Orientador: Danilo Domingues Millen / Resumo: O objetivo deste estudo foi avaliar a redução do tempo de adaptação à rações com alto teores de energia para bovinos Nelore canulados em confinamento com a utilização de virginiamicina (VM) como aditivo alimentar, em que foram avaliadas as seguintes variáveis: pH, temperatura, e potencial de óxido-redução do rúmen, taxa de desaparecimento, digestibilidade total e degradabilidade ruminal de nutrientes, seletividade da ração e comportamento ingestivo, produtos da fermentação ruminal, assim como dados de ingestão de matéria seca. O delineamento experimental foi em quadrado latino 5x5, e cada período durou 21 dias, com 7 dias de washout entre o final e o início de um novo período. Foram utilizados 5 bovinos inteiros, com peso vivo aproximado de 414.86 ± 21.71 kg e com 17 meses de idade. Neste estudo os animais foram divididos em cinco tratamentos: 1) Monensina (MON; 30 mg/kg) com adaptação por 14 dias; 2) MON (30 mg/kg) + VM (25 mg/kg) com adaptação por 14 dias; 3) VM (25 mg/kg) com adaptação por 14 dias; 4) VM (25 mg/kg) com adaptação por 9 dias; e 5) VM (25 mg/kg) com adaptação por 6 dias. Bovinos que consumiram apenas MON tiveram menor concentração de butirato (P=0,02) e maior concentração de propionato (P=0,04), quando comparados aos que consumiram VM e foram adaptados por 14 dias. E animais que consumiram VM e foram adaptados por 14 dias tiveram maiores proporções AGCC quando comparados com animais que consumiram VMMON (P= 0,05) e quando comparados com animais que consumiram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the reduction of adaptation length to the high-energy diet offered to cannulated Nellore cattle using Virginiamycin (VM) as sole feed additive, in which the following variables were assessed: pH, temperature,and ox-redox potential of the rumen, rate of disappearance, total tract digestibility and rumen nutrient degradability, feed particles sorting and feeding behavior, ruminal fermentation end-products, as well as dry matter intake. It was adopted the experimental design in a 5 x 5 Latin square, where each period lasted 21 days, with 7-day washout between the end and the beginning of a new period. Were used 5 Nellore yearling bulls,with approximately 414.86 ± 21.71 kg of body weight and 17 mo-old. In this study, the animals were divided into five treatments: 1) MON (30 mg/kg) adapted by 14 days; 2) MON (30 mg/kg) + VM (25 mg/kg) adapted by 14 days; 3) VM (25 mg/kg) adapted by 14 days; 4) VM (25 mg/kg) adapted by 9 days and 5) VM (25 mg/kg) adapted by 6 days.Bovine animals that consumed only MON had lower concentration of butyrate (P = 0.02)and higher concentration of propionate (P = 0.04) when compared to those that consumed VM and were adapted for 14 days. Animals that consumed VM and were adapted for 14 days had higher AGCC ratios when compared to animals that consumed VMMON (P = 0.05) and when compared to animals that consumed only MON (P = 0.04). As the adaptation time increased for animals that consumed VM, the dry matter inta... (Complete abstract click electronic access below) / Mestre

The ability to predict the dispersion of substances in the Great Salt Lake is a requisite towards making responsible management decisions relating to uses of the lake. The lake is a complex terminal body of water and will require a fairly sophisticated mathematical model to properly simulate the dispersion process in the lake. This finite element convection-dispersion model is a first step towards developing a comprehensive model. The model provides a finite element solution to the two-dimensional convection-dispersion equation and is capable of simulating steady or unsteady-state situations. It utilizes a known velocity field, dispersion coefficients, an introduced substance concentration, substance decay rates, and the region geometry to produce a solution to a given convection-dispersion problem. At the present time, a quantitative verification of the model has not been done, but qualitative use of the model indicates that it yields reasonable solutions satisfying continuity to convection-dispersion problems. Problems tested utilize a uniform flow field and various methods of introducing a substance, such as internal injections, established concentration gradients, and diffusers. This model affords the options in the approximating techniques of linear or quadratic interpolation functions, the Galerkin or "upwinding" methods of weigh ted residuals, and a linearly or quadratically varying velocity field. The model must use a continuous flow field to produce a credible solution. The model does need improvement in its ability to conserve mass in unsteady-state problems when introducing a substance into the modeled region and allowing dispersive transport at the boundaries. Proper nodal spacing (mesh size) is also important because a relatively coarse mesh size can result in poor approximations in some areas of the region modeled.

