In an attempt to determine the value of dry-land weight training on swimming performance, two groups of twenty four intercollegiate male swimmers were equated based upon pre-swimming performance, swim power values, stroke specialities, and collegiate swimming experience. At the start of a swimming season there were no significant differences (p>0.05) between the swim training group (SWIM, N=12) and the combined weight and swim training group (COMBO, N=12). Throughout the 13 weeks of their competitive swimming season, both SWIM and COMBO swam together six days a week. In addition, the COMBO engaged in a weight training program three days a week between the third and eleventh weeks (for eight weeks) of the season. The weight training program, using free weights, was intended to simulate arm actions and muscle actions similar to those used during front crawl swimming. Both COMBO and SWIM groups had significant but similar power gains (p<0.05) as measured on the biokinetic swim bench and during a tethered swim. Swimmers in both groups experienced a significant (p<0.05) increase in competitive swim performance from 1991 to 1992 (0.89 ± 0.60% in COMBO and 0.87 ± 0.4Q% in SWIM) whereas no change in distance per stroke (p>0.05) was observed throughout the course of this investigation. Mean total testosterone levels were not altered during the weight training period in either group. No significant (p>0.05) differences were found between the groups in any of the swim power and swimming performance tests. In this investigation, dry-land weight training did not improve swimming performance despite the fact that the COMBO was able to increase the weights used during strength training by 25 to 35%. The lack of positive transfer between dry-land strength gains and swimming propulsive force may be due to the specificity of training. / Human Performance Laboratory

The use of creative monohydrate (CM) supplementation by athletes to increase strength and lean body mass has great anecdotal support. Therefore, the purpose of this investigation was to document the chronic effects of CM supplementation on resistance trained athletes. Sixteen collegiate football players were randomly separated into a CM and placebo (P) group. Supplementation in capsule form consisted of 5 g CM or P per day throughout a 10 week resistance training program. Pre- and Post-testing consisted of 1) Weight. 2) Body fat estimation. 3) One repetition maximal bench press, squat, and power clean. 4) Cybex testing was also included. Results revealed the CM group was able to significantly increase measures of strength and power, as well as increase body mass without a change in body fat %, while the P group showed no significant changes. Data was analyzed using a paired t-test and ANCOVA (p < 0.05). CM PPrePostPrePostBody Wt (lbs)234.5 + 34.41237.37 + 31.34*215.57 ± 55.12213.0 ± 48.897-site fat %15.37+5.5116.68+6.5813.52 + 10.0913.58+8.33Bench Press (lbs)328.75 + 27.87- 340.0 + 27.65*287.14 + 58.94283.57 + 48.71Squats (lbs)532.86 + 130.92592.14 + 123.86*489.17 + 149.81512.50 ± 161.89Power Cleans271.88 + 47.73288.75 + 45.34*246.00 + 33.99241.00 + 64.65* Denotes significant measureThe data from this study supports the anecdotal claims. Further, contrary to what would be expected with long term resistance training alone, the placebo group failed to increase strength and power measures. This suggests that the resistance program lacked sufficient stimuli or that overtraining might have occurred. However, subjects ingesting CM were able to increase strength and power measures. Thus, it appears that CM may also serve as a buffer to overtraining. / School of Physical Education

It was hypothesized that the number of familiarization sessions may have an effect on the pre-testing measures recorded before a training study. This study considered a group of children (8-12 years old) placed into familiarization (FM, 4 sessions) and non-familiarization (NFM, 2 sessions) groups. Strength values in a vertical chest press and horizontal leg press were recorded for both groups. The FM group displayed strength increases in the chest press, while both groups increased leg press strength (a 0.05). The FM group also displayed significant increases over the NFM group in both exercises. The results demonstrated that, in the FM group, significant changes in chest press strength were made in the last two sessions while significant leg press changes were noted in the first two sessions. It can be concluded that the amount of familiarization sessions performed prior to testing can have an impact on pre-testing strength measures. / School of Physical Education

Timber is widely used in the construction industry, because of its availability and good properties. The compressive strength perpendicular to grain (bearing strength) is one property of wood which is important for structural design. The bearing strength is important for the behavior of the structure in all contact points between wooden members. The calculations models for bearing strength have been a subject of discussion for many years and the different building codes in Europe has treated it differently during the years. The aim of this thesis was to compare different calculations models for bearing strength with the results of an experimental study. In this study the bearing strength for a fully supported beam loaded with a point load was studied. Two different loading lengths were studied as well as loading in a point in the middle of the beam, at the edge of the beam and at a distance of 10 mm between the edge and the loading point. The loading was made with a steel stud. Calculations were also performed according to the following standards; Eurocode 5 (EN1995-1-1:2004) before and after amendment, the German Code (DIN 1052:2004), the Italian Code (CNR-DT 206:2006) and two versions of the Swedish Code (BKR). The results showed that the results from the new version of Eurocode 5 agreed best with the experimental results. The tested results, however, were lower than the values calculated using Eurocode (and all the other codes); this might be explained by the hard loading conditions using a steel stud instead of a wood stud.

