1,300 research outputs found
Italian and UK Manufacturing compared
Although the Italian economy has seen a steady growth in the importance of the
service sector, manufacturing still plays a key role in the economy. It employs
32 per cent of the active population and accounts for about 33 per cent of the
country’s gross national product. For this reason, the performance of Italian
manufacturing plants relative to their international counterparts is of
considerable domestic importance, as well as highly relevant for those
interested in wider European comparisons and benchmarks. This article reports on
a research project that looked at the performance of manufacturing plants in
Italy, and in the
Optical guiding in meter-scale plasma waveguides
We demonstrate a new highly tunable technique for generating meter-scale low
density plasma waveguides. Such guides can enable electron acceleration to tens
of GeV in a single stage. Plasma waveguides are imprinted in hydrogen gas by
optical field ionization induced by two time-separated Bessel beam pulses: The
first pulse, a J_0 beam, generates the core of the waveguide, while the delayed
second pulse, here a J_8 or J_16 beam, generates the waveguide cladding. We
demonstrate guiding of intense laser pulses over hundreds of Rayleigh lengths
with on axis plasma densities as low as N_e0=5x10^16 cm^-3
MAFCONS: managing fisheries to conserve ground fish and benthic invertebrate species diversity
MAFCONS is an EC funded project that combines six partners with research activities in the North Sea. It is an applied ecology research project that wants to provide fisheries managers with a mathematical ‘tool’ to adopt a proactive ecosystem management approach. The relationship between fishing, as a disturbance, and the response of the benthic and fish communities, as the change in species diversity, needs to be clearly defined. For it the ecological ‘Huston’s Dynamic Equilibrium Model’ will be tested. This model relates diversity simultaneous to productivity and disturbance. It expresses that a change in diversity caused by a change in disturbance is dependent on the level of productivity. The Huston model and the relevant variables were discussed and evaluated in different workshops. The main objective of this project is to provide a mathematical tool based on the Huston model, that allows to predict the consequences of fisheries management policies on species diversity. Data for diversity and productivity assessment within different ICES rectangles are collected by each partner. The first campaign of the Belgian and Dutch partners coincided with the yearly IBTS survey, executed by the Tridens. At 29 stations Van Veen grab and 2m beam trawl samples were taken. Since October the processing of data started and first benthic species diversity and productivity results are obtained. A second five week campaign is planned for August-September. The first testing of the model starts in February 2005
02/28/1944 Letter from Friends of Belgium: an Agency of the Belgian War Relief Society
Letter from Robert Goffin and Vicomtesse A. du Parc of Friends of Belgium: an Agency of the Belgian War Relief Society to Louis-Philippe Gagné.https://digitalcommons.usm.maine.edu/fac-lpg-letters-1940-1946/1003/thumbnail.jp
Air hydrodynamics of the ultrafast laser-triggered spark gap
We present space and time resolved measurements of the air hydrodynamics
induced by ultrafast laser pulse excitation of the air gap between two
electrodes at high potential difference. We explore both plasma-based and
plasma-free gap excitation. The former uses the plasma left in the wake of
femtosecond filamentation, while the latter exploits air heating by
multiple-pulse resonant excitation of quantum molecular wavepackets. We find
that the cumulative electrode-driven air density depression channel initiated
by the laser plays the dominant role in the gap evolution leading to breakdown
Upgrading the OMES database: online access to OMES monitoring data using the IMERS web interface
The OMES collection is a database that holds a huge amount of measurement data on stations along the Zeeschelde and Westerschelde. The data collection consists in three main types of data: historical data (1904-1991) derived from literature, more recent data (1995-2007) generated during the OMES monitoring campaigns and some additional data from incidental measurements in the same study area. The measurements vary from water quality and suspended matter to biological data.The OMES project started in 1995 and is a multidisciplinary study on the estuarine environment of the Belgian part of the Scheldt. The main aim of OMES is to create a tool for the Flemish government that can be used as scientific support for the policy on water management of the Scheldt Estuary.In the summer of 2007 the OMES data collection has been integrated as a separate context in the IMERS data system. The Flanders Marine Institute is now responsible for centralizing and management of the newly gathered OMES data and for redistributing the data towards the OMES partners and extern users.The user that is interested in access to and use of the data is presented with a web interface on the OMES website that allows querying the database based on specific search criteria. Search criteria include parameters measured and taxonomic, spatial and temporal scope. The user can visualize the resulting data in tables and export the data to The whole dataset is made available to the project partners on the restricted pages of the OMES website: http://www.vliz.be/projects/omes
Spatiotemporal torquing of light
We demonstrate the controlled spatiotemporal transfer of transverse orbital
angular momentum (OAM) to electromagnetic waves: the spatiotemporal torquing of
light. This is a radically different situation than OAM transfer to
longitudinal, spatially-defined OAM light by stationary or slowly varying
refractive index structures such as phase plates or air turbulence. We show
that transverse OAM can be imparted to a short light pulse only for (1)
sufficiently fast transient phase perturbations overlapped with the pulse in
spacetime, or (2) energy removal from a pulse that already has transverse OAM.
Our OAM theory for spatiotemporal optical vortex (STOV) pulses [Phys. Rev.
Lett. 127, 193901 (2021)] correctly quantifies the light-matter interaction of
this experiment, and provides a torque-based explanation for the first
measurement of STOVs [Phys. Rev. X 6, 031037 (2016)]
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