Applied Mechanics and Materials Vols. 675-677

Abstract: The benthic animal community was examinesd in Danshui River of Dongjiang in November 2013. The river health evaluation system was established, a more comprehensive evaluation of Dongjiang water quality, for the reference in chemical pollutants control and administration.

Abstract: Pollution of urban river is a major risk to human health and water quality throughout the world. The purpose of this study was to determine the influence of ecological remediation process on sediment bacterial community structure. Three sediment samples in urban river located in Changzhou city, the bacterial community structure was studied in the process of ecological remediation period using denaturing gradient gel electrophoresis (DGGE). The results of the microbial community analysis were related to water environmental parameters through the analysis to investigate the relationship between potential impact of water quality and microbial community structure. As the ecological remediated river, T, DO and COD were the important environmental variables influencing the sediment microbial community composition. Microbial community changes determined by DGGE patterns showed that microbial community structures in the same period did not change further, while those in different period changed continuously. In July 2010, Pseudomonas sp, Escherichia sp, Exiguobacterium sp and Bacillus sp as each point jointly owned. In October 2010, Acinetobacter sp, Clostridiales, Dechloromonas sp and uncultured bacterium were belonged to these three sample sites.

Abstract: The mechanism governing activated sludge flocculation under Al³⁺ dosing was studied in this paper. Activated sludge was cultivated in sequencing batch reactors (SBR) at 22°C. Batch dosages of Al³⁺ were 0.00, 0.125, 0.5, 1 and 1.5meq/L respectively, and continuous dosage was 0.1meq/L. As batch dosage increased, the total interaction energy, zeta potential and turbidity tended to decline, which suggested that batch dosing promoted sludge flocculation. Under the equivalent dose, the zeta potential of continuous dosing was higher, while the LB-EPS content showed the opposite tendency and turbidity reduction was similar. Both batch and continuous dosing promoted flocculation performance: in terms of interaction energy, batch dosing was more effective; while in terms of EPS, it was on the contrary.

Abstract: Juvenile sole (Cymoglossus robustus) were exposed to BDE-47 and BDE-99 through feeding in the laboratory for 60 days, followed by 60 days of clean food, to examine bioaccumulation and potential thyroid hormone disruption effect. The results show that both BDE-47 and BDE-99 accumulate in fish tissues. The free tri-iodothyronine (T3) concentrations in the plasma of sole varied significantly throughout the experiment but were not related to PBDEs exposure. In contrast, plasma levels of thyroxine levels (T4) were lower in both groups of PBDE-exposed fish compared with control fish after 60 days of exposure, suggesting that PBDEs may influence thyroid homeostasis.

Abstract: An experimental method has been developed to determine the wettability, i.e., the contact angle, of a CO₂-reservoir brine-reservoir rock system at high pressures and high temperature using the axisymmetric drop shape analysis (ADSA) technique for the sessile drop case. The laboratory experiments were conducted for dynamic contact angle of CO₂-reservoir brine-reservoir rock covering three interesting salinities (0 mg/L, 14224.2 mg/L and 21460.6 mg/L) at P=6–35 MPa and T=97.5 °C. For pure water system, θ_ad (static advancing contact angel) increases from 71.69° to 107.1° as pressure of CO₂ increases from 6 MPa to 35 MPa. θad decreases from 71.48° to 42.01° for the 1# brine system and from 51.21° to 23.61° for the 2# brine system as pressure of CO₂ increases from 6 MPa to 35 MPa. θad for 2# brine system (21460.6 mg/L) is lower than that for 1# brine system (14224.2 mg/L) under the each same pressure.

Abstract: In this paper, the acute toxicity test were used to study the effects of different concentrations of suspended solids on the growth of Nitzschia closterium. The research result showed that the effects of different concentration of suspended solids on the growth of Nitzschia closterium were very significantly (P <0.01);The relationship between concentration of suspended solids and the inhibition rate of Nitzschia closterium growth were linear, the half inhibition concentration of Nitzschia closterium 48h-EC50 was 4.27g/L,r=0.9329, 96 h-EC50 was 4.47g/L,r = 0.9388.

Abstract: In this study, SD rats were used to establish an acetic acid-induced rat gastric ulcer model, and SOD and GSH-PX activities and MDA contents in rats with the gastric ulcer induced by acetic acid were measured. The results showed that smoking could delay the healing of gastric ulcer induced by acetic acid and aggravate the ulceration; compared with those in the model group, serum SOD, GSH-PX activities were significantly reduced, and MDA levels were significantly elevated, in rats with the gastric ulcer induced by acetic acid, suggesting that smoking may reduce the body's antioxidant capacity. The results indicate that smoking may induce or aggravate gastric ulcer by reducing the activity of serum SOD and GSH-PX, and elevating the content of serum MDA in rats with acetic acid-induced gastric ulcer, to affect the metabolism of oxygen free radicals to cause the oxidative damage.

Abstract: In this paper, an activator protein was isolated and identified from crude protein of Botrytis Spp which was separated from the soil of the wheat field with the method of mycelium recycling, breaking and centrifuging,etc. The activator protein appeared a single band on SDS-PAGE whose molecular weight was about 42kD. At the same time, it had a preliminary activity test and investigated on this activator protein. This study indicated that this activator protein is able to promote wheat germination after the deal with it, especially when the density is 3μg/mL, the seed germination is the best. So it is proved that the plant activator protein has really the biological function of improving the wheat germination.

Abstract: The objective of this study was to investigate the effect of H₂O₂/O₃ inactivating Giardia intestinali (G. intestinali) by the fluorescence staining method and vitro excystation. Results suggested that hydroxyl radicals (•OH) was the principal factor during the H₂O₂/O₃ process by testing the effect of t-butyl alcohol (TBA) and concentration change of H₂O₂. The inactivation rate achieved 99.6% when independent addition of O₃ under 1.5 mg·L^-1 with contact time about 10.0 min. While to achieve the same inactivation effect by H₂O₂/O_3, 1.0 mg·L^-1 O₃ ([H₂O₂]/[O₃] molar ratio = 0.8) with 7.0 min was required. The inactivating capability was stronger under acidic condition than in alkaline environment. The effect of turbidity was also found to be significant in synthetic water, when turbidity increasing, the inactivating effect declined. Inactivation rate was improved with a temperature increase from 5 to 35 °C. When dissolved organic matter concentration in the reaction system increased, the competitive reaction between G. intestinal and organics with H₂O₂/O₃ probably took place, thereby reducing the inactivation rate.

Abstract: The physico-chemical properties of iron plaques formed on the root surfaces of Cmarex cinerascens under laboratory conditions were determined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectrometry (EDS) analysis. Iron plaques were present as an amorphous coating on root surfaces with an uneven distribution. EDS analysis showed that iron plaques were composed of Fe , Si, Al and lesser amounts of Ca in plaqued root surfaces.