UTSA Runner Research Press (Univ. of Texas at San Antonio)
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Efficiency Enhancement of a Cone–Column Combined Microchannel Heat Sink Featuring Graphene–Water Nanofluid
Get PDFMicroelectronic technologies are progressing rapidly. As devices shrink in size, they produce a substantial heat flux that can adversely affect performance and shorten their lifespan. Conventional cooling methods, such as forced-air heat transfer and essential heat sinks, are inadequate for managing the elevated heat flux generated by these devices. Consequently, microchannel heat sinks have been developed to address this challenge. The present research is intended to study forced flow convection and heat transfer in a cone&ndash;column combined microchannel heat sink (MCHS). This study examines a regularly shaped MCHS to evaluate its heat transfer rate. The heat transfer medium employed is a graphene&ndash;water nanofluid, and the heat sink&rsquo;s base is assumed to maintain a constant heat flux. The Galerkin weighted finite element method solves the nanofluid&rsquo;s governing partial differential equations. This thesis investigates the impact of varying intake velocities on the Reynolds number (100 &le; <i>Re</i> &le; 900), externally applied heat flux (10<sup>4</sup> &le; <i>q</i> &le; 10<sup>6</sup>), and the volumetric ratio of nanoparticles (0.001 &le; <i>&phi;</i> &le; 0.04). The study conducts a mathematical analysis to explore how these parameters affect pressure drop, friction factor, average Nusselt number, average substrate temperature, and heat transfer enhancement. The findings are compared with those of a conventional MCHS as the <i>Re</i> increases. The results are analyzed and visually represented through isothermal lines for temperature contours and streamlines for velocity. An increase in the inlet velocity of the water&ndash;graphene nanofluid significantly enhances heat transfer and thermal efficiency, achieving improvements of approximately 27.00% and 21.21%, respectively. The research demonstrates that utilizing water&ndash;G as a smart coolant with the cone&ndash;column combined MCHS enhances thermal efficiency by 4.05% compared to standard water. A comparison of the hydraulic performance index at the substrate reveals that the cone&ndash;column combined MCHS is significantly more effective at dissipating heat than the traditional MCHS.Mechanical Engineerin
Technical Report, No. 111
Get PDFIn January 2024, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) conducted an intensive pedestrian survey of the proposed French Creek Greenway Extension Project in northwest San Antonio, Bexar County, Texas. The proposed trail is located along French Creek from Prue Road to Loop 1604. The work was conducted on behalf of the City of San Antonio (COSA) with Adams Environmental Inc. (AEI) serving as the project management team. The project took place on lands that are owned by subdivisions of the state of Texas and therefore are subject to review by the Texas Historical Commission (THC). The project falls under the Antiquities Code of Texas as well as COSA’s Unified Development Code (UDC; Article 6 35-630 to 35-634). CAR obtained Texas Antiquities Permit No. 31448 prior to the commencement of fieldwork. The permit was amended following a project redesign which eliminated approximately 2.5 km of the southern portion of the trail. The trail was originally proposed to run from Loop 1604 to OP Schnabel Park. Cynthia Munoz, CAR Interim Director, served as the Principal Investigator for the project, and Leonard Kemp served as the Project Archaeologist.
The project area of the proposed trail is 2.5 m wide with a 15.2-meter easement. It originally covered a linear distance of 5.0 km, but was revised to a length of 2.5 km, an area of roughly 12.8 acres (5.2 ha.). The northernmost section of the French Creek Greenway Extension project area begins 320 m southwest of the intersection of Loop 1604 and Bamberger Trail. The project area meanders southeast following French Creek where the revised trail terminates at Prue Road. CAR excavated 21 shovel tests (STs) within the project area north of Prue Road. All STs were negative for archaeological material. No artifacts
were documented on the ground surface. CAR recommends that construction of the French Creek Greenway Extension Project proceed as planned.
