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Rheology measurement, a state-of-the-art technology in a multitude of engineering disciplines, has often been used for computational fluid dynamic simulation of wastewater treatment processes, especially in anaerobic digestion and dewatering. In this work, rheological tests were used to study the semi-solid characteristics of sludge and a good result was obtained. The inorganic coagulants polyaluminum chloride (PAC) and ferric chloride (FC) both increased the floc strength of sludge, leading to higher rheology parameters such as elastic modulus, viscous modulus and specific thixotropy area. Curiously, the shape of all rheological curves exhibited little change with increasing coagulant dosage. The results indicated that various physical and chemical actions among coagulants and sludge flocs relate only to rigid structure, not to the nature of rheology behavior. Frequency sweep tests clearly showed that elastic modulus was a logarithmic function of frequency, suggesting that sludge could not properly be called a soft material due to its inorganic particles. An improved viscoelastic model was successfully developed to predict the experimental data of creep and recovery tests in the linear viscoelastic region. Furthermore, complicated viscoelastic behavior of sludge was also observed, and all the rheology tests could provide the optimum dosage of PAC but not the optimum dosage of FC.

Monitoring method for dynamical stress of centrifugal blower vane based on Fiber Bragg Grating (FBG) sensing technique is presented in this paper. Consisting of FBG sensors, FBG interrogator and fiber optic rotary joint, this monitoring system has bare FBG as strain sensor, monitors stresses at the inlet and outlet of the centrifugal blower. Details about stick up method of FBG sensors are shown in this paper, either. In addition, this method has been applied to experimental model of centrifugal blower, and it was found that: stress at the outlet of the air vane is more than that at the inlet; within the working range, stress of air vane increases in company with increment of rotating speed, though it is not linear relation between them.

As Oil & Gas Pipeline of Long Distance has potential mechanical risks caused by geologic hazards, based on sensing technique, Fiber Bragg Grating (FBG) strain sensor, for which unstressed grating temperature compensation method is adopted, is designed to solve problems of FBG temperature and strain cross sensitivity. According to experimental tests, strain sensitive coefficients of the sensor before and after sticking on pipeline sample are 1.20 pm/με and 1.09 pm/με in separate. Finally, applied to a landslide area for monitoring pipeline stress, the sensor got the impact of Wenchuan Earthquake on May 12, 2008 on the pipeline.

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