Debris Flow Monitoring System and Observed Event in Taiwan:A Case Study at Aiyuzi River

Since 2002, the Soil and Water Conservation Bureau, which is responsible for the conservation and administrative management of hillside in Taiwan, has been cooperating with Feng Chia University. Together, they have successfully carried out the establishment and maintenance of 13 fixed debris flow monitoring stations over the island and 2 mobile debris flow monitoring stations. During July 2004, a powerful southwest air current brought by Mindulle Typhoon caused serious flood in central and southern Taiwan. This paper aims to describe the establishment of debris flow monitoring systems in Taiwan and the observation of the debris flow event during Mindulle Typhoon at Aiyuzi River in Shenmu Village, Nantou County by the monitoring station.

Long-period Gratings in-situ Sensing for Flow Monitoring in Liquid Composite Molding

Liquid composite moulding (LCM) processes are used to manufacture high quality and complex-shaped composite parts in the automotive, marine, aerospace and civil industries. On-line sensing plays an important role in controlling the quality of the final product in the LCM manufacturing environment. The long-period fiber grating (LPG) technology, a new real-time fiber optic sensor system, was developed to monitor the flow front progression. The sensor operation and characterization under various process conditions were discussed in detail. The experimental results showed that LPG sensors were robust and reliable to detect the arrival of resin at pre-selected locations in structures with low-medium fiber volume fraction; however were limited at different depths in structures with high fiber volume fraction.

Hydrogel-Assisted Electrokinetics for High-Resolution and Non-invasive Flow Monitoring in Microfluidic Chips

Convenient non-invasive flow monitoring would facilitate the operation and control in microfluidic chips,but is challenging due to the small space of microchannels and complex operation required in traditional optical methods.In this work,we propose a novel non-invasive strategy to probe microfluidic flows via streaming potential phenomenon.By sealing one side of the microchannel with a piece of hydrogel film,streaming potential inside the channel can be clearly detected by electrodes at outer surface of the hydrogel due to ion diffusion in the hydrogel.Flow is detected without sensors contacting with the internal liquid.Moreover,the electrodes shape like a tiny probe,which can move around mapping the flow distribution in a chip with the spatial resolution of 1 mm and flow rate detection limit of 3μL·min–1.Bubbles inside the channels can also be detected,due to the fluctuation of streaming voltage when gas-liquid interface flows through the electrode,showing an easy and potential way for multi-functional flow monitoring in microfluidic chips.

Sample entropy analysis of laser speckle fluctuations to suppress motion artifact on blood flow monitoring

Laser speckle imaging is a common technique to monitor blood flow.The fluctuations in speckle intensity can be related to the blood flow by calculating the speckle contrast,the ratio between the standard deviation of speckle fluctuations and the average intensity.However,this simple statistic calculation is easily affected by motion artifacts.In this study,we applied sample entropy analysis instead of calculating standard deviations of the speckle fluctuations.Similar to the traditional method,sample entropy-based speckle contrast increases linearly with flow rate but was shown to be more immune to sudden movements during an upper arm occlusion test.

Pre-and postoperative changes of regional cortical cerebral blood flow in patients with cerebral arteriovenous malformation

Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery,the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM,CBF returned to the baseline level within 4 hours,but in patients with giant AVM,CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.

Design and implementation of a hybrid circuit system for micro sensor signal processing

This paper covers a micro sensor analog signal processing circuit system（MASPS） chip with low power and a digital signal processing circuit board implementation including hardware connection and software design. Attention has been paid to incorporate the MASPS chip into the digital circuit board.The ultimate aim is to form a hybrid circuit used for mixed-signal processing,which can be applied to a micro sensor flow monitoring system.