All records obtained and or generated during the project were prepared in accordance with the federal regulation 36 CFR part 79 and THC requirements for State Held in Trust collections. Upon completion of the project, all records generated during this project are permanently curated at CAR under Accession Number 2949.City of San Antonio, Public Works DepartmentCenter for Archaeological Researc
Archaeology along the San Antonio River: The Mission Reach Project, San Antonio, Bexar County, Texas, Volume 3: Excavation Summaries
No full textFrom September of 2010 through April of 2014, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) conducted monitoring, survey, test excavation, and data recovery work along the Mission Reach segment of the San Antonio River. The work was conducted under contract with the San Antonio River Authority (SARA) and was associated with construction of this segment of the San Antonio River Improvements Project (SARIP). The SARIP is a multi-year undertaking designed to restore and enhance the San Antonio River. Multiple federal, state, and local agencies were involved in the undertaking, including SARA, the U.S. Army Corps of Engineers (USACE), the National Parks Service (NPS), the City of San Antonio (COSA), and the Texas Historical Commission (THC). The Area of Potential Effect (APE) for the project covered a roughly 200 m wide swath along the San Antonio River in south-central Bexar County. The APE begins at the Theo Avenue Bridge and ends south of Mission Espada, about 11.5 km. Ancillary projects were added to the APE and include the VFW Boulevard Drainage Improvements Project, the Secondary Impacts Survey, the San Juan Facilities Monitoring, the
Espada Portal Monitoring, and the San Juan Trail Expansion. The combined project area is estimated to be roughly 3 km2 in size. CAR conducted the work under THC Antiquities Permit No. 5957, originally issued to Dr. Steve Tomka of CAR. Dr. Raymond Mauldin of CAR completed the permit. Much of the land is currently within the boundaries of the San Antonio Missions National Historic Park.
In the Mission Research section of the project, CAR conducted work at three previously identified archaeological sites (41BX254, 41BX256, and 41BX1628) at which data recovery efforts had been completed. CAR also conducted work at a known but previously untested prehistoric component at site 41BX1785 and performed trenching and testing at four newly defined sites (41BX1888, 41BX1902, 41BX2071, and 41BX2089). Finally, in conjunction with geomorphologic observations, CAR defined four new sites (41BX2113, 41BX2114, 41BX2115, and 41BX2116) along the banks of the San Antonio River in southern Bexar County. Work at these four sites was confined to radiocarbon dating features observed in the river cut banks. These 12 sites span the temporal sequence in the San Antonio area, with occupations stretching from the historic period back to the Paleoindian period. Ancillary projects included monitoring and survey work at 41BX5, 41BX340, 41BX341, 41BX706, 41BX1917, and along sections of the San Juan and Espada acequias.
Reporting on this work is summarized in four volumes. Volume 1 provides background to the project. Volume 2 focuses on the results of monitoring and survey along the San Antonio River, including the results of the ancillary projects. Volume 3 focuses on site testing, data recovery, and analysis. It includes a geomorphic study, excavation details for 41BX2089, 41BX1628, 41BX1888, 41BX1902, 41BX256, and 41BX1785, a regional synthesis of radiocarbon dates, and a summary of burned clay features, many of which have been argued to reflect structures. Volume 4 consists primarily of appendices that support the analysis in Volume 3 and smaller studies that were otherwise associated with the Mission Reach Project. CAR is serving as the curatorial facility for records and artifacts associated with the project. These items are being held in trust for the State of Texas and the National Parks Service. They have been assigned accession number 1883. Buried clay from the Tomka experimental structure is accessioned as number 2730.San Antonio River AuthorityCenter for Archaeological Researc
SDR-Fi-Z: A Wireless Local Area Network-Fingerprinting-Based Indoor Positioning Method for E911 Vertical Accuracy Mandate
No full textThe Enhanced 911 (E911) mandate of the Federal Communications Commission (FCC) drives the evolution of indoor three-dimensional (3D) location/positioning services for emergency calls. Many indoor localization systems exploit location-dependent wireless signaling signatures, often called fingerprints, and machine learning techniques for position estimation. In particular, received signal strength indicators (RSSIs) and Channel State Information (CSI) in Wireless Local Area Networks (WLANs or Wi-Fi) have gained popularity and have been addressed in the literature. While RSSI signatures are easy to collect, the fluctuation of wireless signals resulting from environmental uncertainties leads to considerable variations in RSSIs, which poses a challenge to accurate localization on a single floor, not to mention multi-floor or even three-dimensional (3D) indoor localization. Considering recent E911 mandate attention to vertical location accuracy, this study aimed to investigate CSI from Wi-Fi signals to produce baseline Z-axis location data, which has not been thoroughly addressed. To that end, we utilized CSI measurements and two representative machine learning methods, an artificial neural network (ANN) and convolutional neural network (CNN), to estimate both 3D and vertical-axis positioning feasibility to achieve E911 accuracy compliance.Electrical and Computer Engineerin
Technical Report, No. 112
No full textThe University of Texas at San Antonio’s Center for Archaeological Research (CAR), in response to a request from the City of San Antonio (COSA), conducted archaeological monitoring of an excavation for a sewer line repair at San Pedro Springs Park (41BX19) in north central San Antonio, Bexar County, Texas. San Pedro Springs Park is listed on the National Register of Historic Places and is a State Antiquities Landmark. The Project Area is on public municipal property. As such, undertakings that might affect archaeological or historical sites are subject to regulatory review. At the municipal level, the property falls under COSA’s Unified Development Code (Article 6 35-630 to 35-634) and requires review by COSA’s Office of Historic Preservation. The project also required review by the Texas Historical Commission under the Antiquities Code of Texas. CAR obtained Texas Antiquities Permit Number 32020 prior to the commencement of archaeological monitoring. Cynthia Munoz, Interim Director of the CAR, served as the Principal Investigator and Leonard Kemp served as the Project Archaeologist.
