bluuebunny/crossref_metadata_2025 huggingface dataset:
Anemia and its impact on function in nursing home residents: What do we know?
Authors: Sabol Valerie K. , Resnick Barbara , Galik Elizabeth , Gruber‐Baldini Ann , Morton Patricia Gonce , Hicks Gregory E.
Published: January 2010

Purpose: To provide the advanced practice nurse (APN) information on the prevalence and causes of anemia in elderly nursing home (NH) residents, in order to affect diagnostic and management strategies that may help improve physical function and mobility outcomes.

Data Sources: Literature review of current peer‐reviewed research articles.

Conclusions: In the United States, the prevalence of anemia increases with advancing age, and are reported to be much higher among older NH residents than among community‐dwelling older adults. Causes of anemia among the elderly are often multifactorial. Older individuals with anemia, including mild anemia and even low normal level, have demonstrated lower muscle strength, physical function, mobility, and increased morbidity and mortality outcomes.

Implications for Practice: Given the potentially significant relationship between anemia and physical performance outcomes among NH residents, gaining a better understanding will help guide future evidence‐based care by allowing the APN an opportunity to tailor both medical and restorative care interventions. Because anemia is a potentially modifiable condition, intervention may preserve, limit, or reverse functional impairment and/or disablement, and allow for maximal functional independence.
Assessing the effects of primer specificity on eliminating numt coamplification in DNA barcoding: a case study from Orthoptera (Arthropoda: Insecta)
Authors: MOULTON MATTHEW J. , SONG HOJUN , WHITING MICHAEL F.
Published: January 2010

DNA barcoding is a diagnostic method of species identification based on sequencing a short mitochondrial DNA fragment of cytochrome oxidase I (COI), but its ability to correctly diagnose species is limited by the presence of nuclear mitochondrial pseudogenes (numts). Numts can be coamplified with the mitochondrial orthologue when using universal primers, which can lead to incorrect species identification and an overestimation of the number of species. Some researchers have proposed that using more specific primers may help eliminate numt coamplification, but the efficacy of this method has not been thoroughly tested. In this study, we investigate the taxonomic distribution of numts in 11 lineages within the insect order Orthoptera, by analysing cloned COI sequences and further test the effects of primer specificity on eliminating numt coamplification in four lineages. We find that numts are coamplified in all 11 taxa using universal (barcoding) primers, which suggests that numts may be widespread in other taxonomic groups as well. Increased primer specificity is only effective at reducing numt coamplification in some species tested, and only eliminates it in one species tested. Furthermore, we find that a number of numts do not have stop codons or indels, making it difficult to distinguish them from mitochondrial orthologues, thus putting the efficacy of barcoding quality control measures under question. Our findings suggest that numt coamplification is a serious problem for DNA barcoding and more quality control measures should be implemented to identify and eliminate numts prior to using mitochondrial barcodes for species diagnoses.
Carbon credits and the conservation of natural areas
Authors: Freedman Bill , Stinson Graham , Lacoul Paresh
Published: January 2010

Increasing the amount of organic-carbon stored in the biomass of terrestrial ecosystems is an effective way to reduce the net anthropogenic emissions of greenhouse gases to the atmosphere. This can be done by conserving existing ecological reservoirs of fixed organic-carbon, maintaining or enhancing the rate of sequestration, and restoring stocks that have been depleted by past land-use practices. Most trading systems for greenhouse-gas offsets recognize the validity of projects that gain ecological offsets, and permit them to sell carbon credits in an emerging marketplace for these novel commodities. Although ecological carbon-offset projects have been criticized from a variety of perspectives, most of the supposed problems can be satisfactorily mitigated. In addition to offsetting emissions of greenhouse gases, ecological projects that accumulate carbon credits may have a strong cross-linkage to the conservation of natural values, which in itself is an important action for society to undertake. This is, however, less of a consideration for projects that are based on anthropogenic ecosystems, such as no-till agricultural systems and plantation forests, which provide relatively few benefits to native biodiversity and might even detract from that objective if developed on newly converted natural habitat. Moreover, the existing rules for carbon-offset systems exclude some kinds of ecological projects from the trading markets, even though they would result in avoided emissions or enhanced sequestration of organic-carbon. As the emerging marketplace for carbon offsets grows, it will be important to understand the co-benefits and side effects of offset projects on non-carbon values, including native biodiversity.
A review of research on the development of lake indices of biotic integrity
Authors: Beck Marcus W. , Hatch Lorin K.
Published: January 2010

