Search results for "gradient"
showing 10 items of 725 documents
Optically pumped Cs magnetometers enabling a high-sensitivity search for the neutron electric dipole moment
2020
An array of 16 laser-pumped scalar Cs magnetometers was part of the neutron electric dipole moment (nEDM) experiment taking data at the Paul Scherrer Institute in 2015 and 2016. It was deployed to measure the gradients of the experiment's magnetic field and to monitor their temporal evolution. The originality of the array lies in its compact design, in which a single near-infrared diode laser drives all magnetometers that are located in a high-vacuum chamber, with a selection of the sensors mounted on a high-voltage electrode. We describe details of the Cs sensors' construction and modes of operation, emphasizing the accuracy and sensitivity of the magnetic-field readout. We present two app…
CONVERSIONS DE FREQUENCE ULTRA LARGE BANDE PAR MELANGE A QUATRE ONDES INTERMODAL EN CASCADE DANS LES FIBRES MULTIMODES
2017
International audience; Nous mettons en évidence des effets de conversion spectrale paramétrique avec des décalages spectraux très importants (~200THz) dans une fibre à gradient d'indice qui, pompée avec une source laser picoseconde à 1064nm, supporte quatre modes de propagation. À travers des études expérimentales, analytiques et numériques détaillées, nous montrons que les multiples raies paramétriques sont générées par un processus en cascade complexe faisant intervenir des mélanges à quatre ondes intermodaux. Les longueurs d'onde paramétriques résultantes s'étendent dans le visible jusqu'à 410nm et dans le proche infrarouge jusqu'à 1355nm. MOTS-CLEFS : dynamique spatio-temporelle ; conv…
Investigation of the hygienic safety of aromatic plants cultivated in soil contaminated with Listeria monocytogenes
2012
Abstract The present work was undertaken to investigate the survival of Listeria monocytogenes ATCC 19114T in soil during the whole crop cycle of rocket (Eruca sativa Mill.) and basil (Ocimum basilicum L.), to monitor its transfer to the leaves, and to evaluate its viability at harvest. To this purpose, the soil was N–P–K fertilized and four trials, obtained with different combinations of soil treatment, listerial inoculums and seed planting, were followed for each aromatic plant. Soil was weekly investigated for total microbial counts and L. monocytogenes evolution. At the starting time, un-inoculated autoclaved soil showed a limited microbial load (103 CFU g dw−1), while un-inoculated non…
Global-Scale Environmental Niche and Habitat of Blue Shark (Prionace glauca) by Size and Sex: A Pivotal Step to Improving Stock Management
2022
25 pages, 10 figures, 2 tables, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2022.828412/full#supplementary-material.-- Data Availability Statement: The blue shark habitat data are available on the JRC Data Catalogue (https://data.jrc.ec.europa.eu/dataset?q=fish%20habitat) (or upon request) and habitat maps are available online (https://fishreg.jrc.ec.europa.eu/web/fish-habitat/habitatmapping). Chlorophyll-a data are available online (https://oceancolor.gsfc.nasa.gov/cgi/l3). The abiotic environmental and mesopelagic micronekton data are available online (https://marine.copernicus.eu/access-data).
An optimization-based approach for solving a time-harmonic multiphysical wave problem with higher-order schemes
2013
This study considers developing numerical solution techniques for the computer simulations of time-harmonic fluid-structure interaction between acoustic and elastic waves. The focus is on the efficiency of an iterative solution method based on a controllability approach and spectral elements. We concentrate on the model, in which the acoustic waves in the fluid domain are modeled by using the velocity potential and the elastic waves in the structure domain are modeled by using displacement.Traditionally, the complex-valued time-harmonic equations are used for solving the time-harmonic problems. Instead of that, we focus on finding periodic solutions without solving the time-harmonic problem…
Efecto del entrenamiento de fuerza explosiva sobre las características básicas y específicas de la fuerza en jugadoras de voleibol
2012
La investigación sobre el efecto del entrenamiento de fuerza explosiva sobre las características básicas y específicas de la fuerza explosiva, se ha realizado con 40 jugadoras de voleibol divididas en tres grupos: Un grupo específico formado por 12 jugadoras de elite que ha sido sometido al proceso de entrenamiento específico con objetivo de desarrollar la fuerza explosiva de los extensores de espalda, los extensores de piernas y los extensores de tobillos. Un segundo grupo clásico formado por 11 jugadoras de voleibol que han realizado entrenamiento clásico sin impacto en la fuerza explosiva. Y un tercer grupo control formado por 20 mujeres sanas, no entrenadas y con buena condición física.…
Krāpniecisku kredītņēmēju noteikšana, izmantojot gadījuma meža un gradienta pastiprināšanas algoritmu
2016
Mašīnmācīšanās nozare attīstās ļoti strauji un mūsdienās tā tiek plaši pielietota dažādās nozarēs, ne tikai zinātnē. Viena no šādām nozarēm ir nebanku kreditēšanas sektors. Darbā aplūkoti trīs mašīnmācīšanās algoritmi, kas balstīti uz klasifikācijas kokiem - lēmumu koks, gadījuma mežs un gradienta pastiprināšanas metode. Darba mērķis ir teorētiski iepazīt un praktiski noskaidrot piemērotāko no modeļiem, lai spētu izvērtēt un prognozēt krāpnieciskus kredītu pieteikumus. Darba izpildei tiek izmantota programma R un tajā iebūvētās funkcijas.
The influence of backslopping on lactic acid bacteria diversity in tarhana fermentation
2020
Tarhana is produced at batch systems in which the microbiota has changed accordingly to the microbial load from ingredients. In order to stabilize the microbiota, the effects of backslopping carried out under different temperature regimes (25 and 30 °C), pH (3.70 and 4.00) and inoculation rates (5, 10 and 15%) on lactic acid bacteria (LAB) diversity were determined in tarhana dough. LAB and Total Aerobic Mesophilic Bacteria (TAMB) numbers increased in all tarhana dough samples subjected to backslopping. Temperature and pH significantly affected the microbiological diversity of tarhana whereas the different inoculation rates did not. Tarhana dough showed complex tarhana microbiota following …
Geochemical investigations of submarine volcanic exhalations to the east of Panarea, Aeolian Islands, Italy
1991
Abstract Results are presented on scubadiving investigations carried out on thermal manifestations in the area of Panarea (Aeolian Islands). The area investigated falls inside a caldera which extends from the main island to the group of islets located to the northeast. The distribution of the gaseous manifestations is regulated by the NE-SW, NW-SE and N-S regional tectonic directrices, through which the more recent basic magma intruded, giving rise to dikes and pillow lavas. f O 2 -temperature relation of the gases sampled in the investigated area was calculated to be: log f O 2 = 11−24,593/ T which indicates that a buffering mechanism acted on the gases as they cooled down during their asc…
Parasitoids (Hymenoptera) of leaf-spinning moths (Lepidoptera) feeding on Vaccinium uliginosum L. along an ecological gradient in central European pe…
2011
Parasitoids of leaf-spinning Lepidoptera associated with two isolated central European peat bogs were investigated. Five families of parasitoid Hymenoptera (Braconidae, lchneumonidae, Eulophidae, Pteromalidae and Encyrtidae) were recorded. Three categories were recognised: (1) primary parasitoids, (2) facultative hyperparasitoids and (3) obligatory hyperparasitoids. Ten species of Braconidae, five species and seven marked morphospecies among lchneumonidae, and three species of Chalcidoidea were identified. Despite of some niche-specific (but less host-specific) parasitoids, all these hymenopterans are likely to be generalists and none of them were confirmed to be habitat and/or host special…