Texas A&M University-Kingsville: AKM Digital Repository
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Flexibility quantification and multi-objective decision making model in supply chain management
No full textThe supply chain is essential to coordinate and connect suppliers, distributors, retailers, and consumers (Stevenson, et al. (2007); Lambert, et al. (2017); Lummus, et al. (2003)). The supply chain plays a central role in global trade and as a result, improving the supply chain’s efficiency and performance is critical to enhance business operations and customer satisfaction across industries (Moon, et al. (2012); Cho, et al. (2012); Stevenson, et al. (2007)). Supply chains vary due to different product characteristics, and supply chain managers can adjust the configurations of a chain for greater flexibility, responsiveness, or agility to prevent excessive waste and reduce spoilage if disruptions were to occur (Lambert, et al. (2017); Kumar, et al. (2006); Cho, et al. (2012)). High service level and an increment flexibility increases overall costs, which is a crucial factor to consider in the decision-making process (Wagner, et al. (2018); Gosling, et al. (2010)). This study aims to define the important policies to develop a multi-objective decision-making model to optimize the overall supply chain performance.
This study uses methods such as bullwhip effect ratio, inventory variance ratio, volume flexibility, and the multi-echelon analysis of service level in the chain. The bullwhip effect is influenced by demand, required service level, and the amount of safety stock (Costantino, et al. (2014); Chan (2003)). The inventory ratio will demonstrate variance between actual inventory and forecasted inventory, which can help to enhance flexibility and to reduce overstocking costs, as utilized in Costantino. Applying this formula supports the development of a more flexible chain with increased coordination and agility. Volume flexibility is essential to measure internal flexibility and can provide information to support supply chains agility and flexibility (Vickery, et al. (1999); Bauer, et al. (1970)). The study will use a multi-attribute decision-making tool to assess and prioritize the different flexibility measures using the analytic hierarchy process (AHP) (Cho, et al. (2012)). The emphasis of the AHP is to determine the priorities for any supply chain when evaluating external and internal flexibility, high service level, inventory level, time, and costs. This multi-criteria decision-making tool has been used to make complex decisions that are designed to improve the supply chain priorities and efficiency of any supply chain (Vafaei, et al. (2016)).
Different case studies were analyzed using the developed framework to compare variances and process flexibility at different service levels. A cost analysis was conducted incorporating inventory holding costs, ordering costs, and transportation costs at different service levels. Cost and time normalizations are expected to supplement the decision-making process when modifying the supply chain. The proposed multi-objective model is expected to assist users in generating optimized supply chain management scenarios considering the trade-offs among service level, flexibility, and cost
The design and implementation of soil monitoring systems using UAVs
No full textThis research work will focus on designing and building a UAV-based soil sensor system that can be placed in remote areas where access may be limited. Retrieving data from agricultural sensors, such as soil moisture, temperature, electrical conductivity, etc., outside of established cell phone and Wi-Fi networks can prove to be difficult. Typically, this requires the user to remove a memory card from the sensor and physically transfer the data in the farm fields. This can pose an issue due to a lack of infrastructure to support data logging, including a lack of cell towers for cell service and a lack of passable roads to make accessing the sensors non-feasible. The system can bridge the gap and allow easy access to remote fields even when infrastructure does not allow it. This was done by incorporating a high-efficiency, high-payload fixed-wing drone where the intended area of operations can now be accessed at will. By using a UAV, we can circumvent the issues proposed as the system is no longer dependent on the status of a road or if a cell network is down
Effects of wetlands and their geospatial locations on water quality in the Arroyo Los Olmos watershed, Texas
No full textThe Lower Rio Grande Valley (LRGV) region in South Texas relies on surface water irrigation from drainage ditches and streams, which are experiencing excessive nutrient loadings from agricultural byproducts escaping as runoff. Implementation of Best Management Practices (BMPs) and their optimal placement within a watershed can improve water quality in streams. Therefore, the objective of this study was to quantify the effects of BMPs on water quality in streams of the Arroyo Los Olmos watershed, which is located in the LRGV. This watershed encompasses 1,344 square km of land, primarily the areas north of Rio Grande City. The greater part of agricultural runoff in this watershed is contributed by cattle farms located in the northeast section of this area. To address the aforementioned objective, a Soil and Water Assessment Tool (SWAT) model was implemented in the Arroyo Los Olmos watershed. The model was calibrated and validated to match observed streamflow and water quality indicators at multiple sites within the selected watershed. Subsequently, the model was used to estimate the effectiveness of various BMPs in improving the water quality of streams. Implementation of three wetlands (Scenario 6) in subbasins (147, 149, and 150) was found to be most effective, reducing Total Nitrogen (TN) by 2.6%, Total Phosphorus (TP) by 7.9%, and Total Suspended Solids (TSS) by 3.4% during the 2000-2019 time period. On the other hand, Scenario 5, where a wetland was simulated solely within subbasin 147, achieved reductions for Total N, Total P, and TSS by 1.2%, 4.1%, and 1.7%, respectively, during the simulation period with the least input costs. These findings can help in the assessment and mitigation of the effects of agricultural activities in the LRGV on water quality. Such information is useful to determine the effectiveness of different BMPs in reducing nutrient loadings in the streams
Palladium-catalyzed hydroarylation of alkynes : study of substrate scope
No full textFor decades, the hydroarylation of alkynes has attracted significant interest in the field of homogeneous catalysis due to its great advantages for the synthesis of pharmaceuticals and natural products. Hydroarylation of alkynes is a C-C bond formation reaction by the direct addition of arenes to alkynes producing aryl alkenes as a valuable building block for drug molecules.
