Advanced Materials Research Vols. 875-877

Abstract: Tunable bandpass filters are generally preferred and are used extensively in the mobile communication systems. In this paper, a design of the RF MEMS tunable combline bandpass filter is proposed. Firstly, the theory of the RF MEMS tunable combline bandpass filter is presented. Secondly, a combline bandpass filter which have a tunable frequency range from 18GHz to 27GHz is designed and simulated by using the EDA simulation software. Its bandwidth is about 1GHz in the tunable frequency range. From the simulation results, the designed filter is not only compact and effortless to fabricate but also relatively superior in some aspects.

Abstract: Members of Paramecium species are often referred to as “swimming neurons or sensory cells” applicable to micro-biorobotics or BioMEMS (biological micro-electro-mechanical systems). Paramecium bursaria known as green paramecia is an unicellular organism that lives widely in fresh water environments such as rivers and ponds. Recent studies have suggested that in vivo cellular robotics using the living cells of green paramecia as micro-machines controllable under electrical, optical and magnetic signals, has a variety of engineering applications such as transportation of micro-sized particles (ingested within the cells) in the capillary systems. In the present study, we aimed to test if the swimming environment of green paramecia can be implementable on microchips. For this purpose, the series of microchips were prepared for cellular swimming platform for green paramecia through fabrication of poly(methyl methacrylate) master plates using the programmable micro-milling system followed by polydimethylsiloxane-based micro-casting. Finally, microchips equipped with optimally sized micro-flow channels for allowing the single cell traffic by swimming green paramecia were successfully prepared, and thus further studies for application of green paramecium cells in BioMEMS are encouraged.

Abstract: Paramecium bursaria is an unicellular organism that lives widely in fresh water environments such as rivers and ponds. Recent studies have suggested that in vivo cellular robotics using the cells of P. bursaria as micro-machines controllable under electrical and optical stimuli, has a variety of engineering applications such as transport of micro-sized particles in the capillary systems. The present study aimed to test if the swimming cells of P. bursaria, implementable in capillaries or on chips, are applicable for detection of metal ions. For model assays, rare earth elements (REEs) were chosen as target chemicals. In P. bursaria, LC₅₀ values for REE ions ranged between 2.0 and 62.7 µM. Among them, Sc was shown to be most toxic. In addition to the lethal impacts of REE ions, most of REE ions at sub-lethal concentrations at around 10 - 30 µM, showed inhibitory action against the motility of the cells during the electrically forced motility known as galvanotaxisis. In conclusion, in the non-lethal ranges of REE concentration, swimming cells of P. bursaria report the presence of REE ions, by lowering the motility.

Abstract: A CMOS compatible absolute pressure sensor with extend floating gate is developed with simple circuitry to realize high sensitivity, linearity, and manufacturability. The pressure sensitive membrane formation is based on the standard CMOS process with simple metal sacrificial layer removal step, which is very cost-efficient and fully CMOS compatible, enabling monolithic integration of circuitry. ANSYS and SPICE simulation results show that the proposed sensor can worked properly under 500K Pa, and the square sensing membrane of 100x100 μm ² shows a good linearity over a pressure change ranging from 5 Pa to 500K Pa.

Abstract: In many spheres of human activities devices that work on increased frequency current are widely applied. 50 Hz current can be converted into increased frequency (100-400 Hz) current using synchronous reactive converters, which are based on exude and usage of higher harmonics.

Abstract: A new type of gas-gas jet pump was designed. According to the special structure of the jet pump, the jetting performance of different nozzle structure and the distance between the throat and the nozzle was numerically analyzed based on the Fluent and the standard turbulent model, and the effect of different nozzle geometrical parameters and the distance between the throat and the nozzle was investigated. The optimum nozzle structure and the distance between the throat and the nozzle were obtained according to the driving fluid mass flow quantity (the suction quantity). The results showed that the optimum parameters of the jet pump were as follows: flare mouth diameter was 400mm, the nozzle outlet diameter was 25mm, the optimum distance between the throat and the nozzle was 60mm.

Abstract: This paper presents a software tool developed for aiding the identification process of dynamic systems. This first version of the tool allows the user to generate excitation signals that are suitable for each kind of plant and also to automatically treat the raw process data in order to identify different types of models, which may include multiple-input and multiple-output (MIMO) and nonlinear behaviors. The potential of the tool is illustrated by performing the identification process of an industrial test stand for the energetic performance evaluation of refrigerant compressors. The results compare linear and nonlinear models for the process around an operating point and show that the proposed tool provides good results even for this nontrivial MIMO process, which presents dead times and other nonlinearities.

Abstract: The floor heave is one of the key issues of surrounding rock stability control during the deep well mining process. To solve the problem about floor heave occupying the most of roof and floor convergence deformation, the author analyzed the engineering geological conditions of broken surrounding rock and the floor heave features in PanEr Coal Mine East 2 mining area when it through the fault zone with high pressure. It pointed out that we should make full use of the reinforcement of the roof and laneway's side to limit the deformation of the floor, and make use of overbreak, prestressed anchor cable, bottom corner bolt, deep hole grouting and backfill as direct bottom control countermeasures.

Abstract: At the beginning of 21st century, with the growth of architecture and construction industry, many countries are having a great boom in crane industry. Still, there are some crane accidents, which usually cause startling devastation. As the rapid development of modern science and technology, especially dramatic improvement in internet, domestic and foreign scientists have taken advantages of advanced technology to exploit the safety monitoring system of tower cranes. Although the tower and tower arm are crucial targets of the safety monitoring system of tower cranes, the fact is that few scientists concentrating on the internal stress and strain in tower crane when it has been loaded. Hence, it is necessary to introduce some latest developments of the safety monitoring system of tower cranes in this text, presenting some existed problems and an advanced safety monitoring system basing on infrasonic emission technology.

Abstract: Optimum design of an automotive part under random loading must satisfy two principal conditions: a safe fatigue life and a natural frequency far from the road power spectral density spectrum. Dynamic behaviour of the upper arm suspension was modelled solving the equation of motion. The quasi-static analysis was used in this study as it is highly efficient when the frequency of excitation is below the resonance frequency. The fatigue life was calculated from the multiaxial criterion equivalent to the uniaxial one based on Strain Energy Density. Finally, the critical elements were detected using a Matlab interface developed in previews work.