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Researchers in the Faculty of Science are involved in an impressive variety of fields – from astrophysics to zoology, nanotechnology to virtual reality, metabolomics to mathematics and much more!
In all cases, our faculty researchers, post-doctoral fellows, and graduate and undergraduate students live up to the highest standards in their disciplines, seeking to expand human knowledge through curiosity, innovation, and discovery.
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Item Open Access THE 1,4 C-O SILYL MIGRATIONS OF VARIOUS FURAN AND THIOPHENE SYSTEMS(Elsevier, 1989) Keay, Brian A.; Spinazze, Patrick G.Item Open Access THE 1,4-0->C SILYL MIGRATIONS OF VARIOUS 3-[(TRIALKYLSILYL)-OXYMETHYL]-FURANS AND -THIOPHENES(Elsevier, 1987) Keay, Brian A.; Bures, Edward J.Item Open Access 1-Borabarrelene Derivatives via Diels-Alder Additions to Borabenzenes(American Chemical Society, 2006) Wood, T.K.; Piers, W.E.; Keay, Brian A.; Parvez, M.Item Open Access 14th Meeting of the Canadian Number Theory Association(2016-06)The Canadian Number Theory Association (CNTA) was founded in 1987 at the International Number Theory Conference at Laval University (Quebec), for the purpose of enhancing and promoting learning and research in number theory in Canada and beyond. To advance these goals, the CNTA organizes bi-annual conferences that showcase new research in number theory, with the aim of exposing Canadian and international students and researchers to the latest developments in the field. The CNTA meetings are among the largest number theory conferences world-wide. The previous CNTA conferences were held in Banff (1988), Vancouver (1989), Kingston (1991), Halifax (1994), Ottawa (1996), Winnipeg (1999), Montreal (2002), Toronto (2004), Vancouver (2006), Waterloo (2008), Wolfville (2010), Lethbridge (2012) and Ottawa (2014). 2016 returns CNTA — almost — to its 1988 birthplace of Banff. In the year of its 50th birthday, the University of Calgary in Calgary (Alberta, Canada) is pleased to host the 14th meeting of the CNTA. A highlight of this event is a special session honouring our distinguished colleague Richard Guy, in celebration of his 100th birthday which will take place on September 30, 2016. An exceptional scholar and Professor Emeritus at the University of Calgary, Richard’s numerous and outstanding contributions to number theory have had a lasting impact on the field, and his collection of Unsolved Problems in Number Theory in particular has influenced research articles and inspired graduate theses for decades. The CNTA-XIV Organizers wish all conference participants a fruitful and enjoyable time in Calgary!Item Open Access 2-(1-Naphthyl)cyclohexyl 2-methylfuran-3-carboxylate(Blackwell Publishing, 2001) Parvez, M.; Hunt, I. R.; Keay, B. A.Item Open Access 2-(1-Naphthyl)cyclohexyl 3-furancarboxylate(Blackwell Publishing, 2001) Parvez, M.; Hunt, I. R.; Keay, Brian A.Item Open Access 2-Furyl Phosphines as Ligands for Transition-Metal-Mediated Organic Synthesis(American Chemical Society, 2001) Andersen, Neil G.; Keay, Brian AItem Open Access 2-Phenylcyclohexyl 3-furancarboxylate(Blackwell Publishing, 2001) Parvez, M.; Hunt, I. R.; Keay, Brian A.Item Open Access The 2DR-tree: A 2-dimensional spatial access method(2004-05-04) Osborn, Wendy; Barker, KenThis paper presents the 2DR-tree, a novel approach for accessing spatial data. The 2DR-tree uses nodes that are the same dimensionality as the data space. Therefore, all relationships between objects are preserved and different searching strategies such as binary and greedy are supported. The insertion and deletion strategies both use a binary partition of a node to insert an object or update a non-leaf minimum bounding rectangle. A validity test ensures that each node involved in an insertion or deletion preserves the spatial relationships among its objects. A performance evaluation shows the advantages of the 2DR-tree and identifies issues for future consideration.Item Open Access √3 Multiresolution by Local Least Squares: The Diagrammatic Approach(2015-10-19) Bartels, Richard; Mahdavi-Amiri, Ali; Samavati, FaramarzIn [2, 3, 20, 21] the authors explored a construction to produce multiresolutions from given subdivisions. Certain assumptions carried through that work, two of which we wish to challenge: (1) that multiresolutions for irregular meshes have to be constructed on the fly rather than being prepared beforehand and (2) that the connectivity graph of the coarse mesh would have to be a subgraph of the connectivity graph of the fine mesh. Kobbelt's √3 subdivision [11] lets us engage both of these assumptions. With respect to (2), the √3, post-subdivision connectivity graph shares no interior edges with the pre-subdivision connectivity graph. With respect to (1), we observe that subdivision does not produce an arbitrary connectivity graph. Rather, there are local regularities that subdivision imposes on the fine