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Volume VII, Numéro 3 (avril 2009)
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Numéro complet en format PDF (10.5 MB)
Editorial The beginning of the end... (151 kB)
Original research Anisotropy of the Cosmic Microwave Background (1.51 MB) by Nikita Nikolaev
Abstract
Presented is a review of the 2006 Nobel Prize winning experiment on the anisotropy of the cosmic microwave background radiation, undertaken by George Smoot, as part of the larger COBE experiment. The introduction contains historical and theoretical background for the importance of the discovery, followed by the brief description of the apparatus, techniques, experimental methods and primary results. The review concludes with the discussion of further developments in the eld, such as the WMAP and the PLANCK experiments.
Original research A Simple Derivation of the Equation of Planetary Motion (196 kB) by Andrew Jarvis and Patrick Bruskiewich
Abstract
Normally the general principles describing planetary orbits are first introduced in high school, but a complete derivation is left for second year in university. It is possible to derive the equations of planetary motion using Grade 12 mathematics and calculus. All that is required is the technique of separating the radial and angular equations by using polar coordinates. In a previous article titled Euler’s Treat (CUPJ April 2008) the authors provided a simple introduction to the equation ei(theta).
Original research The Stefan-Boltzman Law, the Wien Displacement Law, and the Temperature of the Sun (171 kB) by Natalia Kalicki, Tatyana Olal and Patrick Bruskiewich
Abstract
In this paper a straightforward approach involving logarithms is used to derive the Stefan-Boltzmann and Wien Displacement laws from measured data of light output. In the final portion of this paper, the Wien Displacement law is used to make an estimate of the surface temperature of the sun using data collected with a quartz prism and a CdS light meter.
Feature The January 2009 Opening Ceremony for the International Year of Astronomy (281 kB) by Annemarie Pickersgill
Feature The Canadian Association of Physicists and You (547 kB) by Robert Thompson
Interview Shelly Page: President of the Canadian Assoication of Physicists (1.21 MB) by Chelsea Braun and Lauren Hayward
News UPPAC 2009 (286 kB) by Henry Ngo
News Rising Stars of Research 2009 (286 kB) by Jenny Phelps
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Volume VII, Numéro 2 (janvier 2009)
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Numéro complet en format PDF (24.3 MB)
Editorial To boldly go... (157 kB)
Original research Stability of Satellite Orbits around Asteroid 243 Ida (418 kB) by Eric Brown
Abstract
Research into the stability of gravitational orbits in rotating, non-spherical potentials has both theoretical merit and practical applications for future visits to irregular asteroids by spacecraft. The current study numerically integrates orbits in a model potential for asteroid 243 Ida over a wide range of orbital parameters. Regions of stability are studied and some very interesting phenomena are observed. Included in this article are the observations of a fractal-like structure to stability-instability boundaries in parameter space and a process of orbital self-preservation in the case of slow asteroid rotation.
Original research Uncovering fluctuations in atmospheric transmission using the VERITAS pointing monitors (1.92 MB) by Ilya Feige
Abstract
This project encompasses the creation of software that provides night-by-night estimates of atmospheric transmission for the VERITAS observations. Using archived image files taken from the pointing monitors (CCD cameras mounted on each telescope), we wrote software that chooses appropriate stars - bright, but not saturated - and extracts their intensity data, which is then used to plot the intensity as a function of the secant of the telescope angle from the zenith. We show that this relation is linear and that the ratio of its slope divided by its intercept has a value independent of the stars chosen. In doing this nightly for several stars and for all four telescopes, one can measure, through the fluctuations in the ratio of the slope over the intercept, the magnitudes of the fluctuations in the transmission of the atmosphere; thus improving the quality of the measurements taken by the VERITAS telescopes.
Original research Photometric Analysis of Asteroid 216 Kleopatra (1.72 MB) by Matthew Patrick
Abstract
The asteroid 216 Kleopatra was imaged with a CCD camera attached to a 10" Schmidt-Cassegrain telescope at the University of Saskatchewan. The asteroid's rotation period was determined from its light curve. Its magnitude range allowed for a determination of the ratio of the maximum and minimum cross sectional surface areas of the asteroid facing Earth at dierent points in its rotation.
Entrevue Marc Garneau: Canada`s First Man in Space, avec une biographie en français (2.12 MB) by Marie-Eve Larivée and Patrick Bruskiewich
Feature "Galileo Moments" during the International Year of Astronomy (962 kB) by James E. Hesser
Feature International Year of Astronomy in Canada (603 kB) by Alison Faulkner
Feature The U-2 and the AVRO Arrow (2.12 MB) by Patrick Bruskiewich
Feature CUPC 2008 in Toronto (2.26 MB) by Alan Robinson
Feature Graduate Studies Table (557 kB) by Kathleen Barnetson
News TEXAS Symposium for Relativistic Astrophysics 2008 (401 kB) by Henry Ngo
News Hawking Takes Post at the Perimeter Insitute (401 kB) by Ian Austen
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Volume VII, Numéro 1 (septembre 2008)
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Numéro complet en format PDF (22 MB)
Editorial Cancer (158 kB)
Original research Measurement of Y(1S) production at BABAR (1.0 MB) by Rocky So and Christopher Hearty
Abstract The purpose of my research is to measure how many Y(1S) originated from Y(4S) in the entire BaBar data set. This research compares on-peak data and off-peak data. On-peak data were taken at centre of mass energy 10.58 GeV. On-peak data, taken at centre of mass energy 10.54 GeV, are not enough to have any BB-bar pairs because 10.54 GeV is less than the mass of an Y(4S). This research can be useful for BaBar physicist because it helps set an upper limit on how many BB-bar pairs there are in the entire BaBar data set. In other words, it sets an upper limit on how much more than 96% does Y(4S) decay to BB-bar. Measurement of the decay of Y(4S) to Y(1S) + X gives evidence for non-BB-bar decays of the Y(4S).
