bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety of Administration of Human Butyrylcholinesterase and its Conjugates with Soman or VX in Rats
Authors: Genovese Raymond F. , Sun Wei , Johnson Christina C. , DiTargiani Robert C. , Doctor Bhupendra P. , Saxena Ashima
Published: December 2009

Abstract: We evaluated the effects of conjugated enzyme‐nerve agent product resulting from the inhibition of bioscavenger human serum butyrylcholinesterase (Hu BChE) by nerve agents soman or VX. Rats were trained on a multiple Fixed‐Ratio 32, Extinction 30 sec. (FR32, Ext30) schedule of food reinforcement and then injected (i.m.) with Hu BChE (30 mg/kg), equivalent amounts of Hu BChE–soman conjugate (GDC), Hu BChE–VX conjugate, oxotremorine (OXO) (0.316 mg/kg) or vehicle (n = 8, each group). On the day of injection and on 10 subsequent daily sessions, performance was evaluated on the FR32, Ext30 schedule. Neither conjugates nor Hu BChE produced a performance deficit under the schedule. OXO produced a substantial decrease in responding on the day of administration, with complete recovery observed on subsequent sessions. None of the treatments affected circulating acetylcholinesterase (AChE) activity when evaluated 24–72 hr after injection. The dose of Hu BChE produced a 20,000‐fold increase above baseline in circulating BChE activity. Pathological evaluation of organ systems approximately 2 weeks following administration of conjugates or Hu BChE alone did not show toxicity. Taken together, these results suggest that Hu BChE – nerve agent conjugates produced following bioscavenger protection against nerve agents soman and VX do not appear to be particularly toxic. These results add to the safety assessment of Hu BChE as a bioscavenger countermeasure against nerve agent exposure.
An Integrated Model for the Glucose‐Insulin System
Authors: Silber Hanna E. , Jauslin Petra M. , Frey Nicolas , Karlsson Mats O.
Published: December 2009

Abstract:  The integrated glucose‐insulin model was originally developed on a variety of intravenous glucose provocation experiments in healthy volunteers and type 2 diabetic patients. The model, which simultaneously describes time‐courses of glucose and insulin based on mechanism‐based components for production, elimination and homeostatic feedback, has been further extended to oral glucose provocations, meal tests and insulin administration. The model has been used to describe experiments ranging from 4 to 24 hr. Applications of the integrated glucose‐insulin model include the clinical assessment of the mechanism of action of anti‐diabetic drugs and the magnitude of their effects. Finally, the model was used for optimizing the design of provocation experiments.
Molecular characterization of two novel esterase genes from carmine spider mite, Tetranychus cinnabarinus (Acarina: Tetranychidae)
Authors: Sun Wei , Xue Chuan‐Hua , He Lin , Lu Wen‐Cai , Li Ming , Cao Xiao‐Fang , Zhao Zhi‐Mo
Published: December 2009

Abstract  Two novel esterase complementary DNAs were identified and cloned from the insecticide‐susceptible strain of Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae), which were designated as TCE1 and TCE2, respectively. The cDNA of TCE1 gene contained an open reading frame (ORF) of 1701 bp encoding 567 amino acids, and a predicted molecular weight of 62.75 kDa, the cDNA of TCE2 contained an ORF of 1680 bp encoding 560 amino acids, and a predicted molecular weight of 63.14 kDa. TCE1 and TCE2 were submitted to GenBank, accession number EU130461 and EU130462. The well‐conserved sequence motif, GXSXG, used as a signature pattern in the esterase family are present in both TCE1 and TCE2 (GQSAG in TCE1, whereas GESAG in TCE2), indicating that these two genes are predicted to be esterases. Comparison of the deduced amino acid sequence with the published mite esterase sequence coming from Boophilus microplus showed that TCE1 shares 33.98% identity and TCE2 shares 33.46% identity. TCE1 and TCE2 share 46.4% identity. Quantitative real‐time polymerase chain reaction revealed that expression level of the TCE2 gene was relatively higher than that of the TCE1 in all instars examined except the protonymph, and the expression level of these two esterase genes in adults of T. cinnabarinus was significantly higher than that in any other instars, respectively. T. cinnabarinus is an important agricultural mite pest and esterases are important in the metabolisms of insects and mites; the genomic information obtained in this study will contribute to esterase molecular biological study on mite pest species.
Mechanical heating of protostellar discs
Authors: Lubow S. H. , Pringle J. E.
Published: December 2009

