Articles de revues : « Push-over tests »

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Lin, S. S., C. H. Lai, C. H. Chen et T. S. Ueng. « Derivation of Cyclic p-y Curves From Instrumented Dynamic Lateral Load Tests ». Journal of Mechanics 26, n^o 2 (juin 2010) : 123–33. http://dx.doi.org/10.1017/s1727719100002987.

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AbstractIn this paper, an efficient method is proposed to derive cyclic p-y curves from either push-over or shaking table test results. The Fourier series function, satisfying the boundary conditions of a pile, is used to represent deflection behavior of the pile-soil system at each instant of time during loading interval. In order to obtain soil reaction along the pile shaft, convergence of the series after differentiation is guaranteed by applying the Cesaro sum technique. Results of four push-over tests and two other shaking table test results, conducted at the National Center for Research on Earthquake Engineering in Taiwan, are then used to verify the feasibility of the proposed method.

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Zhang, X., J. A. Knappett, A. K. Leung, M. O. Ciantia, T. Liang et F. Danjon. « Small-scale modelling of root-soil interaction of trees under lateral loads ». Plant and Soil 456, n^o 1-2 (18 septembre 2020) : 289–305. http://dx.doi.org/10.1007/s11104-020-04636-8.

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Abstract Aim (1) To understand the tree root-soil interaction under lateral and moment loading using a physical modelling technique; (2) To detect the possible factors (e.g. root architecture, water condition, and stress level) influencing a tree’s push-over behaviour; (3) To identify suitable scaling laws to use in physical modelling. Methods Two 1:20 scaled root models with different architectures (namely, deep and narrow, and shallow and wide) were reconstructed and 3D printed based on the field-surveyed root architecture data. Push-over tests were performed both in elevated-gravity (centrifuge 20-g) and normal-gravity (1-g) conditions. Results The shallow and wide model showed higher anchorage strength than the deep and narrow model. Regardless of the root architecture, the root anchorage strength measured from dry soil was higher than that from saturated soil. However, once the effective stress was the same, regardless of water conditions, the root anchorage strength would be the same. Conclusions The presence of water decreasing the soil effective stress and key lateral roots extending along the wind direction play a significant role on a tree’s push-over resistance. Centrifuge tests showed comparable results to the field pull-over measurements while 1-g model tests overestimated the root-soil interaction, which could be corrected for soil strength by using modified scaling laws.

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Robinson, Hugh. « Multiple stud shear connections in deep ribbed metal deck ». Canadian Journal of Civil Engineering 15, n^o 4 (1 août 1988) : 553–69. http://dx.doi.org/10.1139/l88-076.

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This paper summarizes the results of push-out tests conducted on 17 different types of shear connections simulating three distinct components of a composite floor system: (1) an interior beam (perpendicular metal deck), (2) a spandrel beam (perpendicular metal deck), and (3) a girder (parallel metal deck). Each push-out specimen had a layer of 152 × 152 WM9.1 × WM9.1 welded wire mesh at mid-depth of each concrete slab.Two composite beams, each with ribbed shear connections typical of those in two of the types of push-out specimens representing ribbed shear connections in interior composite beams with ribbed metal deck, were tested with third-point loads over a simply supported span. Using the average ultimate shear strengths of the push-out specimens having the same configurations as the ribbed shear connections in the composite beam tests to calculate the ultimate flexural capacities of the composite beams resulted in a very close estimate of the measured ultimate flexural capacities of the composite beams. The average measured static yield strengths of the flanges and webs of the wide-flange sections used in the composite beam tests were included in the calculations of the ultimate flexural capacities of the composite beams. Key words: composite, push-out, ultimate shear, shear stud, ribbed metal deck, deep rib.

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Nezamian, Abolghasem, Riadh Al-Mahaidi et Paul Grundy. « Bond strength of concrete plugs embedded in tubular steel piles under cyclic loading ». Canadian Journal of Civil Engineering 33, n^o 2 (1 février 2006) : 111–25. http://dx.doi.org/10.1139/l05-091.

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Investigation of the load transfer of concrete plugs to tubular steel piles subjected to tension and compression and cyclic loading has been conducted at Monash University over the past 3 years. The work presented in this paper reports on the results of the combination of pull-out, push-out, and cyclic loading tests carried out on 15 steel tube specimens filled partially with reinforced concrete with variable lengths of embedment. The pull-out force was applied through steel reinforcing bars embedded in the concrete plug, and push-out forces were applied through a thick top circular plate on the top of the concrete plug. Test results included the cyclic loading, ultimate pull-out and push-out forces, slip of concrete plugs, and longitudinal and hoop strains along the piles for some specimens. The tests clearly showed that average bond strength significantly exceeds expectations and is higher than the results of previous investigations using plugs without reinforcement. The test results also indicated that cyclic loading tests reduced the bond strength due to the accumulation of damage to the plug–pile interface. The push-out and pull-out tests conducted under symmetric cyclic loading demonstrated that slip between the concrete plug and the steel tube increased with repeated loading, and the rate of slip growth increased with an increase in the peak load.Key words: tubular steel pile, reinforced concrete plug, bond, cyclic loading.

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Speranza, Michael J. A., Tim J. Gabbett, David A. Greene, Rich D. Johnston, Andrew D. Townshend et Brett O’Farrell. « An Alternative Test of Tackling Ability in Rugby League Players ». International Journal of Sports Physiology and Performance 13, n^o 3 (1 mars 2018) : 347–52. http://dx.doi.org/10.1123/ijspp.2016-0701.

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This study investigated the relationship between 2 tests of tackling ability, muscle strength, and power in semiprofessional rugby league players. Thirty-one players, 19 first-grade and 12 second-grade, underwent tests of muscle strength (1-repetition-maximum bench press, chin-up, and squat) and power (plyometric push-up and countermovement jump). Tackling ability was assessed via video analysis of under-and over-the-ball tackle drills. The first-grade players had significantly greater scores in both the under-the-ball (P = .03, effect size [ES] = 0.84, 95% CI 0.07–1.50) and over-the-ball tackling-ability tests (P < .001, ES =1.86, 95% CI 0.83–2.52) than the second-grade players. A large, significant relationship was found between under- and over-the-ball tackling ability (r = .55, 95% CI .24–.76, P = .001). Lower-body strength (r = .37, 95% CI .02–.64, P = .04) was moderately associated with under-the-ball tackling ability, whereas over-the-ball tackling ability was moderately associated with plyometric push-up performance (r = .39, 95% CI .04–.65, P = .03). This study found that over-the-ball tackling ability was significantly associated with under-the-ball tackling in semiprofessional rugby league players. Furthermore, it was found that, compared with the second-grade players, the first-grade players had superior tackle ability in both tackle drills. In this study it was observed that plyometric push-up peak power was significantly related to over-the-ball tackling ability and absolute lower-body strength was associated with under-the-ball tackling ability. These findings provide skill coaches and strength and conditioning staff a greater understanding of elements that contribute to effective tackling ability.

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Lockie, Robert G., Robin M. Orr et J. Jay Dawes. « Justified Concerns ? An Exploration of the Leg Tuck in a Tactical Population ». International Journal of Environmental Research and Public Health 19, n^o 21 (26 octobre 2022) : 13918. http://dx.doi.org/10.3390/ijerph192113918.

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The leg tuck was replaced by the plank in the Army Combat Fitness Test, in part because it was felt it discriminated against women. There is limited leg tuck research, including between-sex comparisons and relationships with other fitness tests. This study investigated the leg tuck in a firefighter trainee population (274 males, 31 females). Archival fitness test data included: Illinois agility test (IAT); push-ups; pull-ups; leg tucks; multistage fitness test; 4.54 kg backwards overhead medicine ball throw (BOMBT); 10-repetition maximum deadlift; and 18 kg kettlebell farmer’s carry over a 91.44 m course. Independent samples t-tests (p < 0.05) and effect sizes (d) compared the sexes. Partial correlations and stepwise regression (controlling for sex; p < 0.05) calculated relationships between the leg tuck with the other tests. Male trainees outperformed females in all tests (p ≤ 0.003). The largest difference was for the BOMBT (d = 2.59) not the leg tuck (d = 1.28). The strongest leg tuck relationships were with pull-ups (r = 0.790) and push-ups (r = 0.553). Sex, pull-ups, and push-ups predicted the leg tuck (r2 = 0.674). Approximately 80% of the females could complete one leg tuck, although female personnel may require specific strength and power training. Pulling strength may be a determining factor in leg tuck performance, which is likely not indicated by the plank.

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Zhong, Wei, Shuai Zhang et Na He. « An Experimental Study on the Dynamic Evolution Characteristics of Soil Arching and the Rational Spacing of Anti-Slide Piles ». Sustainability 14, n^o 14 (13 juillet 2022) : 8566. http://dx.doi.org/10.3390/su14148566.