Current methods of ecological health assessment of lakes within the United States are not adequate for meeting the requirements of the 1972 Clean Water Act (CWA) and assessing the condition of aquatic biota. Impairment status of lakes has typically been measured and classified by individual states via eutrophication standards or through the use of total maximum daily load (TMDL) protocols. These measurements often fail to account for effects of anthropogenic disturbances on aquatic biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective ecological health assessment method that is meant to integrate ecological, functional, and structural aspects of aquatic systems. Furthermore, the IBI is meant to meet the requirements of the CWA by directly examining biological components of an ecosystem. The adaptation of the IBI for use in lake monitoring has increased in recent years as managers address the need to directly examine the biota of aquatic systems. This review is meant to examine research related to the development of IBIs in lacustrine environments. Obstacles and shortcomings to index development that are commonly encountered are discussed within the review. Attention is also given to robust methods and lessons learned from inadequate methods. The review will facilitate use of the IBI for lake monitoring efforts with the overall goal of improving water resource management.
Canadian species at risk (2006–2008), with particular emphasis on fishes
Authors: Hutchings Jeffrey A. , Festa-Bianchet Marco
Published: January 2010

In accordance with the Species at Risk Act (SARA), the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is nationally responsible for assessing wildlife species considered to be at risk of extinction. A parliamentary review of SARA provides impetus for an up-to-date summary of recent assessments (2006–2008) and a spatiotemporal analysis of the status of Canada's largest vertebrate group of species at risk, fishes. From April 1978 through December 2008, COSEWIC had assessed 13 wildlife species as extinct and 564 at some level of risk (extirpated, endangered, threatened, special concern). Among these 577 assessments, 112 are for fishes (76% freshwater and diadromous; 24% marine). Slightly more than one-quarter (27%) of Canada's 205 freshwater and diadromous species of fishes, many of which are in southwestern Ontario and southeastern Quebec, have been assessed as being at risk throughout all or parts of their ranges. The percentage of Canadian freshwater and diadromous fish species assessed by COSEWIC as endangered or threatened (16%) is similar to the percentage of freshwater and diadromous fishes in the US that have been listed under the Endangered Species Act (12%). The proportion of wholly freshwater fishes assessed by COSEWIC that have been added to SARA's legal schedule is somewhat lower than that of other taxa. However, whereas the US listed its first marine fish in 2005, the Canadian government has to date not accepted COSEWIC's advice to list an endangered or threatened marine fish since the proclamation of SARA in 2003.
Limit States Design—An Innovation in Design Standards for Steel Structures
Authors: Kennedy D. J. Laurie
Published: January 2010

The greater rationality of limit states design as compared to working stress design is developed to show that limit states design leads to a more consistent probability of failure and that neither overly safe and therefore uneconomic structures nor structures with insufficient safety should result from this design methodology.This rationality is extended in the limit states design method in that the performance of the structure and its components is checked against the various limit states at the appropriate load levels. Thus the limit states of serviceability are checked at specified load levels and of strength and stability at the factored load levels.Functions are presented for the two sides of the inequality:[Formula: see text]A comparative design of a 20-storey structure selected to provide a wide range of variables shows that limit states design as proposed results in a structure comparable to that designed by working stress method with a moderate saving in the weight of steel. Some simple design examples are worked out to show the basic similarities between working stress design and limit states design and that the two methods are of about equal complexity or simplicity. It is believed, because the designer will have to check the ultimate resistance against the effect of the factored loads, that he will develop a greater awareness of the behavior of the material and members with which he is working.
Sur le dimensionnement optimal de brise–lames à talus en enrochements et en blocs artificiels
Authors: Ouellet Y.
Published: January 2010

The selection of a design wave is best obtained by the use of a relationship showing the construction cost versus the anticipated damage cost. In the present paper, the influence of the main parameters affecting the optimum design criteria has been studied in reference to practical cases.Indeed, this criteria has been applied to three different wave conditions obtained from a wave climate study conducted by the Hydraulics Division of the National Research Council of Canada in the Gulf of St. Lawrence. The damages were evaluated using results from breakwater scale models carried out in the Hydraulics Laboratory of Laval University. Three different types of armour units have been considered: that is, quarry stones, tetrapods, and ‘dolosse’.For the sake of comparison, we have studied, in addition to the three wave conditions and the three types of armour units mentioned above, the influence of the economic losses due to malfunction of the structure and of the choice of an annual interest rate. We have also taken into account the water depth at the structure, a parameter which was found often to play an important role in limiting the value of the design wave.
Vacuum Sewer Systems and their Possible Canadian Applications
Authors: Averill D. W. , Heinke G. W.
Published: January 2010

This paper reviews the basic principles of vacuum sewer systems and the introduction of vacuum sewers to Canada. A vacuum sewer uses air pressure instead of gravity as the driving force for waste water transport. Waste water is moved in plugs, separated by air gaps, at high velocities through small diameter pipes. The pressure differential of about one-half atmosphere is created by a central vacuum pump. Specially designed vacuum toilets, valves, and a central collection tank complete the system. The advantages of a vacuum sewer system over a conventional gravity system are its ability to transport waste water horizontally and to a certain extent upgrade, its much lower water usage, and its lower capital cost. However the length, capacity, and lift potential of vacuum sewers are limited by the available pressure differential, which precludes their use in many cases.
Vibrational Behavior of Long-Span Floor Slabs
Authors: Allen Donald L.
Published: January 2010

