Texas A&M University-Kingsville: AKM Digital Repository
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Coupling of coastal hydrodynamic-wave model and groundwater flow model to simulate storm surge and sea level rise impacts on groundwater flooding
No full textStorm surge events combined with waves, tidal variations and sea level rise, influence groundwater flooding, the rising of groundwater from underground into the surface. Groundwater flooding occurs when there is an unusual high increase of the groundwater levels and/or flow rates. During a storm surge, high tide combined with heavy rainfall and high aquifer porosity usually causes groundwater flooding in coastal urban areas. This flooding can last several days creating impacts for communities and individuals, damaging private properties and destroying public infrastructures. Various models have been developed to understand the tide-induced groundwater dynamics in coastal aquifers, however, limited research has been conducted on the impacts of storm surge combined with sea level rise and rainfall to groundwater flooding. In addition, based on our knowledge, none of these studies have validated the results with field observed data.
A new modeling approach was developed in this study to understand and simulate the storm surge and sea level rise impacts on groundwater flooding. Storm surge events were modeled utilizing meteorological, hydrodynamic and wave simulation capabilities. The Delft3D modeling system was employed as the model platform to simulate the coastal hydrodynamic characteristics and wave effects. Groundwater flooding was simulated by integrating the Delft3D with a variable-density groundwater flow model, MODFLOW.
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The fully integrated model was applied to South Florida specifically to the City of Miami Beach area. The City of Miami Beach was selected as the study area since it is a region where groundwater flooding is often occurring during high king tide and field data has already been collected for this area. Vertical groundwater flooding often occurs in Biscayne aquifer in South Florida due to its characteristics and increase in the groundwater levels combined with other factors such as heavy rainfall.
Simulation results demonstrated the contribution of waves to water level variations and storm surge flooding. Model simulations show that higher levels of wave height result in higher levels of groundwater elevation. This study also demonstrated the influence of local morphology and bathymetric changes on water level variations and groundwater flooding. In addition, model results from this study showed the combined effects of sea level rise and storm surge on groundwater flooding. The new modeling approach developed in this study provides more accurate simulation results and a better understanding of the costal hydrodynamic effects on groundwater flooding
A Snellen chart technique study of visual acuity of the Spanish culture pupils in the Stephen F. Austin Public Elementary School, Kingsville, Texas
No full textIn this study visual acuity is defined as the distinctness of vision or the resolving power of the eye. (9,345) This study was initiated for the purpose of ascertaining the visual acuity of the pupils of the Stephen F. Austin Schoo1. The devices used in determining this acuity will be discussed in some detail later in this report.
The importance of eye sight among school children cannot be over-estimated. Of all the sense organs the eye is the means most frequently used by the school child in collecting information or in otherwise enriching his experience. (31,3) Moreover, the hygiene importance of the eye is a continuing one, for during the first few years of school life the child's eyes are still in the process of development. As long as the school gives the eye the major roll of fact finding so long will school leaders find it essential to make eye health a major consideration of the school program. School tasks involve continuous demands on the eyes and it is out of the pupil performance of these tasks that eye habits are developed
Performance analysis of 7NM FinFET based 6T sram cell - transient and DC analysis
No full textThe semiconductor industry has been able to grow faster and denser devices due to complementary metal oxide semiconductor (CMOS) technology scaling. However, the perpetuated trend of downscaling the transistors led to an increment in Short Channel Effects (SCE). This was surmounted by utilizing FinFET devices, which have minimized SCEs, low leakage current, and better performance, due to their increased gate control compare to bulk CMOS.The primary goal of this study was to assess the reliability, stability, and throughput of a 6T Static Random Access Memory based on a 7nm FinFET predictive technology model (PTM). SRAMs are critical devices widely used in almost every microelectronic device like high performance servers, low-power biomedical devices etc. In this thesis, the read and write stability, and average power of the 6T SRAM cell was analyzed. This study looks at a 6T SRAM cell with a 2:4:2 ratio of the pull-up, pull-down, and pass gate transistors, respectively. Transient and DC analysis was performed at 0.7V and 1V VDD keeping the same PU:PD:PG ratio. Read, write and hold static noise margin was evaluated using butterfly curve. For the PU:PD:PG (2:4:2) ratio, the effects of supply voltage modulation on various DC metrics were tabulated. The average power of a 6T SRAM cell at 1V VDD was almost 2X greater than the SRAM cell at 0.7V VDD, according to this research. SRAM with 1V supply voltage has a better static noise margin. Read current and leakage power increment was seen with an increase in the supply voltage. A minimum read delay of 1.47ps was obtained at 0.8V and a minimum write delay of 41.7ps was obtained at 0.7V VDD. It was observed from the simulations that the functionality of SRAM was retained with a minimum 1RC pulse wave when fed into the WL, beyond which it lost its functionality
Comparative study of different manufactuers with respect to their supply chain management
