THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN CANADA

This paper provides an opportunity to formulate a statement of the current status of masonry engineering in Canada with some perspective from the past and some insight into potential for the future. Notwithstanding the fact that this represents the view of the author only, an attempt is made to provide a balanced and comprehensive overview. When we talk about masonry in Canada, by far the largest part of clay brick production and most of the concrete block used are employed in buildings based on the very simple to apply provisions of Part 9 of the National Building Code that applies to small buildings and is not “engineered” through any proper analysis and does not require the participation of a licensed structural engineer. However, growth potential is greatest in the area of engineered masonry. This paper provides information on education, research, development of codes and standards, and the general state of masonry engineering in Canada. Problems facing masonry in terms of maintaining or expanding market share of construction, areas requiring most attention, and opportunities for enhancement of masonry are discussed

Part 1 of the McMaster University Laboratory Test Program on Brick Veneer/Steel Stud Wall Systems

The behaviour of steel stud backup wall panels subjected to lateral loads was investigated experimentally and analytically. In addition, various steel stud to track connections were investigated experimentally. The experimental work consisted of the fabrication and testing of 109 steel stud to track connections. Thirty-two full size steel stud backup wall panels were also tested. Some of the panels were braced with various types of commonly used steel bridging while others were braced with gypsum board sheathing or Styrofoam SM insulation. Twelve beam tests were also performed in order to establish the flexural bending capacity of the steel studs tested. The analytical study consisted of an evaluation of the results of the test program. A one-dimensional elastic Finite Element program was developed to investigate the distribution of torsional stresses in steel studs as part of the analysis. The model had the limitation of ignoring the effects of web perforations. Based on analysis of the test and analytical results, several recommendations were made for design and construction of steel stud backup walls

Producing Software Using Tools in a Workstation Environment

We discuss how we taught students to build and use translation, interpretive, editing and monitoring tools in an undergraduate software engineering course. Students used the tools on low-cost workstations (Macintoshes) to build large, group projects. The students\u27 projects used all available features of workstation environments, including graphics, windows, fonts, mice, networks, and sound generators. We found that 1) the use of tools increased student productivity, 2) a shift in a data structure and algorithm topics is needed to cover material relevant for workstation environments, 3) new topics in system design are required for a workstation environment, 4) traditional material can be easily illustrated with a workstation environment and 5) students enjoyed being able to manipulate the advanced features of workstations in their work, which in turn increased their motivation for and concentration on the course material

Corporate Earnings as Gains Profits and Income as Depending Upon the Time of Their Accrual

The discussion here has to do with the earnings of corporations as taxable income, whether such earnings remain in the hands of the corporation accumulating them, or are distributed to the stockholders as dividends, the inquiry being limited, however, to the question of the time of their accrual as affecting their taxability

Finding Largest Empty Circles with Location Constraints

Let S be a set of n points in the plane and let CH(S) represent the convex hull of S. The Largest Empty Circle (LEC) problem is the problem of finding the largest circle centered with CH(S) such that no point of S lies within the circle. Shamos and Hoey (SH75) outlined an algorithm for solving this problem in time O(n log n) by first computing the Voronoi diagram, V(S), in time O(n log n), then using V(S) and CH(S) to compute the largest empty circle in time O(n). In a recent paper [Tou83], Toussaint pointed out some problems with the algorithm as outlined by Shamos and presented an algorithm which, given V(S) and CH(S), solves the LEC problem in time O(n log n). In this note we show that Shamos\u27 original claim was correct: given V(S) and CH(S), the LEC problem can be solved in time O(n). More generally, given V(S) and a convex k-gon P, the LEC centered within P can be found in time O(k+n). We also improve on an algorithm given by Toussaint for computing the LEC when the center is constrained to lie within an arbitrary simple polygon. Given a set S of n points and an arbitrary simple k-gon P, the largest empty circle centered within P can be found in time O(kn + n log n). This becomes O(kn) if the Voronoi diagram of S is already given

An O(n^{5/2} log n) Algorithm for the Rectilinear Minimum Link-Distance Problem in Three Dimensions (Extended Abstract)