The magnetic field structure of a protostar truncates the accretion disc at some magnetospheric radius greater than the stellar radius. If the stellar rotation axis is not aligned with the disc rotation then the magnetic stresses at this radius transfer misaligned angular momentum and so lead to a tilt in the inner disc. If the configuration and/or strength of the stellar field changes with time then the degree of induced tilt also changes. Under appropriate circumstances such m= 1 tilting motions of the disc can propagate outward through the disc as warp waves. These waves must damp as they approach the corotation radius where their frequency matches the local Keplerian frequency. If the waves propagate sufficiently far, then the disc heating that results from the wave damping can provide a dominant contribution to a local disc heating, and so cause a disc flaring. This flaring can in turn cause changes in the disc spectral energy distribution.
A PCR‐RFLP assay for gender assignment in the three‐toed sloths (Bradypus, Pilosa, Bradypodidae)
Authors: MARTINELLI ARTURO B. , DE MORAES‐BARROS NADIA , ALVARENGA CLARA S. , CHAVES PAULO B. , SANTOS LUIZ A. D. , FAGUNDES VALÉRIA
Published: December 2009

The three‐toed sloths (Bradypus) are slow‐moving arboreal neotropical mammals. Understanding demographic variables (such as sex ratio) of populations is a key for conservation purposes. Nevertheless, gender assignment of Bradypus is particularly challenging because of the lack of sexual dimorphism in infants and in adults, particularly B. torquatus, the most endangered of the three‐toed sloths, in which sex is attributed by visual observation of the reproductively active males. Here, we standardized a method for sexing Bradypus individuals using PCR‐RFLP of sex‐linked genes ZFX/ZFY. This assay was validated with known‐gender animals and proved accurate to assign gender on three Bradypus species.
Rapid and reliable high‐throughput methods of DNA extraction for use in barcoding and molecular systematics of mushrooms
Authors: DENTINGER BRYN T. M. , MARGARITESCU SIMONA , MONCALVO JEAN‐MARC
Published: December 2009

We present two methods for DNA extraction from fresh and dried mushrooms that are adaptable to high‐throughput sequencing initiatives, such as DNA barcoding. Our results show that these protocols yield ∼85% sequencing success from recently collected materials. Tests with both recent (<2 year) and older (>100 years) specimens reveal that older collections have low success rates and may be an inefficient resource for populating a barcode database. However, our method of extracting DNA from herbarium samples using small amount of tissue is reliable and could be used for important historical specimens. The application of these protocols greatly reduces time, and therefore cost, of generating DNA sequences from mushrooms and other fungi vs. traditional extraction methods. The efficiency of these methods illustrates that standardization and streamlining of sample processing should be shifted from the laboratory to the field.
Strategic Supply Chain Structure Design for a Proprietary Component Manufacturer
Authors: Xu Yi , Gurnani Haresh , Desiraju Ramarao
Published: December 2009

This paper examines the choice of supply chain structure for a proprietary component manufacturer (PCM). The PCM, who is the sole supply source of a critical component used to assemble an end product, can either provide its component to an original equipment manufacturer (OEM) in the end‐product market (component supplier structure), develop the end product exclusively under its own brand (monopoly structure), or provide the component to the OEM as well as develop the end product under its own brand (dual distributor structure). Typically, the end products of the PCM and the OEM will be differentiated, and the OEM tends to have a capability advantage (compared with the PCM) in producing the end product. Our paper studies the impact of this degree of differentiation and capability advantage on the optimal choice of distribution structure. We then investigate how investing in component branding, enhancing the value of the end product, using alternative supply contracts, and product valuation uncertainty influence the PCM's optimal choice of distribution structure.
Hematologic and biochemical reference intervals for Norwegian crossbreed grower pigs
Authors: Klem Thea Blystad , Bleken Elisabeth , Morberg Hanne , Thoresen Stein Istre , Framstad Tore
Published: December 2009

Background: Hematologic and biochemical reference intervals depend on many factors, including environment and age. Reference intervals for Norwegian grower pigs are lacking, and previously published reference intervals for similar pigs from other countries are now outdated due to significant changes in management and breeding on the pig farms.

Objectives: The aim of this study was to determine updated reference intervals for hematologic and biochemical analytes in healthy crossbred grower pigs, and to compare the results among 3 different farms.

Methods: Blood samples were collected from 104 clinically healthy pigs of the most common Norwegian crossbreed (Landrace Yorkshire sow × Landrace Duroc boar). The pigs were 12–16 weeks old, weighed 30–50 kg, of both sexes, and lived on 3 farms in eastern Norway. Automated hematologic and biochemical analysis were performed using ADVIA 2120 and ADVIA 1650 analyzers.

Results: Five samples were excluded because of hemolysis (1) or outliers (4). Reference intervals were calculated using parametric or nonparametric methods, depending on data distribution. Mean, median, minimum, and maximum values were tabulated.

