ALBERT

Description: Evapotranspiration (ET) is an essential part of the hydrological cycle and accurately estimating it plays a crucial role in water resource management. Surface energy balance (SEB) models are widely used to estimate regional ET with remote sensing. The presence of horizontal advection, however, perturbs the surface energy balance system and contributes to the uncertainty of energy influxes. Thus, it is vital to consider horizontal advection when applying SEB models to estimate ET. This study proposes an innovative and simplified approach, the surface energy balance-advection (SEB-A) method, which is based on the energy balance theory and also takes into account the horizontal advection to determine ET by remote sensing. The SEB-A method considers that the actual ET consists of two parts: the local ET that is regulated by the energy balance system and the exotic ET that arises from horizontal advection. To evaluate the SEB-A method, it was applied to the middle region of the Heihe River in China. Instantaneous ET for three days were acquired and assessed with ET measurements from eddy covariance (EC) systems. The results demonstrated that the ET estimates had a high accuracy, with a correlation coefficient (R2) of 0.713, a mean average error (MAE) of 39.3 W/m2 and a root mean square error (RMSE) of 54.6 W/m2 between the estimates and corresponding measurements. Percent error was calculated to more rigorously assess the accuracy of these estimates, and it ranged from 0% to 35%, with over 80% of the locations within a 20% error. To better understand the SEB-A method, the relationship between the ET estimates and land use types was analyzed, and the results indicated that the ET estimates had spatial distributions that correlated with vegetation patterns and could well demonstrate the ET differences caused by different land use types. The sensitivity analysis suggested that the SEB-A method requested accurate estimation of the available energy, R n − G , but was less constrained with the difference between ground and air temperature, T 0 − T a – l o c .

Description: Although there have been numerous studies examining the toxicity and carcinogenicity of nickel compounds in humans and animals, its molecular mechanisms of action are not fully elucidated. In our research, NIH/3T3 cells were exposed to nickel-refining fumes at the concentrations of 0, 6.25, 12.50, 25, 50 and 100 μg/mL for 24 h. Cell viability, cell apoptosis, reactive oxygen species (ROS) level, lactate dehydrogenase (LDH) assay, the level of glutathione (GSH), activities of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) level were detected. The exposure of NIH/3T3 cells to nickel-refining fumes significantly reduced cell viability and induced cell apoptotic death in a dose-dependent manner. Nickel-refining fumes significantly increased ROS levels and induced DNA damage. Nickel-refining fumes may induce the changes in the state of ROS, which may eventually initiate oxidative stress, DNA damage and apoptosis of NIH/3T3 cells.

Description: A novel staged leaching process has been reported in this paper to selectively extract vanadium from roasted stone coal and the mechanisms have been clarified. Results showed that the leaching efficiency of V, Al, P and Fe was 80.46%, 12.24%, 0.67% and 3.12%, respectively, under the optimum dilute sulfuric acid dephosphorization (DSAD)-two-stage pressure acid leaching (PAL) conditions. The efficient separation of V from Fe, Al and P was realized. As apatite could be leached more easily than mica, the apatite could completely react with sulfuric acid, while the mica had almost no change in the DSAD process, which was the key aspect in realizing the effective separation of V from P. Similarly, the hydrolyzation of Fe and Al could be initiated more easily than that of V by decreasing the residual acid of leachate. The alunite and iron-sulphate compound generated in the first-stage PAL process resulted in the effective separation of V from Fe and Al.

Description: In this study, a miniaturized high fundamental frequency quartz crystal microbalance (QCM) is fabricated for sensor applications using a wet etching technique. The vibration area is reduced in the fabrication of the high frequency QCM with an inverted mesa structure. To reduce the complexity of the side wall profile that results from anisotropic quartz etching, a rectangular vibration area is used instead of the conventional circular structure. QCMs with high Q values exceeding 25,000 at 47 MHz, 27,000 at 60 MHz, 24,000 at 73 MHz and 25,000 at 84 MHz are fabricated on 4 × 4 mm2 chips with small vibration areas of 1.2 × 1.4 mm2. A PMMA-based flow cell is designed and manufactured to characterize the behavior of the fabricated QCM chip in a liquid. Q values as high as 1,006 at 47 MHz, 904 at 62 MHz, 867 at 71 MHz and 747 at 84 MHz are obtained when one side of the chip is exposed to pure water. These results show that fabricated QCM chips can be used for bio- and chemical sensor applications in liquids.

Description: Most biochemical processes and associated water quality in lakes depends on their flushing abilities. The main objective of this study was to investigate the transport time scale in a large floodplain lake, Poyang Lake (China). A 2D hydrodynamic model (MIKE 21) was combined with dye tracer simulations to determine residence and travel times of the lake for various water level variation periods. The results indicate that Poyang Lake exhibits strong but spatially heterogeneous residence times that vary with its highly seasonal water level dynamics. Generally, the average residence times are less than 10 days along the lake’s main flow channels due to the prevailing northward flow pattern; whereas approximately 30 days were estimated during high water level conditions in the summer. The local topographically controlled flow patterns substantially increase the residence time in some bays with high spatial values of six months to one year during all water level variation periods. Depending on changes in the water level regime, the travel times from the pollution sources to the lake outlet during the high and falling water level periods (up to 32 days) are four times greater than those under the rising and low water level periods (approximately seven days).