No full textSupply Chain Management is the networking and supervision of business practices across the various organizational structures that form the supply chain. It is presumed that different manufacturing industries have individualized ways of measuring their supply chain key performance indicators, and these KPIs differ based on the types of industries, the product and services they offer, supply chain structure and supply chain challenges. The areas of interest in data collection are how their key performance indicators are evaluated, their supply chain operation processes, strategies and how the key variables influence the supply chain performance. By comparative analysis, the results indicated similarities between the supply chain management processes, strategies and KPIs evaluation method between the furniture manufacturing industry and automotive engine industry. Employing various tables, charts, and ordinary least square regression model, with the aid of IBM Statistical Package for Social Sciences (SPSS), this research shows that the two key variables, Lead time and Inventory level affect the supply chain system’s performance
Nilgai movement ecology: implications for management of Cattle Fever Ticks in South Texas
No full textOne of the most significant vector-borne diseases of livestock worldwide is bovine babesiosis, spread by cattle fever ticks (CFT), Rhipicephalus (=Boophilus) microplus and R. (B.) annulatus. The disease and its one-host vector were introduced to the Americas on livestock in the 16th century. Although CFT were eradicated from the U.S. by 1943, bovine babesiosis is endemic in Mexico. Periodic trans-border outbreaks of CFT still occur in parts of South Texas and pose an ongoing threat to the U.S. cattle industry. The U.S. government maintains a permanent quarantine zone along the southern border to prevent re-infestation from Mexico. Wildlife, including introduced nilgai antelope (Boselaphus tragocamelus), are suitable alternate hosts and can disperse CFT from infested areas. Nilgai are abundant (over 30,000 free-ranging individuals), and make long-distance movements. There are currently no methods to treat nilgai for CFT. Nilgai do not respond to traditional treatment options such as medicated feed; furthermore, little is known about nilgai ecology in South Texas or their native range in India and Pakistan. I monitored 30 GPS-collared nilgai (F=19, M=11) in Cameron County, Texas, USA, from April 2019–March 2020 to better understand: 1) nilgai movement and behaviors, 2) nilgai habitat selection in South Texas, and 3) fence-crossing behavior by nilgai. I observed movement patterns consistent with residency (56.7%), use of seasonal ranges (23.3%), nomadic movements (13.3%), and dispersal (6.7%). Overall, nilgai had large and highly variable home ranges. Annual median home range estimate were 593 ha (range = 105–1,545) and 937 ha (range = 221–1,602) for females and males, respectively. Nilgai selected for woody and mixed cover habitats (suitable tick habitat) regardless of season or sex. Nilgai cross livestock fencing, which may move ticks onto adjacent properties, but crossing sites may be re-visited, presenting an opportunity for treatment via remote sprayers. Movement data suggested that during the year 17/30 nilgai crossed a fence > 1 time per month, 9/30 nilgai had ≥ 1 month with 0 fence crossings, and 4/30 nilgai left the study area. Using trail camera photos to identify crossing events at monitored sites, collared nilgai were captured crossing a fence 63 times, consisting of 17/30 individuals. The movement behaviors and ecology of nilgai challenge the sustainability of CFT eradication efforts in the U.S. Understanding how host species use the landscape can aid in the creation of a more effective cattle fever tick eradication plan for South Texas. This is key information the Cattle Fever Tick Eradication Program can use to adapt new technologies to treat infestations in nilgai
Tagging the fruitless gene in a genomic context: a novel method for cell biology and biochemistry
No full textIn Drosophila melanogaster, the fruitless gene products (Fru) determine male courtship behavior and sexual orientation. The gene encodes a triad of zinc-finger nucleic acid binding factors, but how these products regulate behavior remains a mystery. To study their functions, two plasmid constructs were built to encode a protein tag (SNAP-tag) and inserted into the fruitless gene locus to allow for simple Fru purification. One construct may help elucidate the masculinization targets of the fruitless isoforms, while the other construct was built to determine which molecules bind to the fruitless protein itself, possibly revealing how it is modulated. SNAP-tag technology may also be used to uncover the mechanisms underlying human disease. Dysfunction of the expanded polyglutamine protein (polyQ) in Huntington's disease is poorly understood. To determine how protein expansion alters cellular function, two SNAP-tag constructs were built and inserted into the fruitless locus. These novel tools were designed to express disease-state human polyQ domains with the SNAP-tag in fruitless isoforms. Purification may show what macromolecules interact with the expanded regions of the Huntingtin protein, which could be a small step forward in the understanding of the disease
A study of crack widths of concrete structures reinforced with glass fibers reinforced plastic rebars at elevated temperatues
