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Machinery can suffer from mechanical vibrations since resonance may be generated from time-varying external excitations under different operation conditions. These detrimental vibrations may significantly influence the device's performance, effectiveness and reliability in operation. In this paper, an innovative, simple and high-efficiency tuned vibration absorber (TVA) consisting of shape memory alloy (SMA) wires, which is referred to a wire-type tuned vibration absorber (WTVA), is proposed to reduce the induced vibration. Experiments are carried out using a six-degree-of-freedom platform which is designed to simulate the frame of precision machinery in practical applications. With the equivalent stiffness of SMA wires adjusted by the controlled electric current, the frequency tunability of WTVA can be achieved. When the natural frequency of WTVA tuned in with the disturbance frequency, the experimental results demonstrate that the efficiency in vibration reduction of the platform is drastically increased even with considerable weight difference between WTVA and the platform. Moreover, the tunable frequency span also increases greatly due to the new design of WTVA and the material characteristics of SMA wires.

The swine wastewater has the characteristics of high concentration of organic matter, suspended solids and more high ammonia nitrogen, odor, complex pollution ingredient and large emissions. Microbial fuel cells (MFC) is an electrochemical and biological systems related to chemical energy into electrical energy. A two-chambered cubic microbial fuel cell was used to evaluate the effect of a novel 3D electrode which made of iron and copper on the electricity generation. The swine wastewater containing total chemical oxygen demand (TCOD) 3300±300 mg/L was used as the feedstock in anode chamber, and the potassium ferricyanide was used as electron acceptor in cathode chamber. The MFC reactor was incubated with the initial pH 7.0 in a air-shaker with a temperature (ca. 35°C) and 100 rpm in fed-batch mode. A fixed external resistance (R) of 100 Ω was connected between the electrodes and the closed circuit potentials of the MFCs were recorded every 2 min. The results show that using iron 3D electrode has the peak electricity generation of 176 mV at the first two day and maintained the stable electricity voltage of 110 mV during the 5th to 15th days. The COD removal efficiency could reach 80%. Using copper 3D electrode only can generate the peak electricity of 33.1 mV and stable electricity of 27 mV with the COD removal efficiency of 70%.