Texas A&M University-Kingsville: AKM Digital Repository
Not a member yet
1689 research outputs found
Sort by
Components of Latinx parental involvement in high school
No full textThe Latinx population is the fastest-growing and largest ethnic group in the United States with accompanying growth in the student population. Parental involvement among Latinxs in education is a challenge because of cultural and educational limitations of parents. Understanding components of Latinx parental involvement in high school has the potential to increase parental involvement. The purpose of this quantitative, descriptive survey study was to explore components of how Latinx parents of high school students in a south Texas community are involved in their child’s education. Epstein’s model of parental involvement was the theoretical model which framed the study. Involvement of Latinx parents in their high school student’s education and the components of parental involvement of Latinx parents were researched. Grover’s (2015), Family Involvement Questionnaire – High School Version was utilized to determine how Latinx parents of high school students are involved in their child’s education and how components of involvement cluster into dimensions among Latinx parents of high school students involved in their child’s education. A volunteer sample of 120 participants met sampling adequacy criteria. Participants were sought from a high school of interest in south Texas. A principal components analysis technique was employed. Results indicated that Latinx parents are involved in their child’s education but in unique ways different than traditional parental involvement has been defined, such as volunteering at school, attending parent-teacher conferences, and participating in extracurricular activities. Instead, Latinx parents are involved in home-based academic motivation such as communicating with their children and school staff about expectations and achievements, creating and maintaining expectations at home, holding the child accountable, and talking about their future. Recommended is for school personnel to recognize and encourage continued home-based involvement and implement to encourage Latinx parental involvement in high school
Teacher perceptions of academic functioning in children raised by grandparents during a pandemic
No full textNationally, more than seven million children are being cared for by grandparents. In Texas alone, over 630,000 children live in homes where grandparents are the custodial caretakers. In many cases, children placed in the home of grandparents lived in unpredictable conditions with their parents. Factors contributing to removing children from their home involved parents abusing drugs, incarceration, and violence. Studies have suggested that children raised by grandparents experience increased academic, emotional, and behavioral difficulties than their peers. With students already experiencing traumatic changes, teachers’ perceptions can impact how they educate the child. Furthermore, some studies have shown that teacher perceptions of non-traditional families appear to be unfair and biased. It tends to emphasize particular populations and does not compare teacher perceptions across various groups. With the coronavirus disease 2019 (COVID-19) and the closing of schools, the learning gap has widened. In addition, the closure of schools has had damaging consequences for children who are living in poverty and is likely to worsen inequalities. Studies have suggested that teachers can influence how students learn, and student behaviors can influence the way teachers teach. This study used a qualitative case study approach that focused on a school district in South Texas. Ten elementary teachers from grades 1 thru 4 participated in this study. The researcher examined the perceptions and experiences of teachers toward students’ academic progress and behaviors of children raised by grandparents and those of their peers. With the increasing numbers of grandparents raising grandchildren, additional research is needed to understand better and address the needs and concerns of these caretakers. Recognizing the vital role that grandparents have in raising children that are at most vulnerable and exposed to higher risks should be a beginning. Additionally, it is important for administrators to provide teachers with the proper training to be able to deliver instruction to students without bias. Providing educators with a variety of strategies and interventions can help pave the way for success in education.