Conclusions: The reference intervals calculated in this study will be useful for the diagnosis and monitoring of disease in this widespread crossbreed pig. Compared with previously published reference values, reference intervals for total WBC count, creatine kinase and alanine aminotransferase activities, and albumin, bilirubin, and urea concentrations in this study differed notably.
Automated counting of nucleated cells in equine synovial fluid without and with hyaluronidase pretreatment
Authors: Ekmann Anita , Rigdal Marie‐Louise , Gröndahl Gittan
Published: December 2009

Background: Microscopy is usually used to obtain manual total and differential cell counts in equine synovial fluid. A faster, more precise method is desirable.

Objectives: The objectives were to compare an automated impedance method with a manual method for obtaining total and differential cell counts in equine synovial fluid and to evaluate the effect of pretreatment with hyaluronidase on automated results.

Methods: Synovial fluid samples (n=48) were collected into EDTA and analyzed within 48 hours. Automated total and differential cell counts were evaluated using a Medonic CA620‐VET hematology analyzer before and after pretreatment for 5–30 minutes with hyaluronidase (final concentration 0.01 mg/mL). A hemacytometer count and microscopic evaluation of a direct smear were used as the reference method. Intra‐assay coefficients of variation (CV) were determined.

Results: Thirty‐one of 46 untreated samples and 0/46 hyaluronidase‐treated samples were error‐flagged by the analyzer. Correlation between automated (ANCC) and manual (MNCC) nucleated cell counts in untreated samples (n=15; R2=0.93) and pretreated samples (n=46; R2=0.94) was high, and pseudomedian difference was low. Intra‐assay CVs for samples with medium and high cellularity were significantly lower for ANCC (1.5–2.7%) compared with MNCC (6.1–15.7%) (P<.01). Valid automated differential cell counts were not obtained.

Conclusions: Automated total cell counts obtained on the Medonic analyzer correlate well with manual counts in equine synovial fluid; however, pretreatment with hyaluronidase is required to minimize error flags. Automated differential counts are not accurate for synovial fluid.
Impedance study of hypoxic cells radiosensitizer etanidazole radical anion in water
Authors: Gál Miroslav , Híveš Ján , Sokolová Romana , Hromadová Magdaléna , Kolivoška Viliam , Pospíšil Lubomír
Published: December 2009

Electrochemical transfer of the first electron to cytotoxic radiosensitizer etanidazole (ETN) and ETN radical anion formation in the alkaline buffered aqueous solution were studied by means of electrochemical impedance spectroscopy (EIS). The heterogeneous electron transfer rate constant for the first reduction of ETN (radical anion production),k0, was calculated. The value ofk0from EIS measurements and the previously obtained value of so-calledE71potential indicate that ETN, compared with other possible chemical radiosensitizers, requires lower energy to accept the first electron during the metabolic pathway. However, the necessity of the alkaline pH may decrease the ability of ETN to act as hypoxic radiosensitizer in the human body.
Scientific advice on species at risk: a comparative analysis of status assessments of polar bear,Ursus maritimus
Authors: Hutchings Jeffrey A. , Festa-Bianchet Marco
Published: January 2010

The assessment of species believed to be at heightened risk of extinction must be underpinned by scientific evaluations of past and predicted changes in abundance and distribution. When these assessments are communicated to society and (or) government, they provide an informed scientific basis for public policy decisions pertaining to the protection of biodiversity. The provision of advice for high-profile species can be particularly challenging as different interest groups may seek to over- or under-play a species' degree of endangerment. Those challenges are highlighted here by a comparative analysis of assessments of polar bear (Ursus maritimus) undertaken recently in Canada, the United States, and by the World Conservation Union (IUCN). Perceived differences in these assessments can be partly attributable to differences in the species status categories used by different organizations, the nature and application of assessment criteria, and the legislative responsibilities of those undertaking the assessments. Our analysis also highlights differences in how status assessments have informed the scientific basis for discordant projections of the future magnitude of polar bear habitat and population change. We conclude that evaluations of the scientific merits associated with any species status are hindered by imperfect understanding of differences in assessment protocols. Scientific advice potentially informed, but ultimately undermined, by personal and institutional biases serves neither decision-makers nor society well.
The extent of the North American boreal zone
Authors: Brandt J.P.
Published: January 2010

