A Geoarcheological Survey of the Proposed Plainview Hike and Bike Trail, Hale County, Texas

In March of 2005, the Texas Department of Transportation issued work authorization #575-01-SA005 to the Center for Archaeological Research (CAR) at the University of Texas at San Antonio to conduct a survey of areas affected by proposed improvements to the Plainview hike and bike trail in southern Plainview, Hale County, Texas. The survey was conduced under Texas Antiquities Permit #3707 between March 31 and April 7, 2005. Steve Tomka and Raymond Mauldin served as Principal Investigators. Trail construction included 2.0 miles of additional construction and 1.3 miles of improvements to existing trails. The Right-of-Way is 50 feet and extends from one to three feet below ground surface. Archeological services included a pedestrian survey, excavation of fifty-five auger tests placed no more than 100 m apart, and twenty-one Gradall trenches. Two of these trenches exposed the stratigraphy of Running Water Draw near the Plainview Site, 41HA1. Bulk samples were collected for OSL dating, diatoms analysis, and lithologic analysis for further examination of the age and stratigraphic context of the Plainview Site, which is a State Archeological Landmark, a National Landmark, and a National Register of Historic Places property. Site 41HA12 was re-examined with 10 mechanical auger tests and 1 trench, which found only recent alluvial and cultural deposition. No additional archeological sites were recorded. This report includes descriptions of the fieldwork, results of the special analyses performed on bulk sediment samples collected, and a discussion of the geomorphology of Running Water Draw with specific focus on the results from trenches excavated near the Plainview Site. The single artifact and all documents and photographs generated from this project are curated at the Center for Archaeological Research at The University of Texas at San Antonio

Archeological Survey for the Loop 410 Improvements Project City of San Antonio, Bexar County, Texas

The Center for Archaeological Research (CAR) of the University of Texas at San Antonio was contracted by the HNTB Corporation (contracted by TxDOT) in 2000 to conduct an archeological survey of the proposed Loop 410 Improvements Project, San Antonio, Bexar County, Texas. The Area of Potential Effect (APE) is the current ROW and the proposed new ROW along Loop 410 and the three highways intersected by the loop. The project area is located along the southwestern portion of Loop 410 beginning about 0.61 miles northeast of FM 3487 (Culebra Road) and ending 2.25 miles east of IH 35 South. In addition, the project area included varying distances along three highways that intersect with Loop 410: SH 151, US 90, and US 35. The archeological work was conducted under Texas Antiquities Committee permit #3003 with Steve A. Tomka serving as Principal Investigator during the Phase I and Jennifer L. Thompson serving during Phase II and III. The intensive pedestrian survey was conducted in three phases. Phase I was conducted from July to September 2005. Phase II, was completed in April and May of 2007. No new archeology sites were documented during Phase I and II of archeological investigations. Four sites were revisited (41BX555, 41BX556, 41BX683 and 41BX704). All proved to be impacted by development and no cultural material was recovered. Phase III of the project consisted of 16 backhoe trenches placed in areas where deeply buried cultural deposits were probable. Only one trench (BHT 13) encountered artifacts. Testing was recommended on this site to determine if the site retains enough significance to make it eligible for listing in the National Register of Historic Places (NRHP) and/or for designation as a State Archeological Landmark (SAL). Tex Site forms requesting a trinomial were submitting and the field site was deemed 41BX1749. Access to properties along the proposed ROW was limited and 18 properties within the proposed ROW remain unsurveyed. CAR recommends survey of these properties when access is granted. All artifacts and records collected or generated during this project are curated at the Center for Archaeological Research according to Texas Historical Commission guidelines

Archeological Testing Associated with theStabilization of the Convento at Mission San Juan Capistrano (41BX5), San Antonio, Bexar County, Texas

In January and April, 2005, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted test excavations at Mission San Juan Capistrano (41BX5) for the San Antonio Missions National Historical Park of the National Park Service. The site is located approximately eight miles south of downtown San Antonio on the left bank of the San Antonio River. The purpose of the excavations was to provide information on the nature and content of the subsurface deposits in preparation for a major stabilization campaign around the convento at Mission San Juan that will result in the installation of an impermeable barrier around the structure. Concrete footers will also be installed under each buttress, if necessary. Six 1-x-1-meter units were excavated around the convento and Rooms 19 and 21. Excavations conducted by CAR revealed disturbed deposits on the west side of the convento. A cut-stone step feature was encountered on the southeast side of the convento, along with a footer that was exposed near the northeast corner of the building. Excavations also revealed the original sandstone foundation of San Juan Capistrano on the south side of Room 21. These investigations were conducted under Texas Antiquities Committee permit no. 3655 with Dr. Steve A. Tomka, CAR Director, serving as Principal Investigator. All cultural materials recovered and project-related documents are permanently curated at the Center for Archaeological Research

