Narrow Results

The study examined the summertime behavior of phosphorus (P) and estimated P fluxes in the Inohana Lake Estuary, Shizuoka, Japan through a field observation conducted in the summer of 2007 and a box model approach. The sedimentation flux of P was significantly correlated with the overlying chlorophyll-a concentration. The box model provided a good estimate of the summer-averaged water flux. The P mass balance method yielded the release flux of P, which approximated the observed value. For the P exchange between the Inohana Lake Estuary and Hamana Bay, on the net flux, particulate P flows out into Hamana Bay through the upper layer, while dissolved P (phosphate P) flows into the Inohana Lake Estuary through the lower layer. For the P exchange between the upper and lower layers, the upward transport of P from the lower layer was more than 10 (~100) times greater than the downward transport of P. The results showed that P accumulates in the bottom sediment during the summer. This study indicates the possibility that the P input from Hamana Bay is dominant over the river P input in summer season with significant density stratification.

The gravity recovery and climate experiment (GRACE) satellite mission has been providing near-continuous measurements of Earth's mass variations at regional spatial scales since early 2003, with applications to hydrologic, oceanographic, and cryospheric research. Motivated by recent regional land ice solutions, we analyze an array of simulated GRACE-like signals and seek optimal procedures to denoise the time series and accurately determine the seasonal timing and the corresponding seasonal and net mass balances. For the purpose of signal denoising we consider Gaussian smoothing, wavelet thresholding, the ensemble empirical mode decomposition (EEMD), the complete EEMD with adaptive noise (CEEMDAN), and a Wiener filter. We achieve the best denoising performance with a Wiener filter where the signal and noise spectra are estimated with Gaussian smoothing and the highest frequency wavelet coefficients, respectively. For the purpose of estimating seasonal timing we consider wavelet multiresolution analysis, EEMD, CEEMDAN, and a new cluster analysis of the ensemble of seasonal intrinsic mode functions that result from executing the EEMD and CEEMDAN. We select CEEMDAN cluster analysis as the best approach due to its consistent performance and ability to provide reliable uncertainties. Lastly, we investigate the effect of signal noise, high-frequency signal power, and data gaps, on the accuracy of the estimated parameters.

Specifying and reducing the uncertainty is very important to all kinds of measurements. In order to have a better understanding of the noise mechanism responsible for lowering the quality of mass/force measurements, the Allan variation method is applied to investigate the noise performance of a commercial ultra-microbalance installed on different noise reduction platforms. It turns out that the marble table provides a better noise isolation environment for mass measurements than an optical table. The optimal integration time is found to be 100 sec ~ 200 sec, with a lowest deviation of 0.07 μg. A different data treatment simulating the ABA load/unload cycle is also applied with or without a delay time for signal integration. The consistency between Allan deviation and the ABA simulation plots points out that the optimal integration time is applicable either in single or cyclic mass measurements.

The aim of this study is to investigate the concentration of solid particles inside the furnace. Starting from the material circulating system and distribution of concentration of solid particles in CFBB, the model of material circulating system was established. Finally, the system was simulated in Matlab. Through analysis of the simulation results: along the direction of the furnace, the concentration of solid particles inside the furnace shows in the distribution of ‘the upper part is dilute and the under part is concentrated’. Moreover, in the dense phase zone, the concentration of solid particles decreases rapidly. But in the transition zone and dilute phase zone, it decreases slowly and tends to be stable at the exit of the furnace.