Nationwide, housing authorities demolish public housing communities and relocate the existing residents in an attempt to create more favorable neighborhood environments and to promote safer and more efficacious social interactions for public housing residents. Yet, studies of public housing relocation do not find strong evidence of beneficial social interaction occurring between relocated residents and new neighbors. Despite increased safety and relative increase in neighborhood economic standing, studies find relocated residents socialize outside of their new neighborhoods or else limit existing neighborhood interactions as compared to living in public housing communities. This raises the question of why relocated residents either do or do not choose to interact with their new neighbors within their new residential settings. In an effort to answer this question, I have conducted a study focused on neighborhood social interactions using public housing residents relocated from six of Atlanta, Georgia’s public housing communities. As a backdrop to the study, I present relevant literature concerning both the study of neighborhoods and the study of prior relocation endeavors. I argue that neighborhoods do provide important social landscapes for attempting to benefit public housing residents, though more research and a different framework of analysis are needed in order to manifest theorized outcomes of relocation for all residents involved. I then employ the use of both quantitative survey data from 248 relocated residents and qualitative in-depth interview data from 40 relocated residents to provide further insight into social interaction patterns after relocation from Atlanta’s public housing. This research finds that prior to relocation residents in public housing communities differed in terms of their ideal zones of action and preferred levels of inclusion and engagement in the neighborhood setting and in terms of their surrounding community scene. By examining these different ideal-types of residents in detail, I argue that prior to moving the residents, a better fit between resident and neighborhood can be constructed by housing authorities such that more beneficial social interaction outcomes can be achieved overall in the relocation process.

Delivery of protein therapeutics is restricted to intravenous infusions due to protein-dependent problems including low solubilities, high viscosities, and physical instabilities. The ability to inject high concentrations of proteins via subcutaneous injections would increase accessibility and compliance. Large particles of a protein in a non-aqueous solvent can decrease the viscosity over a solution of equally concentrated individual protein molecules. The lower viscosity of a particle suspension is due to decreased surface area resulting in reduced electroviscous effects, solvation and deviations of the particle shape from a spherical geometry. Additional studies show that aqueous-based dispersions of antibody nanoclusters can be formed by increasing the attractive interactions between protein molecules using the excluded volume effects of extrinsic crowding agents. These novel, equilibrium, nanoclusters are maintained by a balance of highly attractive interactions and weak electrostatic repulsive interactions near the protein’s pI. These protein nanoclusters are ideal for subcutaneous delivery as they have low interactions between the colloids, are reversible in nature, and dissolve rapidly upon dilution in a buffer media. Through in vivo mouse studies, the bioavailability of a monoclonal antibody in the dispersion is prolonged and higher doses can be administered versus a solution. Overall, these studies with high concentration, low viscosity subcutaneous injections of protein therapeutics open new opportunities in biotechnology. For oral delivery of itraconzole, controlled flocculation of individual polymerically-stabilized nanoparticles is used to increase supersaturation. Flocculation of these nanoparticles is achieved by desolvating the polymer by changing the pH. The flocculated dispersions can then be easily filtered. The final amorphous powder maintains high supersaturation with simulated stomach and small intestine conditions and improves bioavailability of itraconazole, over the commercial product, Sporanox®. / text

