With the growing trend in use of 3D laser scanning technology for data collection, it is important to study the various potential applications of this revolutionary technology. One such application is the measurement of road roughness at both large and small scales. At larger extents, terrestrial laser scanning (TLS) is compared to several current techniques to measure road profiles including digital levels, inclinometers, and inertial profilers. An overall indicator of roughness (e.g. International Roughness Index, IRI) can be obtained from these road profiles and is used by state DOTs to determine the pavement quality. Since TLS is able to collect a large, dense set of data relatively quickly, this technology could provide states with an additional tool to both measure pavement roughness and collect data for the entire roadway. TLS has the added benefit of being able to generate multiple profiles across the roadway efficiently. At a fine scale, micron resolution 3D laser scanners can be utilized to determine the influence of asphalt mix designs on the roughness of the pavement. Of particular interest is the selection of predominant aggregate size within the mix. Results showed that TLS can determine pavement profiles and comparable IRI results to those from current methods. The elevation values collected within the profile were accurate within expected ranges. However, cross correlations, which take into account the location of the roughness, were poor, indicating that TLS is not an effective method to determine a reference profile. TLS was used to determine the cross slopes across the roadway, something that cannot be done with data from an inclinometer or inertial profiler. / Graduation date: 2012 / Zipped file contains 4 file types. Excel files (.xlsx and .xls) can be opened using Microsoft Excel. OBJ files (.obj) are geometry definition file formats intended to be imported into a software program to manipulate 3D laser scans and can also be opened using Notepad++ or another powerful text editor. Notepad++ is freely available for download on the Web. PVP files (.pvp) are project files that contain project settings and profile data and can be opened with ProVAL, a freely available engineering software application used to view and analyze roadway profiles. ERD files (.ERD) are standard file formats used for storing numbers in tabular form and can be opened with Notepad++ or another powerful text editor. These files contain roadway profiles and are designed to be imported into ProVAL.

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A 6082 aluminium alloy has been characterized with regard to the influence of surface roughness on fatigue strength. Fatigue life testing of smooth specimens was used to establish reference curves for the material in extruded and forged T6 condition. The extruded material was found to have better fatigue strength than the forged material, although the cyclic stress-strain response was similar for both. The forged material was tested in T5, T6 and T7 tempers, showing no significant difference in fatigue strength. Surface roughness was created by circumferential grinding of cylindrical test specimens, and the surface topography was measured using a white light interferometry microscope. The measurements proved to be accurate, although errors were observed for certain surface features. Residual stresses were quantified by X-ray diffraction. Compressive residual stresses of around 150 MPa were found in both rough and smooth specimens. Load cycling did not significantly alter the surface residual stresses. Stress solutions ahead of all major surface grooves were found using a linear elastic material model. Estimates of cyclic stresses and strains were calculated in the notch roots using different Neuber corrections of the linear solution. The results were compared to finite element analysis employing a bilinear kinematic hardening model. A generalized version of the Neuber correction was found to be within 20% of the nonlinear finite element results. Several empirical models for the notch sensitivity factor were investigated. These were found to be unable to describe the notch influence on fatigue life and initiation life. In order to follow this approach, it was recommended that different test specimens should be used where the short fatigue crack growth could be monitored. It was shown that microstructural fracture mechanics theories could be used to estimate the fatigue limit of rough surfaces. In some cases, initiation from material defects or weaknesses would override the influence of surface geometry. In one specimen, the initiation appeared to have started as at a de-bonded grain, while in other cases, initiation was thought to have started at larger second phase particles embedded in notch roots. Further work in this area should focus on statistical descriptions of surface roughness, inherent material defects, and their interaction.