With the recent trend toward long-span floors in buildings, there has been an accompanying increase in the incidence of complaints of unacceptable floor vibration after occupancy. This paper details acceptable vibration limits for human tolerance. In addition, the magnitudes and time durations of motions of floors of different constructions resulting from foot-falls (persons walking) are examined.The relative floor vibrational behavior resulting from variables such as unsupported span, type of structure (open web joist-concrete deck or reinforced concrete, etc.) composite or noncomposite deck-structure, etc., is discussed. The relative effect of each variable is outlined and ranked. Guidance on the relationship of variables is provided for the designer of long-span floors. Approaches to ‘correcting’ floors exhibiting an unacceptable floor vibrational behavior are discussed. Case histories of floors that have been modified to improve vibrational response are also given.
The Management of Urban Freeway Traffic
Authors: Cook Allen R.
Published: January 2010

The advent of computer-controlled electronic freeway surveillance and control systems in the past decade represents a potentially significant new operational tool for traffic engineers in large urban areas. These systems are capable of responding to rapidly changing traffic conditions and in various demonstration projects they have proven useful in maintaining an acceptable level of service for freeway operations, reducing the extent and duration of traffic congestion, minimizing the adverse effects of accidents and other incidents on traffic operations, and reducing accident experience. Surveillance system goals and techniques for achieving these goals are reviewed in this paper with particular emphasis on the problem of managing unexpected capacity-reducing incident situations. Recent research has demonstrated the feasibility of detecting incidents from traffic flow data, which is desirable for surveillance purposes because this information can be used to implement control strategies which attempt in real-time to divert some freeway traffic to alternate routes. Some of the operational problems involved with freeway traffic management are discussed, particularly the generation of false alarms by detection algorithms and driver willingness to be diverted to alternate routes.
Estimating the Cost of Small Steel Buildings
Authors: Nixon Don
Published: January 2010

A method is presented that will give a reasonably good estimate of the cost of structural steel in one or two storey office or industrial-type buildings made of beams, columns joists (short-span), bridging, V-pan, and roof deck. The unit times apply to buildings of simple construction with summer-time erection.The method is illustrated with two example problems and the results are compared with estimates found using the Canadian Institute of Steel Construction (CISC) method, which was intended mainly for use with medium-sized high rise buildings. Both estimates are compared to the price quoted by a structural steel fabricator in the Ottawa area. It was found that the CISC method can also be used for estimating cost of low rise buildings, although it does underestimate the cost of steel when the bay sizes are small.
Structural Behavior of Buried Plastic Pipe
Authors: Fagnou A. Y. , Nasser Karim W.
Published: January 2010

This investigation is a study of some of the factors which affect the ability of a plastic pipe to support earth loads. Some of the factors that were considered are the strength of the pipe and the soil conditions.Two series of laboratory tests, using two soil densities, were conducted on two types of plastic pipes that had six wall thicknesses. Deflection gauges were used to measure changes in the inside diameter due to an external load that was applied on the buried specimens.The results indicated that loose soil fill will produce about 70% more vertical deflection in a pipe than dense soil fill. Also, it was observed that vertical deflections can best be assessed by considering the resistence of the pipe to membrane forces rather than bending moments as stipulated in the A.S.T.M. Specifications.
Effect of Ice and Wave Forces on the Design of Canadian Offshore Lighthouses
Authors: Danys J. V.
Published: January 2010

Wave and ice forces are the main factors to be considered when designing offshore lighthouses. With the exception of the Pacific and the southern part of the Atlantic coasts, the design of the majority of Canadian lighthouses is governed by the ice forces. For many years very little was known about the magnitude of ice forces. Experience and judgement were the principal factors in the design and construction of such unique structures as lighthouses in the middle of a lake. Even now knowledge of these forces is not complete and there are still no Canadian design standards.Sloped surfaces and cylindrical or conical shapes are used for the substructures of the lightpiers and the ice-structure contact areas are designed as small as practical to reduce ice impact forces.
Utilidors in the Canadian North
Authors: Gamble D. J. , Lukomskyj P.
Published: January 2010

The majority of communities in northern Canada lack piped water and sanitation services. In the permafrost region this is primarily because of the high costs associated with constructing above-ground piping conduits called utilidors.This paper examines the designs and costs of various utilidors in Inuvik, Northwest Territories, and outlines the necessary approaches to reduce costs and to improve performance of utildor-type systems. Technical innovation and establishment of performance standards are called for as a means of achieving these aims. Also, it is evident from the presented information that design engineers and utility system operators, in order to realize savings, should be keenly aware of cost–benefit relationships on a long-range basis.
Mission Bridge—Design and Construction of the Steel Box Girder
Authors: Manniche Knud , Ward-Hall Gordon
Published: January 2010

