The use of unmanned aerial vehicles (UAVs) in various military and civil applications is the subject of much current attention. With recent developments in personal computer technology, and the availability at affordable cost of peripherals, and electronic and optical sensors, UAVs for long endurance missions, with flight autonomy beyond the visual range, have become an attractive challenge for study in universities and research institutes. This paper describes the development of a target-lock-on optical remote sensing system to be used as a payload in a university-class UAV. To accomplish autonomous way-point navigation for the conduct of optical sensing surveillance, a gimbaled-platform with servo control and an Attitude and Heading Reference System (AHRS) navigation system for UAV position and attitude measurements have been developed. The UAV also utilises a Global Position System (GPS) receiver, a pressure altimeter, gyroscopes and an electric compass. A novel mathematical model is proposed to calculate the optimal parameters for orientating the CCD camera line of sight with a ground target, designated in real time from a ground control station. Both ground and flight test results have demonstrated the feasibility of the navigation control scheme and the UAV’s ability to conduct ground target acquisition and image transmission.

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum, is one of the limiting factors for watermelon production in Taiwan. In recent research, the phenylalanine ammonia lyase (PAL) gene expressed in the shoot base of the Fusarium wilt resistant line JSB was related to Fusarium wilt resistance. Phenylalanine ammonia lyase is the key regulatory enzyme in the phenylpropanoid metabolic pathway. The downstream products of phenolic compounds are considered to be involved in the complicated plant defence mechanisms. They could act as signal molecules, antimicrobial substances and/or structural barriers. To study the resistant mechanisms of Fusarium wilt, the resistant JSB line was examined for comparison of F. oxysporum-watermelon interactions with the susceptible Grand Baby (GB) cultivar. Unlike infected GB, which was seriously colonized by F. oxysporum in the whole plant, the pathogen was limited below the shoot base of inoculated JSB, suggesting that the shoot base of JSB may contribute to Fusarium resistance. The data indicated that a significant increase in PAL activity was found in shoot bases of the resistant JSB line at 3, 9, 12 and 15 days after inoculation (DAI). Shoot bases of resistant watermelons accumulated higher amounts of soluble and cell wall-bound phenolics at 3–9 DAI; the susceptible GB cultivar, however, only increased the cell wall-bound phenolics in shoot bases at 3 DAI. High lignin deposition in the cell walls of vascular bundles was observed in the shoot bases of JSB but not of GB seedlings at 6 and 9 DAI. In the roots and shoot bases of JSB seedlings at 6 DAI, peroxidase enzyme activity increased significantly. In summary, the results suggest that accumulation of cell wall-bound phenolics and increase of peroxidase activity in shoot bases of JSB seedlings during F. oxysporum inoculation, together with the rapid deposition of lignin in the cell walls of vascular bundles, may have provided structural barriers in resistant JSB line to defend against F. oxysporum invasion.

Carefully timed tandem microbubbles have been shown to produce directional and targeted membrane poration of individual cells in microfluidic systems, which could be of use in ultrasound-mediated drug and gene delivery. This study aims at contributing to the understanding of the mechanisms at play in such an interaction. The dynamics of single and tandem microbubbles between two parallel plates is studied numerically and analytically. Comparisons are then made between the numerical results and the available experimental results. Numerically, assuming a potential flow, a three-dimensional boundary element method (BEM) is used to describe complex bubble deformations, jet formation, and bubble splitting. Analytically, compressibility and viscous boundary layer effects along the channel walls, neglected in the BEM model, are considered while shape of the bubble is not considered. Comparisons show that energy losses modify the bubble dynamics when the two approaches use identical initial conditions. The initial conditions in the boundary element method can be adjusted to recover the bubble period and maximum bubble volume when in an infinite medium. Using the same conditions enables the method to recover the full dynamics of single and tandem bubbles, including large deformations and fast re-entering jet formation. This method can be used as a design tool for future tandem-bubble sonoporation experiments.

Typical carcinoid tumour of the larynx is extremely rare. We report the case of a 43-year-old man initially diagnosed with typical carcinoid tumour of the larynx, presenting with a foreign body sensation in his throat. Coincidentally, an occult papillary thyroid carcinoma was diagnosed, following detection of a suspicious lymph node on pre-operative imaging studies, and confirmation by neck dissection and subsequent total thyroidectomy. Following surgery and radioiodine therapy for these cancers, the patient was alive, well and free of disease two years later. Typical carcinoid tumour of the larynx with a synchronous occult papillary thyroid carcinoma has not previously been reported. The optimal treatment strategy for this case is also discussed.

In this paper, the FEM with the incremental endochronic cyclic plasticity (EndoFEM) and the rc controlled node-released strategy are employed to study the fatigue crack opened/closed load (Pop) of Al 2024-T3 CCT specimens provided by Mageed and Pandey under several crack lengths and the constant amplitude with various load ratio (R). After statisfactory results are achieved by comparisons of computed Pop values and cited experimental data, the simulations will be extended to the crack lengths with significant bending effect due to short ligaments or high peak (Pmax) or high positive or very low negative R cyclic loads. Through these simulations, the complete map of Pop/Pmax vs. Kmax and R can be constructed and thereafter its correspondant empirical formulae can be proposed. Using these formulae and selecting the traditional fatigue crack growth parameter ΔKeff, the Al 2024-T3 fatigue crack growth rate da/dN vs. ΔK and R data, provided by Hiroshi and Schijve, can be employed to proposed empirical formulae of da/dN vs. ΔKeff and R. After integration, fatigue-crack-growth length a vs. N curves computed by EndoFEM can be obtained. The results are agreed very well with the existing experimental curves.