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In order to analyse the dynamic evolution characteristics of soil arching during sliding processes, we conducted a series of model push-pile and direct shear tests. The tests’ results were used to design a relative displacement monitoring system and to introduce two dimensionless parameters (the push–compaction ratio (e) and the different degrees of push–compaction (t)) to investigate the degree of uneven soil deformation during the sliding processes. This innovative method was used to analyse the rational spacing between adjacent anti-slide piles. The results revealed that there was a push-to-compaction effect in sliding soil during the sliding process. Firstly, in terms of space, the gradual transfer characteristics of the landslide thrust and push-to-compaction effect, rather than a uniform deformation over the entire area, were revealed. In terms of time, the results demonstrated a law for the variation in push-to-compaction ratios: The expansion of e occurred earlier in the rear sliding body than in the front e, while the growth rate of front e was faster than that of e in the rear sliding body. The dynamic evolution process was divided into three stages: an elastic formation stage, a plastic development stage, and a failure stage. Secondly, during the sliding process, the shear strength parameters of the sliding soil did not have constant values but underwent a dynamic process of strengthening, and cohesion responded more efficiently than friction. Finally, the degree of mobilisation of the anti-sliding effect of the sliding soil can be used as a new means of quantitative analysis for rational spacing. The results indicated that the rational spacing between adjacent piles should be five times the width of the pile.

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Zhang, Yongtao, Hehui Zheng, Minghao Tang et Zhiqi He. « An Enhanced UHPC-Grout Shear Connection for Steel-Concrete Composite Bridges with Precast Decks ». Advances in Civil Engineering 2021 (25 mai 2021) : 1–15. http://dx.doi.org/10.1155/2021/5595174.

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This article develops an enhanced UHPC-grout shear connection for steel-concrete composite bridges with precast decks. The primary improvement is the use of ultra-high performance concrete (UHPC) as the connection grout. To validate the constructability and the mechanical performance of the new connection, two series of experimental tests (including grouting tests and push-out tests) were conducted. Results from the grouting tests show that both the pressure grouting method and the self-levelling grouting method are applicable to inject the UHPC grout into the channel void of the connection. Results from the push-out tests indicate that the advanced properties of UHPC allow for a significant improvement of the shear resistance of the adhesive connection over traditional cementitious grouts. The ultimate shear capacity of the adhesive connection is controlled by the interface shear strength between the embossed steel and the UHPC grout, with a cohesion value of approximately 5.87 MPa. Meanwhile, the residual frictional resistance can be taken as approximately one-half of the ultimate resistance. The results of the finite-element analysis show that the trilinear model is reasonable to simulate the shear-slip laws of the embossed steel-grout interface and the rough concrete-grout interface.

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Kanyilmaz, Alper, Giovanni Brambilla, Gian Paolo Chiarelli et Carlo Andrea Castiglioni. « Assessment of the seismic behaviour of braced steel storage racking systems by means of full scale push over tests ». Thin-Walled Structures 107 (octobre 2016) : 138–55. http://dx.doi.org/10.1016/j.tws.2016.06.004.

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Li, Yeou-Fong, Jian-Yu Lai et Chung-Cheng Yu. « The Push-Over Test and Numerical Analysis Study on the Mechanical Behavior of the GFRP Frame for Sustainable Prefabricated Houses ». Sustainability 11, n^o 23 (28 novembre 2019) : 6753. http://dx.doi.org/10.3390/su11236753.

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The glass fiber reinforced plastics (GFRP) composite material is a low carbon emission, low life cycle cost, and sustainable material. In this paper, the structural behavior of the lateral force resistant performance of GFRP composite material frames with steel joints was presented, and the energy dissipation and failure modes of the GFRP frames were discussed. A total of six GFRP frames, including single-span and double-span frames with and without diagonal bracing members, were tested by pushover tests to obtain the lateral load-displacement relationships of the GFRP frames. The force-displacement relationship and the energy dissipation of the GFRP frames were examined in the pushover test. In addition, the numerical analysis was performed to obtain the lateral load-displacement relationships of the GFRP frames under pushover tests. When the numerical analysis results and the experimental results were compared, the absolute average errors of the maximum loads were less than 4%, and the lateral load-displacement relationships were close to each other. The numerical analysis results can predict the experimental force-displacement relationships of the GFRP frames.

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Zhang, Jianwei, Zhengfa Li, Fan Wang, Saiyang Zhuo et Tao Wang. « Seismic Resilience Study of Piers Enhanced by Ultrahigh-Performance Concrete Jackets Based on Cyclic Loading Test and Static Push-Over Curves ». Science of Advanced Materials 14, n^o 11 (1 novembre 2022) : 1679–91. http://dx.doi.org/10.1166/sam.2022.4385.

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The efficiency of novel retrofitting of constructed reinforced concrete piers with ultra-high performance concrete (UHPC) jackets was investigated. Pier specimens were subjected to a series of cyclic quasi-static stress tests, whereby two tests employed UHPC jackets with a single width (UHPC-W), while the other two used UHPC jackets with several narrow widths (UHPC-N). The seismic responses were compared in terms of energy dissipation, ductility, hysteresis curves, and skeleton curves. The seismic capability of reinforced concrete piers is increased by both W-type and N-type UHPC jackets by reducing concrete damage. Reinforced concrete piers with a UHPC-W jacket offer greater lateral strength but are more vulnerable to plastic hinge movement. On the other hand, the UHPC-N jacket increases the ductility of concrete and conceals concrete damage. However, construction quality was critical to ensure tight contact between the multiple strips and the reinforced concrete shaft. Based on the implicit method, a 3D finite element model is recommended for nonlinear static elasticplastic analysis. The nonlinear reinforcement model, bond-slip behavior, and concrete damage plastic model are all included in the finite element model. In order to assess the seismic susceptibility of the retrofitted piers, various limit states were defined, and fragility curves unique to the particular structure were produced.

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Paasche, Hendrik, Ulrike Werban et Peter Dietrich. « Near-surface seismic traveltime tomography using a direct-push source and surface-planted geophones ». GEOPHYSICS 74, n^o 4 (juillet 2009) : G17—G25. http://dx.doi.org/10.1190/1.3131612.

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Information about seismic velocity distribution in heterogeneous near-surface sedimentary deposits is essential for a variety of environmental and engineering geophysical applications. We have evaluated the suitability of the minimally invasive direct-push technology for near-surface seismic traveltime tomography. Geophones placed at the surface and a seismic source installed temporarily in the subsurface by direct-push technology quickly acquire reversed multioffset vertical seismic profiles (VSPs). The first-arrival traveltimes of these data were used to reconstruct the 2D seismic velocity distribution tomographically. After testing this approach on synthetic data, we applied it to field data collected over alluvial deposits in a former river floodplain. The resulting velocity model contains information about high- and low-velocity anomalies and offers a significantly deeper penetration depth than conventional refraction tomography using surface-planted sources and receivers at the investigated site. A combination of refraction seismic and direct-push data increases resolution capabilities in the unsaturated zone and enables reliable reconstruction of velocity variations in near-surface unconsolidated sediments. The final velocity model structurally matches the results of cone-penetration tests and natural gamma-radiation data acquired along the profile. The suitability of multiple rapidly acquired reverse VSP surveys for 2D tomographic velocity imaging of near-surface unconsolidated sediments was explored.

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Bienen, B., M. J. Cassidy et C. Gaudin. « Physical modelling of the push-over capacity of a jack-up structure on sand in a geotechnical centrifuge ». Canadian Geotechnical Journal 46, n^o 2 (février 2009) : 190–207. http://dx.doi.org/10.1139/t08-114.

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Offshore jack-up drilling rigs are subjected to loading from wind, waves, and current in addition to their self-weight. This applies combined loading in all six degrees-of-freedom in space on the footings. Although the foundation–soil interaction is crucial to the overall response of a jack-up structure, current state-of-the-art models to predict jack-up footing behaviour, developed using data from single footing experiments, have not been validated for such multi-footing systems under general combined loading. This paper introduces the experimental development of a three-legged model jack-up and loading apparatus designed to investigate the rig’s response — in particular the footing load paths — under combined loading in three dimensions. Push-over experiments were performed in a geotechnical beam centrifuge on silica sand. Experimental results of two tests on dense sand are discussed, highlighting differences in response and mode of failure depending on the loading direction of the jack-up. The importance of three-dimensional modelling is also stressed by experimentally demonstrating that the symmetric load case is not necessarily conservative.

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Alsubait, Sara A. « Effect of Sodium Hypochlorite on Push-out Bond Strength of Four Calcium Silicate-based Endodontic Materials when used for repairing Perforations on Human Dentin : An in vitro Evaluation ». Journal of Contemporary Dental Practice 18, n^o 4 (2017) : 289–94. http://dx.doi.org/10.5005/jp-journals-10024-2033.