The main span of the four-lane highway Mission Bridge is 440 ft (134.1 m) long with 290 ft (88.4 m) flanking spans, and consists of a steel box girder with an orthotropic steel plate deck. A box girder was adopted due to the structural efficiency of the box section and advantages in using thin plate material. The design is based on CSA Standard S6-1966 and the AISC Design Manual for Orthotropic Steel Plate Deck Bridges as far as applicable and with some deviations. The design was reviewed subsequent to the failure of steel box girder bridges abroad. The strength of the bottom plate in compression and the transverse bolted joints in compression received special attention. The joints of the deck plate made in the field are welded.In the fabrication and erection of the bridge, advantage was taken of the marine location of the fabrication yard. Special erection equipment was developed for the job. A key element in the scheme was ease with which the erection crane scow could be positioned.The application of the hot asphaltic concrete paving caused considerable thermal expansion of the steel structure.The cost of the steel superstructure was about the same as was estimated for a concrete superstructure. However, site conditions were such that the weight of the concrete structure would have increased the foundation costs.
A Long Curved Post-tensioned Concrete Bridge without Expansion Joints
Authors: Campbell T. I. , Francis L. N. , Richardson B. S.
Published: January 2010

A long horizontally curved, post-tensioned concrete highway bridge, continuous over 12 spans, is described. Particular emphasis is placed on a number of original and unorthodox design concepts which make the structure unique.
Analysis of Flexibly Connected Steel Frames
Authors: Frye M. John , Morris Glenn A.
Published: January 2010

A procedure is presented for analyzing steel frames with any combination of pinned connections, fixed connections, connections with any specified flexibility characteristics, or any of seven commonly used connection types. A method is outlined for expressing, in a nondimensional form, the moment–rotation characteristics for all connections of a given type. The dimensionless relationships are listed for the commonly used structural steel framing connection types. The incorporation of connection deformations into a linear structural analysis, by modifying the stiffness matrix and fixed-end-force vectors for each member, is demonstrated.An iterative nonlinear analysis procedure is described in which repeated modifications are made to assumed flexibility characteristics for all connections in a structure. When a suitable set of connection flexibility characteristics has been arrived at, a single analysis is performed to determine the correct structural deflections and internal forces.
Design Aspects of Shear Walls for Seismic Areas
Authors: Paulay Thomas
Published: January 2010

This presentation, taking the form of a state of the art report, considers several aspects of the behavior of tall and squat shear walls. In particular the problems of brittle and ductile failure modes, diagonal tension, construction joints, alternating plasticity, sliding shear, stiffness degratation, and strength loss under reversed cyclic loading are discussed. The behavior of coupled shear walls is examined in some detail and the problems related to the components of this structure are reviewed. The principles rather than techniques of design for earthquake resistance are stated. Wherever possible the issues are studied against the background of experimental evidence. The material presented indicates that carefully detailed shear walls, designed to possess an intelligent hierarchy in their failure mechanisms, can be made to possess the properties so desirable in earthquake resistant structures.
Simplified Analysis of Dynamic Structure–Ground Interaction
Authors: Rainer J. H.
Published: January 2010

A simplified method of analysis is presented for the determination of dynamic properties of single-story structures founded on flexible foundations. The general equations for natural frequency, mode shapes, and modal damping are applied to structures founded on an elastic half-space and on piles. The results of parameter studies, including the effects of hysteretic soil material damping, are presented for these two cases.
Choice of Prismatic Crane Column Selections by Computer
Authors: Gilmor M. I.
Published: January 2010

A method of modelling columns subject to concentrated load or moment along the length so that two existing computer programs may be used is described. An example is used to illustrate the method.
Is High-alumina Cement a Satisfactory Structural Material?
Authors: Neville A. M.
Published: January 2010

Long-term behavior of high-alumina cement concrete is described with an emphasis on the loss of strength due to conversion. Failures in various countries, especially in England, are reviewed. The status of the cement in a number of countries is reported, and it is concluded that there are no grounds for including the cement in Canadian standards.The current discussion on the need for a standard for high-alumina cement concrete in Canada makes the subject of the structural behavior of this material topical. For this reason, experiences in other countries, and especially the recent problems in England, may be of interest.
Ice Forces on Model Structures
Authors: Zabilansky L. J. , Nevel D. E. , Haynes F. D.
Published: January 2010

