TTU DSpace Repository

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Recent Submissions

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Manganese Carbonate/Laser-Induced Graphene Composite for Glucose Sensing
(2023) Thakur, Amit K. (TTU); Sengodu, Prakash; Jadhav, Arvind H.; Malmali, Mahdi (TTU)
Laser-induced graphene (LIG) has received great interest as a potential candidate for electronic and sensing applications. In the present study, we report the enhanced performance of a manganese carbonate-decorated LIG (MnCO3/LIG) composite electrode material employed for electrochemical glucose detection. Initially, the porous LIG was fabricated by directly lasing poly(ether sulfone) membrane substrate. Then, the MnCO3/LIG composite was synthesized via a hydrothermal method. Later, MnCO3/LIG was immobilized onto a glassy carbon electrode surface and employed for glucose detection. The structure of the MnCO3/LIG composite was carefully characterized. The influence of the MnCO3/LIG composite on the performance of the electrode was investigated using cyclic voltammetry curves. The MnCO3/LIG composite exhibited an excellent sensitivity of 2731.2 μA mM-1 cm-2, and a limit of detection of 2.2 μM was obtained for the detection of glucose. Overall, the performance of the MnCO3/LIG composite was found to be superior to that of most of the MnCO3-based composites.
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Development of a Polymicrobial Checkerboard Assay as a Tool for Determining Combinatorial Antibiotic Effectiveness in Polymicrobial Communities
(2023) Black, Caroline (TTU); Al Mahmud, Hafij (TTU); Howle, Victoria (TTU); Wilson, Sabrina (TTU); Smith, Allie C. (TTU); Wakeman, Catherine A. (TTU)
The checkerboard assay is a well-established tool used to determine the antimicrobial effects of two compounds in combination. Usually, data collected from the checkerboard assay use visible turbidity and optical density as a readout. While helpful in traditional checkerboard assays, these measurements become less useful in a polymicrobial context as they do not enable assessment of the drug effects on the individual members of the community. The methodology described herein allows for the determination of cell viability through selective and differential plating of each individual species in a community while retaining much of the high-throughput nature of a turbidity-based analysis and requiring no specialized equipment. This methodology further improves turbidity-based measurements by providing a distinction between bacteriostatic versus bactericidal concentrations of antibiotics. Herein, we use this method to demonstrate that the clinically used antibiotic combination of ceftazidime and gentamicin works synergistically against Pseudomonas aeruginosa in monoculture but antagonistically in a polymicrobial culture also containing Acinetobacter baumannii, Staphylococcus aureus, and Enterococcus faecalis, highlighting the fundamental importance of this methodology in improving clinical practices. We propose that this method could be implemented in clinical microbiology laboratories with minimal impact on the overall time for diagnosis.
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MODELING AND ANALYSIS OF SOCIAL OBESITY EPIDEMIC
(2024) Sandamali, Chathuri T.; Zhang, Wenjing (TTU)
Overweight and obesity have become a global epidemic due to increasing unhealthy eating habits and sedentary lifestyles. An individual can gain weight excessively through social influence, and understanding its underlying interpersonal dynamics is crucial for effective intervention and prevention programs. By considering the social effects on weight gain, this paper presents a compartment model to describe the social spread of overweight and obesity. Bifurcation analysis suggests that a backward bifurcation exists when the relative hazard of weight regain is a larger value. Strategies for eliminating the overweight and obesity epidemic are provided by analyzing the obesity-free equilibrium globally by incorporating Lyapunov functions and the method of fluctuations. Since the pervasiveness of overweight and obesity in the United States seems to be stabilized, we analyze the local stability of the obesity-endemic equilibrium to establish a condition for the plateau, by applying a matrix theoretic method that utilizes compound matrices. The results suggest that weight loss programs can help maintain the plateau; however, weight loss maintenance programs should be promoted to eliminate the disease.
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Louvain-Based Traffic Object Detection for Roadside 4D Millimeter-Wave Radar
(2024) Gong, Bowen; Sun, Jinghang; Lin, Ciyun; Liu, Hongchao; Sun, Ganghao
Object detection is the fundamental task of vision-based sensors in environmental perception and sensing. To leverage the full potential of roadside 4D MMW radars, an innovative traffic detection method is proposed based on their distinctive data characteristics. First, velocity-based filtering and region of interest (ROI) extraction were employed to filter and associate point data by merging the point cloud frames to enhance the point relationship. Then, the Louvain algorithm was used to divide the graph into modularity by converting the point cloud data into graph structure and amplifying the differences with the Gaussian kernel function. Finally, a detection augmentation method is introduced to address the problems of over-clustering and under-clustering based on the object ID characteristics of 4D MMW radar data. The experimental results showed that the proposed method obtained the highest average precision and F1 score: 98.15% and 98.58%, respectively. In addition, the proposed method showcased the lowest over-clustering and under-clustering errors in various traffic scenarios compared with the other detection methods.
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Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory
(2024) Wang, Hui; Yang, Yang; Xi, Bin; Shi, Wei Dong; Wang, Chuan; Ji, Lei Lei; Song, Xiang Yu; He, Zhao Ming (TTU)
The electric submersible pump (ESP) is a crucial apparatus utilized for lifting in the oil extraction process. Its lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production (EP) analysis, which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance.