915 resultados para Sand removal


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Membrane-aerated biofilm reactors performing autotrophic nitrogen removal can be successfully applied to treat concentrated nitrogen streams. However, their process performance is seriously hampered by the growth of nitrite oxidizing bacteria (NOB). In this work we document how sequential aeration can bring the rapid and long-term suppression of NOB and the onset of the activity of anaerobic ammonium oxidizing bacteria (AnAOB). Real-time quantitative polymerase chain reaction analyses confirmed that such shift in performance was mirrored by a change in population densities, with a very drastic reduction of the NOB Nitrospira and Nitrobacter and a 10-fold increase in AnAOB numbers. The study of biofilm sections with relevant 16S rRNA fluorescent probes revealed strongly stratified biofilm structures fostering aerobic ammonium oxidizing bacteria (AOB) in biofilm areas close to the membrane surface (rich in oxygen) and AnAOB in regions neighbouring the liquid phase. Both communities were separated by a transition region potentially populated by denitrifying heterotrophic bacteria. AOB and AnAOB bacterial groups were more abundant and diverse than NOB, and dominated by the r-strategists Nitrosomonas europaea and Ca. Brocadia anammoxidans, respectively. Taken together, the present work presents tools to better engineer, monitor and control the microbial communities that support robust, sustainable and efficient nitrogen removal

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Collection : Bibliothèque contemporaine

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Collection : Bibliothèque contemporaine

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Collection : Bibliothèque contemporaine

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Collection : Bibliothèque contemporaine

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Collection : Bibliothèque contemporaine

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Collection : Bibliothèque contemporaine

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Sand Creek is the most significant recreational fishery in Delaware County because of its location to Manchester and Lake Delhi. It is a feeder stream for game fish to the main stem of the Maquoketa River which is limited by the dams at Manchester and Lake Delhi. Sand Creek encompasses 16,045 acres and is dominated by row crop agriculture. It is being impacted by sediment, nutrients and E coli bacteria. Sand Creek will be a good example for habitat impaired watershed. The purpose of this project is to decrease the amount of sediment and nutrients reaching Sand Creek and to increase the habitat in Sand Creek to make it a better spawning and growing area for the fish and the food chain for the fish. The objectives of this project are to reduce sediment delivery by 40%, to improve in-stream habitat on 40% of identified critical areas and implement an information/education program. The project will install 3,800 acres of new no-till planting, 6 water and sediment control basins, 4,000 feet of terraces, 20,000 feet of improved or new waterways, 3,200 feet of streambank/ habitat enhancement, 4,500 feet of livestock exclusion fencing and 6 acres of wetlands.

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Fly ash, a by-product of coal-fired electricity generating plants, has for years been promoted as a material suitable for highway construction. Disposal of the large quantities of fly ash produced is expensive and creates environmental concerns. The pozzolanic properties make it promotable as a partial Portland cement replacement in pc concrete, a stabilizer for soil and aggregate in embankments and road bases, and a filler material in grout. Stabilizing soils and aggregates for road construction has the potential of using large quantities of fly ash. Iowa Highway Research Board Project HR-194, "Mission-Oriented Dust Control and Surface Improvement Processes for Unpaved Roads", included short test sections of cement, fly ash, and salvaged granular road material mixed for a base in western Iowa. The research showed that cement fly ash aggregate (CFA) has promise as a stabilizing agent in Iowa. There are several sources of sand that when mixed with fly ash may attain strengths much greater than fly ash mixed with salvaged granular road material at little additional cost

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The Iowa Department of Public Health (IDPH), Hazardous Waste Site Health Assessment Program was asked by the US Environmental Protection Agency (EPA) to review a round of air sampling data. The air data was collected and analyzed during a removal action at the Le Mars Coal Gas Site in Le Mars, Iowa. EPA asked IDPH to determine from the air data if additional monitoring is necessary throughout the removal action to protect nearby residents from exposure.