Laboratory tests on freshwater ice were conducted by using model structures of various geometries. Vertical and sloping pile sections with diameters up to 36 in. (91.4 cm) were pushed through the ice with an active testing system. The test variables investigated were size, shape, velocity, and slope or angle from the vertical.The data gathered in this study indicates that nominal ice pressure varies indirectly with pile width/ice thickness (D/T) ratio in the range of 1:10. There was no apparent change in nominal ice pressure due to the change of the pile shape. Data gathered in the velocity tests suggests an inverse effect upon the ice pressure, especially at speeds greater than 3 in./s (7.6 cm/s). In the sloping pile tests it was found that the ice pressure decreased with an increase in the slope angle from the vertical position.An expression correlating the vertical and horizontal forces in the sloping pile tests that failed in bending was developed. Values for this linear correlation were found graphically.A comparison of the test results with other investigations is also presented.
Quality and Variation of Pollutant Loads in Urban Stormwater Runoff
Authors: Droste Ronald L. , Hartt James P.
Published: January 2010

Stormwater runoff from a homogeneous residential area in Windsor, Ontario, was studied over a 1 year period of time. Hourly grab samples were taken and analyzed for 21 constituents. Seasonal and annual concentration data are reported along with the most significant correlations among constituent concentrations. Other influences on runoff quality are discussed. Rainfall for all 25 storms was measured, and discharge was measured for 13 storms. The discharge data and rainfall data were used to generate runoff hydrographs for 9 storms without measured hydrographs. The hourly discharges and concentrations were used to calculate loadings on an annual and seasonal basis. The loadings' variation on an hourly basis is listed. The results of an empirical analysis of the average annual loadings contained in percentage amounts of annual runoff are reported. Significant correlation was found between the preceding two variables for all constituents whose loads were calculated. A comparison is made between annual loadings of stormwater runoff and raw sewage for biochemical oxygen demand and total suspended solids and orthophosphates.
Rotational Components of Earthquake Motion
Authors: Nathan N. D. , MacKenzie J. R.
Published: January 2010

Following the ideas of Newmark, a complete record of torsional ground motion is generated from the two translational components of an earthquake record. The approximate spectra developed by Newmark are generally confirmed. The assumptions and the limits of validity are discussed. Code provisions for this phenomenon are commented upon.
Dynamic Evaluation of Overturning Moment Reduction Factor Used in Static Seismic Loading
Authors: Heidebrecht A. C.
Published: January 2010

The static seismic loading provisions of the 1975 National Building Code of Canada include, as do a number of other seismic codes, an overturning moment reduction factor in order to recognize that the overturning moment computed from the static load distribution is likely to be larger than the actual maximum dynamic moment. The reduction factors specified in the various codes have been based on empirical data and on relatively simplistic evaluations of the contributing effects. The purpose of this paper is to make a dynamic evaluation of the dynamic shear moment relationship and the reduction factor for a class of uniform shear wall–frame buildings subjected to earthquake motions as specified by several design spectra. The results are presented to show the effect of damping, natural period, and the particular response spectrum for different shear wall–frame stiffness proportions.
Problems in Developing a Physically Based Snowmelt Model
Authors: Male D. H. , Gray Don M.
Published: January 2010

Over the past few years several snowmelt simulation models have been developed as an aid to streamflow forecasting in mountainous regions. This paper describes the major difficulties encountered when simulation of Prairie snowmelt conditions is attempted, not only for the purpose of forecasting streamflow, but also soil moisture, evaporation, and snow distribution patterns. Simulation is discussed in terms of the energy equation for the snowpack and it is shown that the improvement of the model depends on the following factors: (i) the adjustment of the radiation flux at the snow surface for slope and aspect, (ii) the development of procedures which will allow estimates of the areal distribution of sensible heat, (iii) successful modelling of the diurnal freeze–thaw cycle common to Prairie snowpacks, (iv) an investigation of the energy exchange processes during the period when the snow cover is discontinuous or patchy, (v) knowledge of the coupling of heat and mass transfer processes in frozen soils, and (vi) the extrapolation of point estimates of significant parameters to an areal basis.
Cyclic Loading of Externally Reinforced Masonry Walls Confined by Frames
Authors: Tso W. K. , Rutenberg A. , Heidebrecht A. C.
Published: January 2010

Experimental results are presented on three externally reinforced concrete block walls subjected to in-plane cyclic lateral loading, the walls being confined by flexible steel frames. All three specimens were of similar construction, the varying parameter being the steel reinforcement ratio in the outer skins. The load deflection curves, stiffness degradation characteristics, energy absorption capacity, as well as axial stress in the confining frame columns, are discussed. The externally reinforced walls held their integrity even under a large number of cycles of reversed load. In this respect, externally reinforced masonry behaves under cyclic loading at least as well as internally reinforced masonry. It is concluded that changes in steel reinforcement ratios do not materially affect the failure load although this ratio may have an important effect on the stiffness degradation and the energy absorption capacity of the assembly. The evaluation of the axial forces in the columns on the basis of the truss analogy appears to be substantiated by the test results.
Wave Forces on a Circular Caisson: Theory and Experiment
Authors: Mogridge G. R. , Jamieson W. W.
Published: January 2010

