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National Security with a Canadian Twist: The Investment Canada Act and the New National Security Review Test
Get PDFThis perspective discusses issues raised by the new national security test for proposed investments in Canada, including the ambiguity of the "national security" term and the possibility of politicized national security reviews. The author cautions the government not to adopt an over-expansive approach to the application of the new test
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Opposed-Flow Flame Spread over Solid Fuels in Different Burning Regimes
Get PDFSeveral aspects of opposed-flow flame spread are experimentally investigated because of their relevance in fire safety studies. Different burning regimes based on the intensity of the opposed flow velocity are identified for acrylic fuels. In downward flame spread, where the flow around a flame is only naturally induced by gravity, the spread rate is highly dependent on fuel size and geometry. The fuel cross-sectional shape is experimentally varied, and a formula which takes into account geometrical effects is proposed by extending previous solutions for two-dimensional flames.The burning region of a solid fuel shows a consistent slope due to the competition between flame spread and surface regression. The angle at the vertex of the pyrolysis region, called burn angle, can be used to indirectly calculate the fuel burning rate. The burn angle depends on fuel thickness; a numerical model and a scale analysis are used to explore the reasons for this behavior.Next, the effect of a forced flow is investigated. The extreme case of blow-off extinction over thin fuels is considered, with flames extinguishing at locations determined by the flow velocity. Results suggest that the interaction between fuel and flow field is more important than the dependence on fuel thickness. The evolution of flame structure and pyrolysis also appear to be driven by flow interactions. A scale analysis is used to explore these dependencies.Finally, previous microgravity experiments are used to explore differences and similarities with ground-based results. By suppressing the buoyant flow, flame radiation becomes essential for the flame spread process. The experimental conditions are simulated numerically to describe the importance of a developing boundary layer in this regime.A numerical parametric study of the radiative emission of flames in microgravity, inspired by the experimental data, shows its dependence on flame area, mass burning rate and flame temperature by changing the burning conditions. For these small flames, soot does not seem to dominate flame radiation, although its generation increases with fuel thickness, oxygen concentration and flow velocity.The experiments in microgravity considered in this work showed flame extinction in a quiescent environment. However, two acrylic cylinders at higher oxygen concentrations from a previous investigation can burn vigorously. To clarify whether these flames are stable, a scale analysis is used to study the influence of surface curvature on radiation losses
Computational modeling of flow and combustion in a Couette channel simulating microgravity
No full textIncludes bibliographical references (pages 95-97).Theoretically a Couette flow in a narrow channel can be utilized to simulate microgravity conditions experienced by a surface flame due to the linear velocity profile. Hence, the Couette channel is a potential apparatus for the study of flame spread in an environment that recreated microgravity flow conditions. Simulated microgravity conditions were achieved by limiting the vertical extent over and under the flame to suppress buoyancy. This numerical study was done for a 2-D channel using Fire Dynamics Simulator (FDS).\ud
This thesis is divided into two sections; the first is the study of Couette flow with a non-reacting cold flow in a finite length channel, a subject with surprisingly little past research, despite the ubiquity of "infinite" Couette channels in text books. The channel was placed in a room to allow for a better representation of a realistic channel and allow the flow and pressure field to develop without forcing them at the inlet and outlet. The plate's velocities, channel's gap and the channel's length were varied and the results of the u-velocity profile, w-velocity profile and pressure were investigated. The entrance length relationship with Reynolds number for a finite Couette Channel was determined for the first time - as far as the author knows - in order to ensure the flame occurs in a fully developed flow. In contrast to an infinite channel, the u-velocity was found to be nonlinear due to an adverse pressure differential created along the channel attributed to the pull force along the entrance of the channel created by the top plate a well as the pressure differential created by the flow exiting the channel. The linearity constant was derived for the one moving plate case. The domain consisted of a rectangular region with the top plate moving and the bottom plate fixed except for a few cases in which the bottom plate also moved and were compared with only one moving plate. \ud
The second section describes the combustion of a thin cellulose sample placed 3.5 mm from the bottom using a combined pseudo-Hagen-Poiseuille-Couette narrow channel. The gap on top of the paper sample as well as the top plate's velocities were varied and the effect on the flame spread rate was investigated. The results were compared between no gravity and normal gravity and it was determined that some of the cases run the 0g created a flame tail that was longer than that of the 1g flame while others that had narrower gaps both 0g and 1g flame tail are similar. The channel is not placed in a room since the entrance velocity profile of the fluid is in fact set at the inlet (hence pseudo-Hagen-Poiseuille). While varying the plate velocity while keeping the height equal, the 0g flames spread faster than the 1g flames. Varying the height and keeping the plate velocity constant presented a crossover phenomenon of the flame spread rate
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
GIS-Based Interactive Tool to Map the Evolution of American Automobile Industry
No full textIncludes bibliographical references (page 39).This is a GIS based tool for showcasing the history of the American Automobile\ud
Industry starting from 1900 to post Second World War. The tool is developed using simple language and is flexible to allow future enhancements.\ud
The application consists of numerous images and textual information, and also some\ud
links that can be used by this software which depict various automobile companies including the steam automobile manufacturers at the American automobile inception. It covers various topics on evolution of different technologies in automobiles. All the automobile industries locations are shown on GIS (Geographical Information Science) maps.\ud
The tool can be tweaked as per user necessities and is created utilizing JAVA and\ud
GIS Technology. The user interface is made utilizing JAVA and MOJO, which help promote learning and understanding of the topic. The user interface in this tool includes the usual zoom-in, zoom-out, as well as legend editing, printing, images, layer control and many menu items
