Biosensor mathematical and computer modeling is an important task for the development of new biosensors and for the improvement of the existing ones. Objects of this study are mathematical and numerical models which describe operation of novel lipase activity assessment biosensors and theoretical biosensor with controllable permeability membrane. Specific aims of this thesis are to identify what mathematical and numerical models are best suited for modeling specific lipase activity assessment biosensors and to identify what parameters of operation are specific for biosensor with controllable membrane. Also to identify the conditions which would reveal the positive and negative features of controllable membrane. It was discovered that in the case of lipase activity assessment biosensor the classic mathematical model should be extended with a non-linear term (in respect to substrate). Also, it was discovered that biosensor with controllable membrane would be useful in cases when biosensor cannot be physically removed from the operating environment, but still needs to be reconfigured for operation in the kinetic or diffusion mode. / Matematinis ir skaitinis biojutiklių modeliavimas yra svarbus uždavinys, kuriant naujus ir tobulinant esamus biojutiklius. Disertacijos tyrimo objektas – matematiniai bei skaitiniai modeliai, aprašantys naujoviškų lipazės aktyvumo nustatymo biojutiklių bei teorinio biojutiklio, padengto valdoma membrana, veikimą. Tyrimo tikslai – nustatyti, kokie matematiniai ir skaitiniai modeliai geriausiai tinka lipazės aktyvumo nustatymo biojutikliams aprašyti, taip pat nustatyti, kokiais parametrais pasižymėtų biojutiklis, turintis valdomą membraną, kokiomis sąlygomis išryškėtų jo privalumai ir trūkumai. Nustatyta, kad lipazės aktyvumo matavimo biojutiklio modeliavimui klasikinį modelį reikia papildyti netiesiniu nariu. Biojutiklis su valdoma membrana pasiteisintų, jei fiziškai neištraukiant jutiklio iš darbinės aplinkos, reikėtų perjunginėti jo darbo režimą iš difuzinio į kinetinį ir atvirkščiai.

Computational fluid dynamics (CFD) has been extensively used in the study of building energy usage and thermal comfort in buildings, however there remains the need to thoroughly evaluate the accuracy of the results given by such CFD methods. The present study involves a numerical investigation of the flow and temperature distribution in the atrium situated in the Concordia University Engineering Building. The study involved a steady-state simulation of the conditions in the atria on August 1, 2007, a date for which experimental data was available for validation of the numerical results. The commercial CFD solver FLUENT was used to solve the equations that govern the flow in the atrium. The realizable k- turbulence model incorporating buoyancy force effects was used. During the period studied a forced airflow through the atrium existed due to a mechanical air supply vent near the floor level. The natural convection in the atrium, induced by the temperature differences resulting mainly from the incoming solar radiation, was modeled using the bousinessq approximation. In general, good agreement was obtained between the numerical and experimental results. The numerical results also predicted the thermal stratification in the atrium relatively accurately. A parametric study was performed to assess the sensitivity of the numerical results to the assumed boundary conditions used in the study. An evaluation of the thermal comfort levels in the atrium was also undertaken using the numerical results. This indicated that while regions of thermal discomfort did exist in the atrium, these regions constituted only a small part of the atrium. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-09-25 17:29:46.857

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Se inadequadamente localizadas ou insuficientemente protegidas, as necrÃpoles apresentam um importante problema de saÃde pÃblica e riscos de contaminaÃÃo a aquÃferos. Em Teresina, PiauÃ, o caso do cemitÃrio Areias, localizado Ãs margens do Rio ParnaÃba e prÃximo do ponto de captaÃÃo de Ãgua para abastecimento pÃblico, chama a atenÃÃo para o descaso da falta de gerenciamento de Ãreas contaminadas e reverbera o estado atual da gestÃo de aquÃferos impactados por necrÃpoles no Brasil. Este estudo propÃs a forma adequada de investigaÃÃo do passivo ambiental causado por necrÃpoles. AlÃm disso, utilizou a modelagem computacional de aquÃferos para melhorar o diagnÃstico de contaminaÃÃo, adequando soluÃÃes que garantissem a qualidade e a simplicidade do modelo. Ademais, este estudo propÃs a implantaÃÃo de dispositivos que melhorassem os critÃrios de licenciamento indicados pela ResoluÃÃo CONAMA 368/2006. Os resultados demonstraram que o uso das etapas sugeridas podem auxiliar no gerenciamento de aquÃferos impactados por necrÃpoles e prevenir o surgimento de novos passivos ambientais em Ãrea urbana. / If inappropriately located or insufficiently protected, the necropolis mean an important problem for public health and contamination risks to aquifers. In Teresina, PiauÃ, the case of the cemetery Areias, located near the ParnaÃba River and close to the water intake for public supply, calls attention to negligence the management of contaminated areas and reflects the current state of aquifers management impacted by necropolis in Brazil. This study indicated the appropriate form of investigation environmental liabilities caused by necropolis. In addition, used the computer modeling of aquifers to improve the diagnosis of contamination, adapting solutions to ensure the quality and simplicity of the model. Furthermore, this study proposed the implementation of devices to improve the licensing criteria set by CONAMA Resolution 368/2006. The results showed that the use of the suggested steps can help manage aquifers impacted by necropolis and prevent the development of new environmental liabilities in urban areas.

A vascular corrosion cast of an entire mouse kidney was scanned with a modular multiresolution X-ray nanotomography system. Using an isotropic voxel pitch of 0.5 μm, capillary systems such as the vasa recta, peritubular capillaries and glomeruli were clearly resolved. This represents a considerable improvement over corrosion casts scanned with microcomputed tomography systems. The resolving power of this system was clearly demonstrated by the unique observation of a dense, subcapsular mat of capillaries enveloping the entire outer surface of the cortical region. Resolution of glomerular capillaries was comparable to similar models derived from laser scanning confocal microscopy. The high-resolution, large field of view and the three-dimensional nature of the resulting data opens new possibilities for the use of corrosion casting in research.