The forces and overturning moments exerted by waves on a vertical circular caisson, extending from the ocean bottom through the water surface, have been measured for a range of wave heights and periods. The wave loads were measured on a 1:60 scale model of a rigid circular caisson, 60 ft (18.3 m) in diameter, in a water depth of 145 ft (44.2 m). A digital computer was used for the acquisition, processing, plotting, and storage of data. Experiments were conducted for a range of conditions described by water depth on incident wavelength d/L from 0.179 to 0.786, wave steepness H/L up to 0.076, and caisson diameter on incident wavelength D/L from 0.074 to 0.325. The experimental results were compared with values computed by the diffraction theory of MacCamy and Fuchs and showed that the theory is suitable for use over the range of conditions described above.
Runoff Regulation for Hydropower and its Effects on the Ocean Environment
Authors: Neu H. J. A.
Published: January 2010

It has not yet been recognized that modification of the natural seasonal discharge of rivers might result in significant consquences to the ecology of the adjacent marine environment. An example of such regulation is the St. Lawrence system in which, in order to optimize power production, large quantities of water from the spring runoff are retained in storage lakes and returned to the river during the low natural discharge period of autumn and winter. It has been estimated that under present conditions the spring and summer runoff at the entrance to the Gulf of St. Lawrence has been reduced by between one third and one half.This drastic alteration of the natural runoff has caused significant changes in the physics and dynamics of the waters of the Estuary, Gulf, and adjacent coastal region. It is argued that such modifications produce a profound impact on the biological balance of the whole ecosystem, as well as changes in the seasonal heat budget.
Simplified Second Order Frame Analysis
Authors: Nixon Don , Beaulieu Denis , Adams Peter F.
Published: January 2010

A method is presented that allows a second order analysis to be performed using a first order computer program, without iteration. Equations of equilibrium are based on the deflected shape of the structure. Computer input for the second order analysis is exactly the same as it is for a first order analysis, except one extra member (a piece of ‘negative’ bracing) is required for each storey. The frame may be braced or unbraced, but must be rectangular.
Influence of Testing Variables on the Concrete Compressive Strength
Authors: Rokosh T. Dale , Nasser K. W.
Published: January 2010

This study assessed the significance of testing variables due to casting, curing, and breaking standard concrete compression test cylinders in three Saskatoon, Saskatchewan commercial testing laboratories. Analysis of the results indicated that these variables have a minor effect on the results when the laboratories have a 'good' rating. Nonuniformity of the concrete mix itself seemed to have the greatest influence on the within-test variation and caused the mean compressive strength in each laboratory to differ by ±4% of the overall mean strength of the mix.
Stabilité hydro-mécanique d'un couvert de glace encore solide
Authors: Michel B. , Abdelnour R.
Published: January 2010

An experimental study has been made on a scale model of a rectangular canal in the hydraulics laboratory of Laval University in order to simulate the destruction of a solid continuous ice cover under the effect of the tangential forces created by the flow.The canal was 6 ft (1.8 m) wide and 46 ft (14 m) long. At the lower end, an ice retention structure of reticular form was built. The ice was simulated with a wax poured in a continuous and uniform layer; whose properties correspond to that of natural ice at an average scale of 1/25. Ice covers corresponding to thicknesses of 8 to 20 in. (20.3 to 50.8 cm) were simulated at that scale.Tests consisted essentially in increasing progressively the discharge feeding the canal until complete failure of the ice cover and accumulation of the pieces in front of the grid retaining structure.Three important phenomena have been observed and measured. By chronological order the first one is the submersion of the frontal edge of the cover. This happens at a relatively constant Froude number but much higher than the one characterizing the stability of unconsolidated ice jams.An increase in discharge makes the ice cover unstable as it oscillates in the flow. This state is followed closely by the failure of the cover, the movement of the pieces with the flow and their accumulation in front of the retaining structure where they form a dry jam. This phenomenon of failure of the ice cover could be interpreted in the first approximation with two dimensionless numbers one being the Froude number and the other characterizing the ratio of failure forces to gravity forces. We have found that an exponential relationship relates these two numbers and the correlation coefficient for the 25 tests is satisfactory.Finally, we have measured the thrust exerted by the dry jams on the ice retaining structure. There is a very direct hydrostatic relationship between the thrust and flow conditions with a dry jam.These laboratory results are interesting to assess the discharges and water levels required in rivers to break-up ice covers of various resistances. One can estimate these conditions for the case of weakened ice covers before spring break-up. However, more importantly, it is possible to approximate the worst conditions of flooding with an early break-up towards the end of the winter when the ice still has its maximum strength.
Spatial variations in seismic motions
Authors: Nair G. P. , Emery J. J.
Published: January 2010

