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Touchdown Club, Atl. Reunion
No full textDigital image created at the Georgia Tech Library, 2010. Scanned at 600ppi.||Physical Condition: Good.Jan 23, 1959? Reunion of Boys high "boys." The Touchdown Club of Atlanta was organized during the football season of 1938. The organization of the club was largely the result of the efforts of Al Voorhees, Geo. M. Phillips, Ben Sinclair, Forest Fowler, Fred Moore, Everett Strupper, James P. Cheves and Herb Bonner. The membership of the club is comprised of college football letter men and others by invitation who are sincerely interested in the game of American football. The objectives of the club are: 1. Promoting the best interests of the American game of football. 2. Fostering of good sportsmanship. 3. Social activities. The club holds weekly luncheon meetings during the football season to discuss the results and activities of the many football games played during the preceding week. First-hand reports on these games are given by various Southern Conference football officials who belong to the club or attend the meetings. There is usually a prominent coach invited to make a short talk on some subject relating to current football conditions. Everett Strupper was first president of the Touchdown Club in 1938 and was re-elected in 1939. M.E. Kilpatrick was elected to the presidency for 1940. Resources: Actual photo; File
Touchdown Club, Atl. Reunion
No full textDigital image created at the Georgia Tech Library, 2010. Scanned at 600ppi.||Physical Condition: Good.Jan 23, 1959? Reunion of Boys high "boys." The Touchdown Club of Atlanta was organized during the football season of 1938. The organization of the club was largely the result of the efforts of Al Voorhees, Geo. M. Phillips, Ben Sinclair, Forest Fowler, Fred Moore, Everett Strupper, James P. Cheves and Herb Bonner. The membership of the club is comprised of college football letter men and others by invitation who are sincerely interested in the game of American football. The objectives of the club are: 1. Promoting the best interests of the American game of football. 2. Fostering of good sportsmanship. 3. Social activities. The club holds weekly luncheon meetings during the football season to discuss the results and activities of the many football games played during the preceding week. First-hand reports on these games are given by various Southern Conference football officials who belong to the club or attend the meetings. There is usually a prominent coach invited to make a short talk on some subject relating to current football conditions. Everett Strupper was first president of the Touchdown Club in 1938 and was re-elected in 1939. M.E. Kilpatrick was elected to the presidency for 1940. Resources: Actual photo; File
Characterization, Evaluation, And Repair of Full-Scale Alkali-Silica Reaction Affected Structural Concrete
No full textAlkali–silica reaction (ASR), a chemical reaction occurring in concrete between reactive siliceous minerals in some aggregates and alkalis in the concrete pore solution, can produce an expansive gel that, in the presence of sufficient moisture,
leads to expansion and cracking. This not only decreases mechanical properties but also increases permeability and, as a result, increases potential for degradation
by other aggressive agents. Traditional methods to mitigate or repair damage of affected concrete include surface coatings and external confinement, but a re-assessment of new repair technologies and materials may offer greater benefit. Additionally, it is known that earlier detection of ASR-affected concrete can increase the long-term success of repair. Therefore, it is necessary to explore new
characterization and evaluation techniques that can aid in detection.
In this research, ASR-affected laboratory-cast and field-exposed ASR-affected concrete are examined and repaired. Laboratory-cast samples are repaired with silane and nanosilica-based coatings, and others are confined with fiber-reinforced
ultra-high performance concrete (UHPC). In the field, cracked concrete traffic (i.e., Jersey) barriers are repaired with flexible caulk and silane and slurry surface treatments. The efficacy of each is monitored through measurements of expansion and crack growth. Additionally, new techniques involving ultrasound-based nondestructive evaluation (NDE) and spatially resolved micro x-ray fluorescence (µXRF) are used to detect and characterize laboratory and field ASR-affected
concrete.
Although the monitoring of repaired samples remains ongoing, initial
measurements of internal expansions of the UHPC-confined columns indicate effective restraint in expansion, compared with chemical-based surface treatments.
Further, internal ASR-induced damage occurring in the laboratory-cast large-scale samples were detected by a novel non-collinear ultrasonic wave mixing technique, where accumulated damage can be quantified through nonlinear parameters measured at varying depths; this new non-destructive evaluation (NDE) approach
shows potential for early detection of ASR-affected concrete in the field. Finally, cored concrete from structures in the field showing indications of ASR were examined by µXRF, which is one of the first application of this method for identification of ASR damage in concrete. Scans of smaller regions of interest (i.e.,1 cm2) were compared with quantitative measurements made through the established petrographic Damage Rating Index (DRI). The small-region scans were then followed by a more intensive, larger 36 cm2
region to understand the influence in scan and elemental map settings in observing ASR-distress features,
serving as a stepping stone for incorporation of µXRF as an analytical technique for ASR identification. From these findings, recommendations for repair of ASR affected concrete are made, based upon the extent of damage, type, and criticality
of structure.Ph.D.Civil Engineerin
Data for Observations of the Gas Phase Composition of the 2024 BioLab Industrial Plume in the Atlanta Metropolitan Area: Conyers, GA
No full textThis dataset contains gas-phase observations of chlorine measured in Conyers, GA following the BioLab chemical manufacturing plant fire in Conyers, GA on September 30, 2024. The fire at the pool chemical manufacturing facility, located approximately 21 miles east of the Georgia Institute of Technology campus, resulted in a significant chemical plume that prompted shelter-in-place and evacuation orders for 17,000 residents.
