966 resultados para Soil-block test


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This paper describes a practical approach for the investigation, assessment and design of existing soakaways. This method can be utilised for measuring the performance and capacity of the systems and examining whether the systems are suitable for reuse when information about the design and installation of the systems is not available. The requirements for field observations and the procedure for a soil infiltration test for the installed system are suggested for successful assessment. The soil infiltration rate of the system is estimated from the field test data without requiring information on the design and construction details of the system. The system's working condition is measured by a performance indicator related to the time taken to empty the soakaway. This is then employed to evaluate the potential reuse of the system. The system's drain capacity is determined by the design principles of current practice and the effect of climate change on its drain capacity is considered. Contamination of soils around the systems after long-term use of discharge service and the water present in soakaway chambers are also investigated. A detailed case study for the reuse of four installed soakaways for a new housing development demonstrates how the proposed approach provides a straightforward process for the infiltration performance and drain capacity assessment of the existing systems. The effectiveness and applicability of the proposed approach are further demonstrated from the assessments for a number of installed systems over various sites

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Various compositions of linear low density polyethylene(LLDPE) containing bio-filler(either starch or dextrin)of various particle sizes were prepared.The mechanical,thermal,FTIR,morphological(SEM),water absorption and melt flow(MFI) studies were carried out.Biodegradability of the compositions were determined using a shake culture flask containing amylase producing bacteria(vibrios),which were isolated from marine benthic environment and by soil burial test. The effect of low quantities of metal oxides and metal stearate as pro-oxidants in LLDPE and in the LLDPE-biofiller compositions was established by exposing the samples to ultraviolet light.The combination of bio-filler and a pro-oxidant improves the degradation of linear low density polyethylene.The maleation of LLDPE improves the compatibility of the c blend components and thepro-oxidants enhance the photodegradability of the compatibilised blends.The responsibility studies on the partially biodegradable LLDPE containing bio-fillers and pro-oxidants suggest that the blends could be repeatedly reprocessed without deterioration in mechanical properties.

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Low-density polyethylene, (LDPE) was mixed with two grades of tapioca starch–lowgrade and high-grade. Various compositions were prepared and mechanical and thermal studies performed. The biodegradability of these samples was checked using a culture medium containing Vibrios (an amylase-producing bacteria), which was isolated from a marine benthic environment. The soil burial test and reprocessability of these samples were checked. The studies on biodegradability show that these blends are partially biodegradable. These low-density polyethylene-starch blends are reprocessable without sacrificing much of their mechanical properties

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Low-density polyethylene was mixed with dextrin having different particle sizes (100, 200 and 300 mesh). Various compositions were prepared and their mechanical properties were evaluated and thermal studies have been carried out. Biodegradability of these samples has been checked using liquid culture medium containing Vibrios (an amylase producing bacteria), which were isolated from marine benthic environment. Soil burial test was done and reprocessability of these samples was evaluated. The results indicate that the newly prepared blends are reprocessable without sacrificing much of their mechanical properties. The biodegradability tests on these blends indicate that these are partially biodegradable

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The irrigation scheduling is basically the adoption of pre-established criteria to define the time and the amount of water to be applied through irrigation systems. Hence, the objective of this work was to develop and test a spreadsheet of easy comprehension, handling and interpretation by growers, which uses as inputs the physical-hydric soil attributes and tensiometer readings to the determination of irrigation depth and time. The spreadsheet enables the grower to make reading and to know in a fast way how much water to apply into the soil. The test of the spreadsheet was performed in an irrigated orchard of grapevines in Petrolina, State of Pernambuco, Brazil. Soil water retention curves and tensiometer readings from the effective rooting depth were used as a basis for obtaining the soil water matric potential, soil water content, water availability, soil water content to be replaced, net and gross irrigation depth and irrigation time. The analysis of the use of the irrigation scheduling spreadsheet resulted in a shorter time for irrigation in relation to the irrigation scheduling based only on the crop evapotranspiration. The spreadsheet can be helpful to growers adjust irrigation depth when irrigation scheduling is based only on crop evapotranspiration.

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This paper presents the first results of a system to carry out seismic SPT, which associates the up-hole seismic technique to the currently used SPT test. This hybrid test allows determining the maximum shear modulus (G 0) together with the SPT test. G 0 is the most important dynamic soil parameter and it is calculated based on the shear wave velocity (V S) measurements. The equipment and the method of analysis will be briefly described. The V s values measured using the S-SPT in one experimental research site located inland of Sao Paulo State-Brazil are presented and compared with down-hole and Seismic CPT test data. These preliminary results indicate that the S-SPT was satisfactory and can be used for dynamic site characterization.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Pós-graduação em Ciência Florestal - FCA

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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STUDY OBJECTIVE: Cyclic Alternating Pattern (CAP) is a fluctuation of the arousal level during NREM sleep and consists of the alternation between two phases: phase A (divided into three subtypes A1, A2, and A3) and phase B. A1 is thought to be generated by the frontal cortex and is characterized by the presence of K complexes or delta bursts; additionally, CAP A1 seems to have a role in the involvement of sleep slow wave activity in cognitive processing. Our hypothesis was that an overall CAP rate would have a negative influence on cognitive performance due to excessive fluctuation of the arousal level during NREM sleep. However, we also predicted that CAP A1 would be positively correlated with cognitive functions, especially those related to frontal lobe functioning. For this reason, the objective of our study was to correlate objective sleep parameters with cognitive behavioral measures in normal healthy adults. METHODS: 8 subjects (4 males; 4 females; mean age 27.75 years, range 2334) were recruited for this study. Two nocturnal polysomnography (night 2 and 3 = N2 and N3) were carried out after a night of adaptation. A series of neuropsychological tests were performed by the subjects in the morning and afternoon of the second day (D2am; D2pm) and in the morning of the third day (D3am). Raw scores from the neuropsychological tests were used as dependent variables in the statistical analysis of the results. RESULTS: We computed a series of partial correlations between sleep microstructure parameters (CAP, A1, A2 and A3 rate) and a number of indices of cognitive functioning. CAP rate was positively correlated with visuospatial working memory (Corsi block test), Trial Making Test Part A (planning and motor sequencing) and the retention of words from the Hopkins Verbal Learning Test (HVLT). Conversely, CAP was negatively correlated with visuospatial fluency (Ruff Figure Fluency Test). CAP A1 were correlated with many of the tests of neuropsychological functioning, such as verbal fluency (as measured by the COWAT), working memory (as measured by the Digit Span – Backward test), and both delay recall and retention of the words from the HVLT. The same parameters were found to be negatively correlated with CAP A2 subtypes. CAP 3 were negatively correlated with the Trial Making Test Parts A and B. DISCUSSION: To our knowledge this is the first study indicating a role of CAP A1 and A2 on behavioral cognitive performance of healthy adults. The results suggest that high rate of CAP A1 might be related to an improvement whereas high rate of CAP A2 to a decline of cognitive functions. Further studies need to be done to better determine the role of the overall CAP rate and CAP A3 on cognitive behavioral performances.