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Methylene blue (MB) and light are used for virus inactivation of plasma for transfusion. However, the presence of MB has been the subject of concern, and efforts have been made to efficiently remove the dye after photo-treatment. For this study, plasma was collected by apheresis from 10 donors (group A), then treated using the MacoPharma THERAFLEX procedure (MB; 1 microM, and light exposure; 180 J/cm(2)) (group B), and finally filtered in order to remove the dye (group C). Proteins were analyzed by two-dimensional electrophoresis, and peptides showing modifications were characterized by mass spectrometry. Clottable and antigenic fibrinogen levels, as well as fibrin polymerization time were measured. Analyses of the gels focused on a region corresponding to pI between 4.5 and 6.5, and M(r) from 7000 to 58 000. In this area, 387 +/- 47 spots matched, and four of these spots presented significant modifications. They corresponded to changes of the gamma-chain of fibrinogen, of transthyretin, and of apolipoprotein A-I, respectively. A decrease of clottable fibrinogen and a prolongation of fibrin polymerization time were observed in groups B and C. Removal of MB by filtration was not responsible for additional protein alterations. The effect of over-treatment of plasma by very high concentrations of MB (50 microM) in association with prolonged light exposure (3 h) was also analyzed, and showed complex alterations of most of the plasma proteins, including fibrinogen gamma-chain, transthyretin, and apolipoprotein A-I. Our data indicates that MB treatment at high concentration and prolonged illumination severely injure plasma proteins. By contrast, at the MB concentration used to inactivate viruses, damages are apparently very restricted.

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Selostus: Kalkituksen vaikutus piparmintun ja Sachalinin mintun satoon Pohjois-Suomessa

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Metallic foreign bodies are rarely found in the maxillary sinus, and usually they have a dental origin.Potential complications related to foreign bodies include recurrent sinusitis, rhinolith formation, cutaneous fistula,chemical poisoning, facial neuralgic pain and even malignancies.Two main surgical approaches are currently used for the removal of foreign bodies in the maxillary sinus: the bone flap and the endoscopic sinus techniques. We are reporting two unusual cases of large high-velocity foreign bodies removed by a modified maxillary lateral antrotomy,with free bone flap repositioning and fixation with a titanium miniplate.

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A new species of lacertid lizard of the genus Psammodromus is described from the Iberian Peninsula. Genetic and recently published phenotypic data support the differentiation of Psammodromus hispanicus into three, and not as previously suggested two, distinct lineages. Age estimates, lineage allopatry, the lack of mitochondrial and nuclear haplotype sharing between lineages, ecological niche divergence, and the current biogeographic distribution, indicated that the three lineages correspond to three independent species. Here, we describe a new species, Psammodromus occidentalis sp. n., which is genetically different from the other sand racers and differentiated by the number of femoral pores, number of throat scales, snout shape, head ratio, green nuptial coloration, and number of supralabial scales below the subocular scale. We also propose to upgrade the two previously recognized subspecies, Psammodromus hispanicus hispanicus Fitzinger, 1826 from central Spain and Psammodromus hispanicus edwardsianus (Dugès, 1829) from eastern Spain, to the species level: Psammodromus hispanicus stat. nov. and Psammodromus edwardsianus stat. nov. Given that the holotype of Psammodromus hispanicus was lost, we designate a neotype. We also analysed museum specimens of P. blanci, P. microdactylus and P. algirus to describe differentiation of the Psammodromus hispanicus lineages/species from their closest relatives.

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Monissasovelluksissa on hyvin tärkeää vähentää valolähteen vaikutusta kohteen oikean värin havainnoimiseksi. Tämä on tarpeen mm. virtuaalisissa museoissa, telelääketieteessä, verkkokaupassa ja verkkorahassa. Tässä tutkielmassa on kehitetty tekniikkaa kirkkaiden heijastusten poistoon spektrikuvista. Työ sisältää katsauksen yleisen värillisen kuvan ymmärtämiseen, mihin perustuen analysoitiin erilaisia kirkkaiden heijastusten poistO'tekniikoita. Työssä kehitettiin uusi kirkkaiden heijastusten poistO'menetelmä, joka perustuu dikromaattiseen heijastus-malliin, joka kuvaa spektrisen datan objektin omaan väriin ja valaisevan valon väriin perustuen. Ehdotettu kirkkaiden heijastusten poistO'menetelmä hyödyntää erilaisia olemassaolevia menetelmiä, kuten pääkomponenttimenetelmää ja tiedon luokittelu-menetelmää. Yritys kehittää nopeasti toimiva algoritmi, joka myös suoriutuu tehtävästä hyvin, on onnistunut. Kokeet toteutettiin ehdotetun menetelmän mukaisesti ja toimivalla algoritmilla saatiin halutut lopputulokset. Edelleentyö sisältää ehdotuksia esitetyn algoritmin parantamiseksi.