mesh that are exploitable to establish, in advance, the decomposition and reconstruction filters of a multiresolution for an irregular coarse mesh.Item Open Access 3,3'-Disubstituted BINAP Ligands: Synthesis, Resolution, and Applications in Asymmetric Hydrogenation(American Chemical Society, 2005) Hopkins, J. Matthew; Dalrymple, Sean A.; Parvez, Masood; Keay, Brian A.Item Open Access 3D Sketching and Collaborative Design with Napkin Sketch-The Video(2011-04-19T16:37:51Z) Xin, Min; Sharlin, Ehud; Costa Sousa, MarioThis is a video presentation of our work on Napkin Sketch, a new 3D Sketching and Collaborative Design tool. The video presentation is based on Min Xin's M.Sc. defense talk. Computer-supported 3D design tools have become increasingly popular and abundant because they offer easy editing, efficient content management, extensive sharing, and rich rendering capabilities. However, many of these tools are focused on generating high quality, visually appealing, and detailed models of baked ideas but often seem to fail in effectively supporting the intricate process and environment which help to create and nurture these ideas in the early design stages. Inspired by the simple yet rich interactions afforded by traditional design tools such as pencil, paper, or napkin in supporting the creative process of the early design stages, this thesis attempts to capture their essential qualities like portability, flexibility, fluidity, expressiveness, ambiguity, and sociability in Napkin Sketch, a computer supported tool which enables 3D sketching and collaborative design. Concepts such as tangible interaction and freeform interaction are explored and applied to create a sketching experience which leverages users' innate ability to physically interact with tools, media, and collaborators and provides freedom to suggest ideas and invite changes without having to commit prematurely. The contributions of the thesis are centered around Napkin Sketch which include a hardware platform that enables users to tangibly explore the 3D design space and manipulate the sketching media, a complementary software platform that facilitates the creation of 3D sketches while maintaining the familiar paradigm of sketching on a flat physical surface, a collaborative sketching environment that supports ad hoc co-located collaboration via multiple instances of the system, and three design critiques that provide preliminary assessment of the potential effectiveness of Napkin Sketch as a useful tool for supporting creativity in the early design stages. This video report highlights the main points of the our project.Item Open Access The 3D Tractus: A Three-Dimensional Drawing Board(2005-08-26) Lapides, Paul; Sharlin, Ehud; Costa Sousa, Mario; Streit, LisaWe present the 3D Tractus: a simple and inexpensive system for interaction and exploration of three-dimensional (3D) data. The device is based on a traditional drawing board-like mechanical structure that can be easily moved up and down while its surface height is being tracked using a simple sensor. Users interact with a tablet or tablet PC that rests on the surface while simultaneously changing its height. The result is direct mapping of virtual and physical spaces allowing intuitive 3D interaction and data exploration. The 3D Tractus allows us to investigate novel 3D interaction techniques based on sketching and drawing as well as intuitive visual indicators and GUI layouts. The 3D Tractus' simple design concept can be easily adapted to other tabletop systems and the simple nature of the physical interaction allows the design of various exciting applications. We detail here the design and development of the 3D Tractus hardware and software as well as preliminary evaluation of a 3D drawing and sketching application realized using the new tabletop interface.Item Open Access 3De Interactive Lenses for Visualization in Virtual Environments(2018-10) Mota, Roberta Cabral Ramos; Rocha, Allan; Silva, Julio Daniel; Alim, Usman; Sharlin, EhudWe present 3De lens, a technique for focus+context 3D visualization of multiple geometric representations. Our lens fuses two categories of lenses (3D and Decal) into a single coherent entity, thus enabling flexible use of either one or the two lenses combined depending on the underlying data geometry. In addition, we incorporate our lens into virtual reality as it enables a rich and natural style of direct spatial manipulation for exploratory 3D data analysis. To demonstrate its potential use, we discuss two domain examples in which our lens technique creates customized visualizations of both surfaces and streamlines.Item Open Access An 8-year record of gas geochemistry and isotopic composition of methane during baseline sampling at a groundwater observation well in Alberta (Canada)(Springer, 2016-02-01) Humez, P.; Mayer, B.; Nightingale, M.; Ing, J.; Becker, V.; Jones, D.; Lam, V.Variability in baseline groundwater methane concentrations and isotopic compositions