The circumpolar boreal zone is one of the world’s major biogeoclimatic zones, covering much of North America and Eurasia with forests, woodlands, wetlands, and lakes. It regulates climate, acts as a reservoir for biological and genetic diversity, plays a key role in biogeochemical cycles, and provides renewable resources, habitat, and recreational opportunities. Poor agreement exists amongst scientists regarding this zone’s delimitation and the areal extent of boreal forests, even though the zone has been well-studied. This paper reviews the literature on the phytogeography of the zone and makes use of a geographic information system (GIS) and published maps to delineate a current map of the North American boreal zone and the hemiboreal subzone, which is a transitional area lying immediately to the south of the boreal zone that is usually included in the boreal zone by Europeans but excluded by North Americans. On the basis of the map described here, the boreal zone covers about 627 million ha, or 29% of the North American continent north of Mexico. If the hemiboreal subzone, at 116 million ha, is included, then 34% of the same area is covered. Forests and other wooded land (362 million ha) cover 58% of the North American boreal zone on the basis of current forest inventory data. With forests and other wooded land of the hemiboreal subzone (68 million ha) factored in, this percentage remains basically unchanged. Values reported in this paper are compared with other published statistics. Important sources of error contributing to differences in areal statistics are discussed.
Ecosystem consequences of potential range expansions ofOrconectes virilisandOrconectes rusticuscrayfish in Canada — a review
Authors: Phillips Iain D. , Vinebrooke Rolf D. , Turner Michael A.
Published: January 2010

Canadian water bodies are presently experiencing fluctuations in orconectid crayfish ranges largely as a result of human activities. The range of Orconectes virilis , Canada’s most widespread crayfish, is expanding westward into previously uninhabited water bodies of Alberta. This species is also set to re-colonize watersheds in the eastern extent of its range as post-acidification recovery of aquatic ecosystems continues. In addition, the non-native Orconectes rusticus has invaded Central Canada. This species has the potential to rapidly invade boreal water bodies and out-compete native congeners, including O. virilis. Both these crayfish species are known to affect benthic ecosystems and their invasions may have adverse consequences for Canadian water bodies if left unchecked. Here we review the current documented distribution of O. virilis and O. rusticus in Canada, and identify the potential impacts that their invasion may have on boreal aquatic ecosystems. Finally, we consider options that resource managers might consider to contend with these invasions.
Effect of Entrained Air on Cavitation Damage
Authors: Russell S. O. , Sheehan G. J.
Published: January 2010

When water flows at high velocity over a surface, quite small boundary irregularities may trigger cavitation which can, in turn, cause extensive damage. Concrete surfaces downstream from high head outlet gates are particularly vulnerable to cavitation damage.Operating experience and previous experimental work suggest that cavitation damage can be greatly reduced and, in some cases, eliminated by entrained air in the water.Experiments were carried out with a special high head test facility in Vancouver to obtain additional data on the effect of air entrainment. These tests confirmed its effectiveness. In this paper, previous evidence is reviewed, the experiments are described, and the results presented. Finally suggestions are made about the design of hydraulic structures which involve high velocity flow.
Simplified Traffic Forecasting Process for Small Cities
Authors: Sargious Michel A. , Morrall John F.
Published: January 2010

Urban transportation studies cost roughly 1 dollar/capita with approximately 50% of the expenditures consumed in the collection of data on travel habits. Many small cities, those 50 000 population and under, have limited budgets for data collection and analysis. In addition, the conventional urban transportation planning process is not only expensive but may be out of scale in terms of the order of magnitude of transportation decision-making in small cities.The simplified traffic forecasting process suggested in this paper requires a minimum amount of data collection and relies to some extent on travel parameters taken from cities of similar size and characteristics. Thus, the problem of costly home-interview surveys is avoided in addition to the fact that the model can be quickly updated by hand. The simplified model is based on the premise that travel time does not affect trip distribution to any extent due to the fact that significant differences in travel times between short and long trips are not perceived by the trip maker. The model was applied to the town of Fort McMurray which is the residential and operations base for the development of Alberta's Tar Sands. Comparisons of model output with traffic counts show that the simplified model gives reliable results.
Insulated Forms and Thermal Shock in Winter Concreting
Authors: Ghosh Ram S. , Mustard J. Neil
Published: January 2010

This paper deals with the problem of cracking due to the thermal shock of concrete. Safe temperature differentials between concrete and air are given with sample calculations in arriving at the values. The required amount of insulation is shown for various weather conditions to cure the concrete in accordance with the CSA specification. Assuming that the stipulated insulation is attached to the formwork, the safe stripping times to avoid thermal cracks are given for various thicknesses of structures under various degrees of restraint. The salient points are illustrated with practical examples, and the vital data are presented in graphical form to make it usable.
Moisture Content – Strength Relationship for Lumber Subjected to Bending
Authors: Madsen Borg
Published: January 2010

The moisture content – strength relationship for lumber was investigated by performing a dry out test. It was found that the increase in strength, as moisture content went down was discernible for initially strong material, whereas weak material did not increase in strength as indicated in the present building codes. However, stiffness did increase over the whole range of initial stiffness as moisture content dropped. It was also found that the present grading rules do not provide consistent overload factors for the different grades.
Nonlinear Seismic Design of Multistory Frames
Authors: Bertero V. V. , Kamil H.
Published: January 2010

