161,244 research outputs found
Characterization of the structural response of a lithiated SiO<sub>2</sub> / Si interface: A reactive molecular dynamics study
No full textWe report the results of a computational study regarding the mechanical properties of a lithiated Si/SiO2 interface using reactive molecular dynamics. The study is motivated by an intended application of SiO2-coated Sinanotubes as fibers in structural batteries with a fiber-reinforced composite architecture while serving as anodes. According to the results, main failure properties due to partly irreversible bond breakage during mechanical deformation are identified, indicating agreement with bond energy/bond order based estimates. Microscopic failure properties are also identified and interpreted in view of the observed processes of bonding degradation. In particular, the effect of Li distribution on the shear deformation response is evaluated as significant.Applied Mechanic
O. A. C. Review Volume XXXVI Issue 12, August 1924
No full textThis slim summer issue contains the address given by the agricultural section of the British Association for the Advancement of Science, and a report on the visit of this association to the O. A. C. Other articles include instructions on increasing strawberry production and a biography of the author John Masefield. The editorial comments on Rhodes Scholars. The Alumni column provides an update of alumni activities. This issue does not contain a Macdonald column.JoyPresent-day problems in crop productionAfter the strawberry harvestJohn MasefieldVisit of the Agricultural Section of the British Association for the Advancement of ScienceEditorialCollege lifeAlumniadvertisin
O. A. C. Review Volume L Issue 5, February 1938
No full textThis issue begins with an article about the history of Red Fife Wheat from its origins in Galicia to its importation to Peterborough. Agricultural articles pertain to the dietary benefits of human consumption of rye and timothy grasses, and continued research in soil nutrient depletion. Other articles include the presentation of A. T. Christie's Victorian medals to the Ontario Agricultural College. An alumnus continues his 1931 story as a stowaway. The English column addresses the use of proper English and the origin of the Little Theatre Movement. While the literary column provides book reviews, an account of the Canadian Author Lecture by H. Napier Moore, and the composition of epitaphs. The athletics column reports on the results of the competitions in basketball, swimming, hockey, boxing, wrestling, and fencing. In the Macdonald Institute column a student describes the O. A. C. campus to foreign students, there are also accounts of the "Feminine Section of O. A. C., and a tally of the food consumed in the dinning hall. The highlight of the campus news column is the Conversazione of 1938 and the social events of the season. The O. V. C. column provides updates of the joint social events between the colleges on campus. A new column - the Club News, reviews events for each of the animal husbandry, field husbandry, dairy, horticulture, and biology clubs. Alumni and Alumnae columns provide alumni updates.EditorialLand of the first Red Fife kernelA. T. (Dad) Christie gives keepsakes to President of farm collegeSo now we eat grassStowaway voyageChemistry department attacks soil depletionDepartment of English bulletinThe Origin of the Little Theatre MovementO. A. C. sportsfolioLiterary highlightsMacdonald newsThis life of oursCollege lifeConversazioneHands across the highwayClub newsAlumni newsMacdonald alumnaeGraduate newsadvertisin
O. A. C. Review Volume XLVI Issue 5, February 1934
No full textThe focus of this issue is the preparation for College Royal and recognizing its tenth anniversary. This month's agricultural article is a report from the Dominion Parasite Laboratory on the biological control of pests. Other articles provide an account of the activities of a stage manager and the development of the field of home economics at Macdonald College in Quebec. Campus news addresses the success of the 1934 Conversazione, the commemorating of the sixtieth anniversary of the founding of O. A. C., the attendance at the Canadian Author Lecture, and the successful productions of "The Apple Cart" and "Iolanthe". The Macdonald Institute column comments on the Conversat and women's athletics activities in basketball and the rifle club. The Alumni Record supplies alumni updates.EditorialTen Years of the RoyalRamblings on the RoyalBlame it on the stage managerBiological control of insect pests in CanadaNot for girls onlyCollege lifeLiterary sectionO. A. C. sportsfolioAlumni recordMacdonald newsLetters to the editoradvertisin
O. A. C. Review Volume XLIX Issue 5, February 1937
No full textThis mid-winter issue begins with a travel diary of a student's journey through the Scottish Trossachs. The highlight of the issue is the success of the Conversazione and its theme of India. A student contributed a humorous piece on traveling salesmen, while another student presents the debate over the seminar method of teaching at the college. The Literary Section reports on the Canadian Author Evening with the speakers addressing the significance of Vimy Ridge. Toronto's debating team visits the campus with a challenge of speaking without "sprouting a whisker" -- saying "er" or "um" while speaking. Campus news provides updates on the numerous banquets and dances, campus humour, and the production of "Arms and the Man". The Macdonald Institute column contains a poem regarding the Conversat, a humorous "letter home", and news about the new recreation room in Mac Hall. The agricultural article pertains to the College's acquisition of Kerry Hill sheep. The athletic column reports on the various athletic team results. The Bits O' Bronze lecture was on the history of agriculture in Upper Canada. The Alumni column contains alumni updates and changes to the graduate list. The Macdonald Alumnae column reports on the teaching of household arts in Toronto public schools and alumnae updates.EditorialAs I recall the TrossacksThe travelling salesmanRound the world in two hoursOur seminar systemOur inquiring reporterThe East comes to the ConversatCranial contortionsMother Nature strains a pointLiterary sectionWhiskers and other weighty mattersOn the Misguided WorldCollege lifeMacdonald newsConversazione 1937Letters to the editorKerry Hill sheep introduced to CanadaO. A. C. sportsfolioAlumni newsMacdonald alumnaechanges to the graduate listadvertisin