Numerical modeling of the effect of histidine protonation on DNA hybridization and pH distribution in electronically active microarray
No full textTitle from first page of PDF file (viewed September 8, 2010)Includes bibliographical references (p. 56-58)This study investigates, through numerical modeling, the effects of protonation of histidine buffer in promoting DNA hybridization in electronically active microarrays within a limited pH range. The numerical model framework developed in this study consists of a number of physical phenomena (conservation and mass transport of species) and chemical equilibrium reactions (hydrolysis of water, heterogeneous DNA hybridization, and protonation of histidine) that govern the hybridization of single-stranded DNA molecules (ssDNA) in active microarrays within an environment of continuous generation of H+ ions and their subsequent consumption by histidine buffer. The study demonstrates, through a numerical model and comparison with published experimental results, that the increase in acidity near anodes due to the hydrolysis of water can be neutralized by a histidine buffer creating a relatively stable pH environment. To account for the dependency of DNA hybridization on the pH of the buffer used, the study also introduces a new hybridization efficiency parameter into the numerical model that is based on experimental data for DNA hybridization
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
An AJAX based design and implementation of a self motivating system for student learning
No full textIncludes bibliographical references (p. 29)The Expert System for Thermodynamics (TEST) is a web application that is developed to help educators create thermodynamic engineering problems and for the students to analyze and solve the problems to gain knowledge in the thermodynamics field. The TEST web application is categorized into 15 chapters. TEST is used as effective and efficient educating medium around the world with thousands of students and educators registered with the web application. Because of the large number of students and educators accessing the TEST web application, servers are located through out the world that makes sure a secure connection is established to cater to the user requests. The type of registered users on TEST has been categorized into three types viz. Students, Educators and Administrators apart from the unregistered Guest users. The Guest users can just browse through the problems but cannot solve them and no history is maintained for these users. The aim of this thesis is to provide the educators an effective interface to edit the problem attributes that makes the thermodynamic engineering problems more understandable to the students and guides the students to gain knowledge in the predefined outcomes (knowledge areas). The outcomes are categorized as follows: (1) free body diagram, (2) mass equation, (3) energy equation, (4) entropy equation, (5) ideal gas model, (6) basic cycle concept, and (7) unit conversion, etc. In this thesis the problems has been divided into three types: Classic, Grade Me and Key problems. The educators can split the answer into parts if the answer to a particular problem has more than one answer. Successful solving of Key problems by students will guide them to solve more problems in the particular outcome to gain more knowledge. As the students solve the problems, there score is updated into the database by which the student can see his score in various outcomes on the TEST website. The educator can also provide notes to the students for successful or wrong solutions, so that the students can take further steps based on the notes provided by the educator. The technologies used in the development of this thesis are CSS, JavaScript, JSON, PHP and MYSQL. CSS is used to handle the styling part of the editor, JavaScript is used to dynamically create the editor, JSON format is used for problem's attributes to be stored into the MYSQL database and PHP is used as server side language. Finally educators, who used TEST in their engineering thermodynamics classes, will be requested to share the grade of students (anonymously). If we can compare students who used SMS with those who did not and show that SMS made a difference, this will change the word as far as thermodynamics education goes
POLYMETHYLMETHACRYLATE COMBUSTION IN A NARROW CHANNEL APPARATUS SIMULATING A MICROGRAVITY ENVIRONMENT
No full textIncludes bibliographical references (pages 103-106).Fire safety is an important part of engineering when human lives are at stake. From everyday homes to spacecraft that can cost hundreds of millions of dollars. The research in this thesis attempts to provide scientific evidence that the apparatus in question successfully simulates microgravity and can possibly replace NASA's current test method for spacecraft fire safety.\ud
Flame spread tests were conducted with thermally thick and thermally thin polymethylmethacrylate (PMMA) samples to study flame spread behavior in response to environmental changes. The tests were conducted using the San Diego State University Narrow Channel Apparatus (SDSU NCA) as well as within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS). The SDSU NCA can suppress buoyant flow in horizontally spreading flames, and is currently being investigated as a possible replacement or complement to NASA's current material flammability test standard for non-metallic solids, NASA-STD-(I)-6001B Test 1. The buoyant suppression attained in the NCA allows tests to be conducted in a simulated microgravity environment-a characteristic that NASA's Test 1 lacks since flames present in Test 1 are driven by buoyant flows. The SDSU NCA allows for tests to be conducted at various opposed flow oxidizer velocities, oxygen percent by volume, and total pressure to mimic various spacecraft and habitat atmospheres.\ud
Tests were conducted at 1 atm pressure, thin fuel thickness of 50 and 75 microns, thick fuel thickness ranging from 3 mm to 5.6 mm, opposed oxidizer velocity ranging from 10 to 25 cm/s, and oxygen concentration by volume at 21, 30, and 50 percent. The simulated microgravity flame spread results were then compared to true microgravity experiments including; testing conducted on the International Space Station (ISS) under the Burning and Suppression of Solids (BASS) research, NASA's 5.2 second Drop Tower, and Micro-Gravity Laboratory's (MGLAB) 4.5 second Drop Tower. Data was also compared to results found by Michigan State University's NCA. Flame spread results from the SDSU NCA compare closely to that of the other experimental techniques. Additionally, an infrared camera and species concentration sensors were added to the SDSU NCA and initial results are provided.\ud
Fire Dynamics Simulator (FDS) was used to model the combustion of PMMA within the SDSU NCA. Both thin and thick fuel beds were simulated and the numerical results were compared to experimental data. The simulation was then used to determine various results that cannot easily be found with experimentation, including how effectively the NCA simulates microgravity under certain environmental conditions, gas and fuel bed temperatures, heat fluxes, species concentrations, pyrolysis rate, and other various data. The simulation was found to give reasonable results and overall flame spread trends, but could be improved upon with further detailed kinetic parameter studies
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