Data Collection: Measurements were conducted from October 2 to October 16, 2024, using a Quadrupole Chemical Ionization Mass Spectrometer (QUAD-CIMS) deployed in Conyers, GA. Post-collection calibrations were performed to quantify chlorine concentrations.
Data Contents:
· Calibrated concentrations of chlorine
· Measurements for particulate matter from Purple Air air quality sensors and a Tapered Element Oscillating Microbalance (TEOM)
· metadata
File Structure: The Excel workbook contains multiple sheets:
· Sheet 1: Metadata and methodology
· Sheet 2: Calibrated chlorine concentrations from the GT QUAD CIMS
· Sheet 3: Particulate matter (PM2.5) measurements from the Purple Air air quality sensor
· Sheet 4: Particulate matter (PM2.5) measurements from the Tapered Element Oscillating Microbalance (TEOM)
Research Significance: This dataset provides critical atmospheric chemistry data for understanding the plume composition from the decomposition of spa and pool chemicals.A fire at a pool chemical manufacturing facility in Conyers, Georgia on September 29, 2024, released a persistent chemical plume that impacted the Atlanta metropolitan area for over two weeks, leading to evacuation of more than 17,000 people. We used high-resolution time-of-flight chemical ionization mass spectrometry at our laboratory in Midtown Atlanta (21 miles from the facility) and deployed a quadrupole CIMS in Conyers to characterize plume composition. We observed unexpectedly high concentrations of Br₂ (up to 1.4 x 10² ppb) dominating early plumes, along with elevated HNCO (31 ppb) and numerous other compounds. Twenty-six species were identified, including reactive nitrogen-containing compounds (HNCO, cyanoacetic acid, cyanamide) and oxygenated volatile organic compounds (acetaldehyde). Br₂ concentrations in Midtown exceeded EPA one-hour AEGL-1 thresholds by a factor of four. Later measurements in Conyers showed Cl₂ reaching 3.7 x 10² ppb during the second week. Given that Midtown observations were 21 miles downwind, concentrations near the source in Conyers initially were likely 1-2 orders of magnitude higher. This study provides measurements of chlorine and particulate matter from a plume of pool chemical decomposition in Conyers, GA. Measurements from Midtown Atlanta of this event can be found at https://doi.org/10.35090/GATECH/79956.NSF #250933
Designing protein-based vaccines for broad protection against coronaviruses and influenza
No full textVaccination is one of the most effective methods of reducing or preventing infectious diseases. A significant remaining challenge is the design of vaccines for long-lasting and broadly protective immunity against highly variable viruses. Many viruses mutate quickly to escape host immune systems, leading to diverse strains with variable surface proteins. The immune response to one of these viruses focuses on the immunodominant but variable regions, which results in a strain-specific response. It is desirable to instead redirect the immune response to conserved areas of viral proteins, producing an immune response that can recognize and effectively eliminate many strains. In this work, we have developed recombinant proteins vaccines with the goal of eliciting broadly protective immune responses. We found that the highly immunogenic SARS-CoV-2 receptor binding domain elicits high titers of neutralizing antibodies against SARS-CoV-2 variants, while the more conserved S2 subunit elicits non-neutralizing though still protective immunity against SARS-CoV-2 and closely related viruses. The S proteins of SARS-CoV-2 and related CoVs can be combined into a cocktail vaccine to elicit neutralizing and broadly protective antibodies against clade 1 viruses. Lastly, we demonstrated that long-lasting immunity can be elicited by VLP-based HA vaccines. Together, the results of these different strategies may aid in the design of broadly protective vaccines.Ph.D.Bioengineerin
An Analytical and Experimental Investigation of Interface Nonlinearity and Reflection-Based Material Characterization Using Non-Collinear Shear Wave Mixing
No full textThis thesis investigates non-collinear shear-wave mixing as a nonlinear ultrasonic technique for interface and material characterization, with an emphasis on experimental validation of available analytical and computational models. The main study examines shear-shear wave mixing at interfaces between two solids in dry contact under varying contact pressures, serving as a model for adhesive and diffuse bonds with different degrees of imperfectness. The results show that under increasing loads, the nonlinear interface interaction coefficients decrease slower in comparison to analogous linear coefficients. These results demonstrate the higher sensitivity of nonlinear coefficients to subtle interface imperfectness as in high quality bonds. This comparison is achieved by integrating approximate phenomenological models and extrapolating onto the measured data. While linear reflection-based methods are simpler to apply, their sensitivity decreases rapidly with increasing load; these linear methods cannot distinguish between merely good and excellent bonded interfaces. The second part of this thesis introduces a reflection-based, single-sided measurement approach. Here two incident shear waves generate a mixed longitudinal wave at the free surface, creating a “virtual source” on this back (opposite) surface. Interesting is, that this experimental configuration generates two nonlinear ultrasonic phenomena simultaneously: the nonlinear wave mixing at the free surface and the second harmonic generation in the bulk of the material. This method overcomes the inherent phase cancellation that prevents normal incidence reflection nonlinear measurement techniques, enabling material nonlinearity characterization by analyzing the mixed wave and second harmonic generation signal accumulated on the propagation path to the top surface. These results show strong potential for a practical single-sided application of nonlinear ultrasonics in non destructive evaluation. Overall, these findings demonstrate applications for non-collinear shear-wave mixing, and establish advantages over linear methods for interface characterization, demonstrating new opportunities for reflection-based nonlinear material evaluation.M.S.Engineering Science and Mechanic
LiDAR-based Pothole Detection and Volume Estimation Pipeline Creation and Trade Space Exploration
No full textPhysical infrastructure, especially well-maintained roads, is essential for both economic growth and quality of life, as it enhances transport efficiency and safety. Potholes, however, present a serious safety risk, making regular road maintenance critical. Traditional pothole detection methods rely on labor-intensive manual surveys, but UAVs equipped with LiDAR provide a more automated and efficient alternative.
