A real need exists for a sensor capable of detecting flow-field separation on an airplane wing during routine flight operations. A sensor of this type could lead to both improved flight safety and increased performance. It would also contribute to future separation control technologies. A new idea is presented for a sensor that is cost effective, easy to maintain, durable, and highly effective. The system, known as a Thermal Grid, works by using a grid of heaters and temperature sensors to trace out the streamlines closest to the surface. Specific singularities in these streamlines are excellent indicators of flow separation. This paper addresses many of the necessary principles that are necessary to making the Thermal Grid an operational device. An analytic design is presented that details the system requirements and potential performance, including heater/sensor spacing, heater power requirements, sensor time response and sensitivity needs and the effects of changes in flow conditions. / Master of Science

One strategy to manage pig slurry is centrifugation and composting of the solids fraction to produce a value added product to distribute manure nutrients further from productions sites. This study determined turned windrow composting was suitable for processing slurry solids throughout winter. It was also the first attempt at combining automated chambers and a Fourier Transform Infrared spectroscopy analyzer to measure multiple gases during the composting process; the system proved capable but captured fluxes better if conducted in an area sheltered from wind. Straw and woodshavings were shown suitable as bulking materials for composting slurry solids, however, the lack of porosity provided by woodshavings created anaerobic conditions that doubled the greenhouse gas emissions compared to those of straw, 1,126 kg CO2-equivalent Mg-1 compared to 526 kg CO2-equivalent Mg-1. Either bulking material produced compost of quality for use in agricultural or soil blending applications and was free of manure pathogens. / May 2016

An extensive review was made to study the wake characteristics of a backward-facing step. Experimental and numerical studies of the backward-facing step suggest that the wake of a separated shear layer to be dependent on parameters such as: expansion ratio, aspect ratio, free stream turbulence intensity, boundary layer state and thickness at separation. The individual and combined effects of these parameters on the reattachment length are investigated and discussed in detail in this thesis. A new scaling parameter, sum of step height and boundary layer thickness at separation is proposed, which yields significant collapse of the available data. Based on the literature review, an axisymmetric model is designed for further investigating the dynamics of the flow independent of aforementioned parameters. Additionally, porous suction strips are incorporated to study the step wake characteristics independent of Reynolds number. This model has been built and will be tested extensively at UTIAS.

An extensive review was made to study the wake characteristics of a backward-facing step. Experimental and numerical studies of the backward-facing step suggest that the wake of a separated shear layer to be dependent on parameters such as: expansion ratio, aspect ratio, free stream turbulence intensity, boundary layer state and thickness at separation. The individual and combined effects of these parameters on the reattachment length are investigated and discussed in detail in this thesis. A new scaling parameter, sum of step height and boundary layer thickness at separation is proposed, which yields significant collapse of the available data. Based on the literature review, an axisymmetric model is designed for further investigating the dynamics of the flow independent of aforementioned parameters. Additionally, porous suction strips are incorporated to study the step wake characteristics independent of Reynolds number. This model has been built and will be tested extensively at UTIAS.

The well-separated pair decomposition (WSPD) of the complete Euclidean graph defined on points in R 2 , introduced by Callahan and Kosaraju [JACM, 42 (1): 67-90, 1995], is a technique for partitioning the edges of the complete graph based on length into a linear number of sets. Among the many different applications of WSPDs, Callahan and Kosaraju proved that the sparse subgraph that results by selecting an arbitrary edge from each set (called WSPD-spanner) is a 1 + 8/(s − 4)-spanner, where s > 4 is the separation ratio used for partitioning the edges. Although competitive local-routing strategies exist for various spanners such as Yao-graphs, Θ-graphs, and variants of Delaunay graphs, few local-routing strategies are known for any WSPD-spanner. Our main contribution is a local-routing algorithm with a near-optimal competitive routing ratio of 1 + O(1/s) on a WSPD-spanner. Specifically, using Callahan and Kosaraju’s fair split-tree, we show how to build a WSPD-spanner with spanning ratio 1 + 4/s + 4/(s − 2) which is a slight improvement over 1 + 8/(s − 4). We then present a 2-local and a 1-local routing algorithm on this spanner with competitive routing ratios of 1 + 6/(s − 2) + 4/s and 1 + 8/(s − 2) + 4/s + 8/s 2 , respectively. Moreover, we prove that there exists a point set for which our WSPD-spanner has a spanning ratio of at least 1 + 8/s, thereby proving the near-optimality of its spanning ratio and the near-optimality of the routing ratio of both our routing algorithms.

