USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Centre pivot irrigation systems are known for their irrigation distribution performance potential. Unfortunately the performance analysis of centre pivot irrigation systems is often restricted to the uniformity of distribution. Depending on the characteristics of the applied rainfall, a system designed for high uniformity does not guarantee a high application efficiency once the system is in operation. A method is proposed in the present paper to analyse the average rainfall depth of application and kinetic energy delivered to the soil by individual droplets all over the machine. The method requires water distribution profiles, the distribution of droplet size and velocity along the radius of coverage for any nozzle, and pressure and height of the emitter installed on the machine. Considering the number of nozzles and the range of pressure applied, there is the need for a method calculating: the emitter maximum radius of coverage, then the rainfall distribution profile, then the droplet distribution and finally the associated kinetic energy delivery. These parameters are calculated on a new model of classical design sprayers proposed by IWT Company. These results are being integrated on a centre pivot nozzle chart design software presented in the poster session

Multiresistant Salmonella enterica serovar 4,[5],12:i:- in Europe: a new pandemic strain?

A marked increase in the prevalence of S. enterica serovar 4,[5],12:i:- with resistance to ampicillin, streptomycin, sulphonamides and tetracyclines (R-type ASSuT) has been noted in food-borne infections and in pigs/pig meat in several European countries in the last ten years. One hundred and sixteen strains of S. enterica serovar 4,[5],12:i:- from humans, pigs and pig meat isolated in England and Wales, France, Germany, Italy, Poland, Spain and the Netherlands were further subtyped by phage typing, pulsed-field gel electrophoresis and multilocus variable number tandem repeat analysis to investigate the genetic relationship among strains. PCR was performed to identify the fljB flagellar gene and the genes encoding resistance to ampicillin, streptomycin, sulphonamides and tetracyclines. Class 1 and 2 integrase genes were also sought. Results indicate that genetically related serovar 4,[5],12:i:- strains of definitive phage types DT193 and DT120 with ampicillin, streptomycin, sulphonamide and tetracycline resistance encoded by blaTEM, strA-strB, sul2 and tet(B) have emerged in several European countries, with pigs the likely reservoir of infection. Control measures are urgently needed to reduce spread of infection to humans via the food chain and thereby prevent the possible pandemic spread of serovar 4,[5],12:i:- of R-type ASSuT as occurred with S. Typhimurium DT104 during the 1990s

Experimental Studies of Prompt Fission Neutron Energy Spectra

AbstractPrompt fission neutron spectra were measured in the reactions 238U(n,f), 235U(n,f) and 237Np(n,f) at different incident neutron energies. The neutrons were detected using a coaxial doped p-terphenyl scintillation detector in coincidence with fission fragments and their time-of-flight was recorded. The properties of the neutron detector were determined and the results are presented in this work. A preliminary neutron detection efficiency was applied to data from the neutron-induced fission of 238U at En = 5.2 MeV, leading to encouraging results

Algues chlorophyceae du jurassique terminal et du crétacé inférieur en Alicante

L'inventaire des Algues Chlorophycées du Jurassique terminal et du Crétacé inférieur de l'«arrière-pays de Benidorm» (province d'Alicante, ESPAGNE) permet de reconnaître 23 espèces, dont trois nouvelles appartenant aux genres Heteroporella, Clypeina et Arabicodium. L'attribution générique de quatre espèces est discutée; ceci conduit à la création d'un nouveau taxon pour l'une, à la conservation et réintroduction d'un taxon pour une autre et à une incertitude quant à l'attribution des deux dernières. La position systématique de microfossiles attribués jusqu'alors à cette classe ou considérés comme incertae sedis est également analysée. Cette étude montre que quelques Algues Chlorophycées ont un intérêt stratigraphique certain.El inventario de las Algas Chlorophyceae del Jurásico terminal y del Cretácico inferior en los alrededores de Benidorm (provincia de Alicante, ESP ANA) permitió el reconocimiento de 23 especies, de las cuales tres pertenecientes a los géneros Heteroporella, Clypeina y Arabicodium son especies nuevas. La atribución genérica de cuatro especies es discutida en este trabajo; esto conduce a la creación de un nuevo taxon para una de ellas y a la reincorporación de un taxon para otra, quedando incierta la asignación de taxon para las dos últimas. La posición sistemática de microfósiles atribuidos hasta entonces a esta clase o considerados como incertae sedis es igualmente analizada. Este estudio muestra que ciertas Algas Cloroficeas presentan un interés estratigráfico definido.A review of the Chlorophycean Algae from Uppermost Jurassic and Lower Cretaceous sediments of the Benidorm area (province of Alicante, SPAIN) leads to the identification of 23 species. Three of them belong to the Heteroporella, Clypeina and Arabicodium genere and are new ones. The generic atributions of four species are discussed: a new taxon is created and another is reintroduced, while a doubt remains for two of them. The systematics of some microfossils which have been previously attributed to this class or considered to be incertae sedis is analysed. This paper shows that some of the Chlorophyceae have a definite stratigraphie interest

Clypeina tibanai, sp. nov. (Polyphysaceae, Dasycladales, Chlorophyta), a mid-Cretaceous green alga from the Potiguar Basin, Brazilian margin of the young South Atlantic Ocean

The fossil genus Clypeina (Michelin, 1845) comprises some 40 species. We describe Clypeina tibanai, a new spe-cies from ? upper Albian–Cenomanian strata of the Potiguar Basin, Brazil, characterised by closely set verticils of tubular, bended laterals. It is compared with Clypeina hanabataensis Yabe & Toyama, 1949, a Late Jurassic species, and with Pseudoactinoporella fragilis (Conrad, 1970), an Early Cretaceous taxon. The new species be-longs to a short list of green algae found in the young South Atlantic oceanic corridor, an assemblage defining a phycological paleobioprovince discrete from that of the Tethyan realm

Réutilisation maîtrisée des eaux usées : approfondir les connaissances pour lever les freins et relever les défis

Le recyclage des eaux usées représente une solution pour faire face à la demande croissante des ressources hydriques pour l’irrigation agricole. Mais leur réutilisation pose des problèmes de sécurité, de réglementation et bien sûr de techniques adaptées, que cet article nous propose de mieux comprendre

Quarkonia production with the Hera-B experiment

Measurements of the dependence of the J/Psi production cross section on its kinematic variables as well as on the target atomic numbers for 920 GeV/c protons incident on different targets have been made with the Hera-B detector. The large collected di-lepton sample allows to study the production ratio of Psi(2S) to J/Psi and of Chic to J/Psi . We also report on measurements of the b-bbar and Upsilon production cross section.Comment: 9 pages, 11 figure

Mechanical Properties of Carbon Composites with Varying Resin Concentration

Center for Electromechanic