Hexahedral refinement increases the density of an all-hexahedral mesh in a specified region, improving numerical accuracy. Previous research using solely sheet refinement theory made the implementation computationally expensive and unable to effectively handle multiply-connected transition elements and self-intersecting hexahedral sheets. The Selective Approach method is a new procedure that combines two diverse methodologies to create an efficient and robust algorithm able to handle the above stated problems. These two refinement methods are: 1) element by element refinement and 2) directional refinement. In element by element refinement, the three inherent directions of a hexahedron are refined in one step using one of seven templates. Because of its computational superiority over directional refinement, but its inability to handle multiply-connected transition elements, element by element refinement is used in all areas of the specified region except regions local to multiply-connected transition elements. The directional refinement scheme refines the three inherent directions of a hexahedron separately on a hexahedron by hexahedron basis. This differs from sheet refinement which refines hexahedra using hexahedral sheets. Directional refinement is able to correctly handle multiply-connected transition elements. A ranking system and propagation scheme allow directional refinement to work within the confines of the Selective Approach Algorithm.

The effect of panel zone (PZ) flexibility and yielding on the stiffness and strength of steel moment resisting frames (SMRF) has been the topic of numerous papers over the past thirty years. When properly detailed, the PZ is an excellent source of energy dissipation, even under large inelastic deformations. Due to these large inelastic deformations, the PZ region may also be a weak link in steel moment frame behavior. Because of the importance of PZ deformation in the behavior of steel frames, accurate modeling of this region is critical. Two of the most commonly used mathematical models for representing PZ behavior are investigated. They are referred to herein as the Krawinkler model and the Scissors model. From the literature review conducted at the beginning of this study, it was determined that there were no PZ models available that accounted for the elastic drift associated with PZ flexure which could be used in computer representations using commercial software that is currently available. This thesis details the analytical work used to establish the estimated elastic drift associated with PZ flexure and a method to include this estimated drift and the contribution of continuity plates in the Krawinkler and Scissors models. This study is initially focused on elastic deformations of individual structural subassemblages. First, formulas are derived to account for each major elastic component of drift in an individual subassemblage. The results from these derivations were implemented into a computer program named PANELS to allow for rapid calculation of the estimated drifts. Then, the properties (elastic and inelastic) for the Krawinkler and Scissors models are derived in their entirety. The Krawinkler model's results are compared to the results from PANELS, neglecting the PZ flexural component in PANELS and any inelastic contributions in the Krawinkler model. Since the Krawinkler model does not include PZ flexure, this established that the derived formulas accounted for all the remaining sources of elastic strain energy, assuming that the Krawinkler model is accurate. The results from PANELS are compared to those from finite element models developed using ABAQUS. Using the ABAQUS results, a method for determining the elastic drift associated with PZ flexure in PANELS is presented. A detailed inelastic study of the Krawinkler and Scissors models is then conducted both on the subassemblage level and on full structural frames to determine any differences associated with them. First, the two models are compared to each other on a subassemblage level to ensure that they both give the same results. Then, both PZ models are included in multiple full structural frames using various design configurations and loading conditions to ascertain their differences. Initially it was believed that there would be a large disparity between the two models. This study shows that there is actually little difference between the two models, although the kinematics of the Scissors model is still questionable. Elastic and inelastic comparisons between the PANELS formulas (elastic) and the ABAQUS models (elastic and inelastic) and data collected from tests performed at Lehigh University by Dr. James Ricles are then presented. This was done to show that the ABAQUS models and the PANELS formulas (including the PZ flexural component) give an accurate estimation of the drift of a subassemblage. The results from these comparisons show that the modeling techniques used are accurate and not including PZ flexural component of drift will cause the overall drift estimate to be unconservative. Finally, a method of including the elastic component of drift attributed to PZ flexure and continuity plates in both models is presented. The Ricles' Lehigh test data is again used in an inelastic comparison between the original Krawinkler and Scissors models and their updated counterparts. These comparisons show that including this component enables both the Krawinkler and Scissors models to more accurately estimate the total drift of an individual subassemblage. / Master of Science

No / Paleoanthropological studies often center on teeth, not only because these elements are commonly preserved in the fossil record, but because they apparently contain a wealth of information with regard to development, phylogeny, and function. However, despite a plethora of studies, somefundamental problems are still unresolved. For example, while it is recognized that the 3-dimensional arrangement of enamel prisms may hold important information with regard to phylogeny (von Koenigswald and Sander, 1997) and function (Rensberger, 2000), many paleoanthropological studies have thus far relied on investigating enamel microanatomy as a 2-dimensional structure (e.g., Dean et al., 2001 C Dean, M.G Leakey, D Reid, F Schrenk, G.T Schwartz, C Stringer and A Walker, Growth processes in teeth distinguish modern humans from Homo erectus an earlier hominins, Nature 414 (2001), pp. 628¿631. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (120)Dean et al., 2001). This is mainly due to difficulties in visualizing and quantifying the 3-D structure of prisms. In order to overcome these limitations a computer model was developed (Jiang et al., 2003) which attempted to simulate the effects of biophysical processes governing enamel formation in modern humans (adapted from Osborn, 1970). Here we extend our model and present preliminary data on inter-specific variation in prism arrangement among primates. Furthermore, during our work torecreate the 3D microstructure of prismatic enamel it became increasingly clear that there are not only limitations with previous dental growth studies, but that these studies are based on fundamentally different concepts regarding evolutionary processes from those assumed in our approach. These limitations and differences will be highlighted also.

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