In our previous studies, the palladium ethylene complex [Pd(PNP)(C2H4)](SbF6)2 was found to efficiently catalyze the addition of pentamethylbenzene to acetylene. This hydroarylation test reaction was conducted at room temperature and for the first time under acid-free conditions.
The impact of essential parameters on the reaction rate was investigated by B. Garcia and L. Garcia comprising (1) water as co-catalyst, (2) the solvent volume, and (3) the substrate-to-catalyst ratio. The highest reaction rate was observed in the presence of 5-10 mol equivalents of water/ mol catalyst. The reaction slows down with increasing solvent volume and equilibrates at lower conversion by increasing the substrate-to-catalyst ratio.
The palladium ethylene complex showed a limited substrate scope in the study by M. Manjahi. For example, reacting 1,3,5-trimethoxybenzene as a highly nucleophilic arene with acetylene leads to the formation of a stable σ-alkyl complex that causes the deactivation of the catalyst.
The main goal of this research is to study the aqua complex [Pd(PNP)(H2O)](SbF6)2 as pre-catalyst to overcome the deactivation issues and thus expand the scope of arenes substrates, whereby those arenes relevant as building blocks for pharmaceuticals are of most interest. In L. Garcia's study it was shown that the aqua complex exhibits the same catalytic activity as the previously investigated ethylene complex. 1H, 13C, and 31P NMR spectroscopy will be used to characterize the molecular structure, the purity of compounds, and to monitor the progress of the catalytic reaction
Exploring the experiences of Arab mothers raising children in South Texas: maintaining Arabic heritage language and cultural identity
No full textIn the United States, language maintenance among minority populations often faced significant challenges, particularly in linguistically and culturally diverse environments like South Texas. This qualitative study explored the experiences of Arab mothers in South Texas as they endeavored to maintain the Arabic language and Arab culture within their families. Utilizing semi-structured interviews conducted via Zoom, this research delved into the personal efforts, strategies, and challenges faced by these mothers in transmitting their heritage language and cultural values to their children. Despite the dominance of English and the absence of substantial institutional support, these mothers demonstrated remarkable dedication and ingenuity in fostering an environment conducive to language and cultural retention. The findings highlighted the central role of the home setting and religious practices in language maintenance, and the profound impact of personal commitment and community support in overcoming the multicultural challenges (Fishman, 2001). This study contributed to the understanding of language maintenance in minority communities and underscored the importance of family dynamics and cultural practices in the intergenerational transmission of minority languages
Synthesis and structural characterization of a gold(I) complex containing a hemilabile bisphosphine monoxide ligand
No full textIn this thesis project the bisphosphine monoxide trifluoroacetate gold(I) complex [Au(PPO)(COOCF3)] (PPO = 1,2-bis(diphenylphosphino)benzene) was synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy as well as by mass spectrometry. The NMR and IR spectroscopic data confirmed the trifluoroacetate gold(I) structure, whereas the mass spectrum showed m/z peaks assigned to [Au(PPO)(NCMe)]+ and [Au2(PP)(NCMe)2]+ (PP = 1,2- bis(diphenylphosphino)benzene). Two X-ray crystal structure analyses were performed. The first structure analysis gave a preliminary structure of the trifluoroacetate gold(I) complex molecule [Au(PPO)(COOCF3)]. A second sample of crystals were analyzed in order to obtain a better refined set of structural parameters, however the R-ray diffraction analysis gave a molecular structure of a dinuclear bisphosphine gold(I) complex [Au2(PP)(COOCF3)2] which reflects the MS results. 31P NMR studies of a solution of [Au(PPO)(COOCF3)] in THF was performed to understand the structural rearrangement of the bisphosphine monoxide gold(I) complex to the dinuclear bisphosphine complex. However, the study did not confirm the rearrangement of [Au(PPO)(COOCF3)] to [Au2(PP)(COOCF3)2]. Instead another species formed, which remains to be further analyzed
A Multi-site Delphi study to identify and prioritize mental health needs of rural communities in Texas Public Health Region 11
No full textThe purpose of this qualitative study was to identify and prioritize the mental health needs of rural communities in Texas Public Health Region 11 utilizing the Delphi method. Rural individuals face unique challenges when attempting to receive treatment for serious mental illness and mental health care. Stigma, a lack of privacy when seeking treatment, a shortage of mental health workforce professionals, a lack of culturally competent care, affordability, and transportation are all factors that complicate the need for treatment. This study utilized the Delphi method to engage rural community members in identifying and addressing critical issues related to mental healthcare delivery in their county. The sample for this study was selected from the population which comprise Texas Public Health Region 11 communities that were identified as rural communities within Health Professional Shortage Areas (HPSA) using an exponential nondiscriminatory snowball sampling method. Knowledge gained from the study will help to address challenges and critical issues in mental healthcare delivery in rural communities, such as workforce shortages, access issues, anonymity, stigma, integration of mental health services into primary care, and suicide prevention. The study’s implications for refining, developing, and increasing rural mental health research, and implications for practice for mental health treatment providers in rural communities are discussed
Real-time fast face detection and verification for secure remote facial authentication system