Keywords: grandparents raising grandchildren, teacher perceptions, behaviors, poverty, student achievemen
Robust modelling and controller synthesis frameworks for power system oscillations
No full textThis study investigates uncertain power system modeling and controller synthesis frameworks for unstructured, structured uncertainty and linear parameter varying plant cases by considering the single machine infinite bus power system that substantiates the rotor oscillations of the synchronous generator at the generation end. Although the power system is highly complex based on the operational characteristics, the corresponding dynamics is modeled as a set of linear time-invariant systems by considering different operating points in two different uncertainty treatments, i.e., unstructured and structured uncertainty cases for global or parametric uncertainties. The corresponding uncertain power system model is utilized to synthesize two robust controllers not only to stabilize the nominal linear time-invariant system but also to improve steady state and transient responses of the uncertain power system dynamics in the same convex hull. The multiplicative uncertainty description with a bounded uncertainty component has been chosen to reflect the power system dynamical variations in the robust modeling framework. The robust controller synthesis utilized the corresponding linear fractional transformation representation to achieve the robust performance of the uncertain power system in terms of perfect tracking to a zero reference, i.e., perfect disturbance rejections under the norm bounded uncertainty. The uncertain power system numerical modeling and two controller synthesis results for structured and unstructured uncertainty cases verify the validity of the proposed framework to reduce the magnitude and duration of the single machine infinite bus power system oscillations under dynamical variations
Design and development of a novel experiment system for measurement of fluid mechanical parameters in valves, fittings, and tubing
No full textA research program is described that transforms a manually operated experimental pressured drop measurement system for measurement of gas-phase pressure drop across pipes, fittings, and valves used for teaching purposes into a fully automated system based upon a process logic controller (PLC) with a custom developed operator interface. The upgraded experiment provided an advanced basis to research both steady-state and transient behavior of pressure drop readings to support both student understanding and graduate research in fluid transport and process control systems. The control system is powered by a Siemens 505 process logic controller with a Wonderware Intouch™ Human Machine Interface (HMI). A variety of field instruments are used to measure local temperatures, flow rates, and differential pressures. Transmitters and transducers are hard-wired to the process logic controller through modules having the appropriate electrical signals for both analog and digital input and output functions. The process and instrumentation drawing, instrumentation, human machine interface and experimental procedures are described along with process safety management (PSM) methodology. A typical operational sequence for the process input variables and the corresponding system output responses that a student might use to perform the experiment is illustrated. The remaining task needed to validate the system iv operation are also summarized. Once completed, the system will have capabilities that are superior to any others available from commercial suppliers
Detection of hazy vehicle license plate with dark channel prior dehazing and optical character recognition
No full textLicense plate detection has become a very important challenge in the modern world due to traffic-rule violations and an increase in the number of accidents. Even though image processing has advanced a lot in today's world the task of recognizing numbers from the license plate is a very complicated and tedious process because the captured number plate can be from different backgrounds like haze and fog. Adverse weather has a massive impact on the images obtained by the outdoor image capturing systems. In this research, we propose a novel image dehazing method focused on the dark channel prior algorithm to remove the haze of the foggy image and then we used an optical character recognition algorithm to detect the hazy vehicle license plate
Over expression of RhNAC2 and RhEXPA4 genes in carrizo citrange to develop potential drought tolerance
No full textCitrus is one of the most important fruit crops with high commercial and nutritional values, planted mostly in subtropical areas. As population growth accelerates and the demand for water increases due to urban development, water becomes scarce for agriculture. The situation tends to exacerbate the need for the development of plants that are more efficient in water usage. In general plants address water stress, by showing several morphological and physiological changes through altered gene expressions. Several studies reported different transcription factors stimulating functional genes downstream leading to tolerance to drought. A study in rose and Arabidopsis has shown that the up regulation of RhNAC2 (Dr1) a transcription factor and RhEXPA4 (Dr2) a functional gene under water stress conditions conferred drought tolerance while silencing these genes has made plants more sensitive to drought. In a preliminary study two separate transgenic lines were created which over express RhNAC2 and RhEXPA4 genes under the control of CaMv 35S promoter and terminator by Agrobacterium mediated transformation. Putatively transgenic Carrizo citrange were tested for transformation efficiency, gene copy number and gene expression. The transformation efficiency for Dr2 and Dr1 were 21.7% and 10% respectively. Transgenic lines with Dr2 gene have 1-3 transgenes per genom
Selection and sizing of energy storage devices for commercial onshore wind farms
No full textThe intermittent nature of wind energy is a major drawback to its popularity as a clean and cost-effective alternative to fossil fuels. The fluctuation in wind introduces imbalance in supply and demand of energy available to the end-users. To combat this challenge, ongoing researches are focused on utilizing energy storage systems to ensure smooth power supply. Energy storage systems store energy from the wind farm amid a time of low demand and discharge this stored energy to the grid amid a time of high demand. This research seeks to develop a method for selecting and sizing storage devices for commercial onshore wind farms. A study of the available energy storage devices is presented together with their advantages and disadvantages. The potential challenges faced by current wind farms are taken into consideration as well as the characteristics of the optimum storage device for a commercial wind farm. While several optimization methods were considered, this research focuses on utilizing the Analytical Hierarchy Process for the multicriteria selection process. The results show that the pumped hydroelectric energy storage and compressed air storage are the most suitable options for commercial wind farms.