The final results of this study show that there were (110 +/- 3) x 105 Y(1S) on-peak, of which (10 +/- 9) x 105 originated from an Y(4S). Increasing the centre of mass energy from 10.54 GeV to 10.58 GeV increases the Y(1S) production by (10 +/- 8)%.
Original research ATLAS detector studies using Z boson leptonic decay (782 kB) by Wilson Brenna and Isabel Trigger
Abstract When the ATLAS experiment on the Large Hadron Collider (LHC) at CERN begins taking real data, it is important that the detector be as well-understood as possible. Using well-understood decays, it is possible to calibrate and align the ATLAS detector so that it can achieve its design performance as quickly as possible.
This approach involves the decays Z0 to mu+ mu- and Z0 to e+ e-. The transverse momenta of the two decay particles are reconstructed to give the mass of the Z boson. By fitting the mass curve to a Breit-Wigner smeared with a Gaussian, a scale can be determined to show the ratio between the reconstructed Z mass and the known Z mass, which was precisely measured at the Large Electron-Positron (LEP) collider. This can be used to quantify various detector effects, most notably the impact of detector misalignment (for the muons) and EM energy scale (for the electrons).
Feature TRIUMF's Five Year Plan (1.3 MB) by Nigel Lockyer
Interview Erich Vogt: teacher, physicist, and curious person (1.7 MB) by Katy Hally and Patrick Bruskiewich; transcribed by Katy Hally
Feature George Michael Volkoff, the University of British Columbia and the TRIUMF Project (2.4 MB) by Patrick Bruskiewich
News CUPC 2008 (514 kB) by Alan Robinson
News UPPAC 2008 (562 kB) by Henry Ngo
Nouvelles Congrès de l'ACP 2008 (278 kB) par Marie-Eve Larivée
News Eighth Annual TRIUMF Summer Student Symposium (278 kB) by Nicole Dublanko
News AUPAC 2008 (484 kB) by Katy Hally
News Rising Stars of Research 2008 (467 kB) by Luke Govia
Web-only feature Tracking an auroral substorm (849 kB) by Rob Lerner and Martin Connors
Abstract We present an auroral substorm that began at approximately 7:52 universal time (UT) on 21 August 2002. This event occurred during a long period of southward interplanetary magnetic field (IMF). The tetrad of probes making up the Cluster mission were at approximately -19 Re X, -4 Re Y, and -2 Re Z in geocentric solar ecliptic (GSE) coordinates, with a magnetic footprint in Canada. Also, the Polar spacecraft was at a position of -8 Re X, -3 Re Y, and -2 Re Z, GSE, with a Canadian magnetic footprint. We will show how various data from these spacecraft, as well as data obtained from the ground, can be interpreted and used to track the progression of this substorm.
Web-only feature Vogt Interview - Full Transcript (182 kB) by Katy Hally and Patrick Bruskiewich; transcribed by Katy Hally
Book Reviews (254 kB)
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Volume VI, Numéro 3 (avril 2008)
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Numéro complet en format PDF (14.1 MB)
Editorial Think small... think quantum mechanics! (154 kB)
Feature Biological physics of bacteria (572 kB) by Andrew Rutenberg
Interview Truth at TRIUMF (1.41 MB) by Yasaman Kouchekzadeh Yazdi; transcribed by Patrick Bruskiewich
Feature A brief introduction to continuous quantum measurement (288 kB) by Alicja Kiełbik
Feature Euler’s treat: exp(ix) = cos x + i sin x (498 kB) by Andrew Jarvis and Patrick Bruskiewich
Feature The Lorentz invariant measure and the Heisenberg uncertainty principle (470 kB) by Patrick Bruskiewich and Alicja Kiełbik
Feature George Michael Volkoff and reactor physics in Canada (732 kB) by Patrick Bruskiewich
Feature The time reversal operator and the quantum harmonic oscillator (710 kB) by Patrick Bruskiewich
Web-only feature Galileo and his inclined plane experiment (1.15 MB) by Briana Lyon and Patrick Bruskiewich
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Volume VI, Numéro 2 (janvier 2008)
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Numéro complet en format PDF (22.5 MB)
Éditorial Le Canada dans l'espace (121 kB)
Original research Searching for asteroids around another star (2.0 MB) by Reka Moldovan and Jaymie Matthews
Abstract We present an ongoing search for Trojan asteroids in the transitting exoplanetary system HD 209458 based on photometry with Canada’s MOST (Microvariability and Oscillations of STars) satellite. MOST monitored this exoplanetary system for 14 and 44 days in 2004 and 2005, respectively, with nearly continuous time coverage. Any Trojan asteroid swarms will orbit in roughly the same plane as the known giant planet in this system and with the same period. Our preliminary analysis of the MOST photometry of HD 209458 to detect a Trojan signal is sensitive to dips in the starlight due to transits of about 10-4 relative to the mean brightness of the host star. This corresponds to a Trojan swarm whose total mass would be of order 10-3 Earth masses, compared to the previous upper limit of about 13 Earth masses.