According to the above procedures of simulation and steps of comparions with experiment, this paper may provides an integrate methodology of numerical simulation in the studies of fatigue crack growth for academic and industrial researches and design analysis.

The endochronic cyclic plasticity with finite element analysis (EndoFEM) is employed to simulate plasticity-induced crack closure phenomenon of Al 2024-T3 CCT specimens under maximum cyclic stress of 80MPa and 0.1 stress ratio (R). Various fatigue crack lengths are generated by a rc dominated-node-released strategy. The suitability of element-mesh planning around crack tip is supported by the real simulations in the decreasing tendencies of crack opening load (Pop) with increased distance behind the crack tip, and the enough elements to reflect the reversed plastic responses at minimum load.

EndoFEM results of vertical stress ahead of the crack tip show a typical distribution of small scale yield (SSY) in the realm of fracture mechanics; and Pop/Pmax ratio determined at 1mm behind crack tip is kept constant i.e. Kmax-independent. In these cases, fatigue parameters based on either the far field loading parameter ΔK, the effective ΔK (ΔKeff) with crack closure effect, or the mechanical responses ahead of crack tip (e.g. stress parameter, reversed (plastic) strain at 1mm) are all equivalent and are linearly correlated with the stage II fatigue crack growth (FCP) rate. However, for longer crack length with the ligament bending effect or shorter crack length with the starter notch effect, the Pop/Pmax ratio decreases and changes the SSY stress distribution. This result reduces the usefulness of the above fatigue parameters. As a consequence, a nonlinear correlation of FCP rates with ΔK or ΔKeff are purely empirical. The Kmax-dependent ΔKeff must be considered in the correlation as suggested by the present study of EndoFEM.

The demand for multi-purpose, high-performance polymer systems has resulted in a need for advancing polymer properties beyond what traditional systems can offer. Only through control/alteration at the molecular level can one maximize property enhancements to meet current military and commercial needs. Over the last seven years the Air Force Research Laboratory has developed and incorporated discrete Si-O frameworks (POSS = Polyhedral Oligomeric Silsesquioxanes) into traditional organic polymer systems. This research has resulted in new hybrid inorganic-organic polymer systems with remarkable enhancements in mechanical and physical properties including dramatic increases in both glass transition and decomposition temperatures, reduced flammability, increased moduli and oxidation resistance. We have shown that these enhancements result from the chemical composition (Si-O core) and size (∼15 A in diameter) of the POSS frameworks, and can be copolymerized, grafted, or even blended using traditional processing methods. Recently, we have focused our efforts on understanding and controlling the molecular level interactions between POSS frameworks and the polymer matrix. The development of new POSS monomers has allowed us to study how functionality, size, and geometry enhances the bulk properties of these hybrid materials. For example, increasing the solubility of side groups on the POSS framework results in greater POSS-polymer matrix interactions and increased Tg and storage moduli. Recent studies with POSS blends have resulted in increases in hardness, and reductions in dielectric constants and coefficients of thermal expansion. New results in polymer synthesis, characterization, and applications will be discussed with a strong emphasis on the versatility of this new nanotechnology to many polymer systems.

Applications of the EndoFEM with node-released methods had been used successfully to simulate the plastic wakes left behind the advancing fatigue crack. In this paper, employing the plastic zone size estimated by LEFM as a guideline, four strategies with various plans of node-released rates and two plans of finite element discretization near crack tip, are proposed to generate various fatigue cracked lengths of A12024-T3 CCT specimen under all tensile-cyclic loading. Evaluations based on the mechanical responses near crack tip and the crack opened/closure behaviors, it can be concluded that the EndoFEM with the rc dominant node-released strategy can lead to not only economical but also reliable results.

We investigate the large-time behaviour of solutions for the outer pressure problem of a viscous heat-conductive one-dimensional real gas. A conclusive answer to the problem of asymptotic behaviour is given in Theorem 1.2.

The polycrystalline silicon films were deposited by electron cyclotron resonance chemical vapor deposition (ECR-CVD) with hydrogen dilution at 250°C and without any thermal annealing. The surface morphology and the microstructure of the poly-Si films are investigated by atomic force microscopy (AFM), plan-view transmission electron microscopy (TEM), crosssectional TEM and high resolution TEM (HRTEM). The low temperature poly-Si films deposited by ECR-CVD show a special leaf-like grain shape (plan-view) and an upside-down cone shape (3-dimensional view). The grains in the poly-Si films have preferred orientation of <112> and the longer side of the leaf-like grain is direction and the shorter side is direction. Lattice bending and interruption are found in the films. The arrangement of the atoms on the grains are well ordered, while atoms in the interfacial regions are randomly distributed. A simple grain formation model based on growth rate differences between different planes and etching effect can explain the film growth mechanism and the formation of the special grain geometry.

We consider a cylinder with arbitrary cross section moving in a viscous incompressible fluid parallel to a plane wall. Formal asymptotic expansions of the solution for small Reynolds numbers are constructed by using boundary integral equations of the first kind. In contrast to the problem without a wall, we show that there exists a unique solution to the zeroth order problem. However, the problem considered here is still singular in the sense that we find the Stokes paradox in the next higher order problem. A justification of the formal asymptotic expansion for the first two terms is established rigorously.