The objective of the present work is to study the vehicle suspension as a vibro-acoustic system of high complexity, consisting of many sub-systems with fundamentally different acoustical properties. In a parallel numerical and experimental modelling effort, important contributions to the understanding of its behaviour have been achieved. These findings are based on a balance between component investigations and global modelling of the complete system; they have been formulated for the transmission of both tyre-road excitation and friction-induced vibrations in the brake system. Initially an experimental study was conducted on a full vehicle test rig studying the broadband interior brake noise problem of, here named, roughness noise. The purpose of the study was twofold: first, to determine if the transmission from the source to the interior of the vehicle was structure-borne; second, to study the complexity of the suspension as a vibro-acoustic system. Parameters a_ecting the vibro-acoustic source were varied to gain understanding of the source mechanisms. This experimental study laid the foundation of the first part of this thesis (paper A) and provided the directions for the second part, the development of a mathematical modelling approach (paper B and C). In these two papers, methods for analysing the complex vibro-acoustic transfer of structure-borne sound in a vehicle suspension system were developed. The last part was then focussed on the wheel rim influence on the vibro-acoustic behaviour (paper D) of the suspension system. As a whole, the work clearly demonstrates that it is possible to conduct component studies of subsystems in the vehicle suspension system; and from these component studies it is possible draw conclusions that very well may avoid severe degradations in the interior noise of future vehicle generations. / <p>QC 20130503</p>

In this thesis a study of the factors affecting virus and virus-sized particle transport in discrete fractured dolomite rocks is presented. Physical and chemical characteristics of two fractured rocks were determined, including fracture aperture distribution, rock matrix porosity, mineral composition, and surface charge. Hydraulic and transport tests were conducted in the fractures with a conservative solute (bromide) and carboxylate-modified latex (CML) microspheres of three sizes (20, 200, and 500 nm in diameter). The earlier arrival of larger microspheres as compared to bromide indicated the effects of pore-size exclusion and preferential flow paths in the fractures. The tailing of the bromide and the smaller microsphere (20 nm) in the breakthrough curves (BTC) indicated the diffusive mass transfer between the mobile water (flowing) and immobile water (stagnant water in the low aperture areas and porous rock matrix). The effects of ionic strength and cation type on the transport of viruses (bacteriophages MS2 and PR772) and virus-sized microspheres (20 and 200 nm) were determined from the transport tests in a fracture at three levels of ionic strength (3, 5, and 12 mM) and composition (containing Na+ and/or Ca2+ ions). Retention of the microspheres and bacteriophages increased with increasing ionic strength. The addition of divalent ions (Ca2+) influenced the retention to a greater extent than monovalent ions (Na+). The effects of the aperture distribution variability, matrix diffusion, and specific discharge on the solute and microsphere transport were determined from the transport tests conducted in two fractures. The higher variability in the aperture distribution contributed to higher solute dispersion, and flow channeling as evident from the breakthrough curves for individual spatially distributed outlets. A three-dimensional model simulation of the bromide transport with varying matrix porosity identified that the porous matrix influenced the solute transport. In the transport tests, retention of the microspheres decreased with increasing specific discharge in both fractures. The results of this research have helped in identifying the important factors and their effects on solute, virus, and virus-sized colloid transport in fractured dolomite rocks, which can be useful in determining the risk of pathogen contamination of water supplies in fractured dolomite rock aquifers.

El conocimiento de las interacciones entre célula/proteína/biomaterial es fundamental para la ingeniería de superficies debido a las numerosas aplicaciones biomédicas y biotecnológicas que se están desarrollando así como al éxito clínico que han alcanzado muchos implantes. La respuesta biológica final inducida por los implantes está fuertemente influenciada por las interacciones superficiales entre los componentes biológicos y el material sintético. Las propiedades físicas y químicas de la superficie de un biomaterial, en lugar de las propiedades en su masa, influyen directamente en la capa de proteínas que se adsorben sobre el biomaterial y, como consecuencia de ello, en la respuesta celular a la misma, tanto in vitro como in vivo.El objetivo de esta tesis doctoral es profundizar en el conocimiento de las interacciones material-biosistema, con el énfasis en el descubrimiento de relaciones entre las propiedades superficiales de las superficies de titanio y su respuesta biológica in vitro.El titanio comercialmente puro (Ti c.p.) está siendo ampliamente utilizado con éxito durante muchos años como biomaterial para implantes en cirugía