Interview Space is a MOST important place to be (633 kB) by Simon Hastings; transcribed by Patrick Bruskiewich
Article de fond MOST : Le premier télescope canadien (1.1 MB) par Marie-Michèle Limoges
News Radarsat-2: Gem in the SAR satellite constellation (1.7 MB) by Patrick Bruskiewich
Feature The solar neutrino problem and SNO (940 kB) by Yasaman Kouchekzadeh Yazdi
Feature George Michael Volkoff and neutron stars (657 kB) by Briana Lyon and Patrick Bruskiewich
Feature CUPC in pictures (3.6 MB) by David Lee
Feature 43rd CUPC Retrospecticus (499 kB) by David Lee and Ricky Chu
Feature So you want to be a grad student? (178 kB) by Andrew Rutenburg
Feature The Nicholls-Hull experiment and Einstein's Mass-Energy Equation (569 kB) by Patrick Bruskiewich
Critiques de livres (229 kB)
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Volume VI, Numéro 1 (septembre 2007)
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Numéro complet en format PDF (22.8 MB)
Editorial A physics education challenge for Canadian premiers (424 kB)
Original research Morphology study of vertically aligned carbon nanotubes (1.2 MB) by Catherine Holloway, Logan Astle, Bobo Eyrich, Gary C.-K. Liu and Jeff R. Dahn
Abstract Vertically aligned carbon nanotubes (VACNT) were synthesised at atmospheric pressure by chemical vapour deposition (CVD) of ethylene and ammonia at 720°C in a tube furnace. The VACNTs were grown on iron films with varied thickness from 0 to 10 nm over a SiO2/Si wafer substrate. The iron film was annealed at 550°C under pure oxygen to promote the formation of catalytic iron nanoparticles before carbon nanotube (CNT) growth. The nanotube morphology as a function of iron film thickness was studied using a scanning electron microscope. The effects of different experimental conditions (iron film thickness, annealing time, CVD temperature) on the nanotube morphology were examined.
Original research An Ha kinematical analysis of NGC 247 (657 kB) by Julie Hlavacek-Larrondo and Claude Carignan
Abstract An Ha kinematical analysis of the Sculptor group galaxy NGC 247 is presented. The data were obtained by Fabry-Perot (FP) interferometry with the 3.6 m European Southern Observatory (ESO) telescope at La Silla, Chile. The optical velocity field and the total integrated Ha emission map are first presented. The rotation curve and optical parameters are then extracted. An inclination i of 74.0° and a position angle PA of 173.2° are found, in agreement with earlier studies. The detailed analysis of the rotation curve suggests that NGC 247 is a perturbed galaxy presenting non-circular motions in the inner parts.
Original research Measurement of the calibration factors of a new b quark identification algorithm (2.1 MB) by Mushtari Afroz and Pierre Savard
Abstract The combined b-tagging algorithm is a new algorithm that combines two algorithms used by the Collider Detector at Fermilab (CDF) group to identify bottom quarks. One of these two algorithms is based on the identification of the secondary vertex, and the other one is based on the impact parameter of reconstructed tracks. The combined tagger combines these two algorithms in a logical OR fashion. Its calibration factor, known as "scale factor," is defined as the ratio of the b-tagging efficiency in data to that in simulation or Monte Carlo. We measure the scale factor of two configurations of this tagger as a function of four kinematic variables: transverse energy of the jet, pseudorapidity, number of tracks and position of the primary vertex along the beam line. We use a data sample that corresponds to 360 pb-1 (pico barn) that is obtained from proton anti-proton beam collision at a centre of mass energy of 1.96 TeV at the Fermilab Tevatron. The scale factors were found to be less than unity and had no significant dependence on these kinematic variables.
News CUPC 2007 (888 kB) by Ricky Chu
News TRIUMF’s seventh annual summer student symposium (319 kB) by TRIUMF Public Relations
Article de fond Modélisation du climat (1.5 MB) par Roxane Sauvé
Feature Interview with Dr. Carl Wieman (1.5 MB) by Gigi Wong
Feature Physics education in Canada (441 kB) by Marina Milner-Bolotin and Tetyana Antimirova
Feature The parity operator for the quantum harmonic oscillator (2.2 MB) by Patrick Bruskiewich
Feature The period of a simple pendulum (722 kB) by Patrick Bruskiewich
Feature The importance of parity (895 kB) by Katy Hally
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Volume V, Numéro 3 (avril 2007)
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Numéro complet en format PDF (15.0 MB)
Editorial Working together for a stronger community (150 kB)
Special Report Inertial confinement fusion: the physics and the future (3.7 MB) by Mikhail Klassen
News Four famous physicists ponder why we are here (217 kB) by Bouchra Hanna Ouatik
Feature Partnership in physics (541 kB) by Marc Baron
Feature Collaboration on a smaller scale (682 kB) by Darren Peets
Feature Understanding Martian geology with X-ray spectroscopy (317 kB) by David Nataf
Article de fond Le Canada au CERN (921 kB) par Andrea Gutierrez et Marie-Michèle Limoges
Feature Hubble's successor (1.3 MB) by Julie Hlavacek-Larrondo
Book reviews (221 kB)
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Volume V, Numéro 2 (janvier 2007)
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Numéro complet en format PDF (22.3 MB)
Editorial Éliminer les frontières de la connaissance (119 kB)
Original research Completing the picture: determining the oxygen composition of spiral galaxies (808 kB) by Sarah I. Sadavoy, Marshall L. McCall
Abstract Spiral galaxies are known to possess gradients in chemical composition, impairing investigations into global evolution. Here, it is shown that the abundance
of oxygen relative to hydrogen in a spiral galaxy reaches an asymptotic value if oxygen and hydrogen atoms are integrated separately out to large radii, thereby providing a robust description of the overall chemical state.
Original research Fonction de luminosité des naines blanches du sondage KUV (579 kB) par Marie-Michèle Limoges, Pierre Bergeron
Abstract Nous avons reproduit presque exactement la fonction de luminosité des naines blanches du sondage KUV fournie dans Darling (1994), et refait le calcul à partir de nos valeurs de MV, déterminées avec une méthode plus précise que celle de Darling (1994). Aussi, plusieurs étoiles de l’échantillon KUV se révélaient être de mauvais type spectral et certaines n’étaient pas des naines blanches. La fonction de luminosité que nous avons calculée avec la partie de l’échantillon dont nous possédions le spectre diffère beaucoup de celle de la thèse de Darling (1994). Un calcul sur un échantillon complet permettera de tirer des conclusions quant aux modèles théoriques et de savoir si nous nous approchons de la fonction de luminosité du sondage PG.
