Shu Rong Yu

Comparative Studies of Two Fenton-Like Catalysts: Fe2O3 and Fe2O3/Attapulgite

Fe2O3 and Fe2O3/attapulgite(ATP) catalyst was used for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Comparative studies indicated that Fe2O3/ATP-catalyzed Fenton system and Fe2O3-catalyzed Fenton system have the same catalysis capability. These two systems all have a widely pH range (2-10), and the catalysts can be reused and have no secondary pollutants. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction has much efficiency than Fe2O3-catalyzed Fenton reaction.

Fenton-Like Mineralization of Anion Surfactant by Fe2O3/Attapulgite Catalyst

Fe2O3/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade anion an surfactant, Sodium dodecyl benzene sulfonate(SDBS). Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing Fe2O3/ATP dosage and temperature. The SDBS degradation ratio will increase with increasing H2O2 concentration at some extent. But too high H2O2 concentration will make degradation efficiency decrease. The system maintains high efficiencies all experimental pH value(2-10).

Risk Analysis of Marine Riser Based on Improved Fuzzy AHP Method

Abstract: Many marine riser risk factors in service were analyzed and the riser risk factor hierarchical structure was modeled, the weight of each riser risk factor was evaluated by the improved fuzzy analytic hierarchy process (AHP) method. The simulation results and accident statistics from both home and abroad are in good agreement. It proves that the method has good practicability, more scientific, reasonable and simple than the traditional fuzzy AHP. The results provide theoretical reference for maintenance and management, danger elimination and reinforcement of marine riser.

The Rotor System Balance Design of Scroll Fluid Machinery

The rotor system balance design is always one of the main concerns in scroll fluid machinery dynamics, as it affects the scroll mechanical reliability, safety and life. According to the scroll fluid machinery working principle and structure, combined with the dynamic balance theory, four kinds of balance weight design philosophy were proposed in this paper and verified by a specific example, in which the bearding loads were calculated using four design methods and compared. The results show that the balance design philosophy will have a significant effect on fluid dynamic characteristics. The result is helpful for optimizing the rotor balance design of scroll fluid machinery and improving the mechanical properties.

Analysis of Orbiting Scroll Overturning for Scroll Compressor

Studies on leakage and friction have received considerable attention in scroll compressor, especially which between the fitting surface of orbiting scroll and fixed scroll, as they affect the scroll compressor performance. According to the scroll compressor working principle and structure, combined with the force model of the orbiting scroll, the overturning moment on the orbiting scroll was analyzed and verified by a specific example, in which the azimuth angle and of the overturning moment action line were calculated and compared. The results show that the overturning moment will have a significant effect not only on the leak and friction loss at the fitting surface of orbiting and fixed scroll, also on the dynamic characteristics of the orbiting scroll due to the linear change of the azimuth angle and the unstable of the azimuth angle . The result is helpful for the study on leakage, friction, and the dynamics and tribology coupling problem research of scroll compressor.

Free Vibration of Functionally Graded Material Beams in a Uniform Electric Field

Free vibration of thermal post-buckled functionally graded material (FGM) beams in a uniform electric field subjected to both temperature rise and voltage is studied. Voltage has a great influence on the deformation of the beam, and Thermo-electric post-buckling equilibrium paths and characteristic curves of the first three natural frequencies versus the temperature, the electricity and the material gradient parameters are plotted. It is found that the three lowest frequencies of the pre-buckled beam decrease with an increase in the temperature, but those of a buckled beam increase monotonically with the temperature rise. The results also show that the tensional force produced in the piezoelectric layers by the voltage can efficiently increase the critical buckling temperature and the natural frequency.

High Cycle Fatigue Properties of Duplex Stainless Steel in Air and 3.5% NaCl Solution

The high cycle fatigue of super duplex stainless steel of SAF 2507 was investigated by rotating bending fatigue test in both air and 3.5% NaCl environment. The results showed that there is no much reduction of the fatigue life in corrosive environment, which is 90% of the air fatigue strength. In air fatigue, failure happens in ductile mode with austenite grains having finer and straighter fatigue striations than ferrite grains. Width and spacing of striations vary with the orientation and locations when the second cracking occurs. It is not reliable to identify the phase by morphology of striations. In 3.5% NaCl environment, the fracture exhibits a mixed mode of cleavage and quasi-cleavage in ferrites and ductile in austenite grains.

SDBS Degradation by a Heterogeneous Fenton-Like Reaction on Three Types of Catalysts

Two kinds of attapulgite (ATP)-based catalysts (Fe (III)/ATP and Fe2O3/ATP) were prepared and their heterogeneous Fenton-like reactions were investigated for the degradation of Sodium dodecyl benzene sulfonate (SDBS) and contrast with that of Fe2O3 catalyst. Compared with the Fe2O3 catalyst, the two new ATP-based catalysts exhibited a higher activity and stability in SDBS mineralization. The effects of pH, H2O2 dosage, catalyst dosage and temperature were investigated. With incorporating ATP, the degradation ratio was more than that of Fe2O3 catalyst. And an enhancement of H2O2 utilization ratio was achieved.

Field Synergy Principle Base on Divergence Equation for Heat and Mass Transfer of Porous Media

According to field synergy principle, analyzes the relationship of the effect for heat transfer with mass transfer in porous media. Using the divergence equation, express the degree of gas phase velocity vector and temperature gradient velocity in the process of heat and mass transfer, and the field synergy angle θ play an important role in heat and mass transfer either global or partial. In the result, the heat and mass transfer would be constrained by each other while πθ>π/2, and be promoted whileπ/2>θ0, and be independency while θ=π/2. The divergence equation of field synergy principle present the method of strengthen the heat and mass transfer in porous media.

Characterization and Catalytic Activity of Fenton-Like Catalyst: Fe2O3/Attapulgite

Fe2O3/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. BET, SEM, FT-IR were performed to characterize Fe2O3/ ATP catalyst. Comparative studies indicated that the SDBS degradation ratios were much higher in presence of Fe2O3/ATP and H2O2 than those in presence of Fe2O3/ATP or H2O2 only, which suggested that the Fe2O3/ATP-catalyzed Fenton-like reaction governed the SDBS removal process. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former can be reused and has no secondary pollutants.