Corrosion of steel reinforcement in Ontario bridges is causing severe soffit spalling in many situations. These spalled areas are often located within the lap splices and curtailment zones of the primary reinforcement. This can lead to inadequate bar development lengths and the possibility of failures. In order to better predict the residual strength of these deteriorated bridges, a test program was designed, which involved mid-sized concrete beam specimens, with partially de-bonded reinforcement. The de-bonding was simulated in various beam locations, with various de-bonding patterns. The test program consisted of thirteen beams; ten under-reinforced and three over-reinforced. All beams had dimensions of 2100×150×100 mm. The span between simple supports was 1900 mm with a single point load applied at the midspan. Rebar strains and displacement at the midspan were recorded. The goal of this experimental study was to determine the correlation between the spatial location and surface area of de-bonding with the strength of the beams. This was achieved by testing beam specimens with different combinations of de-bonding patterns with respect to location and area. Four beams had de-bonded reinforcement in the flexural zones, seven were de-bonded in the anchorage and flexural zones, and two were fully bonded. In a previous study, a so-called “modified area concept” was developed for rapid assessment of the remaining capacity of heavily spalled girders. This concept was integrated in a computer program, which assesses girder capacity, given a graphical spalling survey and a structural drawing of the girder. The developed program can be easily adapted for full bridge analysis, and to evaluate the effects of reinforcement cross section loss and bond deterioration. The research presented in the current thesis investigates several of the assumptions made in this previous study. The current thesis includes the rationale for the design of the experimental program. In addition, the test results are presented and analyzed. By analyzing the failure modes, failure loads, and crack patterns, along with the load-displacement, load-stiffness, and load-strain behaviour of the various beams, it is concluded that: 1) reinforced concrete beams can carry a significant portion of their original capacity after losing cover over a significant portion of their flexural reinforcement, 2) predictions of the beam capacities and failure modes using the modified area concept are reasonably accurate and conservative in most cases, and 3) the flexural stiffness of the beams was seen to decrease with an increase in the length of the exposed area, in most cases. Recommended areas of future research are identified, including: 1) tests of beams with splices in the flexural reinforcing along the span, 2) field investigation of the concrete strength in regions of the soffit immediately adjacent to the spalled regions, and 3) the development of a correction factor to account for the effects of violating the plane sections assumption.

This thesis presents a finite element (FE) modelling approach investigating the effects of corroded shear reinforcement on the capacity and behaviour of shear critical reinforced concrete (RC) beams. Shear reinforcement was modelled using a “locally smeared” approach, wherein the shear reinforcement is smeared within a series of plane-stress concrete elements at the specific stirrup location. This was done with the objective of incorporating both the reduction in cross-sectional area due to corrosion and the corresponding expansion of corrosion products build up. Corrosion damage was incorporated through equivalent straining induced by the corrosion build up on the affected surrounding concrete where the concrete cover was treated as a thick-wall cylinder subjected to internal pressure. Strains were introduced in the FE model using fictitious smeared horizontal pre-stressing steel, with a compressive pre-straining level related to the degree of corrosion penetration of the reinforcement. The FE modelling approach was first validated against published test data of shear critical RC beams with and without stirrup corrosion. The proposed modelling approach successfully reproduces the load deformation response as well as the failure mode and cracking patterns of the published experimental tests. Upon validation of the FE model, the work was extended to a parametric analysis of important shear design variables, such as the shear span-to-depth ratio, beam width and stirrup spacing The FE analyses were carried out for three increasing levels of corrosion (low, moderate and high) applied to affected stirrups within the critical section of the beams and based on steel mass loss (10%, 30% and 50%, respectively). In general, the results show a reduction in load carrying capacity accompanied by a softening of the load-deformation curves with each increasing level of corrosion. In most of the cases, a reduction in deflection associated to peak loads was also observed for moderate and high levels of corrosion. The impact of the various parameters was studied with respect to strength and deformation, as well as crack angle and mid-height horizontal strain. This was done in an effort to compare FE values to those provided by the CSA A23.3 design equations. The CSA A23.3 shear design equations were compared against FE analysis data in terms of residual shear strength estimation and individual component contributions to shear resistance (i.e., concrete and steel). The comparisons revealed an over conservative estimation for both strength and concrete contributions and an overestimation of the steel contribution. This divergence was attributed to a transition in shear behaviour within the critical section. Based on the progression of the concrete compressive struts with increasing corrosion and predicted crack angle, it was found that stresses in affected sections are redistributed towards adjacent undamaged material. The shear resistance mechanism generally transitioned from typical beam behaviour towards an arching-dominated one. Finally, based on important findings from the literature and the work conducted within this research, important considerations for assessment practice are suggested.