Age-related differences of the gaze pattern in a realistic pedestrian traffic task
No full textLaboratory studies suggest that the gaze pattern changes in older age, both in seated and in walking persons. Here we investigate the gaze pattern in a more complex and realistic scenario: walking in a virtual-reality shopping precinct. Seventeen young and sixteen older adults walked at their preferred speed on a treadmill driven by their leg movements, thus controlling the presentation of a virtual 3D world on a screen 130 cm ahead. The screen showed a shopping street with stationary and moving objects, and with six pedestrian traffic lights of whom three turned red upon approach. Gaze direction was registered by a video-based system. We found that each glance at a traffic light took longer in older than in young persons, and the sum of all glances at a traffic light was longer as well. In effect, older persons looked at the traffic light equally long throughout all three light phases, while young ones gradually increased their inspection of the traffic light as the green phase went on. The observed change of the gaze pattern in older age could represent a compensatory strategy to facilitate spatial orientation and/or movement preparation, or it could reflect a deficit of gaze disengagement. Future research should disambiguate these alternatives. In any case, the observed change is detrimental for seniors’ sensorimotor performance in everyday scenarios
Statistical inference on the reliability performance index for electric power generation systems
No full textIncludes bibliographical references (leaves 101-106)A primary objective of this research is to analytically develop a probability density function for the "Loss of Load, " a widely used index in power systems reliability evaluation. The equations to compute the parameters of this distribution for any given load cycle are derived. The forced outage rate (F.O.R.) for a generating unit is instrumental in the computation of reliability indices. This research also suggests a method for obtaining a statistically consistent estimator of F.O.R. using a decision theoretic approach. In order to develop the theoretical structure for the problem stated, classical and decision theoretic (Bayesian) statistical inferences are used as major tools along with the univariate and multivariate asymptotic theory. Consequently, an approximate numerical multiple integration scheme is employed to compute the parameters of the asymptotic pobability density function. The author believes that this statistical approach offers a more realistic alternative to the conventional calculation of an averaged value for the Loss of Load index where deterministic outage data are used
A Laboratory for Prototyping and Testing Multimedia Presentations
No full textIn this article we describe a prototyping environment, which allows an author to set up and test a complex hypermedia presentation. It contains a visual editor, based on a graph notation, in which the nodes are media objects and the edges are the synchronization relations between them; an execution simulator, which helps the author to test the presentation dynamics by manually triggering media related events; and a player, which allows the author to preview the presentation and to visually relate the execution evolution with the interpretation of the synchronization schema
Effective Willis constitutive equations for periodically stratified anisotropic elastic media
No full textA method to derive homogeneous effective constitutive equations for periodically layered elastic media is proposed. The crucial and novel idea underlying the procedure is that the coefficients of the dynamic effective medium can be associated with the matrix logarithm of the propagator over a unit period. The effective homogeneous equations are shown to have the structure of a Willis material, characterized by anisotropic inertia and coupling between momentum and strain, in addition to effective elastic constants. Expressions are presented for the Willis material parameters which are formally valid at any frequency and horizontal wavenumber as long as the matrix logarithm is well defined. The general theory is exemplified for scalar SH motion. Low frequency, long wavelength expansions of the effective material parameters are also developed using a Magnus series and explicit estimates for the rate of convergence are derived.Peer reviewedReceived July 22, 2010; accepted December 15, 2010; published online April 21, 2011. Manuscript dated December 21, 2013
Effective shear speed in two-dimensional phononic crystals
No full textThe quasistatic limit of the antiplane shear-wave speed ('effective speed') c in 2D periodic lattices is studied. Two new closed-form estimates of c are derived by employing two different analytical approaches. The first proceeds from a standard background of the plane wave expansion (PWE). The second is a new approach, which resides in x-space and centers on the monodromy matrix (MM) introduced in the 2D case as the multiplicative integral, taken in one coordinate, of a matrix with components being the operators with respect to the other coordinate. On the numerical side, an efficient PWE-based scheme for computing c is proposed and implemented. The analytical and numerical findings are applied to several examples of 2D square lattices with two and three high contrast components, for which the new PWE and MM estimates are compared with the numerical data and with some known approximations. It is demonstrated that the PWE estimate is most efficient in the case of densely packed stiff inclusions, especially when they form a symmetric lattice, while in general it is the MM estimate that provides the best overall fitting accuracy.Peer reviewe
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