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ABSTRACT Aim This study aimed to evaluate the push-out bond strength of NeoMTA Plus (NMTA), EndoSequence root repair material fast set putty (ERRMF), biodentine (BD), and ProRoot white mineral trioxide aggregate (PMTA) when used as perforation repair materials after exposure to 2.5% sodium hypochlorite (NaOCl) during the early setting phase. Materials and methods Horizontal midroot sections were prepared from single-rooted human teeth. Sections (n = 144) were randomly divided into four groups: PMTA, BD, NMTA, and ERRMF. Materials were condensed and allowed to set for 10 minutes. The groups were further divided into two subgroups. The NaOCl group included specimens that were immersed in 2.5% NaOCl for 30 minutes, and the control group included specimens on which a wet cotton pellet was placed over the test material. After 48 hours, the highest force applied to the materials at the time of dislodgement was recorded. Slices were then examined under a digital microscope to evaluate the nature of the bond failure. The surfaces of two specimens from each subgroup were observed by scanning electron microscopy. Data were statistically analyzed with two-way and one-way analysis of variances, independent t-tests, and chi-square tests. The statistical significance was set at 0.05. Results In NaOCl-treated groups, PMTA showed a significantly higher push-out bond strength than the other three materials (p = 0.00). In the control groups, the bond strength of BD was significantly higher than that of PMTA, ERRMF, and NMTA (p < 0.05). Compared with the control group, NaOCl treatment significantly increased the push-out bond strength of PMTA (p = 0.00) and ERRMF (p = 0.00) and significantly reduced the bond strength of BD (p = 0.00) and NMTA (p = 0.03). None of the specimens showed an adhesive type of failure. The majority of the samples exhibited a cohesive failure type. Morphological observations revealed that the surfaces exhibited cubic crystals. In ERRMF, the crystals were few in number. Sodium hypochlorite enhanced the crystallization of NMTA. Conclusion The push-out bond strengths of PMTA and ERRMF were significantly increased after exposure to 2.5% NaOCl in the early setting phase, and those of BD and NMTA were significantly decreased. Clinical Significance The results of the present study suggest that early exposure of NaOCl increase the push-out bond strength of PMTA and ERRMF. PMTA had the highest push-out values. Therefore, it would be a potentially useful perforation repair material for single visit endodontic treatment. How to cite this article Alsubait SA. Effect of Sodium Hypochlorite on Push-out Bond Strength of Four Calcium Silicate-based Endodontic Materials when used for repairing Perforations on Human Dentin: An in vitro Evaluation. J Contemp Dent Pract 2017;18(4):289-294.

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Paulo, Cristina Rodrigues, Joana A. Marques, Diana B. Sequeira, Patrícia Diogo, Rui Paiva, Paulo J. Palma et João Miguel Santos. « Influence of Blood Contamination on Push-Out Bond Strength of Three Calcium Silicate-Based Materials to Root Dentin ». Applied Sciences 11, n^o 15 (26 juillet 2021) : 6849. http://dx.doi.org/10.3390/app11156849.

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A proper bond between root canal filling materials and dentin surface is essential to resist dislodgement and guarantee long-term success. Blood exposure is likely to occur in various clinical situations in which calcium silicate-based materials are used; therefore, it is fundamental to render data concerning the influence of blood on bond strength. The present study aims to evaluate the effect of blood contamination on the push-out bond strength obtained with three different biomaterials to root canal dentin; Ninety extracted human mono-radicular permanent teeth were selected. The root canals were prepared with Gates Glidden burs until a diameter of 1.10 mm was achieved. Teeth were then randomly divided into six experimental groups (n = 15) according to the presence/absence of blood contamination and biomaterial used for root canal filling (ProRoot® MTA, BiodentineTM, and TotalFill® BC Putty). After one week, each root was sectioned in three segments (coronal, middle, and apical regions). Specimens were then submitted to push-out bond strength tests. Fracture pattern evaluation was performed. The significance level was set at 5%.; Blood contamination did not affect the push-out bond strength of any of the three tested calcium silicate-based cements (p > 0.05). Regardless of blood contamination, TotalFill showed statistically higher push-out bond strength when compared with Biodentine (p = 0.040) and MTA (p = 0.004). Biodentine exhibited higher bond strength than MTA (p = 0.043). Biomaterials’ comparison within each radicular segment revealed statistically superior bond strength of both Biodentine and TotalFill over MTA (p < 0.05) in the coronal segment. TotalFill presented higher push-out bond strength regarding the apical segment compared to Biodentine (p = 0.003). Fractures were mostly adhesive.; Overall results indicate TotalFill presents the highest push-out bond strength values, followed by Biodentine and, lastly, MTA. Blood contamination did not affect the dislodgement resistance. Biomaterials’ comparison within each radicular segment revealed both TotalFill and Biodentine as the preferable alternatives for application in the coronal region. TotalFill might be the biomaterial of choice for placement in the apical region.

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McCall, Wesley, James J. Butler, John M. Healey, Alyssa A. Lanier, Stephen M. Sellwood et Elizabeth J. Garnett. « A dual-tube direct-push method for vertical profiling of hydraulic conductivity in unconsolidated formations ». Environmental and Engineering Geoscience 8, n^o 2 (1 mai 2002) : 75–84. http://dx.doi.org/10.2113/gseegeosci.8.2.75.

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Abstract A new direct-push procedure has been developed for the purpose of conducting discrete-interval slug tests to define vertical variations in hydraulic conductivity (K.) This approach is an extension of existing dual-tube methods developed for soil sampling. In this procedure, nested rods (tubes) are simultaneously advanced to predetermined test intervals. The inner rods are then removed and a screen is inserted into the formation for slug testing and possible water sampling. Once testing and sampling are completed, the screen is retrieved, the inner rods reinserted, and the system is advanced to the next test interval. A series of field tests were performed in a highly permeable sand and gravel aquifer to assess the effectiveness of this new approach. Dual-tube profiling results were compared to multilevel slug tests conducted in conventional monitoring wells for intervals in which hydraulic conductivity ranged from 175 ft/day to over 800 ft/day. An initial evaluation found that the dual-tube profiling results were in good agreement (< or =12 percent difference) with K values obtained from multilevel slug tests in the closest monitoring well. Two more-detailed profiles demonstrate that the dual-tube method can effectively delineate small-scale vertical and horizontal variations in hydraulic conductivity. This field assessment shows that the dual-tube method is an accurate and efficient procedure for obtaining information about spatial variations in hydraulic conductivity. This information can be useful for selecting intervals for well installations, for assessment of various remediation alternatives, and for identifying preferential flow paths and other features that can control contaminant movement in the subsurface. The information is obtained without the need for permanent wells. Because this is a direct-push procedure, drill cuttings are eliminated and the volume of development water generated is significantly reduced.

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Gujba, Abdullahi K., et Mamoun Medraj. « Power Ultrasonic Additive Manufacturing : Process Parameters, Microstructure, and Mechanical Properties ». Advances in Materials Science and Engineering 2020 (28 février 2020) : 1–17. http://dx.doi.org/10.1155/2020/1064870.

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Additive manufacturing (AM) for fabricating 3D metallic parts has recently received considerable attention. Among the emerging AM technologies is ultrasonic additive manufacturing (UAM) or ultrasonic consolidation (UC), which uses ultrasonic vibrations to bond similar or dissimilar materials to produce 3D builds. This technology has several competitive advantages over other AM technologies, which includes fabrication of dissimilar materials and complex shapes, higher deposition rate, and fabrication at lower temperatures, which results in no material transformation during processing. Although UAM process optimization and microstructure have been reported in the literature, there is still lack of standardized and satisfactory understanding of the mechanical properties of UAM builds. This could be attributed to structural defects associated with UAM processing. This article discusses the effects of UAM process parameters on the resulting microstructure and mechanical properties. Special attention is given to hardness, shear strength, tensile strength, fatigue, and creep measurements. Also, pull-out, push-out, and push-pin tests commonly employed to characterize bond quality and strength have been reviewed. Finally, current challenges and drawbacks of the process and potential applications have been addressed.

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Senduran, Fatih. « Effect of a 22-Week Strength- and Endurance-Based Physical Education Programme on Students’ Development ». Journal of Education and Training Studies 7, n^o 4 (14 mars 2019) : 30. http://dx.doi.org/10.11114/jets.v7i4.3968.

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The aim of this study was to examine the effect of a physical education(PE) programme targeting strength and endurance development, in which the main activities were rope climbing, pull-ups, an obstacle course, 3000-m running and kickboxing, implemented over a 22-week period and for 260 minutes per week, on the physical development of students. A total of 477 students aged 19-21 (M= 20.1 ± 0.8) took part in the study, during which an intensive strength- and endurance-based physical training programme was carried out with the students by experienced physical training instructors over a period of 22 weeks. In order to assess the students’ physical development, weight measurement, hand grip, bent arm hang, push-up, sit-up, agility and 20-m shuttle run tests were carried out respectively as pretest and posttest. The tests were completed in two days. The obtained data were examined with paired samples t-test. The varied strength- and endurance-based activities (kickboxing, crossing obstacles, etc.) carried out with a certain intensity and over a specific period by the students made a positive contribution to the development of their strength, endurance (Vo2 Max) and agility characteristics.

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Luo, Qi, et Toyohiko Hachiya. « Bank relations, cash holdings, and firm value : evidence from Japan ». Management Research News 28, n^o 4 (1 avril 2005) : 61–73. http://dx.doi.org/10.1108/01409170510784805.

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This paper tests two views of bank’s role for Japanese firms. The views are confronted with the empirical evidence, allowing them to compete to explain firm’s cash holding decisions and the implication of cash holdings on firm value. We find that firms with closer bank relations hold less cash, but some of them are over‐borrowing. Our results show that banks do not monitor their client firms and are unlikely to push the managers of the firms to take efficient actions on maximizing firm value. We discover that cash holdings cause more severe agency conflicts for the firms who have the closer relations with the banks.

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Stimpson, Brian. « Split Set friction stabilizers : an experimental study of strength distribution and the effect of corrosion ». Canadian Geotechnical Journal 35, n^o 4 (1 août 1998) : 678–83. http://dx.doi.org/10.1139/t98-025.

