SEEPAGE ANALYSIS OF A ZONED EARTH DAM BY FINITE ELEMENTS

ABSTRACT Seepage analysis of earth dams is one of the major interesting points in geotechnical engineering. The amount of water seeping through and under an earth dam together with the distribution of the water pressure can be estimated by using the theory of flow through porous media which is one of the most valuable analytical tools available to the engineer. In this paper, the finite element method is utilized to solve the governing equations of flow through earth dams. The computer program Geo-Slope is used in the analysis through its sub-program named SEEP/W. Eight node isoparametric elements are used to model the dam and its foundation, while mapped infinite elements are used to model the problem boundaries. A case study is considered to be Al-Adhaim dam which consists of zoned embankment 3.1 km long. The dam at its actual design is analyzed using the program SEEP/W. Then several analyses are carried out to study the control of seepage in the dam through studying the effect of several parameters including the permeability of the shell material and the presence of impervious core and its location and thickness. It was concluded that the presence of clay core has an important effect on decreasing the exit gradient, which may increase in the order of 300% when the core does not exist and the factor of safety may be critical when the water level in the reservoir is at 143.5 m. The sloping core of Al-Adhaim dam is the best design for core than other choices since it permits the lowest values of seepage and provides the lowest exit gradients

Hydrodynamic Analysis of a Wave Energy Converter (WEC)

Honorable Mention Winner The UNF CREW competing in the U.S. Department of Energy 2021 Marine Energy Collegiate Competition developed a Wave Energy Converter (WEC) for quick deployment in disaster relief areas. When natural disasters disable coastal power grids, a WEC can be easily deployed close to shore and serve as a source of electricity. The ocean waves move magnets through a coil wired within the WEC to generate electricity. To initiate the design process, ANSYS AQWA software simulated both the oceanic environment and the device’s response in the WEC’s testing conditions. AQWA allows the user to change device dimensions easily and optimize the design ahead of physical construction. The resulting WEC proof of concept minimized prototype manufacturing waste and cost by eliminating poor designs in advance. The simulated geometry neglected hollow sections and used unidirectional, regular waves to account for software limitations. The software simulated the WEC for 20 seconds in an oceanic environment with a 40-meter depth and a 0.25-meter amplitude regular wave. Simulations produced graphs and animations describing the forces acting on the WEC as well as the WEC’s movement. The animation proved that the WEC reacts well in similar physical testing conditions. Based on the simulation results, the team constructed a 3D model for small-scale testing. Future investigations will involve more complex designs. Research conducted onward will focus on mass-damper systems and contact surfaces provided in the software

Cost Analysis of Osprey C.R.E.W.

Renewable energy adoption is on the rise in the U.S. and abroad. More than ever, energy sourcing needs to shift away from harmful fossil fuels and towards fully renewable energy sources. Adapting from traditional fossil fuel energy sources to renewable energy sources is paramount for environmental health and public health. Fossil fuels emit harmful pollutants, which have led to changing weather conditions and exasperated natural disasters. Existing renewable sources are not ideal, either. For instance, solar cannot run continuously and wind turbines are subject to weather changes. The recent energy debacle in Texas shows the need for alternative renewable energy sources. The Osprey C.R.E.W. wave energy converter (WEC) alleviates many of the current problems existing renewable energy systems cannot solve. First, it provides reliable and constant service. With other renewable energy services, there will be stops in production. However, there are no stops in wave energy because the waves are constant. Another positive of the WEC device is that their deployments are flexible and scalable. This means that energy production levels can be changed rapidly and without delay. The average cost per device falls significantly with seamless scalability, making large increments of devices procured in a relatively cost-effective manner. Cost comparisons between competing energy sources show that the WEC is very cost-efficient as well. The cost of producing wave energy is found to be more efficient than solar energy and wind alternatives. Our cost figures also show that Osprey C.R.E.W provides a very competitive alternative to the primary fossil fuel producers such as coal and fuel