No full textThis project explores running continuous face detection based on creating a unique fast face detection technique. This project builds an authentication system that recognizes an authorized user’s face and thus their identity from a video captured from the user’s web camera. Since the face detection is done for each frame captured from the web camera, this system achieves continuous face identification-based user authentication. Authentication is thus achieved by comparing the input images from the webcam to the soft biometrics, which herein is comprised of the dataset of the images of the authenticated users that have been collected and used to train this user authentication system’s face identification model. This research explores real-time fast face detection and recognition to build a framework for a secure biometric authentication system for remote access. The proposed model in this research uses an adapted and modified VGG-16 base model for face detection with classification and regression blocks and a Siamese neural network-based face verification model. It was observed to have an accuracy of about 98% for face detection and around 95% for face verification. The proposed model was found to be more accurate than existing state-of-the-art methods
The development of transferable life skills through high school sports
No full textAdolescence is a challenging time for many individuals. It is often a physical, social, and emotional rollercoaster, where some adolescents do not have the same stability that others do in their home lives. Gaining life skills, through the educational setting, allows many adolescents to learn to navigate life stressors. Educational settings extend beyond the classroom to include organized sports. Through participation in school sports, adolescents can develop skills that enhance their ability to succeed in their current activities and ease their transition into adulthood.
This basic qualitative study explored the perceptions of eight former high school athletes in the South Texas Region and the effect that transferable life skills, which developed through competitive sports, had on their lives after high school. The following research question was used as the foundation of this case study: How did participation in competitive high school sports lead to self-improvement as adults, resulting from the development of transferable life skills? The researcher incorporated qualitative research methods and acted as the human instrument, where data was gathered and analyzed to obtain a better understanding of whether participating in competitive sports may or may have not supported adolescents in the acquisition of transferable life skills and allowed them to lead more responsible and productive lives as adults.
The results of the study confirmed that the involvement in high school competitive sports was significant in their development, particularly the process of acquiring transferable life skills such as teamwork, leadership, self- discipline, time management, and critical thinking. These skills were influential in shaping their professional and personal lives, allowing them to apply values like preservice, working with others, flexibility in their careers as educators, law enforcement, coaches, electrical engineers, account managers, and electrical lineman. Their athletic coaches, through either discipline and tough love or positive reinforcements, were instrumental in creating responsibility, positive work ethics, and leadership skills that extended far beyond high school. Participants reflected on how their athletic experiences laid the foundation for these life skills and benefited them throughout high school and into their lives as adults.
Recommendations for future research include, expanding the sample to include a variety of geographical locations to provide a broader cultural and socioeconomic context. Second, comparing participants with varying numbers of years of experience could potentially shed light on how duration affects skill acquisition. Furthermore, future studies could also contrast multisport versus single sport athletes on leadership and career advancement. Additionally studying how athletic experience is influenced by socioeconomic status and the resources that are available to the different groups. Lastly, a study of coaching styles, gender of coaches, and nonstarting player’s experiences could further clarify the effects of sports. Lastly, considering the psychological impact of sports, particularly related to failure, competition, and resilience, would offer a fuller picture of sports' emotional and developmental effects
Academic transitions analyzing STAAR performance of emergent bilingual students from 4th to 6th grade
No full textThis study examined the academic performance of Spanish-speaking emergent bilingual students in a South Texas district as they transitioned from taking the STAAR Reading Language Arts (RLA) exam in Spanish to English from grades 4 to 6. The shift to mandated English-only testing by 6th grade may misrepresent students' academic abilities when English proficiency is still developing. The study aimed to determine whether the language of STAAR assessment influenced academic outcomes across transitional years. Guided by Cummins’ developmental interdependence theory, which posits that L1 proficiency supports L2 academic success, the study evaluated whether test language predicted or moderated performance over time. A quantitative, causal-comparative design was used. Archival STAAR RLA data from 2022–2024 were analyzed using ANCOVA and moderated multiple regression. A purposive sample of 150 students across 4th–6th grades was selected based on language background and test history. Results showed no significant differences in 4th- or 5th-grade STAAR scores based on test language. However, test language significantly moderated performance in two models. Uniform English testing in 6th grade limited further analysis. These findings support the theoretical framework and highlight the need for flexible, readiness-based assessment policies to improve equity and outcomes for emergent bilingual students