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The pull-out strength of the widely used Split Set stabilizer for rock support, as measured in full-scale field tests in various rock types, has been shown to increase with time after installation. Several physical mechanisms for this increase have been postulated. In a series of laboratory tests in which one of these mechanisms, namely corrosion, was isolated so that its effect could be studied, anchorage capacity as measured by a special push test was found to increase up to 192% after Split Set samples installed in concrete were allowed to corrode for 90 days in a high-humidity environment. It is concluded that one major contributor to the significant increase of pull-out strength with time of Split Sets is corrosion. However, although substantial improvements in strength from this mechanism may be counted on over the short term, it is anticipated that over longer periods of time the strength capacity will decline as the amount of corrosion increases. The study also examined the distribution of strength along the length of the Split Set.Key words: rock reinforcement, friction stabilizers, load capacity, corrosion.

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Mocanu, George D., Gabriel Murariu et Vladimir Potop. « Differences in explosive strength values for students of the faculty of physical education and sports (male) according to body mass index levels ». Pedagogy of Physical Culture and Sports 27, n^o 1 (28 janvier 2023) : 71–83. http://dx.doi.org/10.15561/26649837.2023.0109.

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Background and Study Aim. Explosive strength/muscular strength is demanded at the level of different body segments and regions in most sports. The purpose of the research: is to identify the differences in the manifestation of explosive force between groups of underweight, normal weight and overweight university students; to determine the associations between the anthropometric parameters and the value of the results in the applied tests. Material and Methods. The investigated group consists of 147 students (men) of the Faculty of Physical Education and Sport, divided into 3 distinct groups for the analysis of the results: underweight (age=20.40±1.18, BMI=17.81±0.93), normal weight (age=20.504±1.671, BMI =22.24±1.67) and overweight (age=22.44±2.24, BMI=28.01±2.74). 7 tests were used to evaluate the explosive strength of the lower body (Vertical Jump Test, Standing Long Jump Test, 3-Hop Test, The multiple 5 bounds test, 30s Lateral double leg hop test, 30s Continuous vertical jumps, Speed Test 10m). A number of 6 tests were used to evaluate the explosive strength of the upper body (Overhand ball throw, Shot put, Overhead Medicine Ball Throw-forward, Overhead Medicine Ball Throw-backward, Medicine ball chest throw, 30s Plyometric Push-Ups). Results. Univariate test results indicate F values associated with significant thresholds at the lower body level (P<0.05) for tests based on horizontal jumps (Standing Long Jump, 3-Hop Test and The multiple 5 bounds test), where underweight and normal weight have the better average scores. At the level of the upper body, the situation is changed (for Shot put and medicine balls throws), where the overweight have the best average values, followed by the normal weight, and the worst results are found for the underweight group (P<0.05). Only for the Overhand ball throw and 30s Plyometric Push-Ups, the superiority of the overweight is not statistically confirmed (P>0.05). Correlation calculation (Pearson values) indicates positive associations between body height and vertical and horizontal jumps (except for those repeated for 30s), but negative associations of BMI and body mass with jump-based tests. However, BMI and body mass are moderately, positively and significantly correlated with throw-based tests (P<0.05). Conclusions. We can state that the classification of students in different BMI categories generates differences in explosive strength values between the 3 studied groups. The comparisons indicate the superiority of underweight and normal weights over overweight in all lower body explosive strength tests. The comparisons indicate also the significant superiority of overweight in the medicine ball and shot put tests over normal and underweight. The obtained results cannot be generalized, due to the small size of the underweight and overweight samples. Further investigations on larger groups of university students being necessary.

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Ali, Qaisar, Tom Schacher, Mohammad Ashraf, Bashir Alam, Akhtar Naeem, Naveed Ahmad et Muhammad Umar. « In-Plane Behavior of the Dhajji-Dewari Structural System (Wooden Braced Frame with Masonry Infill) ». Earthquake Spectra 28, n^o 3 (août 2012) : 835–58. http://dx.doi.org/10.1193/1.4000051.

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This paper presents experimental and numerical investigations conducted on typical dhajji buildings found in the northern mountainous areas of Kashmir and surrounding regions to evaluate their in-plane lateral load response. The experimental work included an in-plane quasistatic cyclic test on three full-scale walls as well as monotonic tension and bend tests on main connections. The test results show that the dhajji-dewari system of buildings possesses tremendous resilience against lateral forces. The function of connections, especially the connections between the vertical posts and bottom plate, control the performance of the system. The test results also indicate that although masonry infill does not contribute to lateral load capacity, it significantly increases the energy dissipation capacity of system. The data accrued from the tests has been used in nonlinear static push-over analysis of the numerical models to develop simplified analytical tools for facilitating lateral load performance evaluation of dhajji structures.

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Akhundov, Riad, Adam L. Bryant, Tim Sayer, Kade Paterson, David J. Saxby et Azadeh Nasseri. « Effects of Footwear on Anterior Cruciate Ligament Forces during Landing in Young Adult Females ». Life 12, n^o 8 (26 juillet 2022) : 1119. http://dx.doi.org/10.3390/life12081119.

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Rates of anterior cruciate ligament (ACL) rupture in young people have increased markedly over the past two decades, with females experiencing greater growth in their risk compared to males. In this study, we determined the effects of low- and high-support athletic footwear on ACL loads during a standardized drop–land–lateral jump in 23 late-/post-pubertal females. Each participant performed the task unshod, wearing low- (Zaraca, ASICS) or high- (Kayano, ASICS) support shoes (in random order), and three-dimensional body motions, ground-reaction forces, and surface electromyograms were synchronously acquired. These data were then used in a validated computational model of ACL loading. One-dimensional statistical parametric mapping paired t-tests were used to compare ACL loads between footwear conditions during the stance phase of the task. Participants generated lower ACL forces during push-off when shod (Kayano: 624 N at 71–84% of stance; Zaraca: 616 N at 68–86% of stance) compared to barefoot (770 N and 740 N, respectively). No significant differences in ACL force were observed between the task performed wearing low- compared to high-support shoes. Compared to barefoot, both shoe types significantly lowered push-off phase peak ACL forces, potentially lowering risk of ACL injury during performance of similar tasks in sport and recreation.

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Rezende, Luiz, Rodolfo A. Dellagrana, Luiz Gustavo Rodrigues Oliveira-Santos, Arthur Duarte Fantesia Costa Cruz, Maycon Felipe da Silva Mota et Christianne F. Coelho-Ravagnani. « Physical Performance of Brazilian Military Policemen : A Longitudinal Analysis by Occupational Specialties ». International Journal of Environmental Research and Public Health 19, n^o 24 (16 décembre 2022) : 16948. http://dx.doi.org/10.3390/ijerph192416948.

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Maintenance of good levels of physical fitness is essential during occupational tasks for the general health of the military police. However, no studies have evaluated longitudinal changes in the physical fitness of Brazilian military police officers according to their specialties. Thus, the objective of the current study was to analyze the changes in the physical fitness of military police officers according to their specialty, over a period of five years. Retrospective data (2015–2019) from 290 police officers were analyzed, including age and physical fitness tests (12-min run test, sit-ups, push-ups, and pull-ups on the bar). The sample was divided into four groups (Specialized; Border; Urban; and Environmental). ANCOVA was used to describe differences in physical fitness components between groups of police officers after adjusting for age. Initial fitness was higher among police officers in the Specialized group (i.e., those with greater physical demands). During the five-year follow-up period, there was an age-related decrease in physical capacity for all groups, regardless of specialty. However, Urban police showed improvement in running and sit-up tests (p < 0.05) over time. Changes in physical capacity during follow-up differed depending on the physical component analyzed and the occupational specialty.

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Timoney, Martin J., et Bryan A. McCabe. « Strength verification of stabilized soil–cement columns : a laboratory investigation of the push-in resistance test (PIRT) ». Canadian Geotechnical Journal 54, n^o 6 (juin 2017) : 789–805. http://dx.doi.org/10.1139/cgj-2016-0230.

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The push-in resistance test (PIRT) is an in situ means of verifying the strength of stabilized soil columns. During the test, a winged penetrometer penetrates the stabilized column at a constant rate and the column strength is estimated from the recorded probing resistance using a bearing capacity factor (N). While N values between 8 and 20 (although typically between 8 and 15) are quoted in the literature (based almost exclusively on empirical and Scandinavian experience), there have been few field tests and no laboratory investigations aimed at investigating the value of N and the factors upon which it depends, thereby limiting international confidence in the method. This paper presents the findings of a unique laboratory-scale PIRT series conducted at the National University of Ireland, Galway (NUI Galway). The development of appropriate column construction and testing methods is discussed. The results of 11 PIRT tests on pre-drilled stabilized columns with unconfined compression strengths (UCS) from 150 to over 800 kPa are reported, as well as those of a complementary cone-only series of tests to assess additional frictional forces acting on the penetrometer. Appropriate corrections to the data for temperature and time consistency between the probing forces and UCS values are discussed. Test results indicate that the strength of the column has a mild influence on the N value. Further investigation of this finding is recommended at both laboratory and field scales.

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Adriaanse, Marlou, et Daniel A. Leffler. « Serum Markers in the Clinical Management of Celiac Disease ». Digestive Diseases 33, n^o 2 (2015) : 236–43. http://dx.doi.org/10.1159/000371405.

