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The inability to transport molecules efficiently and easily into cells and across tissues is one of the major limitations of developing drug delivery systems. A novel approach to overcoming this problem could be the use of low-frequency ultrasound to make cell membranes and tissues more permeable. Previous studies show that normally impermeant molecules can be transported into cells exposed to ultrasound; however, the mechanism by which this occurs is not well understood. Our hypothesis is that low frequency ultrasound can reversibly disrupt membrane structure, thus allowing diffusion-driven intracellular delivery of molecules through a breach in the cell membrane. The effects of ultrasound are not limited to uptake of molecules; there can also be significant loss of cell viability after sonication. Therefore, the focus of this work is to determine the mechanisms by which molecular uptake and cell death occur from ultrasound exposure. The long-term goal of this work is to increase the number of viable cells that experience uptake by controlling the effects that cause cell death. Our data have show that large molecules (r ≤ 28 nm) can be taken into cells after exposure to 24 kHz (10% duty cycle for 2 s of exposure time at 0.1 pulse length over a range of pressures) ultrasound and that uptake of these molecules can occur even after sonication ended. In experiments developed to isolate the mechanism(s) of uptake, DU145 prostate cancer cells depleted of ATP energy and intracellular calcium showed no uptake of calcein, a small fluorescent molecule (MW = 623 Da), nor did sonicated lipid bilayers (red blood cell ghosts), suggesting that uptake is calcium mediated and requires active mechanisms in viable cells. Multiple types of microscopy, including electron and laser scanning confocal, showed evidence of large plasma membrane disruptions which support the hypothesis that transport of molecules into cells occurs through repairing wounds. Microscopy studies also indicated that much if the sonication-mediated death can occur by instantaneous cellular lysing and rapid cell death (within minutes post-exposure) due to wound-instigated necrosis; in addition, characteristics of rapidly induced controlled death modes were seen and found to be non-caspase-mediated within an hour after sonication ended.

The resources on earth are limited; thus, the demand for energy, goods and materials is surging because of the growth of the advanced technology and population. The issues of using the resources effectively and changing them into a useful energy are then important. Taiwan creates a vast amount of agricultural waste every year. The traditional way of eliminating the agricultural waste would be burned and buried. However, it is not only the agricultural waste cannot be reused and recycled, but also the problem of air pollution occurred. The objectives of this thesis are thus to transfer the agricultural waste into a useful energy. This study contents two parts. The first part changes the agricultural waste into sugar. The agricultural waste is full of wood fiber and can be transformed to sugar by a microorganism method. A cane which is a common agricultural waste is used; the wood fiber in cane will be added to the thermostable cellulolytic bacterial Geobacillus thermoleovorans T4 isolated from sugar refinery wastewater in southern Taiwan. T4 can convert wood fiber into sugar. Experimental results showed that the rate of reducing sugar is 13.77%. The second part studies the biological hydrogen production by Clostridium acetobutylicum ATCC 824, and the sugar will be added into the process. Also, this study uses ultrasonic treatment in the biological hydrogen production and calculates the natural frequency of ATCC 824. The experiment is designed using the Taguchi method for increasing hydrogen production, hydrogen production rate and hydrogen production efficiency by using an ultrasonic treatment to treat C. acetobutylicum ATCC 824. It is showed that the best combination is temperature 37¢XC, ultrasonic frequency 0.5 MHz, ultrasonic intensity 136 mW/cm2, exposure time 10 s, pH 7.5 and bacterial concentration 20%. This study can apply in bio-energy and fermentation food producing.

Overhead transmission lines are periodically inspected using both on-ground and helicopter-aided visual inspection. Factors including sun glare, cloud cover, close proximity to power lines and the rapidly changing visual circumstances make airborne inspection of power lines a particularly hazardous task. In this research, a finite element model is developed that can be used to create the theoretical dispersion curves of an overhead transmission line. The complex geometry of the overhead transmission line is the primary reason for absence of a theoretical solution to get the analytical dispersion curves. The numerical results are then verified with experimental tests using a non-contact and broadband laser detection technique. The methodology developed in this study can be further extended to a continuous monitoring system and be applied to other cable monitoring applications, such as bridge cable monitoring, which would otherwise put human inspectors at risk.

This study has been carried out to develop and manufacture piezoelectric ceramic materials which are utilized for ultrasonic motor (USM) applications. For this purpose, the effect of compositional modifications on the dielectric and piezoelectric properties of lead zirconate titanate (PZT) based ceramics was investigated. PZT based powders were produced using the mixed oxide method. The base composition was selected as Pb(Zr0.54Ti0.46)O3. The samples in the proximity of morphotrophic phase boundary were doped with strontium, lanthanum, lead manganese niobate (PMnN) and lead manganese antimonate (PMS) in order to improve the structural characteristics and electromechanical properties which are very important for USM applications. The dielectric constant, planar coupling coefficient, mechanical quality factor, piezoelectric strain constant and tangent loss values were evaluated in accordance with standard IRE (Institute of Radio Engineers) test procedures. The results on dielectric and piezoelectric properties showed that piezoelectric ceramics with high mechanical quality factor, high piezoelectric strain constant and low tangent loss could be produced by using the aforementioned dopants. As a result, a new piezoelectric ceramic named as 0.97[PSLZT]-0.024[PMnN]-0.006[PMS] was produced with KT= 1913, Qm= 1240, d33= 540 pC/N, tan delta= 0.89%, kp= 0.57 and Tc= 235 &deg / C. This composition is a good candidate for high power applications. The ceramic samples with the developed compositions were used to produce an ultrasonic-wave type motor and the performance of the USM was evaluated in terms of speed, torque and efficiency.

