Predicting current compressive strength of concrete based on non-destructive testing by way of sound

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaf 27).There are many ways to test the compressive strength of concrete to include both destructive and non-destructive methods. There are many pros and cons associated with the various methods of testing to include cost, size, and method associated with each piece of equipment. The most common types of testing are the hydraulic compression test, the rebound test, and the maturity test. An alternative method proposed that would give individuals another means to test concrete in a non-destructive manner. The purpose of this research is to determine the current compressive strength of concrete by analyzing the acoustic pattern of a sound made by a hammer striking the surface of a concrete cylinder in a lab environment. Concrete cylinders were made in the traditional fashion and the sound generated when a ball-ping hammer strikes the cylinder was recorded then analyzed. The cylinders were tested on a daily basis and their compressive stress was recorded. Linear regression was used to try and predict the compressive strength of the concrete cylinders. The regression model chosen using the stepwise selection method could only account for 43% of the variation in the compressive strength. The duration of the sound wave was the best predictor of the compressive strength

Differences Between Self-Efficacy and Course Engagement Scores Among Postsecondary Academic Cohorts of Athletic Training Students

Athletic Training Students’ (ATS) self-efficacy and course engagement during their educational development and clinical experiences influence their ability to provide proficient health care for physically active individuals. The various classifications of postsecondary academic cohorts of ATS enrolled within Commission on Accreditation of Athletic Training Education (CAATE) accredited postsecondary Athletic Training Programs (ATP) portray divergent levels of self-efficacy and student course engagement. The purpose of this research study was to investigate differences between perceived self-efficacy and course engagement scores among postsecondary academic cohorts. A quantitative, causal-comparative research study employed two survey instruments: The College Academic Self-Efficacy Scale (CASES) developed by Owen and Froman (1988); and the Student Course Engagement Questionnaire (SCEQ) developed by Handelsman, Briggs, Sullivan, and Towler (2005). This study included a convenience sample of 112 participants (N = 112; male, n = 29; female n = 83) enrolled in a CAATE-accredited postsecondary ATP within the Mid-Atlantic Athletic Trainers’ Association (MAATA). A one-way multivariate analysis of variance (MANOVA) was used to determine significant differences in composite mean scores on the CASES and the SCEQ among the postsecondary ATS academic cohorts. The results of the one-way MANOVA were not significant, and the null hypothesis failed to be rejected at the 95% confidence level (alpha level of 0.05), where F(6, 214) = 1.389, p = 0.220, Wilks\u27 Λ = 0.926; partial η2 = 0.037, suggesting there are no significant differences on the dependent variables (CASES and SCEQ) among the independent variable (academic cohorts of athletic training students). The effect size as measured by partial eta squared was medium (η2 = 0.037). Implications from this study suggest the importance of student course engagement and self-efficacy as they progress throughout the ATP. In addition, athletic training faculty’s emphasizing the need for mentoring academic cohorts toward successfully achieving self-efficacy and course engagement within students’ academic coursework and clinical education experiences. Recommendations for further research studies were made

A Beautiful Lady In Blue

Illustration of lady in blue dresshttps://scholarsjunction.msstate.edu/cht-sheet-music/6634/thumbnail.jp

Spatial, temporal, and tri-trophic distribution of imidacloprid, olefin and 5-hydroxy and their effect on hemlock woolly adelgid, Adelges tsugae Annand, (Hemiptera: Adelgidae).

Extensive mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) (HWA), has occurred throughout the eastern United States. Imidacloprid, a systemic insecticide, is used to control hemlock woolly adelgid. The metabolism of imidacloprid in eastern hemlock produces two metabolites of toxicological interest, olefin and 5-hydroxy. The objectives of this study were to 1.) determine the distribution and persistence of the metabolites in eastern hemlock in the southern Appalachians, 2.) their effect on hemlock woolly adelgid mortality, 3.) assess the tri-trophic movement of these compounds, 4.) evaluate the effects of hemlock woolly adelgid infestation levels on water stress, and 5.) assess the use of near-infrared spectroscopy for predicting imidacloprid concentrations in needle tissue. Imidacloprid and 5-hydroxy concentrations in sap was highest at 12 months post-treatment and in twig and needle tissue was highest at 15 months post-treatment. Imidacloprid was detected through month 36 post-treatment and 5-hydroxy was detected through month 15 post-treatment. Olefin concentrations progressively increased in both sap and twig and needle tissue through month 36 post-treatment. Concentrations of imidacloprid were highest in the bottom stratum of the canopy and lowest in the top stratum. Concentrations of olefin and 5-hydroxy were highest in the top stratum and lowest in the bottom stratum. A significant relationship was found between imidacloprid concentrations \u3e 158 ppb and olefin concentrations \u3e 7 ppb and hemlock woolly adelgid mortality greater than 80% in field studies. In dose-response tests imidacloprid concentrations greater than 131 ppb and olefin concentration greater than 7 ppb were associated with high levels of hemlock woolly adelgid mortality (\u3e 80%). Tri-trophic movement of imidacloprid and olefin was documented through 2 years post-treatment. The highest level of water stress was found in those trees with hemlock woolly adelgid infestation levels greater than 75%. The lowest level of water stress was found in those trees with less than 25% hemlock woolly adelgid infestation levels. Near-infrared spectroscopy results indicate that it can be used to predict concentrations of imidacloprid in needle tissue

