Texas A&M University-Kingsville: AKM Digital Repository
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1689 research outputs found
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Numerical simulation on drag reduction in a pipe flow with a patterned riblet surface
No full textThe current study investigates the validation of slip boundary conditions in an internal piping flow comparing no-slip boundary conditions from the classical fluid mechanics with respect to viscous frictional losses occurring at a piping wall. Modifying the surface conditions result in slip boundary conditions that reduce the wall shear stress by the fluid viscosity. Such surface conditions were inspired by the surfaces of fast swimming shark skins, gecko, lotus leaves, etc., and engineers and scientists reported an average of 20% drag reduction obtained for internal flows with trying to mimic the bio-inspired surfaces such as riblets, wall oscillating surfaces, polymer additives, compliant coating, hydrophobic, and superhydrophobic surfaces. As the extensions of these efforts, this study conducted numerical simulation on riblet patterned wall surface to produce slip boundary conditions of an internal piping flow. A numerical approach is performed using commercial software to find slip effects of riblet patterned surfaces on internal pipe walls. Initially, the results from published references were validated by comparisons for no-slip, 95%, 90%, 80% and 50% slip boundary conditions. Then, whole patterned and half-patterned riblet surfaces were designed on the internal wall surfaces of 120 mm and 240 mm long rectangular ducts for the effect of the surfaces on the pressure drops and drag reductions on the surfaces. It was discovered that riblet patterned wall surfaces can reduce the pressure drops in a piping flow by the shear stress reduction at the surfaces, however theses surfaces should be applied after an entrance effect region where the surface shear stress can be increased by the riblet patterned surfaces
Evaluating neural network methods for brain hemorrhage identification and classification from computed tomography imagery
No full textThe classification and detection of brain hemorrhages has drawn more attention in recent years as a critical component in the early detection of hemorrhages, which has become even more important in ensuring accurate diagnosis, preventing increased mortality rates and reducing the tedious tasks of radiologists. Exploring recent improvements in artificial neural networks and its application may be able to improve the accuracy of hemorrhage detection. This project investigates the effectiveness and accuracy of selected methods based on artificial neural networks in detecting hemorrhages. The traditional AlexNet model, which is known for its effectiveness with image detection, is used as a basis of comparison with other networks. Model parameters of AlexNet, MobileNets, VGG-16, and VGG-19 are modified, trained, validated and tested with a test dataset to compare effectiveness and accuracy of these methods in detecting hemorrhages from Computed Tomography images. This project compares the training, validation and test effectiveness and accuracy across the selected neural networks- based methods and provides basis to propose the most suitable model in identifying brain hemorrhage.
KEYWORDS: Hemorrhage, Computed Tomography, Convolutional Neural Networks, Deep Learning, Machine Learning
Bishop, Texas: school transportation; its development and problems
No full textA great many changes have come into the habits and customs of people in the United States in the last few decades. Included in these changes are those in educational procedures. In rural education one outstanding development has been the consolidation of the one-, two-, and three-teacher schools, and the bringing together of their pupils into a single larger school
Security-enhanced cyber-physical battery management system using blockchain and security hardening technology
No full textBlockchain is an emerging technology that has many beneficial properties that can advance power and energy systems within a cyber-physical environment. This thesis focuses on the importance of security for cyber-physical systems (CPSs), specifically battery management systems (BMSs), in order to support the reliability of critical infrastructure and facilities that require the implementation of a battery energy storage system (BESS). For reliability and security purposes, this thesis provides an overview of how blockchain and security hardening technology can be applied toward a next-generation BMS. Three cyber-physical attack vectors were studied and assessed including: 1) physical system attacks, 2) cyber system attacks, and 3) firmware attacks. As a result, the implementation of blockchain and security hardening technology has the potential to lead to the advancement of BMSs by offering a cohesive cyber-physical environment with reliability and security enhancements as compared to conventional BMSs that rely on a traditional-based approach without the implementation of blockchain
Effects of cyclic monensin feeding on ruminally cannulated beef steers consuming low-quality forage