Abstract The objective of this research is to develop a vibration wave technique for pipeline inspection globally. It is known that the pipeline systems are widely used in chemical industry, petroleum company, or nuclear power plant. In addition, the pipeline systems are also very danger since they usually carry high pressure, high temperature, or even highly corrosive fluids. Therefore, the need for careful nondestructive testing on frequent base to determine the damage of the pipeline and the need for repair arise. The nondestructive testing methods usually used to evaluate the cracks in a pipeline are liquid penetrant method, eddy current testing, ultrasonic testing, acoustic emission method, and radiographic inspection, and etc. Technicians will usually apply one of or the combination of the methods to get the testing job done. However, the above-mentioned techniques (except for acoustic emission) can only inspect a small area or spot of the pipeline, which is very time consuming for evaluating the whole pipeline. The error will also build up easily since the technicians have to perform the measurement repeatedly. To overcome the above-mentioned problems, this research proposes a vibration wave technique to measure the resonant frequency and the vibration mode of the whole or a long pipeline. The experimental results can be used to characterize the damage in the pipeline. The knowledge obtained from the research can also be used to define the criteria of inspection or repair procedures and life cycles of the pipeline.

It has been found through experiments at Southwest Research Institute that temperature differences between the gas and wall of the pipe through which the gas is flowing can greatly influence the gas flow in the pipe line and give different velocity magnitudes at the top and bottom half of the pipe. The effect on the flow is observed to worsen at low fluid flow and high temperature differences. This effect has been observed by ultrasonic flow meters which measure the chord average gas velocity at four heights across the pipe. A significant variance in chord averaged velocities is apparent at these conditions. CFD analysis was performed. Low flow velocities of 0.1524 m/sec, 0.3048 m/sec and 0.6096 m/sec and temperature differences of 5.5oK, 13.8oK and 27.7oK were considered. When these conditions were imposed onto the three different geometries, it was seen that the heating caused increased errors in the ultrasonic meter response. For the single elbow and double elbow pipe configurations, the errors were below 0.5% for constant wall temperature conditions but rose to 1% for sinusoid varying wall temperature conditions. The error was seen to increase as the axial velocity became more stratified due to momentum or temperature effects. The case of maximum error was noted for the double elbow geometry with sinusoid wall temperature condition where a swirl type of flow was noted to create localized velocity maxima at the center of the pipe. This part of the pipe was barely touched by the ultrasonic meter acoustic path giving maximum error of 1.4%. A thermal well was placed in the path of the gas flow in the pipe to observe the temperature response on the surface of the thermal well. It was noted that the thermal well surface temperature differed by 1.4% for most cases with gas velocity below 0.6096 m/sec.

This thesis describes the use of an ultrasonic goal-seeking algorithm while using ionic polymer metal composite (IPMC), an electroactive polymer, as the actuator to drive a vessel towards a goal. The signal transmitting and receiving circuits as well as the goal seeking algorithm are described in detail. Two test vessels were created; one was a larger vessel that contained all necessary components for autonomy. The second was a smaller vessel that contained only the sensors and IPMC strips, and all power and signals were transmitted via an umbilical cord. To increase the propulsive efforts of the second, smaller vessel, fins were added to the IPMC strips, increasing the surface area over 700%, determined to yield a 22-fold force increase. After extensive testing, it was found that the three IPMC strips, used as oscillating fins, could not generate enough propulsion to move either vessel, with or without fins. With the addition of fins, the oscillating frequency was reduced from 0.86-Hz to 0.25-Hz. However, the goal-seeking algorithm was successful in guiding the vessel towards the target, an ultrasonic transmitter. When moved manually according to the instructions given by the algorithm, the vessel successfully reached the goal. Using assumptions based on prior experiments regarding the speed of an IPMC propelled vessel, the trial in which the goal was to the left of the axis required 18.2% more time to arrive at the goal than the trial in which the goal was to the right. This significant difference is due to the goal-seeking algorithm’s means to acquire the strongest signal. After the research had concluded and the propulsors failed to yield desired results, many factors were considered to rationalize the observations. The operating frequency was reduced, and it was found that, by the impulse-momentum theorem, that the propulsive force was reduced proportionally. The literature surveyed addressed undulatory motion, which produces constant propulsive force, not oscillatory, which yields intermittent propulsive force. These reasons among others were produced to rationalize the results and prove the cause of negative results was inherent to the actuators themselves. All rational options have been considered to yield positive results.

The spatial movements of yellowfin tunas around the fish aggregating devices which were anchored below 40 meters water with a VEMCO VR2 receiver were investigated using ultrasonic telemetry tags V9P (VEMCO VP9-2H-S256). The experiment was conducted in the Shiao-Liu-Chiu Island of Taiwan from July to September, 2007. A pair of VEMCO VR2 receivers was separated by 400 meter distances in west of south sea ,Taiwan. A total of 9 tagged fishes with different sizes were monitored for maximum 19 days. Preliminary results showed that juvenile fish stayed longer and closer within FADs than the adult fish. Fish could move vertically to as low as 160 meters at daytime. They avoid the surface water where the temperature reach 30oC. In nighttime, juvenile fish that has fork length smaller than 55cm generally moves to the surface mixed layer. On the horizontal movement, there are three types. A) fish stays at FADs site. B) Fish move in and out FADs sites for a few hours period. C) fish moves away from FADs site for a long times (maybe 2~3 days). Sometimes juvenile fish would have B) or C) moved away from the FAD devices during dawn and dusk, and back at daytime. But this would not occurred with large fish. We estimated the attraction radius of FADs at least 1 km.

Thesis (Ph.D.) -- University of Glasgow, 2008. / Ph.D. thesis submitted to the Department of Mechanical Engineering, Faculty of Engineering, University of Glasgow, 2008. Includes bibliographical references. Print version also available.