Texas A&M University-Kingsville: AKM Digital Repository
Not a member yet
1689 research outputs found
Sort by
Automated multi-process transport line for silicon wafer processing
No full textThe semiconductor industry is a rapidly growing industry that has become an integral part of modern technology. Silicon wafer processing is a crucial step in the manufacturing of semiconductors, which requires a high degree of precision and consistency. In recent years, there has been an increasing demand for high-quality, high-volume semiconductor production. To meet this demand, automated multi-process transport lines have been developed for silicon wafer processing. This study is to present a comprehensive analysis of the automated multi-process transport line for silicon wafer processing. The report begins by providing an overview of the semiconductor industry and the importance of silicon wafer processing. It then describes the components and functions of the automated multi-process transport line, including the transport system, process modules, and control system.
The report also discusses the benefits of using an automated multi-process transport line, such as increased productivity, improved process control, and reduced operator error. It also covers the challenges and limitations of the system, including the need for regular maintenance and the high initial investment cost. The automated multi-process transport line for silicon wafer processing is an important technological advancement that has the potential to revolutionize the semiconductor industry. This study provides a detailed analysis of the system, including its components, functions, benefits, challenges, and limitations, to provide a comprehensive understanding of the technology
Modeling nutrient dynamics and algal blooms using DELFT3D - flow, wave, and WAR, in Nueces Bay, Texas
No full textHarmful algal blooms (HABs) and eutrophication are increasing in frequencies in coastal waterbodies including estuaries and bays. Estuaries are vital components to ecosystems, and economics including tourism, fishing, hotels, industries, ports, and other developments which are dependent on the health of these estuaries. Excessive nutrient discharges are degrading their health and causing HABs. Eutrophication, hypoxia and/or HABs have led to negative impacts such as respiratory illnesses, fish kills and economic disruptions. Numerical models have helped us in understanding the inter-relationships of the governing factors of the ecosystem. Nueces Bay in South Texas was modeled in other studies but there has been little study on HABs. In this study, Delft3D was employed to simulate hydrodynamics, nutrient dynamics and algal growth within Nueces Bay. Nitrogen, the limiting nutrient for coastal eutrophication, was focused. Delft3D Flow-Wave coupled model was used to simulate hydrodynamics and wave growth. The results from the coupled model were integrated in Delft3D WAQ to simulate phytoplankton growth. The models were calibrated and validated for water levels, total nitrogen (TN) and chlorophyll-a (algal biomass concentration) with “very good” performance ratings, with NSE and r2 > 0.75 and PBIAS 20 μg/L. Simulation results indicated that wave growth was dominated by wind (>1-foot wave-height). High inflow rates (80 m3/s) increased hydrodynamics and mixing, which yielded in lower chlorophyll-a (50) on the algal growths. Hypothetical scenarios indicated that high TN (>3.0 mg/L) and chlorophyll-a (>100 μg/L) inflows from Nueces River significantly increased algal growth and can potentially induce blooms. The model provided an analysis tool for better understanding the mechanisms and dynamics of algal growth/blooms, and this kind of tool can be an effective means to manage other similar estuaries or coastal waters
Teachers with identified high trait emotional intelligence and their perceived influence on pedagogy and resilience.
No full textPublic school educators have many professional duties that they are required to fulfill to fidelity. Expectations include but are not limited to; curriculum and instructional planning and application of practices; implementing classroom management and behavioral intervention strategies for individual students and whole groups; attending required meetings and professional developments; reviewing and disseminating data to adjust lessons; and staying knowledgeable about, and following, all necessary local, state, and federal education mandates. Teachers often express feeling overwhelmed or experiencing ‘burn out’ within the school year which can cause an increase in stress/anxiety and mental distress potentially affecting their success and efficiency in the classroom, regardless of their years of experience in education. Teachers may even develop negative views of their job as a result of their constant workload. Emotional intelligence is one indicator of an individual’s ability to manage interpersonal and intrapersonal stressors. Individuals who possess higher levels of trait emotional intelligence are likely to understand and process their own emotional reactions and others emotional responses to employment and personal matters more effectively. The purpose of this study was to examine how K-12 educators with identified high levels of trait emotional intelligence compared to one another in the four quadrants of emotional intelligence quotient and their perceptions on how intrinsically modeling such behaviors affect their classroom environment. The data was collected using a
phenomenological qualitative design with elementary and secondary teachers and collect information regarding individual participant emotional intelligence levels and workplace experiences, attitudes, perceptions, and interpersonal and intrapersonal awareness. The information collected provided insight into the potential benefits for emotional intelligence training and coaching to teachers as a reform to enhance a classroom learning environment. The study evaluated teacher perceptions related to emotional intelligence in teachers and the influence it has on pedagogy and resilience. The data analysis process produced the following themes: (1) work-life balance, (2) authentic relationships, (3) lack of well-rounded or effective professional development (4) stress management and self-care practices, (5) growth mindset; subtheme: high expectations for all students. The study indicates that educators and educational leaders at all levels could learn more on capacity building in educators by additional research and practice related to emotional intelligence skills training for teachers
Native seed burial and cover crop considerations for rangeland restoration