The search for more sustainable construction methods has created a renewed interest in straw bales technology. Straw bales are a composite material that is energy efficient and durable. Rectangular straw bales stacked in a running bond and plastered on the interior and exterior faces have adequate strength to resist typical loads found in two-storey structures. The structural behaviour of a load-bearing plastered straw bale wall subject to uniform loading is well researched. However, door and window voids in the wall redistribute vertical load paths and produce areas of concentrated stress. This thesis describes experiments on small-scale plastered straw bale panels subjected to loading conditions that simulate the loading conditions experienced in areas around door and window voids. Twenty-one specimens were tested under two main types of loading conditions. The specimens were rendered with lime-cement plaster, were one to three bales (0.33 m to 0.99 m) in height, and were either unreinforced, or contained metal diamond lath or chicken wire embedded within the plaster. The specimens were pin-supported at various centre-to-centre distances ranging from 200 mm to 500 mm and were loaded either uniformly or by a point load. Two distinct types of failure were observed. Strut-and-tie models were developed to describe the structural behaviour of panels undergoing vertical cracking of the plaster skin at failure. Bearing models were developed to describe the structural behaviour of panels undergoing crushing of the plaster skin beneath the point of applied load. The models predicted the correct failure mode of 92% of the specimens and had an average ratio of experimental strength to theoretical strength of 0.95 with a standard deviation of 0.17. The results show that the behaviour of plastered straw bale walls can be predicted using common methods of structural analysis. A parametric analysis of door and window voids within plastered straw bale walls is presented. / Thesis (Master, Civil Engineering) -- Queen's University, 2010-09-30 11:32:53.613

A background of concentrated solar power, and finite element analysis are provided, along with further technical details on the physics of parabolic light concentration and classical plate theory. The concept of optical efficiency is outlined, including the 5 contributing factors: the cosine effect, mirror reflectivity, blocking and shadowing, atmospheric attenuation, and surface irregularities. Surface irregularities are identified as the least predictable factor of optical efficiency, making them the subject of the experimental section. Physical and computational experimentation is conducted to determine a desirable selection for material of reflector substrate, thickness of reflector substrate, holding method of reflector, and aspect ratio of reflector. Physical and computational results are compared with one another to add validity to both sets of results. Recommendations are made for each design criteria selection, however it is found that in many cases the selection of reflector properties falls to an economic decision.

Plank (tongue and groove) wood decking is a product that is commonly used in post and beam timber construction to transfer gravity loads on roofs and floors. In 2010, The National Building Code of Canada changed the application area of the specified concentrated roof live loads from 750 mm x 750 mm to 200 mm x 200 mm. The change was made to better reflect the area which a construction worker with equipment occupies. Preliminary analysis showed that the change in the application area of concentrated loads may have a significant impact on the design of decking systems. Little research or development has been done on plank decking since the 1950’s and 1960’s. An experimental program was undertaken at the University of Ottawa’s structural laboratory to better understand the behaviour of plank decking under uniformly distributed and concentrated loads. Non-destructive and destructive tests were conducted on plank decking systems to investigate their stiffness and failure mode characteristics under uniformly distributed as well as concentrated loads. The experimental test program was complimented with a detailed finite element model in order to predict the behaviour of a plank decking system, especially the force transfer between decks through the tongue and groove joint. The study showed that the published deflection coefficients for uniformly distributed loads can accurately predict the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009). For unbalanced uniformly distributed loads on two-span continuous layup, it was found that the deflection coefficient of 0.42 was non-conservative. It was also found that under concentrated loads, the stiffness of the decking system increased significantly as more boards were added. A deflection coefficient of 0.40 is appropriate to calculate the deflection for the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009) under concentrated load on an area of 200 mm by 200 mm. Significant load sharing was observed for plank decking under concentrated loads. An increase in capacity of about 1.5 to 2.5 times the capacity of the loaded boards was found. Furthermore, it was found that placing sheathing on top of a decking system had a significant effect in the case of concentrated load with an increase of over 50% in stiffness and over 100% in ultimate capacity.