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The advent of highly reliable noninvasive celiac diagnostic tests has transformed the field of celiac disease, from diagnosis, to evaluation of epidemiology, to clinical and translational research. Serologic tests in their modern forms are highly sensitive and specific for diagnosis, allowing for consideration of avoidance of diagnostic intestinal biopsy in some settings. On the other hand, as predictors of intestinal damage and for use in monitoring disease activity, currently available noninvasive tests have been disappointing. Serologic tests, while a measure of disease activity, do not correlate well with histology or symptomatology, and it is unclear if they predict long-term risk. Additionally, while the many clinically available tests have improved accessibility, they can have widely different cutoff levels and overall performance, making the comparison of levels in individual patients over time and across populations quite difficult. In the future, we can expect to see improvement in the currently available serologic tests including tissue transglutaminase and deamidated gliadin peptide with expansion of the dynamic range of the tests, and the celiac care community should push for a standardization of assays that would simplify research and patient care. Additionally, current serologic tests are measures of the adaptive immune response in celiac disease but do not directly measure intestinal inflammation. Promising work on intestinal fatty acid-binding protein and other assays which directly measure intestinal damage may complement traditional serologic tests and further improve our ability to noninvasively diagnose and monitor celiac disease. The coming years hold promise for the continuing evolution of serum-based tests in celiac disease with the possibility of substantial improvement of patient care and clinical research.

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Antonio, Kenyon, Horn, Jiannine, Carson, Ellerbroek, Roberts, Peacock et Tartar. « The Effects of an Energy Drink on Psychomotor Vigilance in Trained Individuals ». Journal of Functional Morphology and Kinesiology 4, n^o 3 (22 juillet 2019) : 47. http://dx.doi.org/10.3390/jfmk4030047.

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The psychomotor vigilance test (PVT) measures one’s behavioral alertness. It is a visual test that involves measuring the speed at which a person reacts to visual stimuli over a fixed time frame (e.g., 5 min). The purpose of this study was to assess the effects of an energy drink on psychomotor vigilance as well as a simple measure of muscular endurance (i.e., push-ups). A total of 20 exercise-trained men (n = 11) and women (n = 9) (mean SD: age 32 7 years; height 169 10 cm; weight; 74.5 14.5 kg; percent body fat 20.3 6.2%; years of training 14 9; daily caffeine intake 463 510 mg) volunteered for this randomized, double-blind, placebo-controlled, crossover trial. In a randomized counterbalanced order, they consumed either the energy drink (ED) (product: BANG®, Weston Florida) or a similar tasting placebo drink (PL). In the second visit after a 1-week washout period, they consumed the alternate drink. A full 30 minutes post-consumption, they performed the following tests in this order: a 5-minute psychomotor vigilance test, three sets of push-ups, followed once more by a 5-minute psychomotor vigilance test. Reaction time was recorded. For the psychomotor vigilance test, lapses, false starts and efficiency score are also assessed. There were no differences between groups for the number of push-ups that were performed or the number of false starts during the psychomotor vigilance test. However, the ED treatment resulted in a significantly lower (i.e., faster) psychomotor vigilance mean reaction time compared to the PL (p = 0.0220) (ED 473.8 42.0 milliseconds, PL 482.4 54.0 milliseconds). There was a trend for the ED to lower the number of lapses (i.e., reaction time > 500 milliseconds) (p = 0.0608). The acute consumption of a commercially available ED produced a significant improvement in psychomotor vigilance in exercise-trained men and women.

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Du, Zongyang, Shuo Pan, Qi Wu, Zhenling Peng et Jianyi Yang. « CATHER : a novel threading algorithm with predicted contacts ». Bioinformatics 36, n^o 7 (2 décembre 2019) : 2119–25. http://dx.doi.org/10.1093/bioinformatics/btz876.

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Abstract Motivation Threading is one of the most effective methods for protein structure prediction. In recent years, the increasing accuracy in protein contact map prediction opens a new avenue to improve the performance of threading algorithms. Several preliminary studies suggest that with predicted contacts, the performance of threading algorithms can be improved greatly. There is still much room to explore to make better use of predicted contacts. Results We have developed a new contact-assisted threading algorithm named CATHER using both conventional sequential profiles and contact map predicted by a deep learning-based algorithm. Benchmark tests on an independent test set and the CASP12 targets demonstrated that CATHER made significant improvement over other methods which only use either sequential profile or predicted contact map. Our method was ranked at the Top 10 among all 39 participated server groups on the 32 free modeling targets in the blind tests of the CASP13 experiment. These data suggest that it is promising to push forward the threading algorithms by using predicted contacts. Availability and implementation http://yanglab.nankai.edu.cn/CATHER/. Supplementary information Supplementary data are available at Bioinformatics online.

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Zanatta, Rayssa Ferreira, Beatriz Maria da Fonseca, Stella Renata Steves, Carlos Rocha Gomes Torres et Sergio Eduardo Paiva Gonçalves. « Effect of Nd:YAG laser in the bond strength of fiberglass posts ». Brazilian Dental Science 18, n^o 4 (7 décembre 2015) : 19. http://dx.doi.org/10.14295/bds.2015.v18i4.1164.

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<p>The aim of the present study was to compare the effects of Nd:YAG laser application in root canals on bond strengths of fiber posts. Thirty single-rooted bovines were randomly divided into three groups (n=10); root canal instrumentation was performed, and pretreatment was conducted as follows: C group: conventional treatment (without laser irradiation); ALC group: Nd:YAG laser was applied after adhesive; and LAC group: Nd:YAG laser was applied before adhesive. The fiber posts Rebilda 15 DC (Voco) were cemented with an adhesive system and resin cement, in accordance with the manufacturer’s instructions. Six slices with 1.0mm height was obtained for of each root and bond strength was measured by push-out test using a universal testing machine (0.5 mm/min). Data were analyzed using Kruskal-Wallis and Dunn’s tests (p <0.05). Push-out bond strengths to root canal dentin were affected by the type of treatment and root third. The use of Nd:YAG laser after the application of adhesive system had a higher bonding performance compared with the use of laser before the application. Also, cervical and medium third presented higher bond strength values than the apical third. It must be conclude that the laser irradiation over the non-cured adhesive system is more efficient for increase in bond strength than the irradiation after the application of the adhesive. However, the use of 60mJ of laser energy is not sufficient to improve the bonding performance.</p>

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Salin, Kasper, Mikko Huhtiniemi, Anthony Watt, Kaisu Mononen et Timo Jaakkola. « Contrasts in fitness, motor competence and physical activity among children involved in single or multiple sports ». Biomedical Human Kinetics 13, n^o 1 (1 janvier 2021) : 1–10. http://dx.doi.org/10.2478/bhk-2021-0001.

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Abstract Study aim: While there is wide debate around specialization in one sport, there is a lack of information about fitness levels and motor competence of children participating in single or multiple sports. Material and methods: The study involved 358 fifth-grade children who participated in a set of health-related fitness and motor competence tests over two consecutive years. A subsample of children (n = 109) wore an accelerometer for seven consecutive days. The independent samples t-test and ANCOVA were used to compare differences between single and multi-sport participants in study variables and changes between baseline and follow-up. Results: Multi-sport participants performed better in shuttle run (baseline/follow-up; p = 0.001/p = 0.006), push-up (p = 0.006/p = 0.036), and five leap tests (p = 0.001/p = 0.009) in baseline than single sport participants among boys. Likewise, multi-sport participants showed significantly more improvement in the throwing and catching combination test between study years among boys F1,159 = 3.570, p = 0.030. Among girls, no differences were found in any study variable between single and multi-sport participants. Conclusions: From the perspective of fitness and motor competence tests, there are no arguments for participating in just one sport at an early age. Instead, multi-sport participants performed better than single sport participants in the majority of test variables.

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Bellar, David, Cory Etheredge et Lawrence W. Judge. « The Acute Effects of Different Forms of Suspension Push‐Ups on Oxygen Consumption, Salivary Testosterone and Cortisol and Isometric Strength ». Journal of Human Kinetics 64, n^o 1 (15 octobre 2018) : 77–85. http://dx.doi.org/10.1515/hukin-2017-0202.

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Abstract Suspension exercise systems are being used in strength and conditioning facilities, fitness centers, rehabilitation centers and home gyms. Though some evidence exists regarding the impact of training with these systems, more work is needed for a better understanding. The purpose of the present investigation was to examine the acute effects of an exercise session with 2 (hands only) and 4 straps (hands and feet) in the push-up exercise compared to a work-matched bench press exercise session. The participants for this repeated measures, cross-over investigation were 18 healthy college-aged males (age: 24.8 ± 3.5 yrs, body mass: 81.8 ± 7.8 kg, body height: 178.9 ± 4.5 cm). The conditions were 6 sets of 10 repetitions of suspension push-ups using two straps (DUAL) for the hands, fours straps (QUAD) for hands and feet and a traditional bench press exercise matched to the average resistance during the suspension push-up. The participants performed all repetitions at a controlled cadence. Expired gases, and heart rate were monitored continuously during the exercise session. Pre and post exercise saliva samples were collected to quantify changes in testosterone and cortisol. Upper body isometric strength tests ( UBIST) were performed (Post, 1 hr, 24 hr, 48 hr) to evaluate changes in force production during recovery. Data analysis via repeated measures ANOVA revealed a significant trend for increased oxygen consumption in the QUAD condition compared to the bench press (p = 0.019). Additionally, both suspension conditions resulted in a reduced respiratory exchange ratio as compared to the bench press (p < 0.05). A significant main effect was noted for time in all conditions regarding isometric strength (p < 0.001), but no differences between conditions were revealed. Testosterone and cortisol responses did not differ between conditions. Based upon these data, it appears that when matched for work, suspension exercise results in equivalent reductions in muscle force, but greater oxygen consumption compared to isotonic exercise.