Two laboratory incubation studies and a growth room bioassay of forage barley were conducted to investigate nitrogen (N) and phosphorus (P) mineralization, and nitrous oxide emission from two contrasting agricultural soils amended with anaerobically digested cattle manure (ADM). The ADM is a nutrient-rich co-product from manure-based biogas plants which is applied to cropland at rates used for raw manure since scientific information on nutrient release from ADM is lacking. Application of the separated solids fraction of ADM (SS) reduced nitrous oxide emission but resulted in lower N mineralization compared to raw manure in both soils. Raw manure- and SS- treatments had similar biomass yields and P supply capacities while the application of pelletized SS (PSS) caused net N immobilization, lower P release than manure and SS, and depressed barley yields relative to non-amended (control) soils.

Two laboratory incubation studies and a growth room bioassay of forage barley were conducted to investigate nitrogen (N) and phosphorus (P) mineralization, and nitrous oxide emission from two contrasting agricultural soils amended with anaerobically digested cattle manure (ADM). The ADM is a nutrient-rich co-product from manure-based biogas plants which is applied to cropland at rates used for raw manure since scientific information on nutrient release from ADM is lacking. Application of the separated solids fraction of ADM (SS) reduced nitrous oxide emission but resulted in lower N mineralization compared to raw manure in both soils. Raw manure- and SS- treatments had similar biomass yields and P supply capacities while the application of pelletized SS (PSS) caused net N immobilization, lower P release than manure and SS, and depressed barley yields relative to non-amended (control) soils.

<div>The dynamic performance of the momentum and thermal boundary layer linked to the acoustic response dictate the efficiency of heat exchangers and the operational limits of fluid machinery. The specific time required by the boundary layer to establish or adapt to the free stream variations is vital to optimize flow control strategies as well as the thermal management of fluid systems. The proper understanding of the wall fluxes, separated flow regions and free stream response to transient conditions becomes the fulcrum of the further improvement of fluid machinery performance and endurance. Throughout this dissertation the establishment sequence and the main parameters dictating the acoustic response and the boundary layer settlement are quantified together with their implication on the wall fluxes and boundary layer detachment. </div><div><br></div><div>Unsteady Reynolds Average Navier Stokes evaluations, Large Eddy Simulations, Direct Numerical Simulations and wind tunnel experiments are exploited to analyze the transient behavior of attached and detached flow aerodynamics. The core of the research is built upon URANS simulations allowing the realization of multiple detailed parametric analyses. Thanks to its reduced computational cost, hundreds of transient flow evaluations are carried out, enabling the determination of the establishment sequence, the main flow features and relevant non-dimensional numbers. The URANS methodology is verified against experimental and analytic results on the flow conditions of the study. The Large Eddy Simulations and Direct Numerical Simulations allow further characterization of the near wall flow region behavior with much higher resolution while providing an additional source of verification for the coarser numerical tools. An experimental campaign on a novel full visual access linear wind tunnel explores the impact of mean flow sudden accelerations on the boundary layer detachment and reattachment phenomena over an ad-hoc wall mounted hump. The wind tunnel is designed based on the premises of: full visual access, spatial and temporal stability of total and static pressure together with the total temperature and fast flow settlement, minimizing the start-up phase duration of the wind tunnel. A wall mounted hump that mimics the behavior of the aft portion of a low pressure turbine is inserted in the wind tunnel guaranteeing a 2D flow separation phenomena. After steady state test article characterization series of sudden flow discharge experiments reveal the impact of mean flow transients on the boundary layer detachment inception. Finally, taking advantage of the knowledge on transient flow performance, optimum flow control mechanisms to abate boundary layer detachment are proposed. The recommended control approach effectively prevents the boundary layer separation while minimizing the energy requirement.</div>

<p>In this study the semi structured interview method was used to explore what kind of knowledge one In State Authority: The Migration Board, and three Non Governmental Organisations: Red Cross, Save the Children and ISS- International Social Service have about the situation for separated children. Another purpose in this study was to explore if people who are close to the children are working for the best of the children and if their cases were treated with legal security. The result shows that the children’s cases are not treated with legal security and some of the children suffer psychologically from separations from the families and other children need new families because they were maltreated. The result also shows that there are signs that separated children are discriminated compared to children with a Swedish background.</p>

In this study the semi structured interview method was used to explore what kind of knowledge one In State Authority: The Migration Board, and three Non Governmental Organisations: Red Cross, Save the Children and ISS- International Social Service have about the situation for separated children. Another purpose in this study was to explore if people who are close to the children are working for the best of the children and if their cases were treated with legal security. The result shows that the children’s cases are not treated with legal security and some of the children suffer psychologically from separations from the families and other children need new families because they were maltreated. The result also shows that there are signs that separated children are discriminated compared to children with a Swedish background.