This thesis provides empirical evidence on the relation between concentrated ownership and the long term operating performance of acquiring firms. Large shareholders are generally viewed as beneficial monitors of corporate performance but high levels of concentration can lead to potential expropriation from minority shareholders via managerial entrenchment, tunneling, or sub-optimal investment decisions. This problem is potentially greater in firms with separation of voting and ownership rights. This thesis investigates the performance around takeovers in English origin countries other than the US by following the classification of La Porta, Lopez-de-Silanes, Shleifer and Vishny (1998). While generally considered similar to the US, these countries vary with respect to ownership concentration and investor protection. This thesis controls a broad set of corporate governance mechanisms including first generation governance measures like CEO positions, board characteristics, and other blockholders. Furthermore, this thesis also examines whether different degrees of second generation governance mechanisms such as anti-director rights, accounting standards, legal enforcement, and extra-legal institutions lead to different levels of M&A performance. In addition, this thesis includes the new legal indexes recently developed by Djankov, La Porta, Lopez-de-Silanes and Shleifer (2006); these measures have yet to be examined through empirical research. By using an accounting based methodology, this thesis presents Healy, Palepu and Ruback (1992) abnormal post cash flow return regression-based results and results of a change model (Ghosh 2001). Moreover, this thesis refers to the sample matching techniques in Barber and Lyon (1996) and develops the industry, size, and pre performance benchmark. The principal finding of this thesis is that M&A transactions should improve the long-term financial and operating performance of merging firms to reflect that accounting performance can capture real economic creations. After controlling for well documented governance mechanisms and deal characteristics, the relationship between concentrated ownership and the level and change in operating cash flow returns after takeovers is non-linear. Value creating deals are associated with higher levels of concentration consistent with decreasing agency costs as the large shareholder’s wealth invested in the acquiring firm increases. Further, separation of ownership and voting rights leads to greater value destruction; acquiring firms with controlling CEO make significant improvements in post acquisition performance after controlling pre-performance; and the presence of CEO-Chairman duality and board size are both significantly negatively associated with acquisition operating performance. This thesis also finds, although all acquiring firms are from English origin countries, that the greater investor protection, as measured by the initial anti-director right index in La Porta et al. (1998) and revised anti-director rights index in Djankov et al. (2006) has a positive impact on operating cash flow returns from acquisitions. However, this thesis does not document any differential performance with respect to the extra- legal systems of Dyck and Zingales (2004) and the anti-self-dealing index of Djankov et al. (2006).

Riparian buffers are a commonly utilized best management practice (BMP) for mitigating non-point source pollution from agricultural fields. This practice is most effective when runoff enters the buffer as sheet flow. However runoff from becomes concentrated and forms concentrated flow paths (CFPs) breaking through the buffer in critical erosional areas. These critical areas can be determined prior to the implementation of a BMP such as a riparian buffer through incorporation of the Revised Universal Soil Loss Equation (RUSLE) with Geographic Information Systems (GIS). This approach utilizes field characteristics with hydrological processes in order to determine the erosion risk areas from observed field data throughout an entire watershed. In order to re-establish a riparian buffer in critical areas managers need a method that can prevent erosion and the loss of top soil. This study evaluates an innovative method, "Buffer in a Bag", used to restore riparian buffer benefits and to prevent further erosion in CFPs. There were three different treatments initiated for this study the first two treatments the "Buffer in a Bag", and Hand-Planted were implemented prior to the broadcasting of switchgrass seed. The final treatment was the Control, which required no planting within the treatment plot. The "Buffer in a Bag" treatment utilized the placement of giant cane rhizomes within burlap bags along the channel of concentrated flow. The hand planted treatment utilized the placement of giant cane rhizomes planted in the agricultural field adjacent to the path of concentrated flow. The presence of these CFPs breaking through riparian buffers has been noted, but the actual significant soil erosion occurring within the CFP and in the adjacent field has yet to be quantified. Through the use of topographical surveys and geostatistical analysis to produce digital elevation models (DEM) of in-field elevation changes the hydrological processes and volumetric difference for CFPs can be determined. The goal was to define the variability and the spatial pattern from the data as a means of providing comparisons between subsequent survey periods over time and space to estimate the difference and movement of sediment within CFPs. The volumetric differences found when comparing the DEMs between survey periods provide a quantifiable method for evaluating the implementation of a treatment, such as the "Buffer in a Bag". Using geostatistical analysis of volumetric difference between the treatment plots determined that that there was no significant difference between the CFP's over the study period. The mean percentage volumetric difference within the treatment plots between "Buffer in a Bag", Hand-Planted, and Control treatments were -2.49%, -3.72%, and -2.37%, respectively. There was overall net erosion across all treatments with the erosion and accumulation being significantly different across the survey periods for all the treatment CFPs. The mean percentage volume loss across treatments and survey periods varied from positive 10% accumulation to negative 15% erosion for overall loss when looking at each individual survey and CFP. The displayed loss of valuable topsoil and continued expansion of these concentrated flow paths emphasis the need for research in further management applications. There needs to be an effective method developed to address the volumetric difference within CFPs forming in these high risk erosion areas. Using a GIS/RUSLE approach to indicate these high risk erosion areas will hopefully facilitate the prevention of the formation of concentrated flow paths prior to the implementation of a BMP, such as riparian buffers.