A five-step, computer-aided design procedure representing a significant change from current seismic design practices is proposed.In the first step, the ‘design earthquake’ and the safety and serviceability criteria are established, and appropriate values of a damping coefficient and displacement ductility factor are assumed. An iterative preliminary analysis procedure, centered around specified values of a seismic coefficient and a drift index, is used to determine the design story shears using modal analysis.Then, a preliminary design is carried out using a simplified story-wise optimization procedure. This is followed by inelastic static and dynamic analyses of the design. The maximum values of story shears and ductilities and their overall pattern, so obtained, are compared against those used initially. The procedure is repeated until a satisfactory agreement is obtained and the final design story shears are determined. In the fourth step, these shears are used to attain the final optimum design through a procedure similar to that used in the preliminary design, but using an improved story subassemblage and a more formal linear optimization technique.Finally, the reliability of the optimum design is evaluated by determining its nonlinear response to severe earthquakes and its serviceability. The design procedure is demonstrated on a 10-story 3-bay frame.
Progressive Collapse
Authors: Taylor D. A.
Published: January 2010

This paper explains the nature of progressive collapse, with examples, and enlarges considerably on commentary C, supplement No. 4 of the 1975 National Building Code of Canada. Attendant philosophical problems related to code coverage and the design for progressive collapse are considered in discussions of risk, abnormal events that might initiate progressive collapse, and design procedures to reduce the risk of progressive collapse. An example illustrates some of these procedures and indicates how, in a general way, design problems may be approached.
Universal Flow Diagrams for Mobile Boundary Channels
Authors: Peterson A. W.
Published: January 2010

Using dimensional analysis and regression techniques a series of diagrams, involving five dimensionless flow parameters, showing the interrelationship of the discharge intensity, flow depth, mean bed material size and discharge, and channel slope for mobile boundary channels have been prepared. The universal flow diagrams (UF diagrams) cover 10 grain size ranges, from 0.1 to 40 mm, with each diagram based on an analysis of 1300 or more data items. Examples are given showing the use of the UF diagrams for design and analysis of channel and river problems.
The Effects of Shear Reinforcement on the Reversed Cyclic Loading Behavior of Flat Plate Structures
Authors: Hawkins Neil M. , Mitchell Denis , Hanna Samir N.
Published: January 2010

This paper reports one phase of a research program at the University of Washington on the seismic response of flat plate to column connections. In particular the behavior of connections containing integral beam stirrup reinforcement in the slabs is discussed. The paper compares different approaches for designing that stirrup reinforcement, outlines the benefits of placing stirrup reinforcement in the slab, and gives guidelines as to the design and proper detailing necessary for that stirrup reinforcement. The effects of concentration of the flexural reinforcement in the immediate column region are also examined. Ductility ratios, energy absorption, energy dissipation, and degeneration of stiffness characteristics of the specimens are reported together with the lateral loads for first yielding and maximum capacity of the specimens.
Sequencing techniques for project screening
Authors: Rodriguez José B. Martinez y , Russell S. O.
Published: January 2010

Often in the early stages of planning a major development it is necessary to consider a large number of alternative individual projects and alternative sequences of projects. The main problem at this stage is to screen out the less desirable projects quickly so that only a manageable number of the more promising ones remain for detailed study. A number of simple techniques are presented which can be used to assist the screening process. These include a method for finding the sequence of projects which will meet one or more projected demands at minimum discounted cost, and making a sensitivity test of the results; a method for finding the sequence of projects which would yield the maximum present value of benefits; and a way of finding the optimal planning horizon for facilities where there are economies of scale. A comparison is given between results obtained by the sequencing technique presented and results from a more rigorous but more elaborate and time consuming method for the case of multiple demands.
Seismic design considerations for gravity retaining structures
Authors: Emery J. J. , Thompson C. D.
Published: January 2010

Major earthquakes have been observed to damage marginal wharf gravity retaining structures or walls throughout the world, and earthquakes of similar magnitude occur quite often in Canada. These earthquakes generally take place in the British Columbia coastal areas, the St. Lawrence Valley, Baffin Island, and the Yukon Territory. Elsewhere, normally designed marginal retaining structures should have adequate factors of safety to withstand anticipated seismic loads. However, in earthquake-prone areas it is recommended that most marginal retaining structures be designed using the seismic coefficient method. While not all aspects of the suggested seismic design procedure are developed, detail is provided on seismic exposure at the site, earth pressures due to earthquake conditions, and recommended factors of safety for short-term conditions. Design aspects of a more specific geotechnical nature (soils investigation, liquefaction, remedial measures, tsunamis, and backfill specifications) are indicated.
The bearing capacity of ice covers under static loads
Authors: Frederking R. M. W. , Gold L. W.
Published: January 2010