The Project Area is 0.02 hectare (0.05 acre) in size. The permit scope of work (SOW) incorrectly measured the area as 95 m2(0.02 acre). One trench was excavated within the footprint of the existing sewer line. No features were uncovered during this investigation and only one artifact, a uniface fragment, was found in the spoil pile from the northern portion of the trench. CAR recommends that no further action is required under this permit. All generated records and the single artifact collected from this project are permanently curated at the CAR under Accession Number 2992.City of San AntonioCenter for Archaeological Researc
Whole genome uniparental isodisomy detected using single nucleotide polymorphism (SNP) microarray in molar pregnancy: a case report
No full textBackground
Gestational trophoblastic neoplasms consist of complete and partial hydatidiform moles, both of which are considered aberrant conceptuses. Both conditions, complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM), differ in histological characteristics, genetic origin and content and clinical features. CHM have a diploid karyotype, mostly 46,XX but lack maternal genetic contribution with all chromosomes of paternal origin. High-resolution SNP microarray testing is an efficient method used to determine the parental contribution of the genomic material in molar pregnancies and confirm the diagnosis.
Case presentation
We present a case of CHM in a 43-year-old, G3P2Ab1 who presented to the emergency department with 2 episodes of heavy bleeding. Chromosome analysis showed a normal 46,XX karyotype but with a homozygous pericentric inversion on chromosome 9. High-resolution SNP microarray studies detected whole genome uniparental isodisomy.
Conclusion
We present a case of CHM with homozygous pericentric inversion on chromosome 9 and whole genome uniparental isodisomy. This case illustrates the efficacy of high-resolution SNP microarray in confirming the diagnosis of CHM.Pathology and Laboratory medicin
A Stochastic Game-Theoretic Optimization Approach for Managing Coupled Local Electricity and Thermal Markets with Electric Vehicles and Renewable Sources
No full textWith the growing need for sustainable, and environmentally friendly energy ecosystems—alongside the rapid adoption of electric vehicles (EVs), renewable energy sources (RESs), combined heat and power systems (CHPs), and heat pumps (HPs)—local energy markets (LEMs) present a distinct potential to promote clean energy, enhance grid stability, and lower emissions. However, unlocking the full potential of LEMs requires addressing complex challenges related to market dynamics, EVs and RESs integration, and electricity-thermal energy interdependency. Our study presents a stochastic bi-level model for managing LEMs, where the local transaction center (LTC) and other market participants—load aggregator (LA), charging station (CS), pure thermal industrial prosumers (PTIP) and their lower-level prosumers—aim to maximize their profits in a competitive game-theoretic structure. To ensure grid stability and profitability, the LTC, as the leader, designs a robust dynamic pricing strategy under uncertainty, while the LA, CS, and PTIP, as followers, determine the energy transaction amounts under uncertainties in generation and consumption. We address several novel aspects of LEMs, including the heterogeneous behavior of entities, uncertainties in renewable generation and load profiles, and electricity-thermal energy coupling. We propose a centralized solution approach based on Karush–Kuhn–Tucker optimization and a scenario decomposition approach leveraging a parallel hybrid decomposition algorithm for solving the LEM management problem. The centralized method provides optimal solutions for limited scenarios, whereas the decomposition approach achieves high-quality solutions faster with larger scenario sets. Results demonstrate that incorporating electricity-thermal interdependence leads to a 27% higher LTC profit compared to ignoring this key factor.Mechanical Engineerin
A Study of Far-Flank Reconnection and Instrument Calibration at Earth's Magnetopause
No full textMagnetic reconnection is a fundamental plasma process, meaning it occurs in all plasmas. Magnetic reconnection involves the breaking and re-establishing of magnetic field lines in a plasma, such that mass and energy are transferred between plasmas. Notably, magnetic reconnection is extremely prevalent in the Earth’s magnetosphere making it an ideal laboratory to study this phenomenon. The Magnetospheric Multiscale Mission (MMS) was designed to study exactly that.