Maximizing the use of hydrogen as energy vector to cover the final energy demand for stand-alone systems, application and sensitivity analysis for the Canary Archipelago by 2040

[EN] Fossil fuel-based economies must undergo a deep transition for complete decarbonization. To this end, it is widely recognized that all economies must move towards the electrification of energy end uses. Even though there is a part that cannot be electrified, at least at affordable costs; clear examples are heavy road transport, maritime and air transport, and some industrial processes. As a result of the limitations of electrification in certain energy end uses, the potential use of hydrogen as an alternative energy carrier has been examined in recent decades. Hydrogen is seen as a viable option for the medium to long term. Specifically, efforts are being made in the case of the Canary Islands to move towards a carbon-free energy mix. In fact, the aim is to advance the economy decarbonization by 10 years over the date foreseen for both Europe and the rest of Spain. To this end, the HOMER program has been used to analyze the possibility of producing the necessary hydrogen in a scenario applied to the Canary Islands in which the uses of this energy vector have been maximized. This research considers two possible scenarios, together with a sensitivity analysis under the different uncertain conditions associated with the used technologies. The results have been the estimation of hydrogen production costs for high demands, about 230,000 tH2/year, in 2040 for an isolated archipelago under two totally different generation scenarios. The first scenario is totally renewable, while the other is based on nuclear generation by means of high-temperature SMRs. The results show, that it would be possible to produce at a cost in the range of 1 euro/kgH2 using nuclear technology and around 4 euro/kgH2 using renewables, with uncertainty cost ranges of around 40%, i.e. costs between 0.85-1.48 and 3.29-4.99 euro kgH2 respectively.The authors would like to express their gratitude to the Generalitat Valenciana (Spain) for its support under the Santiago Grisolia Program/2018/140. The authors also would like to extend their gratitude to the Ministerio de Economia, Industria y Competitividad and by Agencia Nacional de Investigacion under the FPI grant BES-2017-080031.Berna, C.; Rivera-Durán, Y.; Córdova-Chávez, Y.; Muñoz-Cobo, JL. (2023). Maximizing the use of hydrogen as energy vector to cover the final energy demand for stand-alone systems, application and sensitivity analysis for the Canary Archipelago by 2040. Progress in Nuclear Energy. 163. https://doi.org/10.1016/j.pnucene.2023.10479116

Resolución algebraica de problemas estequiométricos

La resolución de problemas, entendida como la metodología para enfrentar situaciones nuevas que impliquen un reto personal, es una estrategia didáctica eficaz que permite generar, consolidar e integrar conocimientos. La resolución de un problema típico en ciencias parte de la comprensión de su enunciado, constituido por un texto corto escrito en lenguaje natural; la traducción de dicha situación al lenguaje matemático constituye un obstáculo en el proceso de resolución de problemas con estructura matemática subyacente. Para desarrollar en los estudiantes de ingeniería química las habilidades matemática y de traducción de lenguajes coloquial-científico-algebraico, se diseñaron enunciados de problemas basados en la estequiometría de compuestos y reacciones, los cuales involucran el planteamiento y resolución de sistemas de ecuaciones algebraicas lineales

Experimental Measurements and CFD Results of Liquid Film Thickness in Vertical Downward Air-Water Annular Flow

[EN] Annular gas¿liquid flows have been extensively studied over the years. However, the nonlinear behavior of the interface is still currently the subject of study by multiple researchers worldwide. The appearance of a liquid layer on the wall and its turbulent behavior support the heat exchange of multiple systems in the industrial field. Research in this area allows the optimization of these installations as well as the analysis of possible safety problems if the liquid film disappears. This study first shows some of the most important findings obtained in the GEPELON experimental facility (GEneración de PElícula ONdulatoria or Wavy Film Generator). The facility was built in order to analyze the behavior of the liquid film in annular downward air¿water flow. The experimental range of the inlet conditions is 800¿8000 for the ReL and 0¿110,000 for the Reg. Measurements for the mean film thickness show a fairly good agreement with the empirical correlations and the measurements of other authors. One of the most demanded applications of this type of measurements is the validation of computational dynamics or CFD codes. Therefore, the experiment has been modeled using Ansys CFX software, and the simulation results have been compared with the experimental ones. This article outlines some of the reasons why two-phase flow simulations are currently challenging and how the codes are able to overcome them. Simulation predictions are fairly close to the experimental measurements, and the mean film thickness evolution when changing the boundary conditions also shows a good agreement.The authors are indebted to the plan of I+D support of the EXMOTRANSIN project ENE2016-79489-C2-1-P.Rivera-Durán, Y.; J. L. Muñoz-Cobo; A. Escrivá; C. Berna; Y. Córdova (2022). Experimental Measurements and CFD Results of Liquid Film Thickness in Vertical Downward Air-Water Annular Flow. International Journal of Computational Methods and Experimental Measurements. 10(2):93-103. https://doi.org/10.2495/CMEM-V10-N2-93-1039310310

