Developing Dynamic Digital Image Techniques with Continuous Parameters to Detect Structural Damage

Several earthquakes with strong magnitude occurred globally at various locations, especially the unforgettable tsunami disaster caused by the earthquake in Indonesia and Japan. If the characteristics of structures can be well understood to implement new technology, the damages caused by most natural disasters can be significantly alleviated. In this research, dynamic digital image correlation method for using continuous parameter is applied for developing a low-cost digital image correlation coefficient method with advanced digital cameras and high-speed computers. The experimental study using cantilever test object with defect control confirms that the vibration mode calculated using this proposed method can highly express the defect locations. This proposed method combined with the sensitivity of Inter-Story Drift Mode Shape, IDMS, can also reveal the damage degree of damage structure. These test and analysis results indicate that this proposed method is high enough for applying to achieve the object of real-time online monitoring of structure

Energy dissipation behaviours and seismic reduction performance of a proposed velocity and displacement dependent hydraulic damper (VDHD)

A new oil‐pressure Velocity and Displacement Dependent Hydraulic Damper (VDHD) is proposed by adding an additional Relief Valve parallel to the Throttle Valve with a different aperture size. This objective is to obtain an adaptive control by changing the damping coefficient of the VDHD for better control of structural movement during earthquake. In order to simulate its actual energy elimination, a mathematical analysis model is developed based on the Maxwell Model, which is modified by adding a serial friction model and a small damper parallel to the friction model in this study. The mathematical simulated results are compared with the actual energy‐dissipating behaviours of this proposed damper. The comparison shows that this proposed mathematical modelling could accurately simulate the relation of force and displacement as well as the relation of force and velocity during the process of energy dissipation. In addition, results of both the laboratory shaking table test and simulation analyses are used to test and verify the seismic reduction performance of this proposed damper. The experimental and simulation results show that in spite of the magnitude of the earthquake, the proposed VDHD device has a superior effect on the control of structural displacement by achieving effective acceleration reduction. Santrauka Siūlomas naujas hidraulinis i greiti ir poslinki reaguojantis slopintuvas (HGPS), sukurtas prie droselinio vožtuvo su kintama apertūra pridejus atbulini vožtuva. Buvo siekiama užtikrinti geresne adaptyvia konstrukcijos judejimo žemes drebejimo metu kontrole keičiant HGPS slopinimo koeficienta. Norint modeliuoti tikraji energijos pašalinima, buvo sukurtas matematinis modelis, pagristas Maksvelo modeliu. Šis modelis buvo pakeistas prie trinties modelio pridejus nuosekluji trinties modeli ir nedideli slopintuva. Matematinio modeliavimo rezultatai lyginami su tikraja siūlomo gesintuvo energijos sklaida. Palyginimas rodo, kad matematinio modeliavimo rezultatai atitinka tikraja siūlomo gesintuvo elgsena. Lyginant skaičiavimo rezultatus su eksperimentiniais matyti, kad siūlomas matematinis modeliavimas leidžia tiksliai išreikšti jegos ir poslinkio bei jegos ir greičio ryšius, susidarančius energijos sklaidos metu. Laboratoriniai rezultatai, gauti naudojant vibracini stala, ir modeliavimo rezultatai taikomi tirti bei tikrinti siūlomo gesintuvo itaka mažinant seismines konstrukcijos charakteristikas. Eksperimentiniai ir modeliavimo rezultatai rodo, kad nepaisant žemes drebejimo laipsnio, siūlomas gesintuvas labai pagerina konstrukcijos poslinkiu kontrole efektyviai mažindamas judejimo pagreiti. First Published Online: 10 Feb 2011 Reikšminiai žodžiai: HGPS, Maksvelo modelis, diskretusis sprendinys, pasyvusis energijos skaidos prietaisas, vibracinio stalo bandymas, modeliuojamas konstrukcijos reakcijos mažinima

Developing a neutral equilibrium device as dynamic virtual piers for an emergency relief bridge