The Physical Activity and Alzheimer's disease (PAAD) study: Cognitive outcomes

Background: Alzheimer’s disease is a progressive disease that degrades cognitive functioning and ultimately results in death. Currently, there is no cure for Alzheimer’s disease and, hence, the identification of preventative strategies is important. Physical activity (PA) is a behavioral intervention that holds promise with respect to delaying the onset of Alzheimer’s disease. Purpose: The purpose of this study was to explore the differential cognitive benefits achieved in response to PA as a function of a person’s genetic risk for AD. Methods: Older cognitively normal adults (50–65 years) with a family history of AD (FHxAD) participated in an 8-month PA program. Cognitive performance was measured at baseline, pretest, midtest, and posttest and changes over time were assessed as a function of apolipoprotein E (APOE) status (carriers: 1–2 copies of the ?4 allele; noncarriers: 0 copies of the ?4 allele). Results: Improvements in memory were associated with PA participation irrespective of APOE ?4 carrier status. Conclusions: Future experimental studies are needed to confirm that PA causes improvements to cognitive performance in older cognitively normal adults with a FHxAD and that these improvements are equivalent for cognitively normal APOE ?4 carriers and noncarriers

Optimization of Power Performance of a Wave Energy Converter

With climate change on the rise, unprecedented dependence on electricity, and an increased incidence of extreme weather, the UNF team participating in the U.S. Department of Energy 2021 Marine Energy Collegiate Competition: Powering the Blue Economy wants to give an alternative solution to provide renewable energy in areas that lose electricity as a result of a natural disaster, or that due to their isolated location cannot use traditional renewable energy sources. This led to the creation of the Osprey C.R.E.W (Cheap Reliable Energy from Waves). The Osprey C.R.E.W. is a wave energy converter that uses the vertical motion of the ocean waves to generate electricity. The principle of energy conversion is Faraday’s Law of Electromagnetic Induction, which states that a magnetic field moving past a conductor will generate electricity. The UNF team has developed a numerical simulation to test how different parameters influence the output and has built three small-scale prototypes that have been tested in a wave tank. A medium-sized prototype and a wave pool are being constructed, with the expectation that the size will also increase the output

Innovative Research Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults

Physical activity is predictive of better cognitive performance and lower risk of Alzheimer’s disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by APOE e4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting APOE e4 carriers are discussed

COVID-19 Pandemic Driven Knowledge, Attitude, Clinical Practice, Distress Reactions, and Post-Traumatic Growth of Dental Care Providers in Riyadh City, Saudi Arabia: A Cross-Sectional Study

Objective: The present study aimed to assess knowledge, attitude, clinical practices, distress reactions, and post-traumatic growth of dentists during the COVID-19 pandemic in Riyadh City. Methodology: An online questionnaire was developed to assess various dental professionals from both governmental and private sectors during the early COVID-19 outbreak in Riyadh City, Saudi Arabia. The questionnaire was framed to assess the demographic variables, knowledge, attitude, and clinical practices towards handling the COVID-19 pandemic. Furthermore, the general anxiety disorder-7 (GAD-7), worry questionnaire items, short form of post-traumatic growth inventory (PTGI-SF), and life satisfaction questionnaire items were developed to assess the anxiety, worries, post-traumatic growth, and life satisfaction of dental care providers following the traumatic events. Data were analysed using SPSS 22.0 and R environment ver.3.2.2. Continuous measurement results were presented as mean ± SD, and categorical measurements results were presented in number (%). Results: Our study's significant findings revealed that a majority of the dentists were in the age group of 21-30 and practiced general dentistry. The study participants in age groups 51–60 and 41–50 years old showed more liability in perceiving COVID-19 as an extremely dangerous disease than 31–40 and 21–30 age groups. The majority of respondents (63.4%) had an anxiety scale score of greater than 40, followed by 22.8% with scores 20-40 and 13.9% with scores less than 20, respectively. The mean scores for the GAD-7 and the worry items were 8.24 ± 3.21 and 13.92 ± 4.77, respectively. The data showed that most survey participants had adopted moderate post-traumatic changes during the pandemic, as evident by their mean score of 34.17 ± 3.40. The life satisfaction of the participants was neutral, as demonstrated by their mean score of 20.16 ± 4.03. Conclusion: This study’s findings delineated that the COVID-19 pandemic situation has influenced dentists' mental health, with a moderate level of anxiety, and worries among other psychological symptoms. Furthermore, there was adequate knowledge regarding the COVID-19 among dentists; however, the pandemic affected the financial conditions of the respondents. There was a moderate level of post-traumatic growth and neutral life satisfaction of the dental providers