News Underground laboratory closes (758 kB) by Stephanne Taylor
Feature Trendy atmospheric physics (154 kB) by Myriam Francoeur
Feature Is it a protein complex, or a simple engine? (196 kB) by Lindsay Baker
Feature Can we know anything? (83 kB) by Valerie Plaus
Feature CUPC 2006 in pictures (4.6 MB)
Feature Graduate studies table (190 kB) by Stephanne Taylor
Book reviews (359 kB)
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Volume V, Numéro 1 (septembre 2006)
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Numéro complet en format PDF (19.0 MB)
Editorial Playing with fire (155 kB)
Original research Strontium isotopes, a window to the past: researching geological formations at Mount Wapta in the Canadian Rocky Mountains (2.0 MB) by Emily M. Neuheimer, Michael Wieser
Abstract Variations in the isotopic composition of an element are used as a tool to investigate geological processes. In this study, the variations in the 87Sr/86Sr isotope amount ratio are measured in carbonate minerals to interpret the extent of hydrothermal fluid-rock interactions at a Middle Cambrian site. Although the samples were from different types of altered limestone, those in close proximity showed little variation in isotopic amount ratio. There were slight variations in the 87Sr/86Sr isotope amount ratio between host rock and that altered to dolomite, implying there was some interaction with radiogenic strontium enriched fluid. A conclusion can be made that the sample region (Mount Wapta at the Burgess Shale) had not had sufficient fluid-rock interaction in order to result in substantial enrichment in the strontium isotopic composition or a variation in the strontium isotopic amount ratio. However, the 87Sr/86Sr isotope amount ratios for the pre-existing host rock falls within an acceptable range for the Middle Cambrian period.
Original research Geometric phase in optical fibres (766 kB) by Michael Underwood, Karl-Peter Marzlin
Abstract A quantization scheme is proposed which allows for examination of the geometric phase of photons within an optical fibre under the eikonal approximation. A connection is drawn from the classical geometric phase to the resulting one in the quantized field. An overview of the required background knowledge is also included, specifically an introduction to geometric phase and the eikonal approximation of geometric optics, as well as the so-called Frenet frame.
News CUPC 2006 (2.5 MB) by Gigi Wong
News Vignettes from astrophysics (607 kB) by Vincent Campbell Allaire and Myriam Lemay-Gosselin
Feature Keeping the lights on (947 kB) by Matthew Graham Clark
Feature The physics of nuclear weapons (1.2 MB) by Mikhail Klassen
Feature Radioactivity beyond nuclear physics (426 kB) by Julie Hlavacek-Larrondo
Article de fond L'anglais, nouvelle lingua franca (790 kB) par Philippe Marchand
Book reviews (521 kB)
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Volume IV, Numéro 3 (avril 2006)
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Numéro complet en format PDF (16.6 MB)
Editorial Astrophysics and cosmology at crossroads (128 kB)
Original research Solar supergranulation as a result of granular advective interaction: a numerical simulation (1.5 MB) by Kim Thibault, Ashley Crouch, Paul Charbonneau
Abstract This article outlines numerical simulations featuring magnetic flux tubes found at the surface of the solar convection zone. The flux tubes aggregate onto one another, forming moving clusters that can themselves aggregate or accrete more flux tubes. This process, akin to diffusion-limited aggregation, can lead to the emergence of spatial scales much larger than those characterizing the motion of single flux tubes. We associate the former with the pattern known in the solar literature as supergranulation.
News The search for new physics and inverse-square-law violations at sub-millimetre distance scales (309 kB) by Mikhail Klassen
Feature Beneath the ivory towers (792 kB) by Iva Cheung
Feature Instruction manuals, references and guidebooks (340 kB) by Stephanne Taylor
Feature Looking at the northern sky with Canadian telescopes (1.5 MB) by Julie Hlavacek-Larrondo
Feature Building Martian exploration science, one mission at a time (1.6 MB) by David Nataf
Article de fond Irradier le cancer (1.4 MB) par Charlotte Imane Bénaoudia
Feature Ancient Greece (902 kB) by Julie Hlavacek-Larrondo
Book reviews (341 kB)
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Volume IV, Numéro 2 (janvier 2006)
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Numéro complet en format PDF (27.8 MB)
Editorial La science au service des puissances: Pourquoi la recherche est forcément politique (152 kB)
Original research Factors affecting the K-shell x-ray fluorescence bone lead technique (952 kB) by Andrew F.B. McDonald, Naseer Ahmed, David E.B. Fleming
Abstract X-ray fluorescence (XRF) is the main in vivo technique for measuring the concentration of lead in bone. This research investigated some of the factors that may affect the precision and accuracy of this measurement. The two principal factors investigated were the distance of the radiation source from the sample and the possible existence of a lead concentration gradient in a sample phantom. A small, but significant, difference in measured lead concentration was seen as a function of source-to-sample distance. Variations in measured lead concentration as a function of phantom depth appeared more random than systematic. In all cases, average measured lead concentration ranged from 31 to 36 µg/g, consistent with expected phantom concentration of 34 µg/g.