No full textEffects of cyclically feeding monensin to ruminally cannulated steers (12 Bos taurus; 260 kg BW) consuming low-quality forage (LQF; 4.9%CP) were evaluated. Steers were randomly assigned to one of three treatments: 1) CON (0 mg·hd−1·d−1 monensin; Rumensin® 90, Elanco Animal Health, Greenfield, IN), 2) MON (200 mg·hd−1·d−1 monensin) or 3) CYC (200 mg·hd−1·d−1 monensin for 14 d and 0 mg·hd−1·d−1 monensin for subsequent 14 d). Dried distillers’ grains with solubles (1 kg·hd−1·d−1) were fed for monensin inclusion. Each of four periods was 28 days in length. Hay and ort samples were collected d 10-13 for intake determination. Rumen fluid was collected with a suction strainer 0, 2, 4, 8, and 12 h after feeding on d 14 for pH and VFA (volatile fatty acid) analysis. Data were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). A period × treatment interaction was not observed for any measure of digestion (DMD, OMD, NDFD; P ≥ 0.39), intake (DMI, OMI, NDFI; P ≥ 0.86) or pH (P = 0.15). An hour effect was observed for pH during all four periods (P ≤ 0.01). A period × treatment interaction (P < 0.01) was observed for acetate, propionate, and A:P when all periods were analyzed together. An hour effect was observed in all ruminal fermentation parameters (acetate, propionate, A:P ratio, total VFA; P ≤ 0.01). No treatment effects for any ruminal fermentation parameters or interactions were observed by period 4 (P ≥ 0.15). Only an hour effect was observed during period 4 for all ruminal fermentation parameters (P ≤ 0.03)
Irregular hexagon architecture for energy conservation in K-coverage mobile wireless sensor networks
No full textIn recent years, attention has been drawn to Wireless Sensor Networks due to the proliferation of Internet of Things (IOT) applications, environmental monitoring and unmanned/remote surveillance applications. These applications rely on deploying a network that can perform core task of sensing or detecting some phenomenon and communicating the sensed phenomenon to a central or distributed unit for processing. In addition to functional requirements of sensing and communication, a desired non-functional requirement is the quality of the network and its lifetime. The quality of the network and its lifetime are determined by the deployment architecture or pattern of the network nodes, and the energy management scheme employed to minimize the energy consuming operations taking place in the network. This research investigates the effectiveness of a new deployment pattern, Irregular Hexagonal Architecture, in improving network lifetime, by exploiting the unique properties of Irregular Hexagon deployment pattern while still maintaining coverage quality and degree requirements. This research proposed two energy management duty cycle topology management schemes that utilize the properties of the Irregular Hexagon architecture to reduce energy consumption. Both schemes are compared in network simulations carried out on COOJA simulator running the CONTIKI OS, and their network lifetime improvements as well as energy profiles are compared. The results obtained showed that the irregular hexagon architecture with the applied energy management scheme does provide an improvement in the network lifetime of mobile wireless sensor networks.
KEYWORDS:
Wireless Sensor Network, Irregular Hexagon, K-coverage, Distributed system, State Design Pattern
A history of the Rio Grande Valley citrus industry
No full textToday the Lower Rio Grande Valley is simply the southern tip of Texas. This area, which is often called the “Magic Valley,” extends from the Rio Grande City to the Gulf of Mexico, over one hundred miles. Northward from the river, in some sections, its width is near thirty miles. More generally speaking, it includes the four most southern counties of Texas: Starr, Hidalgo, Willacy and Cameron; But to most valleyities the Magic Valley is the rich, irrigated garden spot on both sides of the Mission-Brownsville highway
The probable vector for the transmission of fowl paralysis
No full textA study of this problem was begun three years ago because paralysis in chickens is relatively new as an important destructive disease, and the causative agent exact transmission methods of this disease have not been definitely determined. Also, as yet, no cure has been discovered
A statistical analysis of the relationship of place of residence to grades made by college freshmen
No full textMany opinions have been expressed as to the relationship between the place of the residence and the scholarship of the college freshman. Some opinions have been expressed in favor of dormitories; some have favored privately owned boarding houses; others have, in the light of the presence of parental guidance and supervision, been expressed in favor of the freshman's own home
A study of 281 farm labor families of South Texas
No full textDuring the period from 1930 to 1940 the population of Texas increased slightly more than ten percent. In the same decade the rural-form population of the state decreased eight percent. On e hundred sixty-two thousand four hundred and ninety-nine share copper and tenant farmers were forced to give up their occupation. As the average family in the rural-farm area contained 4.16 persons, such a change meant the uprooting of nearly seven hundred thousand people. The reduction of eight percent in rural-farm population of the state was accompanied by an increase of over twenty-three percent in the rural-nonfarm census