In this paper we consider the Rectilinear Minimum Link-Distance Problem in Three Dimensions. The problem is well studied in two dimensions, but is relatively unexplored in higher dimensions. We solve the problem in O(B n log n) time, where n is the number of corners among all obstacles, and B is the size of a BSP decomposition of the space containing the obstacles. It has been shown that in the worst case B = Theta(n^{3/2}), giving us an overall worst case time of O(n^{5/2} log n). Previously known algorithms have had worst-case running times of Omega(n^3)

Computer Based Conferencing Systems for Developing Countries : report of a workshop held in Ottawa, Canada, 26-30 Oct. 1981

Meeting: Computer Based Conferencing Systems for Developing Countries, 26-30 Oct. 1981, Ottawa, ON, CAFrench version available in IDRC Digital Library: Systèmes de conférence informatique pour les pays en développement : compte rendu d'un séminaire tenu à Ottawa, (Canada), du 26 au 30 oct. 198

Pressure control for managing and optimizing adjacent subsurface operations in large scale CCS

Injecting CO2 in to the subsurface for safe storage of CO2 the pressure propagates far away from the injection point and this can be a potential problem if the overpressure extents to neighbouring subsurface activities or potential leakage pathways. For structural closure trap configurations the CO2 plume is captured within the local structural closure but the pressure footprint is on a more regional scale. This rise the question on, how large the storage complex needs to be for any individual storage operations and how large an area monitoring activities have to cover. The EC CCS guidance document addresses the issues with statements on competitions between subsurface operations but returns no absolute values. Pressure modelling of CO2 injection process with state of the art reservoir simulation tools is challenges by use of realistic model boundary conditions in order to model a realistic pressure level. Combined use of models on a site scale and on a regional scale can instruct how boundary conditions are set-up for a site scale model. Pressure management through pressure release wells could be an option to mitigate undesirable over-pressure developments. For local structural closures the pressure release wells can be placed outside the closure hereby mitigate the overpressure without introducing a potential leakage by drilling inside the trap. The paper addresses the issue of selecting model boundary conditions and modelling mitigation of pressure development by use of a large regional model with local structural traps in the Bunter Sandstone Formation in the UK Southern North Sea

Holocene hydroclimate changes in continental Croatia recorded in speleothem δ13C and δ18O from Nova Grgosova Cave

We present the first stable isotope (δ13C and δ18O) speleothem record from continental Croatia retrieved from two coeval stalagmites from Nova Grgosova Cave. U-Th dates constrain the stalagmite growth history from 10ka to the present, revealing coeval growth between 7.8 and 5.6ka. We interpret δ18O as an autumn/winter hydrological proxy related to changes of vapor source, precipitation amount, and/or seasonal rainfall distribution, while δ13C predominantly responds to spring/summer vegetation status and soil microbial activity. We identify several centennial to millennial-scale hydroclimate oscillations during this period that result from multiple forcing factors. Along with amount and source effect, it appears that some centennial variations were governed also by seasonal moisture balance. From 9.2 to 8.8ka BP, the local environmental setting was characterized by enhanced vegetation activity, while during the 8.2ka event the main feature was a change in precipitation seasonality. The most prominent change, identified in both δ13C records, is a sudden decline of vegetation and soil biological activity around 7.4 ka, indicating a precipitation decrease at a time of maximum plant growth in spring and summer and likely also reduced precipitation in autumn and winter. Although small in magnitude in these speleothems, a peak in δ18O and δ13C values at 4.3–4.1ka suggests that both summer and winter conditions were substantially drier during the 4.2ka event, in accordance with increased Mediterranean aridity and consistent with other global climate changes reported at this time. Compared to the present North Atlantic Oscillation (NAO) influence, we assume that millennial Holocene NAO-like variations were persistent through the Holocene via their effect on modifying local/regional air temperature, vapor origin, and inter- and intrannual precipitation distribution. Anthropogenic deforestation, which was the first major human impact on the environment during the Neolithic agricultural revolution, is excluded as a leading factor in δ13C variability since the first sedentary settlements were established further to the east in more arable locations along river valleys. However, the impact of intensive mining around the cave site during the last millennium is evident, with substantial deforestation driving an increase in δ13C

By-product utilization for animal production : proceedings of a workshop on applied research held in Nairobi, Kenya, 26-30 Sept. 1982

Meeting: By-product Utilization for Animal Production, 26-30 Sept. 1982, Nairobi, KEReviews research achievements that are technically and economically feasible for practical application in animal feeding systems, and recommends research methodologies