The bioavailability of metabolizable organic matter within marine sediments is one of the more important driving mechanisms controlling benthic pelagic communities. Interactions between organic material and mineral surfaces within the sediment, such as adsorption, can cause organic matter to be unavailable for degradation by organisms; therefore for this study we have used the relationship of organic carbon-to-sediment surface area as an indicator of available organic carbon in northern Gulf of Mexico sediments. We have determined that these sediment interactions demonstrate a significant association with benthic fauna abundances; however they are not the most dominant environmental variables. It may be the combination of biogeochemical parameters, such as organic carbon content, sediment surface area, grain size, water depth and other geophysical variables, that is the ultimate control on the bioavailability of metabolizable organic matter in the northern Gulf of Mexico.

Moisture damage in asphalt mixes can be defined as loss of strength and durability due to the presence of moisture at the binder-aggregate interface (adhesive failure) or within the binder (cohesive failure). This research focuses on the evaluation of the susceptibility of aggregates and asphalts to moisture damage through understanding the micro-mechanisms that influence the adhesive bond between aggregates and asphalt and the cohesive strength and durability of the binder. Moisture damage susceptibility is assessed using surface energy measurements and dynamic mechanical analysis (DMA). Surface energy is defined as the energy needed to create a new unit surface area of material in vacuum condition. Surface energy measurements are used to compute the adhesive bond strength between the aggregates and asphalt and cohesive bond strength in the binder. DMA testing is used to evaluate the rate of damage accumulation in asphalt binders and mastics. The DMA applies a cyclic, torsional strain controlled loading to cylindrical asphalt mastics until failure. The DMA results are analyzed using continuum damage mechanics that focuses on separating the energy expended in damaging the material from that associated with viscoelastic deformation. A new approach is developed to analyze the DMA results and calculate the rate of damage. The developed approach is used to evaluate six asphalt mixtures which have performed either well or poorly in the field. The resistance of the field mixes to moisture damage is shown to be related to the calculations of bind energies and the accumulated damage in the DMA.

A two-mass model with a spring and a damper in the vertical direction, accounting for vertical translational motion and a torsional spring and a damper connecting the rotational motion of two masses is used to simulate the dynamics of a tennis ball as it comes into contact with a flat surface. The model is supposed to behave as a rigid body in the horizontal direction. The model is used to predict contact of the ball with the ground and applies from start of contact to end of contact. The springs and dampers for both the vertical and the rotational direction are linear. Differential equations of motion for the two-mass system are formulated in a plane. Two scenarios of contact are considered: Slip and no-slip. In the slip case, Coulomb??s law relates the tangential contact force acting on the outer mass with the normal contact force, whereas in the no-slip case, a kinematic constraint relates the horizontal coordinate of the center of mass of the system with the rotational coordinate of the outer mass. Incorporating these constraints in the differential equations of motion and applying initial conditions, the equations are solved for kinematics and kinetics of these two different scenarios by application of the methods for the solutions of second-order linear differential equations. Experimental data for incidence and rebound kinematics of the tennis ball with incidence zero spin, topspin and backspin is available. The incidence angles in the data range from 17 degrees up to 70 degrees. Simulations using the developed equations are performed and for some specific ratios of inner and outer mass and mass moments of inertia, along with the spring-damper coefficients, theoretical predictions for the kinematics of rebound agree well with the experimental data. In many cases of incidence, the simulations predict transition from sliding to rolling during the contact, which is in accordance with the results obtained from available experimental measurements conducted on tennis balls. Thus the two-mass model provides a satisfactory approximation of the tennis ball dynamics during contact.

Spectral properties of global surface temperature and uncertainties of global climate sensitivity are explored in this work through the medium of Energy Balance Climate Models (EBCMs) and observational surface temperature data. In part I, a complete series of 2D time-dependent non-orthogonal eigenmodes of global surface temperature are analytically derived and their geographic patterns are presented. The amplitudes of these modes have temporal characteristics and present exponentially decaying patterns. Theoretically, if the energy balance model is forced by white noise forcing in time, the autocorrelation functions of the mode amplitudes should present the same exponentially decaying patterns. When observed surface temperature data are projected onto these theoretical modes, the autocorrelation time scales of the mode amplitudes exhibit similar exponential decaying patterns. These modes are believed to be useful for surface temperature studies and model intercomparison. In part II, an objective means of deriving the probability density function (PDF) of global climate sensitivity is investigated. The method constrains the PDF by its fit to the present climate in terms of surface temperature. We found that a wide range of parameter combinations, which corresponds to a broad range of the sensitivity, shows equally good fits to the present climate. It means that the uncertainties in global climate sensitivity are very difficult to eliminate if climate models are tuned to fit observations of surface temperature alone. The origin of the skewness of the PDF is found in very simple terms.