ósea. Su excelente biocompatibilidad se basa en sus adecuadas propiedades mecánicas y, con mayor importancia, en su excelente resistencia a la corrosión. Esta última se debe principalmente a la formación espontanea de una fina película de óxido de titanio que le confiere protección natural contra los ataques degradativos. La modificación de la topografía de la superficie del titanio ha sido objeto de investigación en el pasado con el fin de mejorar la osteointegración. El granallado de partículas es una de las tecnologías más utilizadas para conferir rugosidad a las superficies del titanio. La rugosidad óptima y el tipo de partículas abrasivas del granallado para una respuesta óptima in vitro e in vivo fue previamente determinada en nuestro laboratorio. Sin embargo, todavía están por determinar cuáles son las causas últimas que llevan al biomaterial a su exitosa respuesta biológica.En este trabajo se han estudiado superficies pulidas y rugosas de Ti c.p. obtenidas mediante el granallado con partículas abrasivas de diferente composición química(Al2O3 y SiC) y diferentes tamaños (212-300&#956;m; 425-600&#956;m; 1000-1400&#956;m). La completa caracterización de las propiedades física y química de la superficie, incluyendo la rugosidad, la composición química, la mojabilidad/energía libre y la carga eléctrica de las superficies ensayadas ha llevado a una serie de relevantes conclusiones. Entre ellas, cabe destacar que a) la composición química de las partículas de granallado, así como el método de esterilización fueron los principales factores que influyeron en la mojabilidad y la energía libre superficial de las superficies de titanio estudiadas, b) el método de esterilización cambió en la energía superficial el carácter de donante de electrones de las superficies mediante el cambio de la cantidad y la naturaleza de las sustancias adsorbidas, y c) la composición química de las partículas de granallado no influyó en la carga eléctrica a pH fisiológico ni en el punto isoeléctrico de las superficies.Un segundo paso consistió en el uso de una microbalanza de cristal de cuarzo con monitorización de la energía de disipación, para el estudio de la cinética de adsorción (cantidad y conformación) y de los procesos de adsorción competitiva de tres proteínas de especial interés en los procesos de curación del hueso - la albúmina de suero bovino (BSA), el fibrinógeno (Fbg), y la fibronectina (Fn)- en sensores lisos recubiertos de TiO2. Se determinaron diferentes modelos de procesos de adsorción con una, dos o múltiples pasos distinguibles en función de las proteínas en solución. La capa adsorbida de BSA mostró los cambios más significativos en sus propiedades mecánicas, de conformación y de incorporación de agua hasta que se alcanzaron las condiciones estables de adsorción de proteínas. La BSA, la más pequeña de las proteínas ensayadas, desplazó la Fn y el Fbg cuando se ensayó en condiciones de la competencia por la adsorción, indicando su mayor afinidad por las superficies de TiO2. También se emplearon técnicas de marcaje fluorescente para el estudio de la adsorción proteica en superficies rugosas granalladas. En este estudio, por un parte, se pudo determinar que la cantidad de Fn y BSA adsorbidas en las superficies granalladas está directamente correlacionada con su energía superficial. Por otra parte, se visualizó la adsorción de fibronectina en solución sobre muestras granalladas rugosas de Ti. La Fn formó un patrón irregular de adsorción con una mayor cantidad de proteína adsorbida en los picos que en los valles de la topografía.También se evaluó la organización espacial de la matriz extracelular de los osteoblastos, ECM, sobre superficies de Ti lisas y rugosas por medio de la visualización de las fibrillas de Fn teñidas con marcador fluorescente. Las células osteoblásticas depositaron las fibrillas de Fn con un determinado patrón organizado dentro de la matriz total secretada. Aparecen como una película que cubre la parte superior de las diferentes superficies rugosas de titanio. Un resultado relevante es que el espesor de esta capa aumentó con la rugosidad de la topografía subyacente. Sin embargo no más de la mitad de la máxima distancia pico-valle se cubrió con la proteína secretada y/o reorganizada.Por último, teniendo en cuenta las diferencias en la organización de la ECM y laadsorción de Fn en las superficies ensayadas de Ti, se realizó un estudio de qRT-PCR para determinar la influencia de las propiedades superficiales del titanio, con y sin preadsorción de Fn, en la respuesta osteoblástica. La expresión génica de la subunidad &#61537;5 de la integrina celular, como marcador de la adhesión celular, se incrementó en las superficies granalladas con SiC en comparación con las granalladas con alúmina. Este resultado fue correlacionado con la mayor cantidad de Fn adsorbida debido a la mayor energía superficial de las superficies granalladas con SiC. El aumento de la rugosidad, así como la presencia de partículas de alúmina en las superficies rugosas incrementó la actividad de ALP y la expresión génica de ALP mRNA por los osteoblastos, y por lo tanto su diferenciación. / The understanding of cell/protein/biomaterial interactions is critical to the engineering of substrates for numerous biomedical and biotechnological applications and to the clinical success of implants. The final biological response induced by implants is strongly influenced by the