No full textRangeland disturbance caused by anthropogenic inputs can have long-lasting effects. One of these effects includes invasive grass encroachment and dominance leading to a decline in ecosystem function. In agriculture, annual cover crops are used (1) spatially, within rows between trees and vines or (2) temporally, between crop rotations to reduce invasive plant encroachment. Recent studies have shown that cover crops may translate as restoration strategy when establishing native grasses. This study, a pipeline installation in south Texas, was completed in February 2020. Seeding occurred in two separate trials: a Summer Trial and Winter Trial. Comparisons within each trial were made from seeding a native grass mix with or without a cover crop and timing of seeding native grasses after disturbance by measuring plant density, cover and biomass of all species. For each trial, we seeded eleven locally-adapted native grass species as part of the native grass mix, or permanent mix (PM). Six of these species, classified by two morphologies and three seral stages, were monitored for germination throughout the year with a seed burial study. Again, this study had two separate trials: a Summer Trial and Winter Trial. Plant density data revealed native grasses were most successful when seeded earlier despite the presence of a cover crop. During the Summer Trial, invasive grass density and cover substantially increased from the first year to the second. However, native grasses were not affected by changes from year one to year two. Lastly, most all native grasses, despite morphology or seral stage, if viable, will have successfully germinated within a year. These results indicate that seeding earlier within the season is critical to the success of native grasses in early establishment
Developing spectral signatures of South Texas grasses using multispectral sensors and UAVs
No full textMonitoring rangelands is important however, traditional field-based methods are costly, time consuming, and are not always comparable across different spatial-temporal schemes. Satellite imagery and aerial photography have been used to study vegetation communities, for many years, however, unpiloted aerial vehicles (UAVs) may be better suited for more efficient fine-scale temporal and spatial monitoring to aid in species level classification for rangeland vegetation. Multispectral sensors mounted on UAVs present the opportunity to collect spectral signatures and plot spectral reflectance by wavelength, which can help the assessment of grass composition over large areas. There has been little research on spectral signatures for rangeland species. I evaluated the spectral signatures of 16 grass species between species and years and before and after irrigation and burning. I determined the degree of separability between grass species and the changes in spectral signatures of burned grass. Spectral signatures showed a significant amount of variation within and between years and the blue, red, red edge, and nearinfrared bands showed the most significant differences from year to year. I found that before irrigation, three species could be identified using spectral signatures but after irrigation, no species were identifiable. I observed burned and non-burned spectral signatures of Gulf cordgrass remained significantly different for at least eight months after burning. I attempted to identify vegetation at the species level and were unsuccessful. However, this technology could be used to identify clusters of similar species and monitor spectral signatures across a range of environmental conditions and management strategies. This is one of the first attempts to analyze the temporal variability of spectral signatures in the field and proves the UAV technology could potentially be used to identify vegetation communities with a better understanding of native grass phenology
Identification and characterization of new sources of Zebra chip disease resistance from wild solanum sect. petota
No full textPotato (Solanum tuberosum L.) is among one of the most important food crops in the world. As there is an increasing demand for fresh and processed potato products globally, there is an urgent need to manage and control devastating diseases such as zebra chip (ZC). ZC,
associated with the phloem-limited bacterium Candidatus Liberibacter solanacearum (CLso) and vectored by the potato-tomato psyllid (Bactericera cockerelli Šulc.), causes major yield losses in commercial potato varieties. Currently the management measures for ZC focus on chemical controls against the psyllid to limit the spread of CLso. Identification of genetic resistance to CLso and/or the psyllid provides a sustainable long-term strategy to control ZC. In the present investigation, tuber bearing wild Solanum species, procured from a Solanum sect. Petota
diversity panel, were challenged with CLso-harboring psyllids to screen and identify resistance and/or tolerance the bacterium and insect. Based on the phenotypic evaluations, nine out of 52 accessions showed resistance and/or tolerance to ZC symptoms. Further phenotyping and CLso quantification categorized one as resistant with relative CLso titer of 6.05 % relative to susceptible cultivar (S. berthaultii PI310927) and three as tolerant with relative CLso titer of 52.44 to119.36 %. Unlike inbred cultivars that have fixed traits, wild accessions are heterogeneous, therefore, the ZC resistant trait in S. berthaultii PI310927 was evaluated by single seed progeny analysis. The progeny of single seed lines showed varying degrees of ZC resistance to tolerance with relative CLso titers ranging from 0.62 to 103.80%. The resistance mechanism of a single seed resistant line was further investigated by grafting shoots of the resistant line into
CLso positive Atlantic rootstock. PCR analysis indicated that CLso was acquired from the rootstock into the single seed resistant line indicating that CLso can be transmitted into the plant. Further, morphological characterization of this line showed the presence of dense glandular
trichomes, which may have contributed to ZC resistance by suppressing psyllid feeding and CLso transmission. Further study of the mechanisms underlying this resistance to psyllid and/or CLso such as antixenosis and antibiosis will provide a new source for breeding for insect or bacterial resistance traits into commercial potato varieties
Sustainability analysis of Triethanolamine manufacturing process
No full textTriethanolamine (TEA) is a widely used chemical in the manufacture of emulsifiers, plasticizers, pharmaceutical intermediates, synthetic resins, agricultural herbicides, cosmetics, detergents, and soap. It is also used in cement, petroleum, and coal production. The chemical manufacturing industry is known for its extensive use of energy. Major challenges in TEA manufacturing include the high-water usage and energy requirements. As global consumption increases, there is a corresponding increase in energy and water usage to meet the increasing demands. This spurs the need to incorporate sustainable manufacturing techniques that conserve resources and minimize negative environmental impacts associated with waste generation.