News Election 2006: What to expect for science? (448 kB) by Philippe Marchand
Feature The hands feeding Canadian science (616 kB) by Jeff Mottershead
Feature Extracting the past through archaeometry: Exploring the interplay between physics and archaeology (3.5 MB) by Aviv Keshet
Interview Thoughts from an undisciplined mind (488 kB) by Sean Kelly
Article de fond Les conséquences du programme spatial russe: Ou les réactions d'un président américain à une course amorcée par son pire ennemi: le communisme (484 kB) by Marie-Michèle Limoges
Feature Are we headed towards 'Star Wars: The Next Generation'?: A scientifc look at missile defence (460 kB) by Stephanne Taylor
Feature A summer at Fermilab (1.3 MB) by Mushtari Afroz
Book reviews (444 kB)
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Volume IV, Numéro 1 (septembre 2005)
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Numéro complet en format PDF (16.4 MB)
Editorial Reinventing the study of the wheel: Noble goals of undergraduate curriculum reform lack realism (124 kB)
Original research Highly coherent and localized sub-structures within auroral flicker (2.5 MB) by Geoffrey J. Holmes, David J. Knudsen and Trond S. Trondsen
Abstract Spatially localized, highly coherent sub-structures with multiple discrete frequencies were observed within regions of flickering aurora during a campaign at Churchill, Manitoba in March 2005. A Portable Auroral Imager system was used to visually identify auroral flicker, analysis of which yielded frequencies between 5 and 15 Hz, lifetimes between 1 and 15 s, and physical scales of 1 km or less (presuming an auroral base altitude of 100 km). Additionally, a photomultiplier instrument was implemented to provide greater time resolution and attempt confirmation of a cutoff frequency, above which no auroral flicker is observed. Examination of this data demonstrated flicker frequencies between 3 and 14 Hz, lifetimes at or below 5 s, and very little fluctuation power above 20?Hz. Analysis of a range of region-of-interest sizes within flickering aurora suggests highly localized sub-structures, and the discrete, narrow-bandwidth frequencies detected imply a surprising and previously unreported degree of structure in the frequency spectra of these sub-structures.
Original research Sands of Time (1 MB) by Isaac Tamblyn and Barry Paton
Abstract We investigate the dynamics of an hourglass system, specifically the ticking that is sometimes observed. By closely monitoring pressure within the upper chamber, we gain insight into the mechanisms that cause this discontinuous flow.
News UWO to host CUPC 2005: Celebrating Canadian physics, imagination, and undergraduate research (852 kB) by Philippe Marchand
Profile Pouring light into nature's dark bind: Regina's undergraduates help probe the properties of gluons (376 kB) by Charles-François de Lannoy
Profile Atmosphere decryptors (484 kB) by Philippe Marchand
Profile Seeing the invisible and understanding the unknowable (764 kB) by Stephanne Taylor
Profile Applying physics to human health (460 kB) by David Nataf
Book reviews (780 kB)
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Volume III, Numéro 3 (avril 2005)
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Numéro complet en format PDF (20MB)
Editorial Physics and Journalism: A relationship in need of a counsellor (152 kB)
Original research Characterization of quantum dot behaviour in live mammalian cells (2.1 MB) by Ajit Thakur and Cécile Fradin
Abstract Quantum dots are semiconductor nanocrystals with exceptional optical properties. To assess their usefulness as fluorescent probes in living systems, we studied the reaction of culture cells to the presence of different types of quantum dots. The quantum dots were characterized in solution using fluorescence correlation spectroscopy and then loaded into mammalian cells and imaged using time-lapse video microscopy. While the cells seemed unperturbed by the presence of single quantum dots, they clearly identified large quantum dot aggregates as foreign bodies. Our results highlight the importance of preventing quantum dot aggregation by using a proper hydrophilic layer.
Profile All tied up in knots: UBC's Mark Van Raamsdonk takes string theory to the next dimension (1.0 MB) by Brendan Lloyd
Profile Space physics out in the open: Martin Connors's aurora fascination at Athabasca University (864 kB) by Aviv Fried
Profile Noble neutrinos: Understanding the Sun from under the Earth (692 kB) by David Nataf
Profile Pizza and pulsars: Victoria Kaspi sees just how fast she can spin them (700 kB) by Julie Hlavacek-Larrondo and Marie-Michèle Limoges
Profile "It always makes sense": Manuella Vincter explores the very small with the very big (736 kB) by Philippe Marchand
Profile Exploring Kuiper's wardrobe: Joseph Hahn's research into the other asteroid belt (1.0 MB) by Kyle Hill with John Lindner
Profil Le fondamental et le pratique: Alain Haché choisit d'explorer une vaste gamme de sujets (624 kB) par Vincent Leduc
Profil Comprendre « comment ça marche »: Laurent Drissen espionne les étoiles massives (1.1 MB) par Myriam Francoeur
Book reviews (388 kB)
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Volume III, Numéro 2 (janvier 2005)
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Numéro complet en format PDF (24 MB)
Editorial The third falsehood: Uses and misuses of statistics (116 kB)
Recherche originale Dépendance en taille et en température des propriétés de surface d'agrégats métalliques bidimensionnels (1.3 MB) par Christian Chenard-Lemire et Laurent J. Lewis
Résumé En utilisant la dynamique moléculaire, un modèle d'un agrégat atomique est fabriqué grâce à un potentiel EAM, une méthode souvent utilisée pour approximer les forces quantiques pour des atomes métalliques. Une analyse détaillée de la simulation montre que les facettes à la surface de l'agrégat rétrécissent en longueur et ont une longévité plus courte lorsque la température est augmentée jusqu'au point de fusion de celui-ci. La géométrie de la surface de l'agrégat (moyennée sur plusieurs configurations dans le temps) passe de complètement facettée à basse température à presque circulaire au-dessus du point de fusion. Ces caractéristiques sont observées pour toutes les tailles d'agrégat étudiées, de 300 à 1000 atomes.
Original research Numerical study of quadrupole magnetic traps neutral atoms: anti-Helmholtz coils and a U-chip (3.3 MB) by Hyun Youk
Abstract Anti-Helmholtz coils and micro-fabricated chips are used for magnetically trapping neutral atoms in forming Bose-Einstein condensates and Fermi degenerate gases. Although they are widely used, literature dealing with a detailed numerical study of the magnetic fields involved in these traps is incomplete. Analytical and numerical investigations were carried out to study the physical properties of the magnetic fields produced by the anti-Helmholtz coils and a U-chip. The roles played by electric current and geometric aspects of these magnetic traps are emphasized through numerical modelling.