Tumble In A Rumble Seat

Automobile driving down road with trees and smiling moon in backgroundhttps://scholarsjunction.msstate.edu/cht-sheet-music/11330/thumbnail.jp

Get-Out-The-vote (GOTV) Targeting and the Effectiveness of Direct Voter Contact Techniques on Candidate Performance

In political campaigns the strategic use of resources, including time and money, are often critical in optimizing performance. !twill not always be the difference in winning and losing, but it is often the most important factor in running an effective campaign. Specifically, within field operations, the area in which the campaign directly connects with the voter, and a Get-Out-The-Vote (GOTV) operation, the trade-offs between seemingly miniscule choices can mean the difference in the ultimate success or failure of a political campaign. Using data from the 2010 Lexington Mayoral campaign of challenger Jim Gray, this study evaluates the effectiveness of GOTV targeting using a pro bit model and the individual and overall effectiveness of the field techniques or elements utilized with a liner regression model. Within the pro bit model, there are two dependent variables. The first is the designation by the Jim Gray campaign of precincts as Get Out the Vote target precincts. Of 285 precincts with this information, 105 were so designated. The second is the change in the percentage of votes received by Jim Gray in the runoff. The linear regression has five measures for field operations: Staff/Volunteer canvass, paid employee canvass, staff/volunteer Get Out the Vote activity, paid employee Get Out the Vote activity, and whether a house party was conducted. The pro bit model showed the best predictor of a GOTV target precinct was an Isaac precinct with a predicted effect of 5 percentage points per point of Isaac\u27s primary percentage and a large z score of 6.45 (p\u3c0.001). Closely following the Isaac precinct score, was a Gray primary precinct with a predicted effect of 3.5 percentage points per point Gray\u27s primary percentage and a large z score of 5.92 (p\u3c0.001). On the question of what characteristics tended to make a precinct targeted, the results show very clearly that the precinct being one in which Teresa Isaac was successful in the primary election mattered a lot. This reinforces, on a scientific level, the perception held among informed political observers; that the endorsement of Teresa Isaac had a major impact on her supporters, who did turn out and vote for Jim Gray in the general election. In terms of the effectiveness of the field operations, the results are somewhat surprising, given the review of literature. None of the individual field elements meet the minimum scores for significance, nor did they collectively. The larger take away suggests that voters were going to vote how they were going to vote, regardless of any contact from the campaign

Lubrication and Wear Analysis of a Novel Squeeze Film Artificial Hip Joint

Conventional artificial hip joints are characterized by inadequate `wedge film\u27 lubrication due to cyclic non-reversing loading and low frequency oscillatory ball motion. A novel `squeeze film\u27 design concept is presented which employs elastic restoring action and ellipsoidal cup geometry to enact separation of the bearing surfaces and improve lubrication behavior. Lateral and in-line design configurations were developed and analyzed using established finite element lubrication models with realistic gait cycle and bearing design specifications likely to be found in practice. An Archard-based wear formulation that relates contact pressure and sliding distance to linear wear depth was applied to the design configurations utilizing ANSYS to investigate the wear characteristics of the novel implant design. From a lubrication perspective, it was found that significantly larger minimum film thicknesses and significantly smaller maximum film pressures are predicted over the stance phase when compared with conventional designs, while complete reformation of the lubricant film is predicted over the swing phase of the gait cycle. From a wear perspective, it was found that low-modulus elastic elements with bonded high-modulus metal coatings offer significant improvement in volumetric wear rates and maintain acceptable levels of linear wear rates when compared with conventional implant geometries

Wear Assessment of a Novel Squeeze-Film Artificial Hip Joint

Abstract— This paper investigates the wear characteristics of a novel hip implant design. Key features of the design are elastic elements attached to the cup which provide a mechanical means for ball separation during the swing phase of the gait loading cycle. An Archard-based wear formulation was implemented utilizing the ANSYS finite element analysis program which relates contact pressure and sliding distance to linear wear depth. It is found that low-modulus elastic elements with bonded high-modulus metal coatings offer significant predicted improvement in linear and volumetric wear rates when compared with conventional implant geometries for gait cycle loading and kinematic conditions found in practice