Experiments in free falling and downward cocurrent annular flows-Characterization of liquid films and interfacial waves

[EN] Falling liquid films and downward cocurrent flows in rounded shape pipes have been experimentally studied during the last decades, estimating the evolution of its major characteristics. The most important variables during the formation and growth of surface waves in falling downward flows have been measured using conductance probes. The main objective of the current research paper is to study the dependency of the characteristics of the thin liquid layer for downward cocurrent annular flows. The GEPELON experimental facility consists of a vertical pipe with 3.8 m of useful test length. Two pipe diameters have been analysed in this experimental study, 42 and 30 mm, in which the range covered by the liquid Reynolds number varies between 570 and 8500 and 800-7900 respectively, while the gas Reynolds numbers vary from 0 to 7.9.10(4) and from 0 to 1.1.10(5) respectively for the mentioned pipe diameters. Up to five conductance probes have been placed along the pipes test sections to capture the liquid film thickness fluctuations along time at different distances of the pipe entrance for both developing and fully developed regions. After the study and analysis of the experimental data, the central point of this paper has been the development of new correlations for the liquid film thicknesses and the two major properties of the interfacial waves. Their adjustment procedure has been carried out in terms of dimensionless numbers, aiming to provide more general relationships. In particular, the magnitudes that characterise the interface behavior have been measured, particularly film thicknesses, average disturbance wave amplitudes, and disturbance wave frequencies for each boundary condition. An additional part of the document contains an extensive comparison between the results obtained in this study and the data and expressions of other authors. It has been confirmed the significant dispersion existing among different researchers, especially when analysing variables related to the interfacial waves. This highlights the lack of knowledge in some aspects even today. The different correlations proposed have been calculated based on the best fit of the data from all the series of experiments carried out in this study. Comparisons of the behaviour of these correlations with data from other researchers have also been included.This research is supported by the EXMOTRANSIN project ENE2016-79489-C2-1-P included in the I + D Spanish plan. Funding for open access charge: CRUE-Universitat Politècnica de València.Rivera-Durán, Y.; Berna, C.; Muñoz-Cobo, JL.; Escrivá, A.; Córdova, Y. (2022). Experiments in free falling and downward cocurrent annular flows-Characterization of liquid films and interfacial waves. Nuclear Engineering and Design. 392:1-23. https://doi.org/10.1016/j.nucengdes.2022.11176912339

Numerical simulation of air discharged in subcooled water pool

[EN] Turbulent jet discharges in subcooled water pools are essential for safety systems in nuclear power plants, specifically in the pressure suppression pool of boiling water reactors and In-containment Refueling Water Storage Tank of advanced pressurized water reactors. The gas and liquid flow in these systems is investigated using multiphase flow analysis. This field has been extensively examined using a combination of experiments, theoretical models, and Computational Fluid Dynamics (CFD) simulations. ANSYS CFX offers two approaches to model multiphase flow behavior. The non-homogeneous Eulerian-Eulerian Model has been used in this work; it computes global information and is more convenient to study interpenetrated fluids. This study utilized the Large Eddy Simulation Model as the turbulence model, as it is better suited for non-stationary and buoyant flows. The CFD results of this study were validated with experimental data and theoretical results previously obtained. The figures of merit dimensionless penetration length and the dimensionless buoyancy length show good agreement with the experimental measurements. Correlations for these variables were obtained as a function of dimensionless numbers to give generality using only initial boundary conditions. CFD numerical model developed in this research has the capability to simulate the behavior of non-condensable gases discharged in water.This work was supported by the project THAIS co-financed by the CSN (Nuclear Safety Council of Spain) and the UPV (Polytechnical University of Valencia). The authors also would like to express gratitude to the Generalitat Valenciana (Spain) for its support under the Santiago Grisolia Program/2018/140.Córdova, Y.; Blanco, D.; Rivera, Y.; Berna, C.; Muñoz-Cobo, JL.; Escrivá, A. (2023). Numerical simulation of air discharged in subcooled water pool. Nuclear Engineering and Technology. 55(10):3754-3767. https://doi.org/10.1016/j.net.2023.06.04137543767551