For this research work, the TEA manufacturing process was simulated using the ASPEN Plus simulator. Heat integration and water conservation analysis were carried out based on results from the simulator. Economic analysis of the TEA production process with sustainability improvements was compared to the baseline process. By incorporating heat integration, the capital cost increased by 25%. The utility cost saved after heat integration was about 260,000 was determined with HI
Effect of nutrient source on growth, development, and water use efficiency of Capsicum annum (Jalapeno early)
No full textJalapeno early (Capsicum annum) is widely grown around the world due to its multipurpose usage. It grows in moderate temperatures ranging between 16-21°C. Apart from the moderate temperatures, soil amendments play a crucial role in impacting the species’ yields. This study assesses the growth and development of jalapeno early as a consequence of alternative soil amendment using either organic fertilizer (alfalfa) or inorganic fertilizer (Miracle
Gro). A randomized complete block experiment was designed to assess the effects of treatment fertilizer forms on jalapeño growth and development. The organic fertilizer was alfalfa mill known to have an NPK value of 3:1:2. and the inorganic Miracle-Grofertilizer had an NPK value of 9:4:12. Treatment plots receiving different concentrations of organic fertilizer (9g, 18g and
27g) and inorganic fertilizer (12g) were compared to the control plants grown without any fertilizer. Response variable of the plants and soil levels included chlorophyll content, stomatal conductance, leaf area, soil nitrogen content, transpiration rate, flowering efficiency, soil pH,
fresh and dry vegetative and root biomass, and fruit formation and development. The results of the study indicate that growth and development of the species due to 27 g of organic fertilizer was significantly higher compared to the other treatments due to more amount of nitrogen is given to the plants
Modeling and analysis of grace-period policy in high-performance computing systems using game theory and data analytics
No full textHigh-performance computing (HPC) systems play a crucial role in modern scientific and industrial applications. However, the efficiency of HPC systems can be significantly reduced due to the inaccuracy of user time and resource estimates. This research aims to improve the utilization efficiency of HPC systems by studying the interactions between users and facility providers. Specifically, a game-theoretic approach is proposed where the users estimate job runtimes, and the facility provider adjusts the runtime period of the job. The game is modeled as a sequential game, and the best responses of both the users and the provider are obtained using backward induction. The Nash equilibrium solution is then presented, and sensitivity analysis is conducted to investigate the impact of different variables on the decision-making process. In addition, various regression models are trained on real dataset to predict the job runtime based on user’s job request information. This research contributes to the development of efficient job scheduling strategies and provides insights into the interactions between users and provider
Assessment of chemistry and geochemical reactions for alternative hydraulic fracturing water supplies and produced waters
No full textSince the expansion of hydraulic fracturing for oil and gas, use of freshwater resources as a hydraulic fracturing fluid has been increasing rapidly. As many areas across the U.S. are facing drought, the oil and gas industry will require water management strategies that maximize the use of non-potable water. In this study, the feasibility of using brackish groundwater reverse osmosis (RO) desalination reject concentrate and produced water as alternative water supply for frac fluid was evaluated. The results of water chemistries analysis showed a high concentration of alkalinity and sulfate in the RO concentrate. Also, significant concentrations of barium and calcium were observed in the produced water samples. Therefore, the down-hole scaling potential associated with different blend ratios of produced water and RO desalination concentrate were simulated using geochemical modeling software. Results showed possible calcite formation in all simulations. Simulations performed for the desalination concentrate showed less potential for barite formation, whereas a high potential for barite scale formation was observed in model simulations for the produced water (PW) and RO/PW blended samples. Finally, produced water dissolves rare earth elements (REE) as it flows through shale formations. Geochemical analyses of the Marcellus Shale have indicated that geothermal brines contain relatively high concentrations of REE. However, presence of high concentrations of barium can interfere with inductively coupled plasma – mass spectrometry (ICP-MS) analysis of produced water samples for REE due to the formation of polyatomic interferences. As an initial step towards assessing the feasibility of developing an economic strategic element recovery process, an accurate and reliable analytical ICP-MS method was developed to determine concentrations of REE in complex brine matrices with high barium concentrations. As a last step of this study, REE concentrations were analyzed in produced water and desalination concentrate samples