There is a growing interest in the use of ice covers to support loads for extended periods of time. Current practice for determining safe ice thicknesses for over-ice operations is essentially empirical, being based on experience and limited prototype testing. In this paper, the implications of a design criterion for the static load problem, which limits the maximum vertical deflection to the freeboard, are considered. An expression relating strain and deflection is developed. Field results for a static loading case were analyzed and indicated that the time dependent deflected shape of the ice cover could be represented using elastic theory and a time dependent Young's modulus. By combining the strain–deflection relationship with the deflection limit criterion it is shown that strains are small (i.e. less than 10−3 and in the primary stage of creep) for most cases of practical interest. A method, based on a correlation of observed deflection rates and associated initial elastic stresses from reported cases of static loading of ice covers, is proposed both as a design approach and a framework for analysis of field data.
The Nelson River — an energy source
Authors: Bateman L. A.
Published: January 2010

The great potential of the Nelson River for the development of hydro-electric power has excited the imagination of many engineers as early as the turn of the century.The dream became a concept approximately a decade ago with the start of what has been termed Phase I of the Nelson River Development.The purpose of the paper is to provide a progress report, to indicate future plans as we see them today and to describe some of the engineering challenges that have to be met in the development of this great renewable energy resource.
Longitudinal shear capacity of the slabs of composite beams
Authors: El-Ghazzi M. N. , Robinson H. , Elkholy I. A. S.
Published: January 2010

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.
The conception, design, and construction of Metropolitan Toronto mid-Toronto interceptor sewer
Authors: Hogarth L. N.
Published: January 2010

This paper is concerned with a major intercepting sewer currently being tunnelled between 50 and 100 ft (15 and 30 m) below the streets of mid Metropolitan Toronto. The sewer is 43 210 ft (13.17 km) long, varies from 5–10 ft (1.5–3.0 m) in diameter and will serve an area of 9466 acres (3834 ha). Flows in the sewer will be remotely controlled by sluice gates and level sensing devices. Vortex structures are used to transfer flow from street level to the tunnelled sewer. The paper describes the conception, design, and construction of the interceptor system.
Planning regional network systems for minimum cost
Authors: Smith Alan A. , Tufgar Ray H.
Published: January 2010

The paper considers the planning and design of networks whereby a public utility service such as water supply or solid waste disposal is made available to a number of separate communities distributed throughout a region. A procedure is described which facilitates the selection of service processing centres from a number of possible alternatives and the identification of the most efficient system of connecting links with the objective of minimizing the total system cost. These costs may be associated with both the processing and transportation aspects of the process, and may include both capital and recurring annual costs over the economic life of the system. The problem is presented as the minimization of a nonlinear, separable concave objective function subject to a set of linear constraints in terms of the design or decision variables. A technique is described involving the iterative application of a linear programming algorithm, and a description is given of a package of FORTRAN subroutines by means of which econometric models of this type may be easily set up for networks of different types and which incorporate user-defined cost functions. The package is suitable for both batch and time-sharing use, but emphasis is placed on the latter for greater interaction with the planner or designer. Details are given of program availability and application to a typical problem is illustrated.
Strengthening and widening of steel pony truss bridges
Authors: Bakht Baidar , Csagoly Paul F.
Published: January 2010

There are many thousands of existing pony truss bridges in North America which were constructed in the earlier part of this century and are still serving as important traffic carriers. The present economic situation demands that these bridges should usefully serve their purpose for as long as is safely possible.These bridges could be found inadequate for either or both of the following reasons. With the exception of remote areas, operational traffic safety would require two 12-ft lanes plus adequate shoulders. Many of these old bridges are therefore unsatisfactory from the geometrical point of view. Some bridges were designed for live loads that are only a fraction of present commercial vehicle weights.A computer-oriented method of rigorous analysis of lateral buckling behaviour of pony truss bridges is briefly discussed. The method is implemented through a computer program which has been validated by experimental data. It is expected that the program would predict realistic values of load-carrying capacity of such bridges and would help to avoid many an unnecessary replacement.Various methods of strengthening and widening pony truss bridges, and their pros and cons, are discussed. It is shown that the strengthening of a few components of a pony truss bridge does not always lead to an increase in the load-carrying capacity of the bridge.
Climatology of snowfall and related meteorological variables with application to roof snow load specifications
Authors: Isyumov N. , Mikitiuk M.
Published: January 2010