biological-components/synthetic-material surface interactions. It is well accepted that the physical and chemical surface properties of a biomaterial rather than its bulk properties will influence the protein adlayer and then the cell response to it, both in vitro and in vivo.The aim of this PhD thesis is to gain an increased understanding of the materialbiosystem interactions, with an emphasis on establishing correlations between surface properties of titanium surfaces and its in vitro biological response.Commercially pure titanium (c.p. Ti) is being widely and successfully used implant biomaterial in bone surgery over many years. Its excellent biocompatibility is based in its appropriate mechanical properties and, more importantly, in its excellent corrosion resistance, which is mainly due to the presence of a naturally-occurring thin protective titanium oxide film. Modification of titanium surface topography has been a subject of research in the past with the purpose of improving its osseointegration. Grit blasting is one of the most used technologies to roughen titanium surfaces for this purpose. The optimal roughness and type of abrasive blasting-particles for a better in vitro and in vivo response was previously determined in our lab. However, which and how different relevant surface properties of the blasted titanium surfaces induce that optimal biological behavior is still poorly understood.Smooth/polished and rough c.p. Ti surfaces obtained by blasting with abrasiveparticles of different chemical composition (Al2O3 and SiC) and different sizes (212-300&#956;m; 425-600&#956;m; 1000-1400&#956;m) were studied. The comprehensive characterization of physical and chemical surface properties, including roughness, chemical composition, wettability/free energy and electrical charge of the tested surfaces led to a series of relevant conclusions. Among them, it is worth noting that a) the chemical composition of the grit-blasting particles as well as the method of sterilization were found the main factors influencing wettability and surface free energy of the titanium surfaces; b) the sterilization method changed the electron donor character of the surfaces by changing the amount/nature of physisorbed substances on the surfaces, and c) the chemical composition of the blasting particles did not influence on the electrical charge at physiological pH and the isoelectric point of the surfaces.A second step consisted in the use of a quartz crystal microbalance with monitoring of the energy dissipation to study the adsorption kinetics (amount and conformation) and adsorption competition processes of three proteins of special interest in the healing processes of bone -bovine serum albumin (BSA), fibrinogen (Fbg), and fibronectin (Fn)-on smooth TiO2-coated sensors. Different patterns of adsorption with processes in one, two or multiple distinguishable steps were determined depending of the protein in solution. The BSA adlayers showed the most significant changes in their mechanical properties/conformation/incorporation of water until steady protein-adsorption conditions were reached. BSA, the smallest of the tested proteins, displaced Fn and Fbg when in competition for adsorption, which is an indication of its higher affinity for TiO2 surfaces. Fluorescent labelling techniques where used to study protein adsorption on blasted rough surfaces. Most significantly, the amount of Fn and BSA adsorbed on blasted surfaces was positively correlated with their surface energy. The adsorption of fibronectin from solution on shot-blasted rough titanium surfaces resulted in an irregular pattern of adsorption with a higher amount of protein adsorbed on peaks than on valleys of the topography.Further, the spatial organization of the osteoblast extracellular matrix, ECM, on smooth and rough Ti surfaces was evaluated by visualizing fluorescently-stained Fn-fibrils. Osteoblast-like cells deposited Fn- fibrils in a specific facet-like pattern that was organized within the secreted total matrix. It appeared as a film overlying the top of the different rough titanium surfaces. Interestingly, the thickness of this layer increased with the roughness of the underlying topography, but no more than half of the total maximum peak-to-alley distance was covered.Finally, taking into consideration the differences in ECM organization and Fn adsorption on the tested Ti surfaces a qRT-PCR study was carried out to elucidate the influence of titanium surface properties with and without Fn-precoatings on the osteoblast response. The expression of &#61537;5 integrin subunit gene, as a marker for cell adhesion, was increased in SiC-blasted surfaces compared to alumina-blasted surfaces. This was related to the higher amount of adhesive-protein Fn adsorbed caused by the higher surface energy of SiC-blasted surfaces. The increase of roughness as well as the presence of alumina particles on blasted surfaces increased ALP activity and ALP mRNA gene expression by osteoblasts, and so their differentiation.This research work contribute to increase our knowledge on the interactions taking place at the bio/non-bio interface between different biological components -water, proteins, cells- and materials of clinical relevance, such as rough titanium. Theintertwined effects of the different properties of the synthetic surfaces appear as a challenge to unravel the ultimate causes that determine the fate of cells on synthetic biomaterials.