Every year, many natural disasters strike Taiwan, destroying bridges and disrupting traffic. To allow shipping of relief provisions and salvage, fabricated steel bridges are often used to construct emergency relief bridges. This kind of bridge must meet strength and functionality requirements. Strength depends on the materials used, while functionality depends on displacement control. These two requirements affect the section design of the bridge deck. In order to quickly build a light-weight bridge for emergency relief with displacement control, a neutral equilibrium mechanism is proposed and developed to control the deflection of an emergency relief bridge. A neutral equilibrium mechanism is a system with an internal control mechanism that can actively change the internal structure. Structural transformation causes the size variation of the action force to respond to continuous changes in bridge deflection. This mechanism can expand the effective span of the bridge, maintain its strength and functionality, and increase the convenience of building and mobility. Experimental results reveal that a virtual pier at the center of a bridge with this proposed mechanism installed can control vertical deflection caused by vehicles carrying heavy loads. Test and analysis records also reveal that the vertical displacement at the center of a bridge with the neutral equilibrium mechanism installed is close to zero. The practicality of this neutral equilibrium mechanism has been verified by experiment

Neural Network Control-Based Drive Design of Servomotor and Its Application to Automatic Guided Vehicle

An automatic guided vehicle (AGV) is extensively used for productions in a flexible manufacture system with high efficiency and high flexibility. A servomotor-based AGV is designed and implemented in this paper. In order to steer the AGV to go along a predefined path with corner or arc, the conventional proportional-integral-derivative (PID) control is used in the system. However, it is difficult to tune PID gains at various conditions. As a result, the neural network (NN) control is considered to assist the PID control for gain tuning. The experimental results are first provided to verify the correctness of the neural network plus PID control for 400 W-motor control system. Secondly, the AGV includes two sets of the designed motor systems and CAN BUS transmission so that it can move along the straight line and curve paths shown in the taped videos

Role of pirenoxine in the effects of catalin on in vitro ultraviolet-induced lens protein turbidity and selenite-induced cataractogenesis in vivo

Purpose: In this study, we investigated the biochemical pharmacology of pirenoxine (PRX) and catalin under in vitro selenite/calcium- and ultraviolet (UV)-induced lens protein turbidity challenges. The systemic effects of catalin were determined using a selenite-induced cataractogenesis rat model. Methods: In vitro cataractogenesis assay systems (including UVB/C photo-oxidation of lens crystallins, calpain-induced proteolysis, and selenite/calcium-induced turbidity of lens crystallin solutions) were used to screen the activity of PRX and catalin eye drop solutions. Turbidity was identified as the optical density measured using spectroscopy at 405 nm. We also determined the in vivo effects of catalin on cataract severity in a selenite-induced cataract rat model. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) was applied to analyze the integrity of crystallin samples. Results: PRX at 1,000 μM significantly delayed UVC-induced turbidity formation compared to controls after 4 h of UVC exposure (p<0.05), but not in groups incubated with PRX concentrations of <1,000 μM. Results were further confirmed by SDS–PAGE. The absolute γ-crystallin turbidity induced by 4 h of UVC exposure was ameliorated in the presence of catalin equivalent to 1~100 μM PRX in a concentration-dependent manner. Samples with catalin-formulated vehicle only (CataV) and those containing PRX equivalent to 100 μM had a similar protective effect after 4 h of UVC exposure compared to the controls (p<0.05). PRX at 0.03, 0.1, and 0.3 μM significantly delayed 10 mM selenite- and calcium-induced turbidity formation compared to controls on days 0~4 (p<0.05). Catalin (equivalent to 32, 80, and 100 μM PRX) had an initial protective effect against selenite-induced lens protein turbidity on day 1 (p<0.05). Subcutaneous pretreatment with catalin (5 mg/kg) also statistically decreased the mean cataract scores in selenite-induced cataract rats on post-induction day 3 compared to the controls (1.3±0.2 versus 2.4±0.4; p<0.05). However, catalin (equivalent to up to 100 μM PRX) did not inhibit calpain-induced proteolysis activated by calcium, and neither did 100 μM PRX. Conclusions: PRX at micromolar levels ameliorated selenite- and calcium-induced lens protein turbidity but required millimolar levels to protect against UVC irradiation. The observed inhibition of UVC-induced turbidity of lens crystallins by catalin at micromolar concentrations may have been a result of the catalin-formulated vehicle. Transient protection by catalin against selenite-induced turbidity of crystallin solutions in vitro was supported by the ameliorated cataract scores in the early stage of cataractogenesis in vivo by subcutaneously administered catalin. PRX could not inhibit calpain-induced proteolysis activated by calcium or catalin itself, and may be detrimental to crystallins under UVB exposure. Further studies on formulation modifications of catalin and recommended doses of PRX to optimize clinical efficacy by cataract type are warranted

Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown disposal. Membrane treatment (nanofiltration or reverse osmosis) can be employed to reduce TDS and sulfate concentrations to acceptable levels for reuse of the blowdown in the cooling systems as makeup water