News Einstein's legacy: Canada's plans for the World Year of Physics (536 MB) by Zerah Lurie
News You are the product of frozen accidents: Nobel physicist addresses student research conference (1.1 MB) by David Nataf
Feature The other relativity: Henri Poincaré's contribution to Einstein's theories (788 kB) by Elise Paradis with Edinah Koffi Gnang
Feature Rotational sorcery: The inertial properties of magic squares and magic cubes (276 kB) by Adam Rogers
Feature It's about time: One square's search for herself in space (1.1 MB) by Moira Peters
Feature CUPC 2004 in pictures (3.6 MB)
Book reviews (820 kB)
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Volume III, Numéro 1 (septembre 2004)
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Numéro complet en format PDF (11 MB)
Editorial « C'est vraiment une mafia. » D'autres bonnes raisons de vouloir un emploi d'été en physique (116 kB)
Original research Design and modelling of a zero-emission power system for Coral Harbour, Nunavut (456 kB) by Christine Apold and Jordan Morelli
Abstract Providing remote communities with reliable, inexpensive power has long been a challenge. Coral Harbour, Nunavut, with a population of 721, was selected as a test site for analyzing the feasibility of implementing a zero-emission power system. The current distribution grid has 1310 kW of installed capacity and experiences a peak demand of approximately 600 kW. In the proposed design, all energy requirements will be met by wind turbines and a two-phase storage system consisting of deep-discharge batteries and hydrogen storage. The system was modelled in MATLAB and the components were optimized for the least expensive arrangement. As renewable technologies are still developing, three cost scenarios were simulated for 5, 10, and 15 years hence. The per-kWh cost for these technologies post-commercialization is estimated at 34.9?/kWh, which is very competitive with the current diesel price of 53.5?/kWh. Therefore, further research into this opportunity is recommended.
Original research Phase transitions in trapped ion mixtures via sympathetic cooling (1.4 MB) by Aviv Fried and Robert I. Thompson
Abstract Transitions of ionic species from gas phase to Wigner crystals using sympathetic laser cooling of ions stored in a linear-geometry, radio-frequency (RF), electric quadrupole trap have been investigated using computational techniques. The simulations, which allowed 5 sample ions to interact with 15 laser-cooled ions, showed that as the ratio of the laser-cooled ion mass to the sample ion mass decreased, the collisional cooling rate declined relative to the instability heating rate, to the point where the sample ion temperature ceased to fall and crystallization failed to occur. However, changing the laser and trap parameters proved useful, as the former modified the cooling rate while the latter reduced the ion heating mechanisms. Together, these controls permitted cooling and crystallization of low mass ions. Specifically, the effect of changing both the laser detuning and the applied electric trapping potential were investigated to optimize the cooling of low mass sample ions.
Feature Summer jobs in physics (712 kB) by Chris Avis and Gavin Cranmer-Sargison
Feature Fisica en ultramar: Employment abroad for the physics undergraduate (624 kB) by John Lindner
Feature Getting the most of MOST: One year of Canada's first space telescope (608 kB) by Magda Konieczna
News The UVic physics handbook (296 kB) by Mike Froese with John Lindner
Feature Making room at the bottom: New state-of-the art nanoscience facilities poised to make Edmonton the hub of nanotechnology research in Canada (784 kB) by Iva Cheung
Book reviews (388 kB)
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Volume II, Numéro 3 (avril 2004)
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Numéro complet en format PDF (12 MB)
Editorial A brief pseudohistory of time: Curbing junk science calls for active scientific engagement of the public (120 kB)
Original research In-class concept quizzes using personal responders: Evaluating an interactive engagement physics teaching method (640 kB) by Joshua M. Bray and A.J. Sarty
Abstract A new teaching method was implemented in an introductory algebra-based physics course at Saint Mary's University starting in the 2001/2002 academic year. It involved a short conceptual quiz given at both the beginning and the end of each lecture conducted through the use of wireless personal responders. In an attempt to evaluate whether or not this method helped the students retain the concepts addressed by the quizzes, we searched for qualitative trends in the relationship between students'performance on the in-class quizzes with their performance on the final exam. The trends found show only some hints that the quizzes assisted in long-term retention of the material, but, overall, the trends do not show strong evidence to confirm such assistance.
Original research Singularity excision for one-dimensional relativistic supernova simulations (728 kB) by David Richmond and Matthias Liebendörfer
Abstract Current supernova models struggle to survive past the time at which an apparent horizon (AH) appears within their computational domain. A routine was developed to remedy this problem by excising the region containing the AH from the computational domain of the simulation. This program was successful when applied to a simplified model of stellar collapse invoking a polytropic equation of state (EoS), and disregarding any neutrino transport. The extension of this result to a simulation that includes both neutrino transport and a realistic EoS has not yet been accomplished, but if successful, it should allow the neutrino signal to be tracked during the late stages of stellar collapse.
Feature The Canadian Light Source (1.4 MB) by Zerah Lurie
Feature Canada's TRIUMF: The Tri-University Meson Facility (752 kB) by Magda Konieczna
Feature The Sudbury Neutrino Observatory (776 kB) by Chiara Mingarelli with Chris Kyba, Laura Blue and Iva Cheung
Feature The lowdown on LaTeX: A crash course for the TeX virgin (668 kB) by Iva Cheung
Feature AUPAC 2004 (464 kB)
Book reviews (292 kB)
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Volume II, Numéro 2 (janvier 2004)
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Numéro complet en format PDF (15.8 MB)
Editorial The costs of academic freedom: More than science awaits beyond graduation (100 kB)
Perspectives Physics, beyond classes: Graduate school secrets (232 kB) by Kris Lui
Original research Enhancing the study of the aurora using low-cost magnetometers (828 kB) by Christy Bredeson and Martin Connors
Abstract Athabasca University has developed and is in the final stages of testing a low-cost alternative to existing magnetometers -- crucial instruments in the study of the aurora which act as ground-based monitors for the magnetic effects of overhead auroral currents. By incorporating pulsed fluxgate magnetic sensors, GPS heartbeat pulses and microcontroller technology, a triaxial magnetometer can be built for under $500, compared to $15 000 for currently used instruments. This magnetometer will be a cost-effective alternative to current models, as it utilizes inexpensive parts and readily available technology.
