bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation and Description of the Performance of Radon Mitigation Systems
Authors: Wray CP , Yuill GK 
Published: March 2009

Several mitigation techniques such as subslab depressurization and subslab pressurization have been used recently to reduce indoor radon concentrations to acceptable levels. Unfortunately, there is a lack of understanding of the mechanisms that influence the effectiveness of these systems and of their impact on the building and surrounding soil. As a result, no systematic approach has been established to determine which remedial procedure to implement in a given situation.
The objective of the work described here was to use a microcomputer program to make a comparative assessment of the effectiveness of subslab radon mitigation systems in an unoccupied house and to identify potential problems associated with their operation. For each of the mitigation systems, the following steady-state parameters were predicted: airflows into and out of the house (above-grade and below-grade), pressures in the house, soil airflow and pressure fields, interzone airflows, differential pressures, and radon levels throughout the soil and in the house. Comparisons of the program predictions with results obtained using hand-calculations, with predictions of other programs, and with experimental data were used to validate the program.
Program predictions for the unoccupied house showed that the lowest indoor radon levels occurred when the subslab depressurization system was used. Most of the air removed by this system came from inside the basement. Simulation results also indicated that the house was adequately ventilated when the subslab depressurization system operated. However, they showed the subslab pressurization system did not adequately ventilate the house, because most of the air exhausted from the house and supplied to the soil by this system returned to the house through the basement. These predictions were confirmed by field monitoring of the house and of ten other houses with subslab depressurization systems.
The results obtained indicate it is unlikely that cold air drawn through the soil by subslab depressurization systems could cause the soil to freeze near the footings. However, the flow of air from the basement could depressurize the basement enough to create two problems: (1) excessive inflow of cold outside air, which would waste heating energy and (2) furnace backdrafting.
Fair-Play: An Approach to Hockey for the 1990s
Authors: Marcotte G , Simard D 
Published: March 2009

To limit rule infractions and aggressive and violent behavior in ice hockey, Fair-Play, a simple formula integrating sportsmanship in the structure of hockey without changing the game was used with great success in the province of Quebec (1988). This Fair-Play formula grants one fair-play point to the team that ends a game with less than a preestablished number of penalties.
To know the effects of this Fair-Play system on competitive hockey (CC), the Quebec regional hockey association decided to fund a comparative study during the 1989/1990 hockey season. The study compared the number and type of penalties of seven Pee-Wee CC teams and eight Bantam CC teams playing with the Fair-Play formula with sixteen Pee-Wee CC teams and sixteen Bantam CC teams that did not use the system. The game sheets of 329 regular season games in the Pee-Wee category and 338 encounters in the Bantam section during the 1989/1990 season were used to compile the number and type of penalties for the comparative analysis. Six penalties and eight penalties, respectively, were allowed to the Pee-Wee CC and Bantam CC teams before they lost their fair-play point.
In the Pee-Wee CC league using Fair-Play, an average of 4.5 penalties per team per game were handed out compared to 5.7 penalties per team per game in the league not using Fair-Play. The league playing with Fair-Play averaged 1.3 major penalties per team for the entire season, five times less than the other league, which averaged 6.3 major penalties per team. In the league committed to Fair-Play, there were no type B major penalties (fighting, spearing) throughout the entire season. Moreover, the Fair-Play league registered, on average, half the number of game suspensions (1.0) per team per season than the other league (2.2). Among teams using Fair-Play, 71% of them did not receive a single game suspension throughout the season.
In Bantam CC, the league using Fair-Play averaged slightly fewer penalties than the other league (7.8 versus 8.4 penalties per game), but the difference is not significant. There were 30% less major penalties (Type B, C, D, E) called against Fair-Play teams and 25% less game suspensions.
Eye Protection in Ice Hockey: An Historical Review
Authors: Pashby T 
Published: March 2009