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Cil, Deniz, et Alyssa K. Prorok. « Selling Out or Standing Firm ? Explaining the Design of Civil War Peace Agreements ». International Studies Quarterly 64, n^o 2 (2 mars 2020) : 329–42. http://dx.doi.org/10.1093/isq/sqaa010.

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Abstract When do rebel leaders “sell out” their constituents in the terms of peace by signing agreements that benefit group elites over the rebel constituency, and when do they instead “stand firm,” pushing for settlement terms that benefit the public they claim to represent? This article examines variation in the design of civil war settlement agreements. It argues that constituents, fighters, and rebel elites have different preferences over the terms of peace, and that rebel leaders will push for settlements that reflect the preferences of whichever audience they are most reliant on and accountable to. In particular, leaders of groups that are more civilian-reliant for their military and political power are more likely to sign agreements that favor broad benefits for civilian constituents, while leaders who do not depend on civilian support for their political and military power will sign agreements with fewer public benefits. We test this argument using original data on the design of all final peace agreements reached between 1989 and 2009, and several proxies for the group's level of reliance on civilian supporters. Using a variety of statistical tests and accounting for nonrandom selection into peace agreements, we find strong support for our hypothesis.

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Heweidak, Mohamed, Bidur Kafle et Riyadh Al-Ameri. « Shear-Bond Behaviour of Profiled Composite Slab Incorporated with Self-Compacted Geopolymer Concrete ». Applied Sciences 12, n^o 17 (25 août 2022) : 8512. http://dx.doi.org/10.3390/app12178512.

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Composite slab systems have become increasingly popular over the last few decades because of the advantages of merging the two building materials, profiled steel sheets and concrete. The profiled composite slab’s performance depends on the composite interaction at the longitudinal direction of the concrete–steel interface. Geopolymer concrete has emerged over the last few years as a potential sustainable construction material, with 80% less carbon dioxide emissions than cementitious concrete. Recently, self-compacted geopolymer concrete (SCGC) has been developed, synthesised from a fly ash/slag ratio equal to 60/40, micro fly ash (5%), anhydrous sodium metasilicate solid powder as the alkali-activator and a water/solid content ratio equal to 0.45. The production of SCGC eliminates the need for an elevated temperature during curing and high corrosive alkali-activator solutions, as in traditional geopolymer concrete. The bond characteristics of the profiled composite slab system incorporated with the SCGC mix have not yet been thoroughly investigated. The cost-effectiveness of small-scale tests has popularised its usage by many researchers as an alternative technique to large-scale testing for assessing composite slab load shear capacity. In this paper, small-scale push tests were conducted to investigate the load slip behaviour of the SCGC composite slab compared to the normal concrete (NC) composite slab, with targeted compressive strengths of 40 and 60 MPa. The results indicate that SCGC has better chemical adhesion with profiled steel sheets than NC. Additionally, the profiled composite slab incorporated with SCGC possesses higher ultimate strength and toughness than the normal concrete composite slab.

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Achtemeier, Gary L. « Planned Burn-Piedmont. A local operational numerical meteorological model for tracking smoke on the ground at night : model development and sensitivity tests ». International Journal of Wildland Fire 14, n^o 1 (2005) : 85. http://dx.doi.org/10.1071/wf04041.

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Smoke from both prescribed fires and wildfires can, under certain meteorological conditions, become entrapped within shallow layers of air near the ground at night and get carried to unexpected destinations as a combination of weather systems push air through interlocking ridge–valley terrain typical of the Piedmont of the Southern United States. Entrapped smoke confined within valleys is often slow to disperse. When moist conditions are present, hygroscopic particles within smoke may initiate or augment fog formation. With or without fog, smoke transported across roadways can create visibility hazards. Planned Burn (PB)-Piedmont is a fine scale, time-dependent, smoke tracking model designed to run on a PC computer as an easy-to-use aid for land managers. PB-Piedmont gives high-resolution in space and time predictions of smoke movement within shallow layers at the ground over terrain typical of that of the Piedmont. PB-Piedmont applies only for weather conditions when smoke entrapment is most likely to occur––at night during clear skies and light winds. This paper presents the model description and gives examples of model performance in comparison with observations of entrapped smoke collected during two nights of a field project. The results show that PB-Piedmont is capable of describing the movement of whole smoke plumes within the constraints for which the model was designed.

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Wang, Xizhi, Yuqing Liu et Yangqing Liu. « Experimental study on shear behavior of notched long-hole perfobond connectors ». Advances in Structural Engineering 22, n^o 1 (2 juillet 2018) : 202–13. http://dx.doi.org/10.1177/1369433218782991.

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It is restricted in applying perfobond connectors in steel-concrete composite bridges with shallow rib heights or narrow connector distances, because it is unfavorable to enhance shear connection by enlarging hole diameter of perfobond connectors and difficult to install transverse rebars in perforated holes. To address this issue, an alternative perfobond connector was proposed by making a notch on the outer edge of the lengthened circular hole in this paper. To investigate the differences of failure mode, shear strength, slip behavior, and load transferring mechanism between circular-hole and notched long-hole perfobond connectors, a total of eight push-out tests were performed. Experimental results show that the shear strength of notched long-hole perfobond connectors exhibits an increase of about 20% compared with that of circular-hole perfobond connectors, and the shear stiffness and peak slip increase by over 10%. The enlarged hole area in notched long-hole perfobond connectors could weaken contribution percentage of concrete dowel to shear capacities, although the shear strength increases as the product of concrete compressive strength and hole area raises. Repeated loading hardly impacts shear strength of perfobond connectors but raises peak slip by 11% and 14% of circular-hole and notched long-hole perfobond connectors, respectively. Compared with single-row connectors, multi-row connectors exhibit a reduction of about 5% in shear capacities and an increase of about 10% in peak slips. The first row along the shear direction in multi-row connectors would bear the maximum percentage of shear load. Based on push-out test results, several typical existing equations for predictions of shear strength are compared and evaluated.

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Yusran Rizki. « RELATIONSHIP BETWEEN THE STRENGTH OF ARM AND HAND MUSCLES TO PASSING RESULTS FOR AEK MEN'S volley ball NEW NABARA VC YEAR 2020 ». Journal Physical Health Recreation 1, n^o 2 (30 juin 2021) : 140–47. http://dx.doi.org/10.55081/jphr.v1i2.282.

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The research objective in this thesis is to determine how much the relationship between arm muscle strength and hand muscle strength on the passing results of men's volleyball volleyball Aek Nabara Barumun VC in 2020. The location of this research was conducted at Aek Nabara Barumun VC Volleyball Club. Data collection was started from 18 December - 27 December 2020. The sample of this study was male athletes who had been selected from the population with purposive sampling, totaling 10 people. The method used in this research is descriptive method with tests and measurements. The research instruments used were arm muscle strength using push-ups, hand muscle strength using a hand grip, and passing tests to the wall. The results of the study can be concluded that: (1) There is a significant relationship between arm muscle strength and volleyball passing results in male athlete Aek Nabara Barumun VC in 2020 (tcount> ttable = 5.398> 2.262). (2) there is a significant relationship between hand muscle strength and volleyball passing results in male athlete Aek Nabara Barumun VC in 2020 (tcount> ttable = 6,782> 2,262). (3) there is a significant relationship between arm muscle strength and muscle strength hand on the results of the results of passing over volleyball in the male athlete Aek Nabara Barumun VC in 2020 (Fcount> Ftable = 32 <4.46).

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Lindgren, B. S., et J. H. Borden. « Displacement and aggregation of mountain pine beetles, Dendroctonusponderosae (Coleoptera : Scolytidae), in response to their antiaggregation and aggregation pheromones ». Canadian Journal of Forest Research 23, n^o 2 (1 février 1993) : 286–90. http://dx.doi.org/10.1139/x93-038.

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Deployment of verbenone release devices at 10-m centres significantly reduced the percent of available lodgepole pines (Pinuscontorta Dougl. var. latifolia Engelm.) that were mass attacked by mountain pine beetles (Dendroctonusponderosae Hopkins) in 50 × 150 m subplots flanked on each side by identical subplots, regardless of whether the flanking plots were baited with tree baits or left untreated. Verbenone treatment also increased the percent of unsuccessful attacks (<31.25 attacks/m2) in the central subplot compared with when the central subplot was left untreated. Tree baits, composed of trans-verbenol, exo-brevicomin, and myrcene, applied in flanking subplots did not affect significantly the percent of trees mass attacked nor the attack density. However, assuming a 2:1 expected ratio of attacks in the two flanking subplots over the central subplot, χ2-tests indicated that the attack distribution was consistently altered only when both verbenone and aggregation pheromones were applied. This study suggests that a "push–pull" tactic using aggregation and antiaggregation pheromones may be feasible for managing this destructive pest.

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Roşculeţ, Ioana, Corina Ţifrea, Alves Vilaça-Alves et Ana-Maria Vasiliu. « Preliminary Research on Physical Performance in Junior Tennis Players U16 ». Revista Romaneasca pentru Educatie Multidimensionala 14, n^o 1Sup1 (24 mars 2022) : 145–54. http://dx.doi.org/10.18662/rrem/14.1sup1/542.