Sediment and nutrient loss from agricultural landscapes contributes to water quality impairment and has the potential to impact crop yield. Best management practices (BMPs) such as riparian buffers have been designed to combat these issues; however, concentrated flow paths (CFPs) reduce their effectiveness and are often overlooked in agricultural fields. Conventional management of CFPs is to fill and grade them, however this provides only a short term solution leading to their reformation and increased sediment loss. The objectives of this project were: i) to determine if the filling of CFPs influence crop growth (yield and biomass), ii) determine a distance at which crop growth is no longer influenced by CFPs, iii) assess the impact that topography and CFPs have on crop growth, iv) analyze water quality in surface runoff leaving crop fields via CFPs, and v) develop an economic analysis for CFP’s influence on crop returns. Six small agricultural catchments, CFPs, and topographic positions (i.e., depositional, backslope, and shoulder) were delineated using ArcGIS and LiDAR data. In each catchment, six 4 m2 plots were established along CFPs where crop biomass and crop yield were measured. Additionally, six plots with no influence from CFPs were established as reference plots. Surface water quality was assessed by taking edge-of-field grab samples at the CFP outlet during significant rain events (i.e., precipitation exceeding 2.5 cm). Water samples were analyzed for total suspended solids (TSS), total phosphorus (TP), dissolved reactive phosphorus (DRP), ammonium-nitrogen (NH4+-N), and nitrate-N (NO3- -N). Through this study it was shown that CFPs served as a conduit for transporting nutrient and sediment laden runoff to receiving waters, that increasing/decreasing distance from CFPs had an impact on crop yields, and that there was no crop yield advantage from the filling of CFPs vs. leaving them unfilled. Median values for NO3-N (1.85 mg L-1) and TSS (140 mg L-1) in the Fill catchments were higher than the No-Fill catchments (0.77 mg L-1 and 35.5 mg L-1, respectively), while DRP and TP concentrations were higher in the No-Fill catchments (1.31 mg L-1 and 2.37 mg L-1, respectively) compared to the Fill catchments (0.91 mg L-1 and 1.83 mg L-1, respectively) over the growing season. Crop biomass and yield results between the depositional and backslope positions were similar regardless of treatment, but were lower than the reference plots and shoulder position. Results from the economic analysis on the cost of farming in/near CFPs indicated that the economic return was greatly dependent on precipitation. CFPs are generally concave positions on the landscapes and have been eroded to a clayey subsoil, both resulting in greater water accumulation and retention than elsewhere in the field. During wetter years, an economic loss was incurred nearest to the CFP and during drier years, sites nearest to CFPs saw positive returns. Farmers and land managers may consider implementing stabilization measures, such as grassed waterways, in CFPs since crop yields are typically lower in wetter years, there’s increased cost to maintain these areas, and accelerated sediment loss can exacerbate the crop yield losses and impact on water quality.