A method for evaluating the spatial variations in strong seismic motions for a linear, homogeneous, and horizontally stratified soil layer system is presented. The procedure accounts for the focal depth and the epicentral distance, the corresponding angle of incidence, and the relative contributions of both shear and Rayleigh waves. The inclined propagation of shear waves is studied using the multiple reflection refraction theory. The range of possible values of Rayleigh wave phase velocity in the soil layer system is determined, and using an averaging procedure the Rayleigh wave amplification factors are computed. The influences of various factors on the spatial variations in seismic response are discussed. The method is general so that it can be used for various problems involving spatial motion computations. The application of the method in computing the responses of a soil–pile system is described and some typical results given.
The Highway 8 review: A systems analysis and corridor evaluation study
Authors: Thompson G. A. , Kobelak A.
Published: January 2010

A freeway project in the vicinity of Cambridge, Ontario was stalled in the planning stage because of citizen reaction to the route proposal. A multidisciplined team was assembled under the direction of the recently formed Waterloo regional government. The team studied the need for and alternatives to a new transportation corridor for a major section of Ontario's Highway 8 between Kitchener and Cambridge.The study examined present and future transportation needs. Alternatives were evaluated as they affected community goals, including environmental, social, economic, and transportation considerations. It was a reactive process involving three levels of government, various institutions, regional bodies, and the public.The study had several unique features. The project team conducting the study was a joint venture of staff from five affected governing bodies and a private consulting consortium working under the direction of a steering committee. The study was constrained in time by other feasibility studies and ongoing official plan study schedules but was not compressed in scope. Public participation involved uniquely differing interest groups and communities (urban, semi-urban, and rural).In this paper, the major features of the project organization, the traffic systems analysis, the corridor evaluation, and the public participation program are described.
Design of a stormwater sewer by nonlinear programming—1
Authors: Lemieux P. F. , Zech Y. , Delarue R.
Published: January 2010

A methodology to design a stormwater sewer system using a nonlinear programming approach is developed. It is divided in five steps: (1) hydrology, (2) set up of the technological constraints, (3) optimization with the Rosen's projected gradient method with the pipe diameters considered as continuous variables, (4) standardization of the diameters, and (5) post-optimal analysis of the piezometric surface. The cost function includes the purchase and installation and the excavation costs of every pipe. It is a convex programming problem; therefore the minimum solution is an absolute minimum. A subsequent paper to appear in this journal will illustrate the complete design procedure and the effect of certain parameters on the design.
Analysis of wave action in permeable structures
Authors: Nasser M. S. , McCorquodale J. A.
Published: January 2010

This study treats wave motion within rectangular and sloping rockfill embankments with impervious cores. The non-Darcy flow in the rockfill is solved by a finite difference one-dimensional model. The characteristic directions are used to control the discretization of the solution domain. The entrance boundary condition (outcrop point) is computed from the external wave motion on the face of the rockfill. An equivalent rectangular section is used to approximate a sloping embankment, and waves on slopes are classified as 'fast' or 'slow rising.' The mathematical model yields phreatic line profiles with time. The model is supported by several wave flume experiments.
Dynamic analysis of an unsymmetrical high rise building
Authors: Tso W. K. , Bergmann R.
Published: January 2010

A complete time history response dynamic analysis is carried out to establish the design seismic loading for the Harbour Centre building in Vancouver. The building has an elevated observation deck and restaurant offset from the centre of the structure. The paper describes the steps and considerations involved in the dynamic analysis such as the dynamic modelling of the structure, the choice of input ground records and the interpretation of the computed results. Whenever possible, the calculated values are compared with the 1975 National Building Code of Canada requirements to provide a proper perspective of the various approaches in establishing design loads for this building.
Measurements of coastal dispersion in Ontario lakes
Authors: Palmer Merv. D.
Published: January 2010

A series of dye injection experiments were carried out near the surface in the coastal waters of lakes Erie, Ontario, and Simcoe. The purpose of the experiments was to determine whether the relative dispersion in these regions was similar to that obtained in other oceanographical experiment. Rhodamine BA dye was injected at a constant rate (approximately 150 mg/s) at a depth 1 m below the surface from a raft anchored in 9 m of water (approximately 1.5 km offshore) for 6 to 8 h. Two-dimensional dye plume concentrations were measured at cross sections 60 to 830 m from the source. Relative dispersion coefficients were determined numerically from the measured concentration profiles. The horizontal dispersion coefficients (80 to 4100 cm2/s) were comparable to oceanographical values and exhibited a 1.33 power growth with distance from the source. Vertical dispersion coefficients were very small (less than 1 cm2/s) and relatively independent of distance from the source.
Influence of imperfections on the maximum strength of biaxially bent columns
Authors: Vinnakota Sriramulu
Published: January 2010