This thesis explores UAV-based LiDAR scanning for pothole detection and volume estimation by creating roadway Digital Elevation Models, using HELIOS++ for laser scanning simulation, and creating a process for pothole detection and volume estimation to develop an efficient and cost-effective pipeline for road maintenance and to investigate how flight and LiDAR parameters impact pothole detection rates and volume estimation accuracy.
The study found that low-severity potholes (7.5 cm radius, -2.5 cm depth) were detected at least 88\% of the time when the UAV velocity was 1 m/s and 75\% of the time at 2 m/s across 1 accuracy levels up to 2.4 cm using a rotating VLP16-based scanner at an altitude of 10 m. At both 1 m/s and 2 m/s, no false positives occurred when LiDAR accuracy was below 1 cm. At accuracies up to 1.4 cm, the false alarm rate remained low at 9\%. For moderate-severity potholes (20 cm radius, -4 cm depth), their volume was estimated at an average error of less than 10\% at UAV speeds through 6 m/s.
A key finding was a relationship between speed, altitude, and scan frequency that leads to a reduction in the probability of detection and increase in volume estimation error due to subsequent head rotation and channels aligning, creating gaps in the point cloud.
Results show that potholes with square cross-sections are detected more often than circular ones of the same dimensions, due to their larger cross-sectional area. Potholes with flat indentations are detected at higher rates and have volume estimated at higher accuracy than those with spherical or conic indentations due to their larger detectable area and relative indentation shape.M.S.Electrical and Computer Engineerin
Strategic Intra-Logistics Optimization in Large-Scale Assembly Facilities
No full textThe rapid growth in industrial production and the need for efficient logistics management have highlighted significant challenges in intra-logistics centers design and operations. Traditional approaches often fall short in addressing the stochastic requirements and complexities of modern logistics systems. This dissertation aims to address these challenges by proposing innovative solutions for optimizing logistics facility layouts and configurations, enhancing operational efficiency, and reducing overall costs.
In chapter 2, we concentrate on optimizing the dimensions and configuration of an inbound parts storage center in an assembly factory that stores modular containers. This center employs block stacking alongside racking systems for container storage. Given storage and throughput requirements for each part and stacking constraints, the objective is to determine the center size (rows, row length & depth) and the assignment of parts to stack locations to minimize total handling and space costs. We use a mixed-integer programming model (MIP) and introduce a heuristic approach to optimize the warehouse layout. The results of a large-scale experiment based on a major-brand carmaker factory are reported.
In chapter 3, we address the block stacking storage optimization problem using a simulation optimization approach. The total cost including area cost and material handling cost is used as the performance measure. We incorporate a heuristic algorithm into the simulation technology to design the layout and compare eight configuration options for 2 days restock cycle time vs various restock cycle time, deterministic vs stochastic consumption/inter-arrival time, shared vs dedicated storage policy. In order to implement the shared storage policy optimally, we also propose a new inventory control policy and compare different bays assignment policies. We report on the results of a large-scale experimentation based on the carmaker factory.
In chapter 4, we address the logistics facility configuration problem by defining protomodels. Protomodels are preliminary layout models that specify the relative locations of storage centers. Once a protomodel is established, we configure the logistics center by setting the dimensions of the storage centers and the flow of parts. We then optimize each center using a center optimization algorithm, such as block stacking optimization, rack optimization, floor optimization, or flow rack optimization. The overall objective is to minimize the total cost across all centers. The protomodel configuration algorithm is highly efficient, and we present the results of six protomodels using data from a large vehicle assembly factory.Ph.D.Industrial Engineerin