Representative statistical models of snowfall and related meteorological variables, important in snow hydrology research, are also required for many engineering design problems. Design roof snow loads, if based on the balance between deposition of snow by individual snowfalls and subsequent depletion by wind action and various thermodynamic mechanisms, in addition to aerodynamic characteristics of particular roof shapes, require the development of statistical models of various meteorological variables which influence the process.Mathematical models suitably describing the statistics of individual snowfall amounts, wind speed and directions, and air temperature are presented in this paper. These results are based on the analysis of daily meteorological data obtained at some 28 Canadian stations with typical record lengths of about 30 years. The suitability of the developed probability distribution of daily snowfall magnitudes is examined through comparisons of both derived parent and extreme value statistics with available full scale observations. The joint statistics of these meteorological variables are also examined and a methodology for approximately accounting for their interdependence is presented.The relevance of the overall winter climatology of an area to roof snow load formation is discussed. Results of a Monte Carlo simulation, which show the dependence of the snow load for a particular roof shape on the climatology of snowfall and related meteorological variables, are presented.
Longitudinal shear in wood beams: a design method
Authors: Foschi Ricardo O. , Barrett J. David
Published: January 2010

The results of a study on longitudinal shear strength of Douglas fir, based on Weibull's theory of brittle fracture, are implemented in a design method. Design formulae are given and required parameters are calculated for several common configurations of beams and loadings. A method for extending the results to other species is proposed.
Impact of community planning on quality of life in the North
Authors: Grainge Jack
Published: January 2010

Long range planning is required in order to avoid impending environmental disasters in most northern communities. Present short range planning should consider more closely the basic needs of the inhabitants. These needs include piped water and sewer systems, more careful avoidance of sewage pollution of drinking water and the immediate environment, better cross cultural integration, greater emphasis on recreational facilities, awareness of the need for energy savings, less ice fogs, and relatively warm and sunny microclimates.The Scandinavians have been leaders in this field, and offer many examples of advanced planning of northern communities in Lapland, Iceland, and West Greenland. We should study their approach towards the solution of our common problems. Through dialogue with them a clearer understanding and possibly better solutions to existing problems will be found.A basic necessity in making the studies is a better understanding of the nature of the North and of the people. We must learn to work with both nature and the people.Now is the time for long range planning by considering climatic, environmental and cultural factors, and integrating them into a more harmonious system with the aim of a higher quality of life.
Roof loads resulting from rain on snow: results of a physical model
Authors: Colbeck S. C.
Published: January 2010

A physical model is used to calculate roof loads due to rain on a snow covered roof. A snow depth of 0.5 m and the twenty-five year rainstorm in Hanover, New Hampshire, are used in the examples. For a flat roof with 10 m parallel flow to gutters, the total liquid weight can increase the roof load by about 50%. The weight of the transient liquid is greatly increased if the mode of flow is radial to central drains and is decreased if the roof is slightly inclined or if significant melt channels form in the basal layer. However, the wetting of the snow over its entire depth will still cause a significant weight of transient liquid. Snow drifting can cause very large, local loads but the effects of snow temperature and antecedent moisture are not too important.Depending on the circumstances, the largest load can occur for either a long duration, low intensity rainstorm or a short duration, high intensity rainstorm. The former occurs if the saturated layer makes a significant contribution to the total live load whereas the latter occurs when the liquid weight is due mainly to the unsaturated layer. Further study is needed to establish the joint probabilities of combined snow and rain loads, especially when rain and snowmelt occur simultaneously.
Composite open-web joists with formed metal floor
Authors: Robinson H. , Fahmy E. H. , Azmi M. H.
Published: January 2010

Composite beams incorporating ribbed and cellular metal deck have been used as the floor system in building construction now for many years. In addition it has been demonstrated that composite action can be achieved between solid concrete slabs and open-web joists.It is demonstrated that good composite action can be achieved between open-web joists and slabs incorporating ribbed metal deck. It is shown that the mode of failure of a composite open-web joist is influenced by the degree of shear connection. In addition it is shown that are spot welds as well as studs can provide an effective shear connection.
Performance, design and operation of northern extended aeration plants
Authors: Given Patrick W. , Smith Daniel W.
Published: January 2010

An extensive literature review and a study of unpublished documents were undertaken to summarize information on the performance, design and operation of "northern" extended aeration waste water treatment plants. This information was compared with that for 'non-northern' plants and National Sanitation Foundation (NSF) plants, the latter providing an indication of optimum performance.The study revealed that the northern plants generally performed more poorly than their non-northern counterparts and much worse than the NSF plants.Reasons for poor performance of the northern plants were related to design and operation deficiencies. The most frequently observed conditions indicating design errors were organic and hydraulic overloading. The most common operating errors were failure to scrape hopper-type clarifiers and failure to maintain sludge returns operative.Very few design and operating problems relating specifically to northern plants were identified since many of the smaller plants were encapsulated for freeze protection.
Development of a hydrologic model for a Canadian watershed
Authors: Kite G. W.
Published: January 2010