There is little discussion of magnetic reconnection on the flanks of the Earth’s magnetosphere. The flanks are regions near or past the terminator (dawn-dusk line) of Earth. I address this problem directly, first by completing a statistical study of far-flank magnetopause crossings. The magnetopause is the boundary between the Earth’s magnetic field and the Sun’s. In these magnetopause crossings, I looked for signatures of reconnection in both the ions and the electrons. I find that reconnection is prevalent in this region under the right circumstances, like the IMF being predominantly southward. Reconnection occurs despite some theory and simulations suggesting otherwise. I also find that there are some discrepancies in the observations, such as occasional disagreement between ion and electron signatures.
Plasma flows into the reconnection region at a slow rate and gets expelled in two oppositely directed “jets” or beams. The direction of the beam tells us where the spacecraft was with respect to the reconnection x-line. Therefore, the mismatched reconnection signatures found in the first study were of particular note.
To investigate this finding, I completed a study of reconnection events very close to the reconnection site and compare these observations with a simulation. These events are referred to as beam switch events, as you can see the physical reversal of the ion or electron beam. I established basic parameters for these events. From the comparison to the simulations, I discovered that spacecraft data and more accurate simulations are comparable.
I assisted in the calibration of the ion instrument, ACI1, onboard one of the TRACERS satellites. This calibration was completed such that the instrument was characterized and the data received from the instrument, in counts, could be converted to the more physically useful flux. The calibration of this instrument is vital to the work in this dissertation, as it showcases a real-life example of how data are obtained and processed.
In conclusion, in this thesis I find that far-flank reconnection occurs regularly under the correct circumstances and there are some discrepancies in the observations when comparing electron and ion reconnection signatures. I then find boundary conditions for far-flank reconnection and compare them to presently existing simulations, finding the two to be comparable. Finally, I assisted in the calibration of an ion instrument to reinforce the importance of data collection and processing.Physics and Astronom
Façade Psychology Is Hardwired: AI Selects Windows Supporting Health
No full textThis study uses generative AI to investigate the influence of building façade geometry on human physiological and psychological health. Employing Christopher Alexander's fifteen fundamental properties of living geometry and a set of ten emotional descriptors {beauty, calmness, coherence, comfort, empathy, intimacy, reassurance, relaxation, visual pleasure, well-being} in separate tests, ChatGPT 4.5 evaluates simple, contrasting window designs. AI analyses strongly and consistently prefer traditional window geometries, characterized by symmetrical arrangements and coherent visual structure, over fragmented or minimalist–modernist alternatives. These results suggest human cognitive–emotional responses to architectural forms are hardwired through evolution, privileging specific geometric patterns. Finally, ChatGPT o3 formulates ten detailed geometric rules for empathetic window design and composition. It then applies these criteria to select contemporary window typologies that generate the highest anxiety. The seven most anxiety-inducing designs are the most favored today worldwide. The findings challenge contemporary architectural preferences and standard window archetypes by emphasizing the significance of empathetic and health-promoting façade designs. Given the general suspicion among many readers of the frequently manipulative and unreliable use of AI, its use in this experiment is not to validate design decisions directly, which would put into question what the AI is trained with, but to prove a correlation between two established methodologies for evaluating a design. AI is used as an analytical tool to show that Alexander's geometric rules (the guidelines proposed beforehand) closely match emotional reactions (the desirable outcomes observed afterward). This novel use of AI suggests integrating neurodesign principles into architectural education and practice to prioritize urban vitality through psychological well-being.Mathematic
Teaching with Primary Sources: Vote
No full textBased on United States Government Texas Essential Knowledge & SkillsThese easy to incorporate activities will inspire inquiry-based learning that will teach your students how to analyze and interpret primary sources, and bring the museum experience to your classroom! This activity includes images and documents intended to inspire civic education and participation, while focusing on young voters