Keywords: Wind Energy; Energy Storage Systems; Analytical Hierarchy Process; Sizing
Design of a sensor based smart restroom system for elderly people
No full textOver the past few decades sensor technologies are becoming increasingly popular. Elderly people who are living independently require full monitoring for their health status so that the unprecedented events (i.e., fall) can be avoided. This report describes the basic concepts, methodologies, and researches behind the concept and tries to highlight the necessity and scopes of a restroom system to assess the frailty of elderly people in order for them to have a comfortable, independent and more secured life at home. The concept of the designed restroom is created based on the necessary scenarios depending on the context of user analysis, socio-cultural and technology trends and user requirements study results. The restroom is prototyped with a multi-sensory space with interconnected devices where interactive content and services are accessible for the caregivers of the elderly people during their daily activities. The prototype is then demonstrated at Advanced Energy Simulation Laboratory in Texas A&M University-Kingsville. To predict the locations of the sensors, a Naïve Bayes classifier is used which helps in providing a constantly updated reference for the signals coming from different sensors and devices placed in different locations in the restroom. Some pilot data set was collected, and relevant online data was also explored. All methods have been passed through Institutional Review Board IRB, Texas A&M University- Kingsville
Synergistic effect of chlorine and nitrate on the photochemical degradation of carbamazepine in aqueous solution
No full textOver the past decades, special interest has been given to the presence and removal of pharmaceutical and personal care products, one of the most prevalent groups of contaminants of emerging concern (CECs), in water and wastewater. This research work investigated the use of free chlorine for UV-AOP applications to better understand its implications in the UV/Cl systems for the removal and transformation of carbamazepine (CBZ), and its photochemical synergy with nitrate for the production of .OH along with the removal of CBZ. First, the production of .OH by the UV irradiation (254 nm) of free chlorine and/or nitrate was studied, under different conditions, by using salicylic acid (SA) as the chemical probe for .OH. Selected conditions included UV irradiation, initial aqueous concentration of 30 mg/L SA, 5 and 10 mg/L Cl, 0 – 10 mg/L NO3 - in a photochemical reactor. Aqueous solutions containing 10 mg/L Cl and spiked with 4 mg/L NO3 - gave the highest reproducible generation of .OH. Aqueous solutions containing 10 mg/L CBZ were then irradiated with UV light in the presence of 10 mg/L Cl and/or 4 mg/L NO3 - resulting in 60% CBZ removal and 12% higher CBZ removal without and with nitrate respectively. Corresponding dark reactions were also conducted, with no apparent degradation of CBZ under all conditions. The samples were analyzed via UHPLC, LC-MS and TOC analyzer for detection of CBZ concentrations, by-products formation, and TOC removal. The results indicated that the addition of 4 mg/L NO3 - had the positive synergy of increasing the removal efficiency of CBZ
Targeted DNA demethylation in ovarian cancer cells
No full textThe Spalt-like transcription factor 2 (SALL2) is a member of the SALL family of transcription factors, and it is implicated in many ovarian cancers. The gene product of SALL2 is the p150 protein, a multi-zinc-finger transcription factor. Normal ovarian epithelial cells maintain high levels of the p150 protein. In comparison to normal cells, p150 protein levels are low in many human ovarian cancers, suggesting tumor suppressor functions and proapoptotic properties. The p150 is absent or reduced largely in cancers due to SALL2 promoter hypermethylation. DNA methylation is the addition of a methyl group to DNA, that occurs at the fifth carbon of cytosine base within CpG dinucleotide. CRISPR-Cas9 is a genome editing technology capable of precise targeting and editing DNA. Using a modified CRISPR-based DNA demethylase system (dCas9 Tet1), the targeted demethylation of the SALL2 promoter would possibly induce recovery of the p150 protein expression in ovarian cancer cells. This system encompasses a Tet1 (Ten-Eleven Translocation dioxygenase 1) catalytic domain fused to dCas9 (deactivated Cas9 that does not cut DNA but acts as a carrier for Tet1) with the help of a flexible linker. Small guide RNA clones were constructed to direct the dCas9-Tet1 to three specific sites in the promoter region of SALL2 to accomplish targeted demethylation. SKOV-3 ovarian cancer cells were transfected with plasmids carrying pdCas9-Tet1 and different guide RNAs to perform targeted demethylation based on the accompanying guide RNA. To test successful demethylation of SALL2 promoter and re-expression of p150, bisulfite treatment followed by pyrosequencing on genomic DNA, immunoblotting of cell lysate and 5-hmC assays were performed