In architectural and sculptural practice, the eventual goal is constructing the shapes that have been designed. Due to fabrication considerations, shapes with planar faces are in demand for these practices. In this thesis, a novel computational modeling approach to design constructible shapes is introduced. This method guarantees that the resulting shapes are planar meshes with 3-valence vertices, which can always be physically constructed using planar or developable materials such as glass, sheet metal or plywood. The method introduced is inspired by the traditional sculpture and is based on the idea of carving a mesh by using slicing planes. The process of determining the slicing planes can either be interactive or automated. A framework is developed which allows user to sculpt shapes by using the in- teractive and automated processes. The framework allows user to cut a source mesh based on its edges, faces or vertices. The user can sculpt various kinds of developable surfaces by cutting the parallel edges of the mesh. The user can also introduce in- teresting conical patterns by cutting dierent vertex, edge, face combinations of the mesh.

This paper aims to design and simulate the surface-micromachining micro tunable capacitor for parameters optimization. This work also creates an equivalent circuit model of micro tunable capacitor and proceeds relative electromechanical analysis, including the distribution of field and charge, resonant frequency and pull-in voltage analysis. This micro tunable capacitor is constructed by one suspended top metal plate and two stationary bottom metal plates (one is signal electrode and the other one is bias electrode). By driving electrostatic force, the gap between top and bottom electrodes will be changed and results in a variation of capacitance. To increase the tuning range, the micro tunable capacitor with two different gap space will be presented in this research. High frequency analysis, equivalent circuit analysis and electromechanical dynamic analysis are using Ansoft HFSS, Agilent ADS and the IntelliSuite software respectively. Through these simulation and analysis, it is possible to obtain the optimized specification of micro tunable capacitor. The quality factor (Q) and the pull-in voltage extracted by simulation software well match to the measured results; thus, the function of the analysis method and equivalent model adopted in this thesis can be demonstrated.

ABSTRACT In this study, the properties of the high impedance surface structure are studied. We proceed to design the low profile and miniature high impedance surface structure. In order to conform to the IC chips of RFID and reduce the influence of metal objects, we add a layer of electromagnetic band-gap (EBG) structure on the back of the antenna. The EBG behaves as a high impedance surface, similar to a perfect magnetic conductor. This property of the EBG structure is able to isolate the antenna and backside environment and reduce the metallic effect. In order to achieve the requirements of small size and low cost on RFID tag antenna, we design the miniature, low profile and low cost high impedance surface structure. In this study, we use the slots and chip capacitance to miniaturize the dimension. Both approaches can reduce the influence of metallic objects. Although using slots can reduce the metallic effect, it does not have the advantage of low profile. Using chip capacitor can miniaturize the dimension and reduce metallic effect effectively. It also has advantages of low profile, low cost and low sensitivity to the frequency of the tag antenna. Finally, the high impedance surface structures are fabricated and measured when they combine with the tag antenna attached to the metallic object. The measured results agree with simulated ones well.