was assessed while comparing free and dissolved gas sampling approaches for a groundwater monitoring well in Alberta (Canada) over an 8-year period. Methane concentrations in dissolved gas samples (n = 12) were on average 4,380 ± 2,452 μg/L, yielding a coefficient of variation (CV) >50 %. Methane concentrations in free gas samples (n = 12) were on average 228,756 ± 62,498 ppm by volume, yielding a CV of 27 %. Quantification of combined sampling, sample handling and analytical uncertainties was assessed via triplicate sampling (CV of 19 % and 12 % for free gas and dissolved gas methane concentrations, respectively). Free and dissolved gas samples yielded comparable methane concentration patterns and there was evidence that sampling operations and pumping rates had a marked influence on the obtained methane concentrations in free gas. δ13CCH4 and δ2HCH4 values of methane were essentially constant (−78.6 ± 1.3 and −300 ± 3 ‰, respectively) throughout the observation period, suggesting that methane was derived from the same biogenic source irrespective of methane concentration variations. The isotopic composition of methane constitutes a robust and highly valuable baseline parameter and increasing δ13CCH4 and δ2HCH4 values during repeat sampling may indicate influx of thermogenic methane. Careful sampling and analytical procedures with identical and repeatable approaches are required in baseline-monitoring programs to generate methane concentration and isotope data for groundwater that can be reliably compared to repeat measurements once potential impact from oil and gas development, for example, may occur.Item Open Access A Fast Fourier Transform with Rectangular Output on the BCC and FCC Lattices(2009-05) Alim, Usman R.; Möller, TorstenThis paper discusses the efficient, non-redundant evaluation of a Discrete Fourier Transform on the three dimensional Body-Centered and Face-Centered Cubic lattices. The key idea is to use an axis aligned window to truncate and periodize the sampled function which leads to separable transforms. We exploit the geometry of these lattices and show that by choosing a suitable non-redundant rectangular region in the frequency domain, the transforms can be efficiently evaluated using the Fast Fourier Transform.Item Open Access A METHOD TO EXTERNALLY ADJUST THE COLUMN LENGTH IN GAS CHROMATOGRAPHY USING A WATER STATIONARY PHASE(Springer, 2023-12-06) Thurbide, Kevin; Shepherd, KadeItem Open Access A new tyrannosaurine (Theropoda:Tyrannosauridae) from the Campanian Foremost Formation of Alberta, Canada, provides insight into the evolution and biogeography of tyrannosaurids(Cretaceous Research (Elsevier), 2020-01-23) Voris, Jared Thomas; Therrien, Francois; Zelenitsky, Darla Karen; Brown, Caleb MarshallUpper Cretaceous tyrannosauroid material from North America was primarily known from upper Campanian through Maastrichtian formations until the recent discovery of derived tyrannosaurid taxa from lower-to-mid Campanian deposits in the southwestern United States. However, diagnostic material from contemporaneous deposits further north in Alberta (Canada) and Montana (USA) has yet to be documented. Here we report the discovery of a new tyrannosaurine tyrannosaurid from the mid- Campanian Foremost Formation of Alberta, Thanatotheristes degrootorum gen. et. sp. nov, which helps fill this gap. The new tyrannosaurine, diagnosed by five autapomorphies, is found to be the sister taxon to the late Campanian genus Daspletosaurus. Thanatotheristes is distinct from Daspletosaurus based on several features, and lacks at least two apomorphies of the latter taxon. Together, these taxa form the newly established Daspletosaurini, a clade of long-, deep-snouted tyrannosaurines endemic to northern Laramidia during the Campanian. Our study demonstrates that Tyrannosauridae is composed of several geographically-segregated clades rather than a series of monogeneric successive sister taxa as recovered by previous studies. The geographic segregation of tyrannosaurid clades within North America provides renewed evidence for provinciality among large theropods during the Late Cretaceous.Item Open Access A novel switchable water stationary phase for supercritical fluid chromatography(Elsevier, 2023-08-08) Emmanuel Nai; Kevin ThurbideItem Open Access A vinylogous Norrish reaction as a strategy for light-mediated ring expansion(Royal Society of Chemistry, 2022-02-03) Evgueni Gorobets; James W. Papatzimas; Jorge Dourado; Goonay Yousefalizadeh; JinGyu Lee; Duncan K. Brownsey; Kevin Stamplecoskie; Rebecca Davis; Darren J. DerksenThe reactions of bicyclic divinyl ketones display wavelength-dependent changes in product formation. UV irradiation results in the formation of competitive and tricyclic unsaturated ketones that subsequently undergo ring expansion and reaction with a range of nucleophiles. DFT calculations and transient absorption experiments were completed that are consistent with a vinylogous Type II Norrish pathway.