Off-road and racing motorcycles require a particular setup of the suspension to improve the comfort and the safety of the rider. Further, due to ground unevenness, off-road motorcycle suspensions usually experience extreme and erratic excursions in performing their function. In this regard, the adoption of nonlinear devices, such as progressive springs and hydro pneumatic shock absorbers, can help limiting both the acceleration experienced by the sprung mass and the excursions of the suspensions. For dynamic analysis purposes, this option involves the solution of the nonlinear differential equations that govern the motion of the motorcycle, which is excited by the stochastic road ground profile. In this study a 4 degrees-of-freedom (4-DOF) nonlinear motorcycle model is considered. The model involves suspension elements with asymmetric behaviour. Further, it is assumed that the motorcycle is exposed to loading of a stochastic nature as it moves with a specified speed over a road profile defined by a particular power spectrum. It is shown that a meaningful analysis of the motorcycle response can be conducted by using the technique of statistical linearization. The validity of the proposed approach is established by comparison with results from pertinent Monte Carlo studies. In this context the applicability of auto-regressive (AR) filters for efficient implementation of the Monte Carlo simulation is pointed out. The advantages of these methods for the synthesis of excitation signals from a given power spectrum, are shown by comparison with other methods. It is shown that the statistical linearization method allows the analysis of multi-degree-of-freedom (M-DOF) systems that present strong nonlinearities, exceeding other nonlinear analysis methods in both accuracy and applicability. It is expected that the proposed approaches, can be used for a variety of parameter/ride quality studies and as preliminary design tool by the motorcycle industry.

The frictional behavior of soil-construction material interfaces is of significant importance in geotechnical engineering applications such as retaining structures, pile foundations, geosynthetic liners, and trenchless technologies. Since most failures initiate and develop on the interfaces, special attention is required to predict the capacity of these weak planes in the particular application. Pipe-jacking and microtunneling technologies are being more widely used over the past decade and there is significant interest to predict the jacking forces and jacking distances achievable in order to achieve more efficient design and construction. This study focuses on the evaluation of the frictional characteristics and factors affecting the shear strength of pipe-soil interfaces. Eight different pipes made from fiber reinforced polymer (FRP), polycrete, steel, concrete, and vitrified clay were tested in the experimental program. For this purpose, a new apparatus was designed to conduct conventional interface direct shear testing on pipes of different curvature. This device allows coupons cut from actual conduits and pipes to be tested in the laboratory under controlled conditions. The apparatus includes a double-wall shear box, the inner wall of which is interchangeable to allow for testing against surfaces of different curvatures. By considering a narrow width section, the circular interface of pipes was approximated with a surface along the axial direction and the boundary is defined by the inner box. Roughness tests were performed using a stylus profilometer to quantify the surface characteristics of the individual pipes and relate these to the interface shear behavior. The surface topography showed different degrees of variability for the different pipes. To extend the range of roughness values tested and force the failure to occur in the particulate media adjacent to the interface, two artificial pipe surfaces were created using rough sandpapers. Interface shear tests were performed using the new apparatus with air-pluviated dense specimens of Ottawa 20/30 sand. Additional tests were performed using Atlanta blasting sand to evaluate the effect of particle angularity. The effect of normal stress and relative density were also examined. The interface strength was shown to increase with surface roughness and finally reach a constant value above a certain critical roughness value, which corresponded to the internal strength of the soil itself. This represented the failure location moving from the interface into the soil adjacent to the interface. Both the strength and the shearing mechanism were thus affected by the surface topography. It was also shown that the interface shear strength was affected by particle angularity, relative density and normal stress.

The effect of environmental modification of predator sensory abilities remains largely unknown, despite the importance of predators to ecosystem function. I conducted a series of experiments to investigate effects of hydrodynamics on the chemosensory search behavior and foraging success of two species of marine gastropods, knobbed whelks (

Fuel cells represent a promising energy alternative to the traditional combustion of fossil fuels. In particular, solid oxide fuel cells (SOFCs) have been of interest due to their high energy densities and potential for stationary power applications. One of the key obstacles precluding the maturation and commercialization of planar SOFCs has been the absence of a robust sealant. A leakage computational model has been developed and refined in conjunction with leakage experiments and material characterization tests at Oak Ridge National Laboratory to predict leakage in a single interface metal-metal compressive seal assembly as well as multi-interface mica compressive seal assemblies. The composite model is applied as a predictive tool for assessing how certain parameters (i.e., temperature, applied compressive stress, surface finish, and elastic thermo physical properties) affect seal leakage rates.