Eye injuries in ice hockey have occurred in unacceptable frequency. More than 25 professional players have had their careers shortened because of eye injuries. To date, 262 amateur players in Canada have suffered a blinding eye injury. In one season alone (1974/1975), 43 eyes were blinded.
In the early years, the hockey stick caused most of the injuries (75%). As a result, the Canadian Amateur Hockey Association (CAHA) introduced new high stick rules in 1975.
Because many blinding injuries were puck-induced and because stick injuries persisted, eye protectors were needed. The early design was unsatisfactory because most protectors would allow a regulation hockey stick blade to penetrate immediately over the eye area. Therefore, a standard for face protectors was required. In 1978, a national standard of Canada, Canadian Standards Association (CSA) Z262.2-M78, was published. Safer protectors were produced and mandated for all CAHA minor hockey players in Canada.
No blinding eye injury has occurred to a player wearing a CSA-certified protector.
CSA Standard Z262.2M90, published in 1990, includes visors. Hopefully, older players who refuse to wear a full-face protector will at least wear a certified visor. No blinding eye injury has been recorded in a player wearing a visor. Visors, however, must be worn properly—perpendicular to the ground, extending to the tip of the nose, and lying within a finger's breadth of the nose tip.
When all players including professionals, major Junior “A,” and oldtimers wear certified protectors, blinding injuries will no longer occur.
Realization of the Projected Impact of a Chemistry Workflow Management System at Bridgeport Hospital
Authors: Bernstein LH 
Published: March 2009

Any approach to improving the quality of laboratory operations by data management has to be concerned with its effect on patient test management. For the laboratory to be effective, instruments have to communicate with computers that improve the speed and efficiency of the work in a real-time distributed-processing environment. Chemistry services are highly information-intensive in terms of quantity, variety and rate of generation.
We used a systematic process with defined and measurable outcome expectations to restructure automated chemistry. Our goal was to improve dissemination of medical information. We had spectacular success, allowing effective reassignment of staff to support our service base. This study uses laboratory and hospital trends for staffing, work volume, workload statistics, and carefully designed time studies to analyze the crossovers in replacing chemistry analyzers and modifying a computer interface to realize automatic results verification with callup of results outliers for review.
In 1987 work in automated chemistry was mainly done on two of five analyzers supported by six technologists on three shifts. We considered replacement of these five with two instruments and constructed a model comparing the measured characteristics of the existing system with its replacement with a projected savings of $1.2 million over seven years. Measurements were made on an intermediate, and on the final installed system, and on the contribution of technical and nonlabor expenditures to the expected savings. The expected savings are adjusted to $1.5 million over seven years based on a 30% increase in testing. 22% of the time eliminated is in test generation and 30% is accounted for by interface changes with an effect on information transfer, editing, and rechecking the results generated.
Field Methods for Dynamic Geotechnical Testing: An Overview of Capabilities and Needs
Authors: Campanella RG 
Published: March 2009

This overview is presented from a user's point of view and will consider the practical aspects, nature of the problem to be studied, information requirements, their applications and costs involved. The discussion also reviews the perceived advantages and limitations of various methodologies with suggestions and needs for future developments. Contributions to this symposium are also discussed within the above framework. The comments given are those of the writer and are based on reported research, and personal experiences and perceptions.
Conclusions suggest that most field seismic tests are quite capable to measure the low strain, shear wave velocity profile. However, the testing must rely on other tests to provide ground truthing and identify stratigraphy, except for the downhole seismic cone penetration test where the seismic sensor was added to a tool primarily used for stratigraphic logging. It is recommended that since the downhole seismic method for the cone has evolved into a simple, reliable, cost effective tool, it be added to the ASTM Standard D 3441-86 for cone penetration tests in soil which is currently being revised.
Also, most current field dynamic test methods do not routinely measure the important parameter, material damping. A preliminary procedure for damping measurements with the seismic cone is outlined in this symposium. It is suggested that researchers focus their efforts to measure damping in-situ, compare and scrutinize their results in order to establish an acceptable standard procedure.
It is also apparent that little progress has been made in the in-situ measurement of shear modulus and damping as a function of strain, even though it is generally accepted that such properties are necessary to predict dynamic response of high energy events like earthquakes and should be a high priority for future R and D. It currently appears that the self-boring pressuremeter, a downhole impulse test and a proposed tool reported in this symposium have the best chance of providing such information.
Injection-Correction for Compliance in Liquefaction Testing of Gravelly Soils
Authors: Nicholson PG , Seed RB 
Published: March 2009