The effect of imperfections on the maximum strength of isolated, simply supported biaxially bent steel H-columns is studied with the help of a computer program. The influence of the pattern and intensity of residual stresses is considered first. The effect of the sign and magnitude of initial crookedness is then examined. Finally, the variation of the influence of residual stresses and initial crookedness with slenderness is presented. It is indicated that the numerical results given and the computer program, could be used to check the validity of the existing design methods, after selecting the representative imperfections.
Longitudinal shear strength of Douglas-fir
Authors: Foschi Ricardo O. , Barrett J. D.
Published: January 2010

Weibull's theory of brittle fracture is applied to the determination of strength of Douglas-fir wood in longitudinal shear. Ultimate stresses, at a given survival probability, are derived for beams under different loading conditions. The theory allows an explanation for the difference in shear strength between beams and the standard American Society for Testing Materials shear block, as well as for the dependence of shear strength upon beam size. The theory is verified by comparing theoretical predictions and test results on Griplam nailed connections loaded parallel to the grain and shear tests on torque tubes. Very good agreement is shown. Finally, allowable shear stresses for beams under different loading conditions are derived.
Quantitative application of ice climate data to winter navigation studies
Authors: Cowley J. E.
Published: January 2010

In a recent study of the feasibility of developing a marine terminal at Grande Ile, Quebec, in the St. Lawrence Estuary, the economic influence of winter ice conditions on shipping schedules was a major uncertainty. Data on ice conditions were available from several years of operation of aerial ice reconnaissance programs. An abstract of these records was used in the derivation of estimates of vessel delays.Passage time statistics were estimated by numerical simulation of the passage of vessels from the Atlantic Ocean to this site for the full range of conditions which have been observed. By these calculations the severity of ice conditions was expressed in the terms of delay, a factor which has direct economic implications. The distribution of risk of delay over the winter season and the probabilities of total delay affecting cargo inventories were derived.Since the same basic information on prevailing ice conditions is available for most Canadian navigable waters, this approach might find more general application. The greatest weakness in the approach at present lies in the data on the resistance imposed by ice. A program of data gathering to improve the empirical basis of the speed loss estimates is suggested.
Etude hydraulique d'un type particulier d'ouvrage d'évacuation de crues
Authors: Ouellet Yvon
Published: January 2010

The details of an experimental hydraulic study on a scale model of a particular type of spillway for the Savage Mills dam project on the Yamaska River near Granby in the Province of Quebec are presented. This multipurpose dam is a joint project between the Office of Planification and Development of Quebec and the Natural Resources Department of the Province of Quebec. Preliminary studies have shown that the use of a standard type of spillway such as a shaft spillway or a side channel spillway would be less economical than a structure that would make use of the diversion channel which is usually only a temporary work. A particular type of spillway, being a combination of the side channel and shaft spillways which discharges into the diversion channel, has then been proposed by engineers of the Department of Natural Resources. In order to evaluate the capacity, the operation and the efficiency of that structure, a scale model study has been carried out. That study has established the hydraulic properties of the proposed structure and has enabled one to properly design its different components.
Toward automated elastic design of skeletal structures using computer graphics
Authors: Curran John H. , Wright Peter M.
Published: January 2010

The purpose of this paper is to demonstrate that the introduction of computer graphics to the field of automated structural design alleviates many of the problems inherent in the use of high speed digital computers in structural design by permitting an interaction between the designer and the design program.This interaction provides significant advantages over conventional computer-aided design. The input of data is facilitated, and the designer can verify that the data are correct by having them displayed on the screen. The designer is able to control the optimization while it is in progress. By examining the results after each iterative cycle, he is able to implement design decisions and terminate the design when satisfactory convergence is achieved. Foremost, the designer is given an intuitive knowledge of the structural problem he is dealing with because he is able to examine in one session with the computer, the effect of various structural parameters, such as column spacing and displacement constraints.
Etude comparative de différents types d'ouvrages pour lutter contre l'agitation dans une rade portuaire
Authors: Ouellet Yvon
Published: January 2010

Some results of an experimental study on a scale model of the project of Rivière-au-Renard Harbor improvements in the Province of Quebec, carried out for the Department of Public Works of Canada, are presented. This study has been dictated by the construction of new wharfs inside the harbor where the wave agitation could attain a level such that ship manoeuvring can be affected. The hydraulic model study was then undertaken in order to evaluate the relative efficiency of different types of solutions proposed by engineers of the Department of Public Works in order to reduce the wave agitation inside the harbor near the proposed structure to an acceptable level. The main constraints on these protection structures are that they should not hold up the maritime traffic and that they should be economical. This paper presents the results of most promising structures to be used in order to provide an additional protection.