Influence of Mechanical Layering and Natural Fractures on Undercutting and Rapid Headward Erosion (Recession) at Canyon Lake Spillway, Texas, U.S.A

This study investigates the role of mechanical layering and fractures on flood-related erosional undercutting and resulting rapid spillway recession. In the summer of 2002, 86 cm of rain fell in an 8-day period across the Guadalupe River drainage basin in central Texas, causing Canyon Lake reservoir to completely fill and overtop the emergency spillway for the first time. The resulting flood incised a gorge into the mechanically layered Glen Rose Formation and caused headward erosion (recession) at the downstream edge of the emergency spillway. Comparison of pre- and post-flood imagery and assessment of flood records indicates that maximum recession localized at the northern end of the emergency spillway where 28 m recession occurred. This recession occurred at an estimated rate of up to 10 m/day during the first ~3 days of the flood, which is among the highest rates of recorded bedrock recession. Analysis of historical photographs, field observations and measurement of erosional undercutting, along with measurements of fracture orientation, fracture spacing, and mechanical rebound are used to understand rock mass characteristics that influenced erosional undercutting and rapid recession of the spillway. Evidence of significant undercutting was observed where incompetent argillaceous wackestone (marl) underlies competent limestone. These results reveal that the greatest amount and rate of recession of the spillway was associated with undercutting and toppling collapse of fracture-bounded limestone blocks. Block size may be a factor in continuation of the process, in that large blocks may accumulate at the base of the scarp and inhibit continued erosional undercutting, whereas in other areas smaller eroded blocks can be carried away by the floodwaters and undercutting may continue, facilitating recession. The combination of mechanical contrast between layers and natural fractures in competent layers together contributed to exceptionally high rates of headward erosion. Observed rock mass erodibility behavior was in the range of medium to high erodibility in limestone with widely spaced fractures that would normally be expected to have very low erodibility. Bulk rock mass erodibility in this situation was similar to the most erodibile layer, specifically, the marl at base of spillway pour-off cliff

A comparison of academic achievement and retention of community college students in college algebra after completion of traditional or technology-based instruction

This study was designed to compare the success rates in College Algebra between two groups of students attending a Mississippi community college. Eighty students enrolled in a College Algebra course were taught using traditional instructional techniques, and 70 students received technology-enhanced instruction. This study considered the effects of grade scores on a mathematics-achievement pretest and posttest, student attitudes toward mathematics, time-on-task while using technology during mathematics study, mathematics subscores on the American College Test, and withdrawal rates. Data collected for this study were derived from the official transcripts of students enrolled in spring 2007 College Algebra classes of a Mississippi community college serving as the study site. A total of 150 students participated in the study. Statistical analysis included t tests, chi-square tests, Pearson product-moment correlations, and analysis of covariance to examine relationships between the two groups of students. The results indicate that the students who received College Algebra instruction via technology-based methods learned equally as well as the students who received the same instruction via traditional methods. The findings also indicate that the students who participated in the traditional College Algebra course had improved attitudes toward mathematics upon completion of the semester. With regard to those who participated in the technology-based College Algebra course, the amount of time devoted to technology use during mathematics study did not correlate to their final grades (i.e., grades were not higher as this expenditure of time increased)

An analysis of systems that train and release servant leaders for the edification of the church and the evangelization of the world

https://place.asburyseminary.edu/ecommonsatsdissertations/1228/thumbnail.jp

An Analysis of the Modern Mathematics Program in Grades Four Through Eight of the Cashmere School System

The purpose of this study was to analyze the modern mathematics program of the fourth through eighth grades of the Cashmere School District, Cashmere, Washington

Buzzwords, bureaucracy, and badges: an ethnographic exploration of how versions of wellbeing are constructed through social ideology projects in a UK police organisation

Buzzwords, bureaucracy, and badges: an ethnographic exploration of how versions of wellbeing are constructed through social ideology projects in a UK police organisatio

Development of the technology for the fabrication of reliable laminar from control panels

Materials were assessed and fabrication techniques were developed for use in the manufacture of wing surface materials compatible with the application of both aluminum alloys and nonmetallic composites. The concepts investigated included perforations and slots in the metallic test panels and microporosity and perforations in the composite test panels. Perforations were produced in the metallic test panels by the electron beam process and slots were developed by controlled gaps between the metal sheets. Microporosity was produced in the composite test panels by the resin bleed process, and perforations were produced by the fugitive fiber technique. Each of these concepts was fabricated into test panels, and air flow tests were conducted on the panels

A Community Health Outreach Project Focused on Developing and Implementing a Culturally Competent Tobacco Cessation Education Toolkit

Tobacco use disorder is a public health problem with a heavy economic burden as tobacco users are more likely to suffer from premature death and debilitating diseases. Literature supports clinicians engaging their patients in smoking cessation conversation with each visit. However, the lack of appropriate training as well as the lack of a handy toolkit on smoking cessation makes this difficult. The challenge of engaging in smoking cessation conversations is more apparent with specific vulnerable populations such as the underserved community of East St Louis. This DNP project utilized evidence-based guidelines with best practice research, the Five A\u27s framework, and cultural competence to create an educational PowerPoint training for the staff at the We CARE Clinic in East St. Louis. In addition, the project involved the development of an educational pamphlet to engage with patients and provide education. The Staff was surveyed utilizing pre- and post-implementation surveys to test the effectiveness of our education on assisting the staff in engaging their patients on smoking cessation. On the post-test, 100% of respondents agreed they feel comfortable initiating a culturally competent conversation using the Five A\u27s framework compared to 40% on the pre-test. While limitations included a small respondent pool of five, this data shows a favorable result of the toolkit and the potential for further project expansion