A large-scale computer-controlled injection correction system has been developed to continuously and completely mitigate the adverse effects of membrane compliance for undrained testing of coarse soils and rockfill. The magnitude of volumetric compliance was pre-determined as a function of effective confining stress and soil parameters. Computer-controlled injection or removal of water to continuously offset the volumetric errors was then used to eliminate the deleterious effects of membrane compliance throughout the duration of each test.
The measured volumetric compliance errors were evaluated as relationships between effective confining stress and volumetric compliance. A relationship between material grain size and volumetric compliance was expanded with compliance evaluations for a wide range of gravel sizes which supported the use of a “representative” grain size less than the mean grain size as an indicator to estimate expected volumetric compliance for a given soil. Monotonic and cyclic undrained triaxial load tests were performed on uniformly-graded gravels with and without implementation of the computer-controlled compliance mitigation system. The test results support the hypothesis that such soils are much more susceptible to liquefaction than had previously been considered.
Complementary Shear Stresses in Dynamic Centrifuge Modelling
Authors: Madabhushi SPG , Schofield AN , Zeng X 
Published: March 2009

Dynamic centrifuge modelling offers the geotechnical engineer an opportunity of testing reduced scale models at correct prototype stresses and strains while subjecting them to earthquake-like vibrations. In testing of such models the boundary effects require special consideration. A technique of using an absorbing ‘duxseal’ boundary was developed at the Princeton University and was extensively used at the Cambridge University. It was proved that at least 65% of the incident stress waves are absorbed by such a duxseal boundary. In addition to the absorption of incident stress waves an ideal boundary must carry the complementary shear stresses generated on every vertical plane in the far field. A natural semi-infinite soil stratum carries these complementary shear stresses when it is subjected to earthquake vibrations. If the artificial boundary in the centrifuge model is unable to carry these complementary shear stresses, the fact that the centre of mass of the soil body lies above the base plane at which shear waves are applied leads to generation of a dynamic ‘rocking’ moment which will result in the variation of the vertical stress along the base plane of the soil body. These are incorrect model conditions. In this paper a new correct boundary scheme was developed with a thin, vertical, inextensible durai sheet placed between the duxseal block and the soil body. This sheet was designed to impose the complementary shear stresses at the ‘far-field’ boundary interface during the earthquake loading.
A series of dynamic centrifuge tests were conducted on a horizontal sand bed with the new boundary scheme. Stroud cells were used to measure the vertical and shear stresses along the base of the model. The thin, inextensible complementary shear sheet was strain gauged at three levels to measure the shear stresses along the vertical boundaries at either end. The results from these centrifuge tests are presented. The signals generated from the strain gauges were superposed with line noise. A frequency windowing technique was used to obtain the correct complementary shear stress traces. A simple De Alembert's type of calculation was made to estimate the performance of this boundary scheme. Based on this calculation it appears that two-thirds of the required complementary shear stress will be applied by the present boundary scheme. The other one-third will result in the generation of pressure waves in the model. The vertical stresses recorded by the Stroud cells placed on either side of the centroid were 180° out of phase suggesting the presence of a dynamic moment. When the complementary shear stress is completely borne by the boundary then this dynamic moment will vanish. Based on this study a series of centrifuge tests which will be conducted in future are discussed.
Centrifuge Models of Underground Mine Backfill Blast Damage
Authors: Mitchell RJ , Nnadi GN 
Published: March 2009

Cemented classified tailings sands are used worldwide as backfill in large underground mining operations. During the past decade, research has resulted in substantial reductions in backfill cement content. As the cement content of statically stable backfills is reduced, however, a concern arises with regard to dynamic stability under blast or earthquake loadings. The centrifuge model work reported in this paper represents an initial attempt to evaluate the effect of the lateral impact loadings caused by ring blasting on the stability of an exposed face of cemented classified tailings.
Centrifuge models, 300mm in height and having an in-flight static stability safety factor of about 1.3 under 100 gravities, were subjected to lateral impact loadings, impinging on the exposed vertical face to simulate the effect of ring blasting of an adjacent pillar. Cracking and face failures were induced in several of the models by the impact loadings but the model results generally indicate that cemented backfills having a static safety factor of 1.3 or greater are not likely to be damaged by controlled blasting operations. The potential effects of earthquake loadings on cemented mine backfills are also briefly discussed in the paper. Accelerometers and dynamic stress transducers were embedded in the backfill models. The design, fabrication and calibration of the dynamic stress transducers are referenced in the paper. The paper includes similitude analysis indicating that accelerated modelling is necessary to examine prototype dynamic behaviour.
Computer Simulation of Road-Vehicle Dynamic Interaction Forces of Three- and Four-Axle Trucks
Authors: Huhtala M , Vesimaki M , Halonen P 
Published: March 2009

