microK, with a density of 10^17 atoms.m-3, resulting in an increase of the phase-space density, still limited to 7.10^-6 by inelastic collisions. To investigate the thermalization issues in the truncated trap, we measure the free evaporation rate in the RF-truncated magnetic trap, and deduce the average elastic cross section for atoms in the 5D4 metastable states, equal to 7.0 10^-16m2.Comment: 9 pages, 10 Figure

Enzimas hidroliticas detectadas en cultivo filtrado de Septoria tritici (Teleomorfo, Mycosphaerella graminicola)

Una serie de tes fueron conducidos para verificar actividad de enzimas hidrolíticas (pécticas y celulolíticas) producidas por Septoria tritici como evaluar sus efectos en hojas de trigo. Por tanto fue cultivada en medio líquido y el cultivo filtrado fue parcialmente purificado. Una actividad enzimática fue detectada a través de mediciones regulares de viscosidad del sustrato. Las enzimas celulolíticas y pécticas actuan en la mancha de la hoja del trigo.Tests to detect activity ofhydrolitic enzymes (pecúc and ceUulolitic) were comed ota (o study their production by Septoria tritici and assert their effect on wheat leaf blotch The fungas wos cultivated in a liquid médium; and the culture fíltrate was partialfy purified Enzymatic activity was measured by reading viscometrical reductions and detecting free reducing groups as producís of reaction. Consdtudve character of celhiloliúc enzymes and the adaptive one ofpectic enzymes were determined Both enzymes acted on wheat leaf blotch.ISSN 0100-540

Fine Structure of the N=1 (1s3p)3Πu State of the Hydrogen Molecule Determined by Magnetic Resonance

International audienceIn the preceding paper some of our results on the magnetic-resonance experiments performed at 64 MHz indicated a beginning of N.S decoupling on the N=1 (1s3p)3Πu state of H2 excited by electron impact. In the present paper we present further results on the resonance experiments performed at higher frequencies in order to determine the fine structure of this level. Our findings indicate that the energy separation between J=1 and J=2 levels is 160+/-5 MHz and between J=1 and J=0 levels it is 2100+/-600 MHz, and in addition the former exhibits a small dependence on the vibrational number. The relative order of these levels is J=1, 2, 0 instead of the theoretically predicted 2, 1, 0. The Landé g factor is 1.249+/-0.010, which corresponds to a pure Hund's-coupling case (b)

O naturalnym pragnieniu doskonałości uszczęśliwiającej

Artykuł wysłany przez Josepha Maréchala 3 lipca 1930 roku do „Gregorianum” nie został w nim jednak opublikowany, lecz ukazał się dopiero po śmierci Maréchala, w wydaniu zbiorowym: Mélanges Joseph Maréchal. T. 1. Bruxelles-Paris 1950, s. 323-337

Pierwszy zarys doktryny całkowicie ukształtowanej (Louvain, kwiecień 1920)

Prezentowany szkic autorstwa Josepha Maréchala ukazał się po raz pierwszy w dwutomowym wydaniu zbiorowym, poświęconym pamięci tego belgijskiego jezuity, uznawanego za twórcę „tomizmu transcendentalnego” (J. M a r é c h a l: Première formule d’une doctrine complètement formée (Louvain, avril 1920). In: Mélanges Joseph Maréchal. T. 1: Oeuvres. Paris 1950, s. 298—303). Stanowi on, jak pisze o tym jego autor, najstarszy, roboczy zarys koncepcji, rozwiniętej następnie w składającym się z pięciu zeszytów dziele: Le point de départ de la métaphysique (Punkt wyjścia metafizyki). Zeszyt 5. owego dzieła, o którym w zamieszczonym poniżej liście wspomina również sam Maréchal, zatytułowany Le thomisme devant la Philosophie critique (Tomizm wobec filozofii krytycznej), to najsłynniejsza część owego dzieła, zawierająca próbę transpozycji tomistycznej teorii poznania na sposób transcendentalny. Próba ta dała impuls do powstania tak zwanej szkoły Maréchala, do której zalicza się dzisiaj takie nazwiska, jak Lotz, Marc, Rahner, Lonergan, Brugger, Isaye, Coreth, Muck, i wiele innych - J.S., A.B

Lifetimes, g Factors, and Collision Cross Sections of Hydrogen Molecules in the (1s3p)3Πu Level

International audienceExperimental results obtained by Hanle and Bitter-Brossel effects on the N=1 and N=2 (v=0, 1, 2, and 3) levels of the (1s3p)3Πu state of the parahydrogen molecule excited by electron impact are presented. Resonances are found at the experimentally lowest possible frequencies (21-64 MHz) in a region where the N. S decoupling is nonexistent for the N=2 level [the measured Landé g factors are 0.77 +/- 0.01 and 0.48 +/- 0.02 corresponding to a pure Hund's-coupling case (b)] and just beginning for the N=1 level (at 21 MHz the apparent measured g is 1.235 +/- 0.01). These results together with the calculations carried out in the case of complete N.S coupling lead to lifetimes τ=(3.10+/-0.3)×10-8 see (N=1) and τ=(3.15+/-0.3)×10-8 sec (N=2) and H2* - H2 cross sections τ=232+/-30 Å2 (N=1) and σ=240+/-30 Å2 (N=2). The quantities g, τ, and σ were all found to be independent on the vibrational number. Risk of cascade was eliminated