University of the Littoral Opal Coast

About: University of the Littoral Opal Coast is a education organization based out in Dunkirk, France. It is known for research contribution in the topics: Catalysis & Dielectric. The organization has 1242 authors who have published 2383 publications receiving 46230 citations. The organization is also known as: ULCO.

Geomorphology of high-latitude coastal dunes: A review

Abstract: The purpose of this review is to assess if there are any specific processes and morphologies distinguishing coastal dunes developed in cold-climate conditions, in order to illustrate how climate can exert a control on coastal dune morphologies. In the Arctic, availability of sand supply and the duration of winter conditions are limiting factors for the development of large coastal dunes. They are small in size, and embryo dunes including nebkha are the dominant and often only coastal dune type. In milder subarctic settings, characterized by a longer surficial ice-free season, a greater variety of coastal dunes are found, mainly foredunes, blowouts and parabolic dunes. In subarctic areas, as along the SE coast of Hudson Bay, niveo-aeolian processes actively affect coastal dune development. These processes do not generally imprint permanent morphologies, although some distinctive sedimentary structures owing to the melting of snow are observed. The coastal dunes of the arctic regions differ from the dunes of subarctic and temperate regions mainly because of their limited spatial and morphological development. Extreme climatic conditions (low precipitation, extreme cold), and very limited vegetation growing season, combined with low sediment supply, explain the fact that only embryo dunes develop in arctic environments.

Telecom-grade fiber laser-based difference-frequency generation and ppb-level detection of benzene vapor in air around 3 μm

Abstract: We report on the development of a field deployable compact laser instrument tunable over ∼232 cm−1 from 3.16 to 3.41 μm (2932.5–3164.5 cm−1) for chemical species monitoring at the ppb-level. The laser instrument is based on widely tunable continuous-wave difference-frequency generation (DFG), pumped by two telecom-grade fiber lasers. DFG power of ∼0.3 mW near 3.3 μm with a spectral purity of ∼3.3 MHz was achieved by using moderate pumping powers: 408 mW at 1062 nm and 636 mW at 1570 nm. Spectroscopic performance of the developed DFG-based instrument was evaluated with direct absorption spectra of ethylene at 3.23 μm (∼3094.31 cm−1). Absorption spectra of vapor-phase benzene near 3.28 μm (∼3043.82 cm−1) were recorded with Doppler-limited resolution. Line intensities of the most intense absorption lines of the ν12 band near 3043.8 cm−1 were determined to support development of sensitive mid-infrared trace gas detection of benzene vapor in the atmosphere. Detection of benzene vapor in air at different concentration levels has been performed for the first time using multi-pass cell enhanced direct absorption spectroscopy at ∼3.28 μm with a minimum detectable concentration of 50 ppb (1σ).

Innovation, evolution and economic change: New ideas in the tradition of Galbraith

Abstract: Providing an analysis of the main features of contemporary capitalism, and the conflict between shareholders and managers, this book also focuses on the consequences of globalization in the decision-making process of big firms.

Using constraint programming to schedule an operating theatre

Abstract: The daily operating rooms scheduling is a highly constrained problem. It is also hard to find an optimal solution or at least high quality solutions. To solve this scheduling problem, we use the “expressive power” of the constraint programming paradigm to include as many as possible real-life constraints in our model, such as the availability and the preferences of the staff. We develop a “generic” adaptive model which embeds most of the characteristics of the problem encountered in the literature as well as real-life constraints coming from practical problems in hospitals.