Collective oscillation of conduction electrons in metallic nanoparticles known as localized surface plasmon resonance has been studied for nano-optics applications. The excitation of localized surface plasmons on nano-structured metal material leads to strong light scattering and absorption. Since the localized surface plasmon resonance is strongly dependent on the shape, size, size distribution, and dielectric property of surrounding environment of nano-structured metal, the dependence can be applied in wide applications. However, the direct and non-destructed observation of nano-structured metal is required to the development of nano-technology, we proposed a real time optical observation due to the optical respons of metal nano-particles system. Furthermore, we proposed a fast and simple method to fabricate a high order metal nano-particles array and used liquid crystal material to directly modulate the surface plasmon effect on the metal nanoparticles. The purpose of this work is to study the surface plasmon effect excited on metal nanoparticles. These works are described as follows: A. The topic of the first work is ¡§Real time absorbance spectra due to optical dynamics of silver nano-particles film¡¨, we report the real time absorbance spectra due to optical dynamics of silver nano-particles film under a heating treatment from 28 to 300 ¢J. A 7nm-thicked sliver film was thermally deposited on an indium tin oxide glass substrate. In the process of heating, the real time absorbance spectra of silver nano-particles film were measured by an optical spectrometer. It was noted that the absorbance spectra of the film varied with the heat-treating temperature and time. The peak position in the spectra curve shifted to shorter wavelength below the temperature of 250 ¢J, then shifted to red band due to higher temperature treatment. With the comparison of scanning electron micrograph analysis, the real time absorbance spectra exhibited a particular optical property confirmed by the dynamic dark-field optical microscopy system. The real-time absorbance spectra and dark-field micrographs analyses lead to a direct and non-destructed observation of growing evolution of metal nano-particles. B. The topic of the second work is ¡§Laser pulse induced gold nanoparticles grating¡¨. We report the results of our experimental investigation of laser induced gold nano-particle gratings and their optical diffraction properties. A single shot of a pair of Nd-YAG laser pulses of the same polarization is directed toward a thin gold film of thickness 6 nm on a substrate of polymethyl methacrylate (PMMA). As a result of the laser illumination, the thin gold film is fragmented into an array of nano-particles. Using scanning electron and dark-field optical micrographs, we discovered that the morphology of the gold nanoparticles grating is dependent on the fluence of laser pulse. The spectrum of first order diffraction shows a spectral dependence, possibly due to the presence of the nano-particles of various sizes. The ablation of thin films of nano-thickness via the use of laser pulses may provide a simple and efficient method for the fabrication of nano-scale structures, including 2D arrays of nano-particles. C. The topic of the second work is ¡§Surface plamons induced extra diffraction band of cholesteric liquid crystal grating¡¨. We investigated the diffraction behavior of cholesteric liquid crystal (CLC) grating with the surface plasmon effect was investigated. One indium-tin-oxide plate of the CLC grating cell was covered with silver nanoparticles. With the application of a proper voltage, a well formed phase grating was constructed in the CLC cell. The CLC grating was probed by a beam of the polarized-monochromatic light, and the wavelength range was from 450 to 700 nm. It was shown that an extra first-order diffraction band was observed around 505 nm. The physical reason of the extra diffraction band could be the surface plasma effect emerged from silver nanoparticles. The extra diffraction band due to the surface plasmon effect can offer potential applications in nano-optics, such as the optical switch function.

Surface gravity waves and internal waves are two of the most common natural phenomena in the ocean. While oceanographers believe that internal waves have greater influence over the surface waves, if is not clear to what extent that the former have affected the latter. As an internal wave propagating in the ocean, short period flow could be induced on the free surface layer. Moreover, as internal waves propagating over a submarine ridge, internal breaking accompanying by large vortex may have occurred, which may also affect the properties of the surface waves. To prove the relationship between them, basic mathematical equations have been derived, but had never been proven in the laboratory experiments or field observations. In this thesis, the results of a series of laboratory experiments conducted at the National Sun Yen-sen University are employed to study the waveform evolution and change to the physical parameters of the surface waves, resulting from the generation of internal waves induced on a stratified fluid, as both propagate together above a plane bottom or across single ridge. These experiments were carried out in a stratified two-layer fresh/brine water system (upper layer with fresh water density 996 kg / m3; bottom layer brine water with 1030 kg / m3) in a steel framed wave tank of 12m long with cross-section of 0.7 m high by 0.5 m wide. A plunging-type wave maker was used to produce the designated surface waves, from which the internal waves were induced at the interface. Based on the experimental results in the fluid system with uniform density, wave height and period of the surface wave were first calibrated. It was found that the amplitude of a surface wave decreased first due to the breaking of the internal wave on the apex of a submerged ridge and then increased due to wave regeneration at the back of the ridge, when the surface wave propagated over single ridge. Beyond the ridge, the peak period with maximum energy associated with the transmitted wave remained almost the same with that of the incident waves. In a stratified fluid system, wave height of the surface waves and internal waves did not suffer much change but the peak period of a surface wave increased as an internal wave just across the apex of the obstacle, under a condition referred to as weaken interaction between the waves and the obstacle. For the intense wave breaking condition at the interface, wave height of the internal waves decreased and the period of surface waves or internal waves shortened. However, wave height of the surface wave above the apex of the obstacle increased due to the intense wave breaking. The results obtained from the present laboratory experiments on the interaction between a surface wave and the induced internal wave could benefit others interested in surface and internal wave interaction for practical applications in oceanography or numerical modeling.

A strategy was proposed to make machining rate stable and the machining precision achieved by properly tool dwelling time when surface still has form error after previously machining. Using computer simulation to plan tool dwelling time and to estimate practicability of this strategy. As a result of curvatures are different on the every points of the work piece surface. Normal vectors that between tool and work pieces surface are not stable in polishing process.HDP conditions and film thickness will be changed by curvature radius of work pieces.So HDP conditions must be controlled when the planning of tool motion. Analyzing all of different aspheric surfaces to make sure this strategy can be used. The different thing that between axially symmetric and axially non-symmetric is tool dwelling time should be a linear function the product of the depth function of profile and the radius for symmetric work pieces, but that of axially non-symmetric work pieces only should be linearly proportional to the depth function of profile.