Objective: To evaluate the effect of an in-office plus at-home bleaching protocol on shear bond strength of orthodontic buttons when using a fluoride-releasing sealant. Methods and Materials: One hundred and sixty extracted human molars were randomly divided into bleached (N=80) and unbleached groups (N=80). The bleached group was treated with 45% carbamide peroxide for half an hour, followed with five applications of 20% carbamide peroxide at 24 hour intervals. After two weeks, lingual buttons were bonded on the teeth in both groups using either Transbond XT primer or Pro Seal sealant. The teeth were then stored in artificial saliva and subjected to shear testings at 24 hours and 3 months using a Zwick Universal Test Machine. Results: The ANOVA analysis of the 24-hour results indicated a significant difference between the four subgroups (p<.0011). Further simple t-tests indicated that the differences were significant only between bleached and unbleached subgroups (p<.0011). The 3-month results showed the mean shear bond strengths of the unbleached group using Pro Seal sealant was statistically significantly lower than the others although still greater than clinically minimal suggested bond strengths. Interestingly, 15% of the bleached teeth exhibited enamel fracture at the 3-month testing. Conclusion: At 24 hours, both Pro Seal sealant and Transbond XT primer appear to be a reliable choice on both bleached and unbleached teeth. However, at the 3-month period, Pro Seal sealant yielded significantly lower shear bond strength on unbleached teeth, nevertheless well within the range of values considered to be "clinically acceptable".

The purpose of this study was to profile international level female sevens athletes and determine if anthropometric and physical qualities are able to differentiate between backs and forwards. Twenty-four subjects with a mean (±SD) age of 22.75±3.99 years and body weight of 69.36±5.21kg were sampled from the national team training program. Anthropometric measures (height, body mass and sum of 7 skinfolds) and performance measures (power clean, front squat, bench press, neutral grip pull up, 40m sprint and 1600m run) were collected across the 2013-2014 centralized period and compared across playing position. Thirteen backs (mean age±SD= 21.28±3.54 years) and eleven forwards (mean age±SD= 24.47±3.95 years) had significant differences in body mass (66.40±3.48kg vs. 72.87±4.79kg) and initial sprint momentum (366.81±19.83kg*m/s vs.399.24±22.42*m/s). However no other measures showed positional differences. It is possible that the lack of positional differences in female rugby sevens is due to the multifarious physical requirements of a sevens player, leading to a generic player profile or perhaps due to a lack of selective pressure. It is also possible that the anthropometric and physical qualities measured in this study lacked the necessary resolution or failed to capture the unique attributes of each position. In conclusion, this is the first research profiling international level female sevens athletes. The normative data presented within this paper highlights the physical requirements of female sevens athletes for strength and conditioning practitioners. In addition, the lack of positional differences discovered should impact training program design. / Graduate

No description available.

Plain specimens of two batches of the commercial spring steel BS 251A58 of nominally identical processing but significantly differing levels of non-metallic inclusion levels, have been tested in rotating bending. The data produced has been analysed against some recent methods for the prediction of fatigue properties in high strength materials containing defects. The materials tested were specifically selected for their disparate cleanliness levels, yielding specimens with differing inclusion distribution and maxima. The morphology of critical inclusions is identical between the two material batches. Material microstructure is tempered martensite with ultimate tensile strength of approximately 2000 MPa, which renders it well above the strength level where sensitivity to defects causes variability in fatigue behaviour. Models have been selected from the literature for the prediction of fatigue limit using characterisation of the local microstructural state and the size and critical position of non-metallic inclusions. These models have been validated by the analysis of specific failures after fractographic analysis. It has been shown that these models are acceptably accurate and generally conservative. Difficulties in experimental work have precluded the planned measurement of crack growth rates during the current test work. These difficulties have yielded a superimposed mean stress to the rotating bend test. This mean stress has been quantified for each test and the result coupled with a parameter for mean stress correction. The validity of the mean stress correction has been proven in this work to be valid. More consistent results are observed for the mean stress corrected data. A statistical method for the prediction of maximum non-metallic inclusion size for a given number of specimens or components from small sample microsection analyses has yielded good results when compared to the fractographic observations. This work has investigated the effect of varying magnification level and number of fields surveyed on the accuracy of prediction and recommendations are made for the method for obtaining best accuracy. A 'unified' crack propagation life model from the literature has been applied which combines long and short crack growth regimes. The model has shown good correlation to the current data but only after fitting of constants and only within the low cycle regime. Relationships presented in the literature between constants and the material ultimate tensile strength were found to be inapplicable to the current material at this strength level.