Description: The effects of aflatoxin B1 (AFB1) exposure and sodium selenite supplementation on cell apoptosis of jejunum in broilers were studied. A total of 240 one-day-old male AA broilers were randomly assigned four dietary treatments containing 0 mg/kg of AFB1 (control), 0.3 mg/kg AFB1 (AFB1), 0.4 mg/kg supplement Se (+ Se) and 0.3 mg/kg AFB1 + 0.4 mg/kg supplement Se (AFB1 + Se), respectively. Compared with the control broilers, the number of apoptotic cells, the expression of Bax and Caspase-3 mRNA were significantly increased, while the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio were significantly decreased in AFB1 broilers. The number of apoptotic cells and the expression of Caspase-3 mRNA in AFB1 + Se broilers were significantly higher than those in the control broilers, but significantly lower than those in AFB1 broilers. There were no significant changes in the expression of Bax mRNA between AFB1 + Se and control broilers; the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio in AFB1 + Se broilers were significantly lower than those in the control broilers, but significantly higher than those in AFB1 broilers. In conclusion, 0.3 mg/kg AFB1 in the diet can increase cell apoptosis, decrease Bcl-2 mRNA expression, and increase of Bax and Caspase-3 mRNA expression in broiler’s jejunum. However, supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se may ameliorate AFB1-induced apoptosis by increasing Bcl-2 mRNA expression, and decreasing Bax and Caspase-3 mRNA expression.

Description: Photonic bandgap fiber optic gyroscope (PBFOG) is a novel fiber optic gyroscope (FOG) with excellent environment adaptability performance compared to a conventional FOG. In this work we find and investigate the backward secondary-wave coherence (BSC) error, which is a bias error unique to the PBFOG and caused by the interference between back-reflection-induced and backscatter-induced secondary waves. Our theoretical and experimental results show a maximum BSC error of ~4.7°/h for a 300-m PBF coil with a diameter of 10 cm. The BSC error is an important error source contributing to bias instability in the PBFOG and has to be addressed before practical applications of the PBFOG can be implemented.

Description: Changes in ecological vulnerability were analyzed for Northern Shaanxi, China using a geographic information system (GIS). An evaluation model was developed using a spatial principal component analysis (SPCA) model containing land use, soil erosion, topography, climate, vegetation and social economy variables. Using this model, an ecological vulnerability index was computed for the research region. Using natural breaks classification (NBC), the evaluation results were divided into five types: potential, slight, light, medium and heavy. The results indicate that there is greater than average optimism about the conditions of the study region, and the ecological vulnerability index (EVI) of the southern eight counties is lower than that of the northern twelve counties. From 1997 to 2011, the ecological vulnerability index gradually decreased, which means that environmental security was gradually enhanced, although there are still some places that have gradually deteriorated over the past 15 years. In the study area, government and economic factors and precipitation are the main reasons for the changes in ecological vulnerability.

Description: UV/H2O2, which is an advanced treatment technology used to reduce multiple contaminants, is effective in potable water treatment. Simultaneous degradation effects and kinetics of three types of coexisting micropollutant estrogens (steroid estrogens, SEs), including estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2), in deionized water were studied. Experiments were carried out with ultraviolet-C (UVC) radiation, together with hydrogen peroxide (H2O2), in a cylinder photoreactor. The results demonstrated that the degradation processes of all of the estrogens strongly fit first-order kinetics. Single solutions of E1, E2 and EE2 showed higher degradation rates and removal efficiencies under the same reaction conditions compared with those under mixed conditions. Coexisting combinations of estrogens were put into the UV/H2O2 system to estimate their possible competitive influences on each other by examining their removal efficiencies and reaction rate constant, k, values. E1 is predominantly reduced rapidly during the competition, while the presence of other estrogens has negligible impacts on E1; however, the degradation of E2 and EE2 is affected by the competitive background, not in relation to the types but to the existing amounts. In the UV/H2O2 system, photocatalysis of the estrogens can stably produce an intermediate X, with the highest quantity coming from E1, while considerably lower quantities are obtained from E2 and EE2.

Description: This paper deals with a current sensor fault reconstruction algorithm for the torque closed-loop drive system of an interior PMSM. First, sensor faults are equated to actuator ones by a new introduced state variable. Then, in αβ coordinates, based on the motor model with active flux linkage, a current observer is constructed with a specific sliding mode equivalent control methodology to eliminate the effects of unknown disturbances, and the phase current sensor faults are reconstructed by means of an adaptive method. Finally, an αβ axis current fault processing module is designed based on the reconstructed value. The feasibility and effectiveness of the proposed method are verified by simulation and experimental tests on the RT-LAB platform.