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Physical performance regarding the rankings of U16 junior tennis players is not precisely understood. The purpose of this preliminary research was to check if the top-ranked players had better results in the evaluation of physical tests than the lower-ranked ones. Therefore, the scope was to determine if the national ranking is related to the physical characteristics. The physical tests used were approved by the Romanian Tennis Federation. The following research methodology has been used: protocol methodology, the recording of data in research methodology, test in research methodology, and the statistical methodology. The tennis players followed their usual physical training for three months and at the end of this period, they were tested. Twenty-two tennis players, eleven girls, and eleven boys, between 14 and 16 years old, were part of this preliminary research. The following measures were conducted: 5-10 m sprint, 30 m sprint test, 6 x 20 m sprints, long jump, repeated lateral jumps performed on both legs over the gym bench, one-handed medicine ball throw with, overhead medicine ball throw test, lateral steps test, Hexagon test, agility test, and push-ups test. Results The group of tennis players was followed during 12 weeks of their usual training. The variables were expressed in mean and standard deviation. The purpose was to check if there is any correlation between the ranking and the morphological parameters. Pearson correlation has been used. The normality of the variance and covariance was certified with Shapiro-Wilks Normality Test. Conclusion After comparing the results, it was shown that the players from the group with better ranking positions, had superior results in the evaluation tests.

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Muscat, Danielle Marie, Pinika Patel, Sharon Reid, Tammy Hoffmann, Loai Albarqouni et Lyndal Trevena. « Content analysis of clinical questions from Australian general practice which are prioritised for answering : identifying common question types and perceived knowledge gaps ». BMJ Evidence-Based Medicine 25, n^o 1 (24 juin 2019) : 15–21. http://dx.doi.org/10.1136/bmjebm-2019-111210.

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Perceived knowledge gaps in general practice are not well documented but must be understood to ensure relevant and timely evidence for busy general practitioners (GPs) which reflects their diverse and changing needs. The aim of this study was to classify the types of questions submitted by Australian GPs to an evidence-based practice information service using established and inductive coding systems. We analysed 126 clinical questions submitted by 53 Australian GPs over a 1.5-year period. Questions were coded using the International Classification of Primary Care (ICPC-2 PLUS) and Ely and colleagues’ generic questions taxonomy by two independent coders. Inductive qualitative content analysis was also used to identify perceived knowledge gaps. Treatment (71%), diagnosis (15%) and epidemiology (9%) were the most common categories of questions. Using the ICPC-2 classification, questions were most commonly coded to the endocrine/metabolic and nutritional chapter heading, followed by general and unspecified, digestive and musculoskeletal. Seventy per cent of all questions related to the need to stay up-to-date with the evidence, or be informed about new tests or treatments (including complementary and alternative therapies). These findings suggest that current guideline formats for common clinical problems may not meet the knowledge demands of GPs and there is gap in access to evidence updates on new tests, treatments and complementary and alternative therapies. Better systems for ‘pulling’ real-time questions from GPs could better inform the ‘push’ of more relevant and timely evidence for use in the clinical encounter.

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Uglešić, Davor, et Ante Uglešić. « Reinforcement of Stone Masonry Walls with Carbon Fiber Tissue and Tapes, a Case Study ». Key Engineering Materials 747 (juillet 2017) : 182–89. http://dx.doi.org/10.4028/www.scientific.net/kem.747.182.

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The reconstruction project of an existing masonry building will be presented in this paper. The building was erected in 1911. The building has a ground floor and three floors. Its façade is protected as cultural heritage. Due to the conversion of the building into a hotel, a lot of interventions have to be done on the existing structure, which significantly changes the properties of the structure and increases the weight of the building, and thus seismic forces. Due to structural assessment, the project was preceded by different on site structural tests. A very detailed 3D FEM model with solid elements was created on which the analysis of the structure was carried out. The results of nonlinear analysis for vertical loads, modal (eigenvalue) analysis, response spectrum analysis and push-over analysis (nonlinear construction stage analysis “sequence analysis”) will be shown. Only when carbon fibers reinforcement was included in the FEM model, the vertical loads were applied. It can be activated for earthquake forces. The comparison between the results for unreinforced and reinforced structure proves increasing carrying capacity of the stone masonry walls after reinforcement with carbon fibers was combined with the masonry walls grouting.

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Willam, K. J., C. Citto et P. B. Shing. « Recent Results on Masonry Infill Walls ». Advanced Materials Research 133-134 (octobre 2010) : 27–30. http://dx.doi.org/10.4028/www.scientific.net/amr.133-134.27.

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The paper summarizes the main research findings on masonry infill walls which were obtained within the framework of a comprehensive NSF-NEESR-SG project directed by Prof. Benson Shing at UC San Diego (Shing et al. 2009). The main focus of this contribution are experimental and computational observations on 2/3 scale unreinforced masonry panels bounded by a reinforced concrete frame which were subjected to cyclic push-over testing at CU Boulder under constant vertical pre-loading. This study included two-wythe masonry panels of 133in x75.5in size (3.378 x1.897m) with and without openings in form of eccentric windows and doors. The background experiments did include a suite of masonry prism tests on rectilinear and slanted masonry prisms providing important insight into the composite behavior of mortar and brick construction. The paper concludes with remarks on the experimental observations when the panels were integrated into infill walls of two-bay width and three-story height with and without retrofits of reinforced ECC layers (engineered cementitious composites) which were attached to one side for quasistatic testing at CU Boulder, and to both sides of the wall for dynamic shake table testing at UC San Diego.

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Hein, Gary L. « Corn Root Protection Against Corn Rootworm Larvae, 1988 ». Insecticide and Acaricide Tests 15, n^o 1 (1 janvier 1990) : 193. http://dx.doi.org/10.1093/iat/15.1.193.

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Abstract Planting-time soil insecticides were applied at 2 locations in the Nebraska Panhandle. The experimental design was a randomized complete block design with 4 replications. Plot areas were planted on 6 May (Mitchell) and 9 May (Scottsbluff) by the cooperating growers and maintained with standard cropping practices. Care was taken to ensure that no insecticides were applied when the corn was planted. Immediately after planting, single-row test plots were established by applying different insecticide treatments in 7-inch band over the seed row with a bicycle-type push applicator. Insecticides were metered by using calibrated Noble metering units. A dragchain was used to provide incorporation for the granules. Cultivation applications were applied by directing the insecticide at the base of the plants and covering with soil. Evaluations were made by digging 5 roots/rep for each treatment on 20 Jul. Roots were washed and rated for corn rootworm feeding damage by using the Iowa 1-6 damage rating scale. Corn in these tests was grown under furrow irrigation. Irrigation began about Jun 20-25. The soil in this area is a sandy loam with low organic matter content (0.5-1.5%) and high pH (7.1-7.7).

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Novelli, Viviana Iris, Raffaele De Risi, Ignasio Ngoma, Innocent Kafodya, Panos Kloukinas, John Macdonald et Katsuichiro Goda. « Fragility curves for non-engineered masonry buildings in developing countries derived from real data based on structural surveys and laboratory tests ». Soft Computing 25, n^o 8 (18 février 2021) : 6113–38. http://dx.doi.org/10.1007/s00500-021-05603-w.

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AbstractMalawi is located within the southern branch of the active East African Rift System, where earthquakes of moment magnitude (Mw) 7.0 or greater can occur along major faults. The majority of dwellings in the country are non-engineered unreinforced masonry constructions, built by local artisans with little input from engineers. These constructions are highly vulnerable to seismic events due to poor-quality materials and lack of construction detailing. This study presents a new methodology to assess the seismic fragility curves of typical dwellings located in the Central and Southern Malawi. On-site inspections of buildings are carried out to assess geometrical and structural features of 646 façades, and an experimental campaign is performed to characterise the mechanical properties of local construction materials. The collected data allow the identification of different building typologies in terms of quality of materials and construction techniques. The critical failure modes for each of the inspected façade at their ultimate limit state are evaluated analytically. Damage limit states are defined and adopted to derive simplified Static Push-Over (SPO) curves, transformed into incremental dynamic analysis (IDA) curves by using SPO2IDA. The IDA curves are then used to obtain fragility curves for the specific damage limit states. The fragility curves presented herein are the first to be calculated for these building typologies, based on local data, and unfortunately, they show that buildings in Malawi are far more vulnerable to earthquakes than estimated from previously available international reference data. The fragility curves developed in this study may prove useful for assessing the seismic risk of these building typologies in Malawi and other East African countries.

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FOWKES, NEVILLE, STEVE DURKIN et ANDREW P. BASSOM. « TRUCK SAFETY BARRIERS FOR MINING SITES ». ANZIAM Journal 59, n^o 1 (juillet 2017) : 35–50. http://dx.doi.org/10.1017/s1446181117000281.

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Safescape is a Western Australian company that has recently developed a device for improved safety in open-pit mines. Serious accidents can occur when large trucks veer off the roads running around the edge of the mine. The conventional technique to mitigate the risk is to pile waste rock to form a so-called bund on the edge of the road. This method is not fail safe though as vehicles can, and do, drive completely over the bund. In this paper, we describe a new device that consists of a row of filled polyethylene shell units which are linked together and sit on the road side of the rock bund. The vertical front face of the edge protector prevents out of control dump trucks from climbing over the bund and into the pit, so that they push against the barriers and heave the broken rock behind the bund. The models developed here suggest that the primary resistance to an impacting truck is provided by the large heaving force with the barrier simply facilitating this process. The theory indicates that the total resistance is independent of truck speed, meaning that simple barrier pushing experiments are sufficient to validate the analysis. The conclusions of the theory and field tests suggest that in a worst-case scenario involving the normal impact of a 500 tonne filled dump truck, the barriers and bund move a few metres before coming to rest.