Three large well-known hydrologic models, the Streamflow Synthesis and Reservoir Regulation, the National Weather Service River Forecast System, and the Saskatchewan River Model No. 6, were calibrated and verified on a 2000 km2 watershed in northern Ontario over two spring snowmelt periods. Although results obtained were adequate it was thought that a smaller simpler model could be designed that would give results at least as good with much less expenditure of time, money, and effort. Details of the relative performances of the three existing and one new model are given and comparative hydrographs are shown. Although use of the models on only one basin cannot provide conclusive evidence of the models' relative goodness, the results obtained do show significant differences between the models as well as certain advantages for the new model.
Analysis of buildings with interconnected shear walls
Authors: Harman D. J. , Johnson A. A.
Published: January 2010

A method for analysis of interconnected shear walls is described that accounts for the torsional stiffness caused by non-uniform warping. Floor to floor, plane wall members are idealized as part of the input to a three-dimensional frame analysis program. Where walls in different planes intersect, constraints that ensure common vertical displacements are imposed. These constraints appear in the computer input as special types of 'members'; however, within the solution, the Lagrange multipliers method is used to process the constraint equations. A frontal method that handles the constraints efficiently along with members and loadings is used to organize the analysis.The use of this method of analysis is simple and versatile relative to comparable methods. Most arrangements of shear walls that form open cross sections can be analyzed in conjunction with frames and other walls. Location of the shear centre of groups of walls and their torsional properties are not required.Analysis results are compared to experimental results and the results of other methods of analysis. The accuracy of the proposed method depends upon the number of storeys in the model because force transfer between adjacent wall segments occurs only at floor levels; in reality, a continuous transfer of force occurs through the height of the walls. In the opinion of the authors, using the proposed method for buildings of 20 or more storeys would certainly provide adequate accuracy for design.
Ice and ship effects on the St. Marys River ice booms
Authors: Perham Roscoe E.
Published: January 2010

The St. Marys River connects Lake Superior with Lake Huron. It contains many navigation improvements that make it an important commercial shipping route. The operation of ships in winter tinder a federal (USA) program to extend the navigation season has led to troublesome ice movements and accumulations. To help conteract these effects, two ice booms with a 250 ft (76 m) wide navigation opening between their adjacent ends were installed at the southerly outlet from the harbor at Sault Ste. Marie, Michigan and Ontario.The ice booms contained six force measuring devices. Records of these forces and pertinent data on the weather, water levels, ship passages, and ice conditions were kept the following winter of 1975–1976.The ice booms reduced the harbor ice losses to an acceptable level and provided much information about their interactions with the ice cover and the ships. Ship and environmental effects kept the ice behind the west boom broken-free from shore and moveable much of the winter. The maximum force measured in the west boom was 88 000 lb (391 kN) and the maximum in the east boom was an impact load of about 160 000 lb (712 kN). The forces associated with ship passages averaged 25 000 lb (111 kN).
Computer simulation of bubbler-induced melting of ice covers using experimental heat transfer results
Authors: Keribar Rifat , Tankin Richard S. , Ashton George D.
Published: January 2010

After a brief description of the physical phenomenon associated with artificial suppression of winter ice sheets over water bodies by ‘Bubbler systems’ or submerged air injectors, results of laboratory experiments conducted to determine bubbler-induced heat transfer coefficients are reported. Implications and validity of results are discussed.As a second step, a procedure for computer-simulating the behavior of an ice sheet whose thickness is controlled by a bubbler system operating intermittently over a long period of time is developed. The simulation uses experimentally determined bubbler heat transfer coefficients, weather data, site characteristics, and desired performance as input data, and a finite difference method to solve the equations governing the ice thickness and temperature profile. Through an example simulation, the usefulness of the procedure in predicting ice thickness and temperature profile histories, and the effectiveness or suitability of a given bubbler system are demonstrated.
Systems analysis of airport parking facilities
Authors: Sargious Michel A. , Olsen Harvey E.
Published: January 2010

In this study, a multi-stage systems approach has been discussed for implementation to planning of airport parking facilities. Six objectives were selected for comparing alternatives. Two sets of questionnaires were distributed to identify the relative importance of the objectives and the degree to which they are satisfied by the alternatives from the point of view of users and planners. A computer program, based on dynamic programming technique, was used in evaluating the alternatives and searching for the ones that are most effective in satisfying the objectives.The technique was tested, using actual data for the proposed parking facility of the new Air Terminal Complex, Calgary International Airport. The results show the applicability of the method and its usefulness as a planning tool. The actual alternative implemented at Calgary Airport, independent of this study, ranked second according to this analysis.