No full textFiber reinforced polymer (FRP) reinforcing bars have been used where corrosion of steel is a major problem. The use of FRP for construction is gaining popularity among design professionals due to its inherent characteristics over regular concrete designs. Elevated temperature together with inadequate bond strength of FRPs produce enhanced crack widths. Unfortunately, no clear guidelines are available for serviceability of FRP reinforced concrete structures exposed to practical elevated temperature. In an attempt to get some practical procedures, this research illustrates the fundamentals of direct flexural crack control for the serviceability design of concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars at practical elevated temperatures. American Concrete Institute (ACI) code is selected as a starting point to develop an appropriate model for predicting the direct crack widths at elevated temperatures. A basic finite element model of commonly used simply supported rectangular beam in bending with varying cover at elevated temperature was developed along with fracture mechanics to verify the effectiveness of the crack width model. In addition, comparison is also made with an indirect reference to the real behavior of the material. A good first insight into crack widths at elevated temperature is observed from these models
Susceptibility of commercial cotton Gossypium hirsutum to bacterial blight Xanthomonas citri pv. malvacearum
No full textBacterial blight of cotton, caused by Xanthomonas citri pv. malvacearum (Xcm), is a pathogen of concern in cotton production. Bacterial blight of cotton causes leaf defoliation and boll shed which results in yield loss. Bacterial blight has been controlled effectively for more than 50 years by breeding for host plant resistance, however recent outbreaks of the disease have raised concerns amongst growers and scientists about the possible development of new Xcm races that could cause disease in commercially available resistant varieties. The objectives of the study were to evaluate infection of eleven commercial cotton varieties to determine their resistance or susceptibility to the bacterial blight infection and to evaluate the most efficient and reliable inoculation method to conduct greenhouse and field evaluations. Cotton plants were inoculated with Xcm (prospective race 18) isolated from Texas cotton fields in the Fort Bend and Wharton County areas in 2015. Research was conducted during from April 2017 to September 2018 at the Texas A&M University – Kingsville research farm and greenhouse facilities. Treatments included spray application of bacterial suspension at 106 per ml, coupled with mechanical wounding and the use of the organosilicone non-ionic wetting agent, Silwet L-77® (0.25% v/v) (wounding vs no wounding, then the addition of Silwet L-77® to enhance infection). To evaluate the inoculation technique, plots were rated for disease incidence and severity 7 days post inoculation (DPI) and for variety resistance trials 7, 14, and 21 DPI. Results show that there was a significant increase of disease incidence when Silwet L-77® was used compared to the no Silwet L-77® treatment. However, wounding did not increase the disease incidence of seedlings. The no wounding with Silwet L-77® technique was used for the variety resistant trials. Results indicate that varieties known to be resistant were resistant and those known to be susceptible were susceptible against Xcm. Susceptible varieties had up to 100% more disease incidence than those resistant ones. The results found in this study indicate that the commercial cotton varieties tested remain resistant to Xcm. More studies need to be conducted to evaluate the development of new Xcm races that may challenge the resistance to cotton bacterial blight
Iris liveliness detection using transfer learning on small cyber dataset
No full textIris recognition is one of the most popular and secure physical biometric identification methods, that have been realized to date. It is largely used in several applications nowadays, therefore, iris presentation attack detection (PAD) is of prime importance. This research features liveliness detection in which spoof (paper-printed) iris images are distinguished from real ones. The key challenge in this research was the utilization of small dataset in training a deep convolution neural network (CNN) to achieve maximum accuracy. Although deep CNNs are immensely popular and successful in solving computer vision and pattern recognition problems but, with small datasets it is highly probable to overfit data. To solve this problem, this research makes use of a popular machine learning technique, transfer learning, for iris liveliness detection. It utilized MobileNets architecture [1] pre-trained for object detection, reused it for iris liveliness detection by manipulating the model to properly identify specific biometrics. It was achieved by retraining the last layer with small iris dataset. Necessary changes in the model's hyperparameters and feature vectors were made for iris liveliness detection. High accuracies were achieved. This technique will provide a gateway into security features that are being adopted in modern technology and prevention of attacks improving cybersecurity, even with a limited amount of resources (data) to begin with
Human motion imitation robot
No full textFor many years, the field of robotics has been bedeviled by a fundamental problem: If a robot can be teleported through the world, it needs to be able to generate virtual world and understand its place within it. Roboticists have developed tools to accomplish this task, known as simultaneous localization and mapping, or SLAM. But the sensors required to build that map have traditionally been either expensive and bulky or cheap and inaccurate. Laser arrays cost a few thousand dollars and weigh several pounds, and the images they capture are only two-dimensional. Stereo cameras are less expensive, lighter, and can construct 3-D maps, but they require a massive amount of computing power. Until a reasonably priced easier method could be designed, autonomous robots were trapped in the lab. Therefore, the presented research is chiefly concerned with developing a low-cost, easy to use wirelessly tele-operated 4 DOF robotic arm with motion characteristics similar to a human arm. It presents an overview on the optimum utility of the Gesture Replicating Robotic arm functioning. A detailed discussion of each concept involved in the process is presented. This research will avoid long coding process to perform a simple task which humans can do it easily like pouring water into a glass