Original research PTW-Freiburg ionization chamber and electrometer characterization (828 kB) by Gavin Cranmer-Sargison, Wayne Beckham and Mike Roney
Abstract The goal of this study was to characterize the PTW-Freiburg 0.6 cm^3 Farmer-Type ionization chamber for response linearity, count rate stability and electrometer polarization. This was done using a PTW-Freiburg radioactive check device, secondary and field standard ionization chambers and two PTW-Unidose E Electrometers. Each ion chamber was paired exclusively with one of the electrometers and data measured for various exposure times. Current and accumulated charge readings were performed as a function of time using both the medium- and low-range electrometer settings. It was found that in each data range both ion chambers had a linear response to exposure time. The count rate was found to be stable to within approximately ±0.10% and the electrometer polarity effects to be below the PTW-Freiburg quoted 0.5%. The results of the ion chamber characterization would be used in the development of a clinical quality control routine established to monitor ion chamber response stability.
Original research Generation of atmospheric vortices through small-scale forcing (1.4 MB) by Roy P. Wilds and David J. Muraki
Abstract Observations of the jetstream show that atmospheric vortices are continually created, grown and dissipated. Additionally, there are observations that small-scale disturbances (under 500 km) are present at the tropopause level. We set out in this investigation to determine if weak, small-scale perturbations in an atmospheric model, beginning from zero initial conditions, can produce larger scale vortex dynamics. Results presented here show that weak smallscale forcing does produce vortices which are both larger in spatial size, and stronger in amplitude than the underlying forcing. We demonstrate this by analyzing the distribution of vortices on the tropopause as our model is evolved, and also by looking at the cascade of energy from the small scales of the forcing perturbations to the large scales of the emerging vortices.
News Is a Master's degree what it used to be? Changes to NSERC scholarship policy could mean less Master's funding and a graduate structure similar to that in the US (184 kB) by Megan Thomas
News Canadians petition for mars (348 kB) by Lara Thompson
Feature CUPC 2003 in pictures (1.1 MB)
Feature GRE facts and figures (416 kB) by Iva Cheung
Feature Graduate studies table (100 kB) by Jonathan Ruel with Iva Cheung
Book reviews (284 kB)
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Volume II, Numéro 1 (septembre 2003)
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Numéro complet en format PDF (10.3 MB)
Editorial Gender Gape: What accounts for the scarcity of females in physics? (124 kB)
Original research Dusty galaxies: modelling spectral energy distributions (792 kB) by John Lindner
Abstract A simple dust cloud model is presented to explain the spectral energy distributions (SEDs) that incorporates a central luminosity source surrounded with concentric shells of dust grains, with a radially decreasing dust particle density. The central source heats each shell to a given temperature, where the dust will radiate as a greybody. The code sums the emission from each shell to determine the total dust flux at each wavelength from the entire cloud. The model was used to compute the infrared (IR) flux of M82, a nearby starburst galaxy, and IZw 1, a low redshift radio-quiet quasar (RQQ).
Original research Collisions between red giant and white dwarf stars (1.4 MB) by Catherine Lovekin and Alison Sills
Abstract We investigate the properties of collisions between giant branch stars and white dwarfs in dense globular clusters. The amount of mass lost by the giants varies with impact parameter, velocity and stage of evolution of the giant. Giants at the tip of the giant branch lose more mass than those halfway up. In all simulations, most of the mass completely escapes the system. We conclude that although this mechanism will not remove bright giants from clusters, it could be used to increase the population of blue stars.
News Qubits, not cubits: CAP lecturer gives students a brief glimpse into the growing field of quantum computing (416 kB) by Iva Cheung
Nouvelles Une avancée pour la représentation francophone à la CCÉP (244 kB) par Jonathan Ruel
Feature Struggling to contribute (904 kB) by Jhenifer Pabillano
Feature Mileva Maric: Mrs. Einstein (364 kB) by Moira Peters
Book reviews (304 kB)
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Volume I, Numéro 3 (avril 2003)
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Numéro complet en format PDF (9.3 MB)
Editorial Edifying physics education: Englightened minds begin with enlightened attitudes (108 kB)
Perspectives Physics, beyond classes: Know what you'll be getting into (312 kB) by Kris Lui
Reproduced research Anisotropy of the VariSource 200 Series brachytherapy source (1.0 MB) by Gavin Cranmer-Sargison, Will Ansbacher and Mike Roney
Abstract The aim of this study is to investigate the dose distribution of the VariSource 200 Series HDR Afterloader brachytherapy system. Using the American Association of Physicists in Medicine (AAPM), Task Group No. 43 (TG-43) protocol1, the dose calculation of the HDR brachytherapy source will be made using the isotropic point-source model. Approximating the geometry factor as 1/(r^2), the anisotropy function of the Ir-192 source will be verified using film as a simple dosimetric tool.
Reproduced research Correction for the specular reflectance from a transparent dressing covering an integrating sphere (644 kB) by Diana F. Moscu, Joseph E. Hayward, Tom J. Farrell
Abstract A technique to quantify skin redness, or erythema, is an important tool in medical fields, as increased erythema is associated with an infection or injury at a particular site. The degree of erythema can be measured with an integrating sphere as the absorbance spectrum from the reflectance signal. The opening of the sphere is covered with a transparent dressing, which adds to the measured signal through specular reflectance. A correction is applied by including the specular reflectance in the measurement of the background light. The results are consistent with those from an uncovered sphere allowing comparisons to be made between measurements.
