Silty Soils
Mostrando 13-23 de 23 artigos, teses e dissertações.
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13. Análise paramétrica da infiltração e sua influência na estabilidade de taludes em solo não saturado / Parametric analysis of infiltration and its influence on unsaturated soil slope stability
A parametric study is presented about water infiltration and its repercussion in the safety factor of unsaturated soil slopes. In the analysis it is adopted a reference slope with determined geometry according to the typical inclination for slopes in silty clayey sand, characteristic of the mid-western region of São Paulo State, in Brazil. The parametric an
Publicado em: 2004
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14. Análise da potencialidade de alguns solos não lateríticos para utilização em barreiras impermeáveis / Analysis of the potential use of non lateritic soils in hydraulic barriers
It is presented an evaluation of the potential of certain non-lateric soils, compacted, for lining system use, based on their hydraulic conductivity and axial shrinkages. Ten different types of soils were analyzed; six of them were classified as non-lateric clayey (NG) and the other four as non-lateric silty (NS), according to the classification system MCT.
Publicado em: 2003
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15. Transport of Cryptosporidium parvum Oocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency
Vegetated buffer strips were evaluated for their ability to remove waterborne Cryptosporidium parvum from surface and shallow subsurface flow during simulated rainfall rates of 15 or 40 mm/h for 4 h. Log10 reductions for spiked C. parvum oocysts ranged from 1.0 to 3.1 per m of vegetated buffer, with buffers set at 5 to 20% slope, 85 to 99% fescue cover, soil
American Society for Microbiology.
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16. Use of polymerase chain reaction and electroporation of Escherichia coli to monitor the persistence of extracellular plasmid DNA introduced into natural soils.
A modified protocol for DNA amplification by polymerase chain reaction (PCR) coupled with laser densitometric determination of the amount of PCR products, which allowed quantitation of target sequence numbers in soil extracts, was developed. The method was applied to monitor target loss during incubation of purified plasmid DNA in natural nonsterile soils. I
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17. Persistence of Free Plasmid DNA in Soil Monitored by Various Methods, Including a Transformation Assay
The persistence and stability of free plasmid pUC8-ISP DNA introduced into 10-g samples of various soils and kept at 23°C were monitored over a period of 60 days. The soils were sampled at a plant science farm and included a loamy sand soil (no. 1), a clay soil (no. 2), and a silty clay soil (no. 3). Four different methods allowed monitoring of (i) the prod
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18. Escherichia coli Contamination of Vegetables Grown in Soils Fertilized with Noncomposted Bovine Manure: Garden-Scale Studies
In this study we tested the validity of the National Organic Program (NOP) requirement for a ≥120-day interval between application of noncomposted manure and harvesting of vegetables grown in manure-fertilized soil. Noncomposted bovine manure was applied to 9.3-m2 plots at three Wisconsin sites (loamy sand, silt loam, and silty clay loam) prior to spring a
American Society for Microbiology.
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19. Environmental Factors Influencing Numbers of Rhizobium leguminosarum biovar trifolii and Its Bacteriophages in Two Field Soils
Fluctuations in numbers of Rhizobium leguminosarum biovar trifolii and its bacteriophages in two fields with different soil types were followed during a 17-month period in 1981 and 1982. Mean levels of both phage and rhizobia varied significantly (P < 0.05) on different occasions, with rhizobial levels varying from 1.6 × 102 to 2.0 × 104 cell per g of soil
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20. Virus and Bacteria Removal from Wastewater by Rapid Infiltration Through Soil
A rapid infiltration land wastewater application site, composed of unconsolidated silty sand and gravel, which has been in continuous operation for over 30 years was examined for the accumulation and/or migration of a tracer virus (coliphage f2), indigenous enteroviruses, and enteric indicator bacteria in the soils and underlying groundwater. Tracer f2 penet
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21. Method for Detection and Enumeration of Cryptosporidium parvum Oocysts in Feces, Manures, and Soils
Eight concentration and purification methods were evaluated to determine percentages of recovery of Cryptosporidium parvum oocysts from calf feces. The NaCl flotation method generally resulted in the highest percentages of recovery. Based on the percentages of recovery, the amounts of fecal debris in the final oocyst preparations, the relatively short proces
American Society for Microbiology.
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22. Salmonella enterica Serovar Typhimurium and Escherichia coli Contamination of Root and Leaf Vegetables Grown in Soils with Incorporated Bovine Manure
Bovine manure, with or without added Salmonella enterica serovar Typhimurium (three strains), was incorporated into silty clay loam (SCL) and loamy sand (LS) soil beds (53- by 114-cm surface area, 17.5 cm deep) and maintained in two controlled-environment chambers. The S. enterica serovar Typhimurium inoculum was 4 to 5 log CFU/g in manure-fertilized soil. T
American Society for Microbiology.
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23. Serological and Ecological Characteristics of a Nodule-Dominant Serotype from an Indigenous Soil Population of Rhizobium leguminosarum bv. trifolii †
Although at least 13 antigenically distinct serotypes of Rhizobium leguminosarum bv. trifolii exist in an Abiqua silty clay loam soil, one serotype, AS6, occupies ≥50% of the root nodules formed on field-grown subclover and between 33 and 78% of the nodules formed on five annual clover species grown in the same soil under laboratory conditions. The dominan