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Sara B. Akkas Ayse O. Kepenek Meryem Beklioglu Feride Severcan 《Aquatic Sciences - Research Across Boundaries》2010,72(1):71-83
Diel vertical migration (DVM) bioassay-guided Fourier transform infrared spectroscopy can be a prominent non-destructive and
innovative approach for ecological studies. During the characterization of the nature of the fish-exuded kairomone, the peak
area results from the spectroscopic analysis of the control, fish-conditioned (F) and temperature incubated fish-conditioned
(IF) treatments of the DVM bioassays demonstrated that there was a strong correlation between the alterations of the amine
N–H, amide II, amide IV and CH3 asymmetric vibrations, suggesting that both N–H and CH3 molecules may be main components of the fish-exuded kairomone cocktail. The IF treatment, which showed similar results with
the control treatment, supported that the kairomone is inactivated by bacterial biodegradation. The seasonal variations in
the peak areas of the N–H and CH3 bands suggested that DVM response varied seasonally, where migration response developed quickly in warmer seasons. The peak
area of the amine N–H band of the F and IF treatments relative to control conditions can be used as an ideal indicator of
the absence or presence and the promptness of migration, at all seasons. 相似文献
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Fenton process was investigated for the purpose of biological sludge disintegration. The Box–Wilson experimental design was employed to evaluate the effects of major process variables (Fe(II) and H2O2 concentrations) on both disintegration and dewatering performance of sludge. Results showed that 4 g Fe(II)/kg total solids (TSs) and 60 g H2O2/kg TS are efficient for floc disintegration. Fenton pre‐treatment enhanced the biodegradability of sludge. For 4 g Fe(II)/kg TS and 60 g H2O2/kg TS, 19.4% higher methane production was achieved compared to raw sludge in biochemical methane potential assay. Fenton pre‐treatment resulted in the release of organic sludge components into the liquid phase. For 4 g Fe(II)/kg TS and 60 g H2O2/kg TS, dissolved organic carbon and total nitrogen in sludge's supernatant increased by 75.74 and 60.60%, respectively. Fenton pre‐treatment enhanced the filterability of sludge and it can be applied for conditioning purpose before mechanical dewatering units. 相似文献
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Abstract Reliable estimation of sensible heat flux (H) is important in energy balance models for quantifying evapotranspiration (ET). This study was conducted to evaluate the value of adding the Priestley-Taylor (PT) equation to the METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration) model. METRIC was used to estimate energy fluxes for 10 Landsat images from the 2005, 2006 and 2007 crop growing seasons in south-central Nebraska, USA, where each image owing to recent rainfall exhibited high residual moisture content even at the hot pixel. The METRIC model performed satisfactorily for net radiation (Rn ) and soil heat flux (G) estimation with a root mean square error (RMSE) of 52 and 24 W m-2, respectively. A RMSE of 122 W m-2 for H indicated the limitation of the METRIC model in estimating H for high residual moisture content of the hot pixel (Alfalfa reference ET fraction, ET r F > 0.15). The modified METRIC model (wet METRIC or wMETRIC) incorporating the PT equation was applied to calculate H at the anchor pixels (hot and cold) for high residual moisture content of the hot pixel. The α coefficient of the PT equation was locally calibrated using hourly meteorological data from an automatic weather station and Rn and G data from a Bowen ratio flux tower. The mean α coefficient value was 1.14. The wMETRIC model reduced the RMSE of H from 122 to 64 W m-2 and that of latent heat flux, LE, from 163 to 106 W m-2. The RMSE of daily ET decreased from 1.7 to 1.1 mm d-1 with wMETRIC. The results indicate that treatment of anchor pixels for high residual moisture content with the PT approach gives improved estimation of H, LE and daily ET. It is recommended that the wMETRIC model be used for estimating ET if the hot pixel has high residual moisture (i.e. reference ET fraction > 0.15). Citation Singh, R. K. & Irmak, A. (2011) Treatment of anchor pixels in the METRIC model for improved estimation of sensible and latent heat fluxes. Hydrol. Sci. J. 56(5), 895–906. 相似文献