Article de fond Nouvelles méthodes d'enseignement et rôle de l'étudiant (148 kB) par Jonathan Ruel
Feature Post-baccalaureate teacher education programs in Canada (180 kB) by Iva Cheung
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Volume I, Numéro 2 (janvier 2003)
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Numéro complet en format PDF (5.2 MB)
Editorial Global citizens first; physicists second (116 kB)
Original research Investigation of possible detection of earth-orbiting particulates by SKiYMET meteor radars (892 kB) by Omer Dushek and W.K. Hocking
Abstract Earlier studies have presented evidence that an abnormal peak in the entrance speed histogram of radar-detected meteors could be associated with Earthorbiting objects. Using data collected from several radars around the world, this possibility has been extensively investigated, with particular emphasis on determining that the observed peak is not an instrumental artifact. The abnormal peak was not correlated to the ordinary meteor entrance-velocity peak, it showed no seasonal variations, and there was no apparent contamination of the meteor entrance speeds related to radial velocity determinations. This information, along with Newtonian orbital calculations, leads us to believe that the abnormal peak is caused by Earth-orbiting particulates. No correlations were found between the abnormal peak and larger-scale orbiting objects being tracked by NASA. These results could suggest that the Earth contains a population of small dust-like particles in continuous orbit, forming a ring or cloud around the Earth, and that some of these are entering the atmosphere and burning up on a regular basis. It appears that significant enhancements in entrance count rates can occur on occasion, but the trigger for these events is not known. The origins of these particulates is not clear -- they could be dust left over from previous asteroid or comet breakup, or they could be small residual particles like paint left behind by orbiting satellites.
Original research Numerical simulations of magnetic vortices in high-temperature superconductors (352 kB) by Mike Gallamore, G.E. McCormack and T.P. Devereaux
Abstract Numerical simulations of magnetic vortices in high-temperature superconductors are discussed. The behaviour of the depinning force as a function of the number of vortices, defects, and the angle of the defects is presented. The structure of pinned and moving vortex systems is also explored. Our simulations show the complex interplay of disorder and interactions in dynamical systems.
Original research Applications of radiation within the wine industry (156 kB) by Kyle Wilson, G. Moran and D. Boreham
Abstract The objective of this research was to test the feasibility of taint removal in industrial wines through the use of radiation. The process used the cobalt-60 source in the McMaster University Nuclear Reactor. When wine, composed mainly of water (~87%), alcohol (~10%), acid (~2%), and anthrocyanins/tannins (~0.1%),1 is irradiated, water molecules are hydrolyzed generating free radicals in solution2. These free radicals are oxidizing agents that will oxidize other molecules in the wine. The focus has been a specific taint introduced into 2000-2001 vintages by the Multicoloured Asian Lady Beetle (Harmonia axyridis) whose population has increased dramatically of late3. This taint -- thought to be a methoxy-pyrazine -- is detectable by taste in 1-2 parts per trillion (ppt). Preliminary sensory evaluation (performed in our lab by a trained panel and industry expert tasters) has shown that radiation dramatically improves tainted wines by eliminating the lady beetle taint. Chemical tests indicate that radiation is acting as an oxidizing agent, reducing levels of sulfur dioxide (SO2) (introduced into wines to prevent oxidation) by nearly 40-70%. Research ongoing involves the detection of the taint (the implicated methoxy-pyrazine) by mass spectrometry as a taint assessment tool, and an indicator that radiation has removed the taint.
Feature The Canadian Undergraduate Physics Conference 2002 (1.6 MB)
Feature Canadian physics societies (876 kB) by Iva Cheung, Kyle Elliott, Catherine Neish and Lara Thompson
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Volume I, Numéro 1 (septembre 2002)
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Numéro complet en format PDF (12.2 MB)
Editorial The academic rites of passage: Are undergraduate studies preparing us for what's really to come? (96 kB)
Original research Measurement of sound absorption of occupied and unoccupied chairs in university classrooms (588 kB) by Katherine Kousaie and Murray Hodgson
Abstract Measurements were made to determine the sound-absorption contributions of unoccupied and occupied chairs in classrooms. Test configurations consisted of different seat/student/heavy-clothing ("absorber") combinations. The total room absorption was found from measured reverberation times, using diffuse-field theory. The absorption contributions of chairs, people sitting in chairs, and heavy clothing worn by these people, were found using multi-variable linear regression; their contributions varied with frequency, chair type and classroom. The results can be used in empirical models for predicting the acoustical conditions in classrooms.
Original research Multiphoton absorption and the evolution of green plants (120 kB) by John Robertson and Robin Marjoribanks
Abstract Why terrestrial plants evolved to scatter so much of the green portion of the solar spectrum is something of a mystery in evolutionary biology. A quick calculation shows that DNA damage from multiphoton absorption may have been a small factor in this development.
Original research Nonlinear evolution of a laser beam in plasmas (2.3 MB) by Mark Roebuck and Wojciech Rozmus
Abstract Endeavors into understanding the propagation of laser light through low-density plasmas have led to many interesting discoveries. One such endeavor is the full 3D (F3D) code run at the Lawrence Livermore National Laboratory. The purpose of this project in part is to show that many of the same properties may be displayed using the variational method. Three different cases are considered, and the unique properties of each are shown. The results presented here are for small values of P/P_{c} and n_{e}/n_{c}. This paper shows that from a theoretical standpoint, the computational results can be described by a very useful and relatively simple approach to the problem of nonlinear evolution of a laser in plasmas.
Reproduced research Zero modes and radiation in an external gravitational field (480 kB) by Kory Stevens and Valeri Frolov
Abstract We discuss the resolution to what appears to be a violation of the equivalence principle: while an accelerated charge radiates, a charge in a static gravitational field does not. This apparent contradiction is explored through a mathematical discussion comparing a charge in an accelerated frame described by a Rindler coordinate transformation, and a charge near the event horizon of a black hole.
Feature Canada's conferences for physics undergrads (328 kB) by Iva Cheung and Larry Reeves
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