The road-vehicle interaction forces were studied with two truck models, one with four axles (twelve tires) and the other with three axles (ten tires). The truck models were created using the multibody system analyzing program (ADAMS). The input data for the models are based on real values derived from the truck manufacturer. Two modifications of suspensions were made, one with three dampers. The suspensions were multileaf, parabolic, and air suspensions.
The road profiles were measured by VTT. The model computes instantaneous locations, speeds, and road contact points of tires. Then it computes vertical and longitudinal forces acting on tire-road contact surfaces as a function of tire stiffness, damping, and longitudinal slips. These forces are then used to study repeatability of dynamic axle loads along the road profile.
Heavy Truck Properties Significant to Pavement Damage
Authors: Gillespie TD , Karamihas SM 
Published: March 2009

Heavy trucks are a primary source of road damage due to the stresses imposed by heavy axle loads. The mechanics of truck-pavement interaction are examined to determine which truck characteristics have the most direct and strong relationship to road damage.
Static axle loads are found to be one of the most important factors affecting both rigid and flexible pavement fatigue damage because of the power relationship of load to damage. As a result, the load-sharing capabilities of tandem suspensions are also important. Tandem axle spacing is only significant to performance on rigid pavements and is always beneficial. Dynamic loading effects dependent on road roughness, travel speed, and truck dynamic properties are also quantified. Finally, the relevant tire properties are examined. Tire size and inflation pressure have strong influences on fatigue damage of flexible pavements. Tire construction type (radial and bias) appear to have influences on tracking that may explain the recent problems with accelerated rutting.
Interim Results from the Heavy Section Steel Technology (HSST) Shallow-Crack Fracture Toughness Program
Authors: Theiss TJ , Shum DKM , Rolfe ST 
Published: March 2009

The Heavy Section Steel Technology Program (HSST) is investigating the influence of flaw depth on the fracture toughness of reactor pressure vessel (RPV) steel. Recently, it has been shown that shallow cracks tend to exhibit an elevated toughness as a result of a loss of constraint at the crack tip. The HSST investigation is a joint analytical/experimental study combining the use of shallow-cracked laboratory specimens with finite element analysis. All tests have been performed on beam specimens loaded in three-point bending using specimens about 100 mm deep. Primarily two crack depths have been considered: a = 50 and 10 mm (a/W = 0.5 and 0.1). Test results indicate a significant increase in the fracture toughness associated with the shallow-flaw specimens in the lower transition region compared to the conventional fracture toughness. Little or no toughness increase is present on the lower shelf where linear elastic behavior takes place. In addition, the test data indicate that specimen thickness had little influence on fracture toughness for either the deep- or shallow-crack specimens.
Posttest analyses were performed for the deep- and shallow-crack specimens to compare the experimental and analytical toughness values and to quantify the constraint in terms of the Q-stress parameter. The Q stress at initiation was found to be about 0 for the deep-crack beam and about -0.7 for the shallow-crack beams. These results indicate no loss of constraint in the deep-crack specimens but a significant constraint loss in the shallow-crack specimens, which is consistent with observed behavior. The posttest analysis has been used to construct a Jc(Q) locus of toughness data.
A Theoretical Framework for Addressing Fracture in the Ductile-Brittle Transition Region
Authors: Anderson TL , Stienstra D , Dodds RH 
Published: March 2009

Fracture in the ductile-brittle transition region of ferritic steels is complicated by scatter, produced by local sampling effects, and specimen geometry dependence, which results from relaxation in crack tip constraint. Scatter and constraint are interrelated in that each influences the magnitude of the other. This article summarizes recent research on fracture in the transition region and presents a unified framework for addressing size effects and scatter.
A stress volume model for quantifying constraint effects is described briefly, and a comparison between theory and experiment is presented. This model has been applied only to stationary cracks in plane strain, but methods to account for ductile crack growth and three-dimensional effects are described.
The inadequacies of the weakest link model for cleavage fracture are discussed, and an improved statistical model is introduced. This new model considers the probability of propagation and arrest of cleavage microcracks.
A number of recommendations for analyzing cleavage fracture toughness data are presented. Transition region data for a given material should be viewed as a statistical distribution rather than a single value. However, these data should be corrected for constraint effects and ductile crack growth before applying statistical analysis. One of several statistical distributions may be applied to cleavage data; each of the proposed distribution functions has advantages and disadvantages. One of the unknowns in transition region fracture is the threshold toughness of the material, that is, the absolute lower bound.