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Prashanth, T. Guna Durga. « Electrodynamic Tethering : An Energy Source for Satellite ». International Journal for Research in Applied Science and Engineering Technology 9, n^o 10 (31 octobre 2021) : 360–74. http://dx.doi.org/10.22214/ijraset.2021.38361.

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Abstract: There is a tremendous force interest for the satellites which the nations have been utilizing over a long time for correspondence, spying, tests, analysis, etc; and tracking down an elective energy hotspots for satellite has been a major undertaking that must be settled as quickly as time permits and electrodynamic tie situation can be the ideal decision for the force supplanting framework. The current existing strategies are somewhat more established, fusy and should be changed for expanded use office of a satellite. Electrodynamic ties are long, dainty conductive wires which are conveyed in space appended to the plasma bend generator of the satellite framework and can be utilized to create power by eliminating the motor energy from their orbital movement, or to deliver push while adding energy from an on board source. regardless , the frictional or push power is created electrodynamically , through the communication between the moving charges only the electrons of the ionospheric plasma and the attractive field of earth. Electrodynamic ties work by temperance of the power an attractive field applies on a current conveying wire which is only the lorentz power. Generally, it is a shrewd method of getting an electric flow to stream in a long directing wire that is circling Earth, so that world's attractive field will apply a power on and speed up the wire and thus any payload appended to it. By switching the bearing of current in it, a similar tie can be utilized to de-circle old satellite and once again circle them if necessary under the fundamental circumstances. Electrodynamic ties have solid potential for giving propellant less impetus to rocket in low-Earth orbit(LEO) for applications, for example, satellite deorbit circle boosting, and station keeping. The tie, in any case, is anything but an unbending pole held above or beneath the rocket. Keywords: Electrodynamic, Ionospheric plasma, LEO, Tethers, Deorbit, Reorbit, plasma arc generator.

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Maitland, Scott B., Paula Brauer, David M. Mutch, Dawna Royall, Doug Klein, Angelo Tremblay, Caroline Rheaume, Rupinder Dhaliwal et Khursheed Jeejeebhoy. « Evaluation of Latent Models Assessing Physical Fitness and the Healthy Eating Index in Community Studies : Time-, Sex-, and Diabetes-Status Invariance ». Nutrients 13, n^o 12 (26 novembre 2021) : 4258. http://dx.doi.org/10.3390/nu13124258.

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Accurate measurement requires assessment of measurement equivalence/invariance (ME/I) to demonstrate that the tests/measurements perform equally well and measure the same underlying constructs across groups and over time. Using structural equation modeling, the measurement properties (stability and responsiveness) of intervention measures used in a study of metabolic syndrome (MetS) treatment in primary care offices, were assessed. The primary study (N = 293; mean age = 59 years) had achieved 19% reversal of MetS overall; yet neither diet quality nor aerobic capacity were correlated with declines in cardiovascular disease risk. Factor analytic methods were used to develop measurement models and factorial invariance were tested across three time points (baseline, 3-month, 12-month), sex (male/female), and diabetes status for the Canadian Healthy Eating Index (2005 HEI-C) and several fitness measures combined (percentile VO2 max from submaximal exercise, treadmill speed, curl-ups, push-ups). The model fit for the original HEI-C was poor and could account for the lack of associations in the primary study. A reduced HEI-C and a 4-item fitness model demonstrated excellent model fit and measurement equivalence across time, sex, and diabetes status. Increased use of factor analytic methods increases measurement precision, controls error, and improves ability to link interventions to expected clinical outcomes.

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Liu, Huan, Yumeng Cheng, Xiaoqing Wang, Frédéric Francis, Qian Wang, Xiaobei Liu, Yong Zhang et Julian Chen. « Biochemical and Morphological Mechanisms Underlying the Performance and Preference of Fall Armyworm (Spodoptera frugiperda) on Wheat and Faba Bean Plants ». Insects 13, n^o 4 (23 mars 2022) : 317. http://dx.doi.org/10.3390/insects13040317.

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Spodoptera frugiperda (J. E. Smith), which attacked China in 2019, remains a significant threat to wheat production. Wheat–faba bean intercropping systems prevent damage caused by wheat aphids; however, the potential role in S. frugiperda control remains unclear. Here, the adaptability and preferences of S. frugiperda to wheat and its common intercropped plant, faba bean, were evaluated to implement an eco-friendly approach for S. frugiperda management. Their adaptability showed that both hosts could support S. frugiperda to complete their life cycle; however, the larvae performed worse on faba bean compared with on wheat. The biochemical analysis revealed that faba bean plants had lower contents of soluble sugars and total proteins but higher levels of phenolics and tannins than in wheat leaves. The gravid S. frugiperda preferred (during the preference assays) to oviposit on wheat rather than on faba bean plants in cage tests. The wheat odor was preferred over the faba bean odor in the Y-tube olfactometer bioassays. The morphological scanning electron microscopy (SEM) showed increased trichome density on wheat leaves. Therefore, the faba bean plants displayed antibiosis on larvae and were repellent to female moths, thus, suggesting that faba bean plants could serve as a push crop to be intercropped with wheat for S. frugiperda control for wheat fields.

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Silva Santos, Marta, Francisco José Vera-Garcia, Leury Max Da Silva Chaves, Leardro Henrique Albuquerque Brandão, Danilo Rodrigues Pereira Da Silva et Marzo Edir Da Silva Grigoletto. « Does core exercises important to functinal training protocols ? » Revista Andaluza de Medicina del Deporte 11, n^o 4 (5 décembre 2018) : 240–48. http://dx.doi.org/10.33155/10.33155/j.ramd.2018.02.002.

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Objective: Our aim is to analyze the effects of 12 weeks of functional training with and without core exercises on core functional and performance indicators. Method: This is a three-arm randomized controlled trial, which will take place over 12 weeks. Participants will be randomly grouped into three training programs, namely: functional training group, which will perform global, multi-articular, and functional exercises, with no exercises for the core; functional training + core group, which will perform a similar protocol to the functional training group, but with the inclusion of specific exercises for the core region; and core training group, which will only perform specific exercises for the core. In both moments, tests will be carried out in the following order: McGill's torso muscular endurance test battery, unilateral hip bridge endurance test, sit up test, isometric dead lift, push up, sit to stand, functional movement screen, handgrip test, countermovement maximal vertical jump test, one repetition maximum in bench press, row and leg press, T- run agility test, Yo-Yo test. Discussion: These findings will provide new evidence to aid physical education professionals in decision-making regarding exercise prescription. Conclusion: We hypothesize that the inclusion of exercises specifically targeting the trunk in functional training protocols will lead to higher functional and core performance

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Seracino, R., D. J. Oehlers et M. F. Yeo. « Behaviour of Stud Shear Connectors Subjected to Bi-Directional Cyclic Loading ». Advances in Structural Engineering 6, n^o 1 (janvier 2003) : 65–75. http://dx.doi.org/10.1260/136943303321625748.

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Almost all stud shear connectors in composite steel-concrete bridge beams are subjected to bi-directional cyclic loading at some stage during the fatigue life of the structure. In the assessment of an existing structure, it is desirable to predict the extent of fatigue damage experienced by the stud shear connectors as accurately as possible as this component of the structure can not be visually inspected. However, very little research has been carried out to quantify the fatigue behaviour of stud shear connectors subjected to bi-directional cyclic loading. This paper presents a new push-pull specimen that was developed to provide a better understanding of the bidirectional cyclic fatigue behaviour of stud shear connectors. The tests confirmed that for a given range of load, the fatigue life of connectors subjected to bi-directional cyclic loading is longer than those subjected to unidirectional loads only, and that the strength and stiffness of the connectors reduce immediately upon cyclic loading and continues to do so throughout the fatigue life. It was also shown that the rate of increase in slip per cycle is constant over most of the fatigue life with a rapid increase near the end so that, if monitored, can be used to provide adequate warning of failure.

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Wild, JP. « Reminiscences ». Australian Journal of Physics 47, n^o 5 (1994) : 497. http://dx.doi.org/10.1071/ph940497.

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I would like to take up something that John Whiteoak said at the symposium yesterday in relation to Cowra or Parkes as the possible site for the 64-m telescope. In my memory, what really happened was that E. G. (Taffy) Bowen was determined to locate the telescope on the Nepean River near Camden. It would have been a very beautiful, but very noisy site, and most people were resigned to having the telescope there. But I argued very strongly that it should go 'over the mountains'. Taffy was good enough to arrange a meeting of radio the result that a group, an unlikely team consisting of B. Y. (Bernie) Mills, W. N. (Chris) Christiansen and me, set out to look for an alternative site, and we finished up at Cowra. We were going to recommend Cowra but Chris had second thoughts, and said he would like to push on a little further-and he found this magnificent site near Parkes. So it was really Chris's discovery. was left to Kevin Sheridan, Frank Gardner and me, with the aid of a low-flying aircraft, to do some tests to make sure that the site did not suffer from interference from industrial noise from the town of Parkes itself.

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