Pedestrian Survey and NRHP Eligibility Testing of Sites within a Proposed Detention Facility in Webb County, Texas

The Center for Archaeological Research (CAR) of The University of Texas at San Antonio was contracted by MACTEC Engineering & Consulting, Inc. (hereafter, MACTEC) to perform Phase I archaeological survey and Phase II testing prior to the construction of a detention facility in Webb County, Texas. Section 106 of the National Historic Preservation Act (NHPA) requires federal agencies to take into consideration the effects of proposed undertakings on cultural resources within the Area of Potential Effect (APE). While the proposed undertaking is being developed by The GEO Group, Inc. on privately owned property and is funded by private resources, the anticipated use of the facility by the United States Marshals Service makes this project a federal undertaking as defined under 36 CFR part 800.16(y). As such, the project must comply with Section 106 of the NHPA. The Texas Historical Commission (THC) is the reviewing agency for the project. In December, 2004, CAR conducted an intensive survey of the APE for the proposed construction of the detention facility. The survey followed MACTEC’s preliminary cultural resources assessment and included pedestrian survey with shovel testing within an approximate 160-acre tract, and backhoe trenching of selected locations within the approximate 30-acre APE of the proposed undertaking. Eleven field sites were defined as a result of the intensive survey (Field Site 1 [41WB634], Field Site 2, Field Site 3 [41WB636], and Field Sites 4–11). Subsequently, Phase II investigations were conducted by CAR to evaluate National Register of Historic Places (NRHP) eligibility and State Archeological Landmark (SAL) designation for eight of the originally identified field sites (numbers 2 and 5–11). The Phase II investigations included the hand excavation of test units as well as mechanical auger testing. Based on the combined results of the Phase I survey and Phase II investigations, seven sites were reported to the Texas Archeological Research Laboratory and assigned trinomials (41WB634 through 41WB640). Site 41WB639 was identified as containing archaeological components with significant research potential and therefore is recommended eligible for nomination to the NRHP and for formal designation as a SAL. The site contains a Middle Archaic component buried between 100 cm and 130 cm below surface that may yield information on a regional level. Based on the findings within the proposed project area, the site is interpreted as eligible for listing in the NRHP under Criterion D. Likewise, the site is interpreted as having the potential to contribute to a better understanding of the prehistory of Texas, and therefore eligible for SAL designation based on Criterion 1. Given the depth of the component and the shallow nature of the anticipated disturbances in the vicinity of the site (two feet or about 60 cm below surface), no construction impact is likely to effect the buried component and no further work is recommended at the site. However, in the case that construction parameters are changed and anticipated impacts reach below two feet (60 cm) in depth, data recovery efforts are recommended at the site. In addition, site 41WB634 was identified during the survey as having some research potential, although the NRHP and SAL eligibility of the site has not been determined. According to present construction plans, the site falls outside of the facilities footprint and will not be disturbed by construction activities. No additional archaeological investigations are recommended at the present time. The site contains a temporally unassigned, shallowly buried (10–50 cm below surface) archaeological component. If at a future date the facilities footprint is relocated or hitherto unanticipated subsurface disturbances are planned in the vicinity of this site, Phase II testing is recommended to establish the NRHP eligibility of the site. Finally, archaeological components buried at a depth of 70 cm below surface or deeper have been identified at sites 41WB637, 41WB638, and 41WB639. The NRHP/SAL eligibility of these deposits has not been fully assessed. However, the impacts of activities above these sites will consist of the planting of a grass cover and will otherwise be limited to foot traffic and therefore will be consistent with the guidelines set in the Intentional Burial of Sites as defined by the Texas Historical Commission. Therefore, no adverse affects will come to the deeply buried deposits at sites 41WB637, 41WB638 and 41WB639. The cultural materials recovered during these investigations were processed at the CAR laboratory. Following analysis, several artifact classes possessing little scientific values were discarded in consultation with MACTEC and the landowner. These artifact classes included snail shells, unburned rocks, heat spalls, modern glass, plastic, and unidentified metal fragments. In all instances, discarded materials were documented and their counts included in the report and curation documentation. All data was entered into Access and Excel spreadsheets, and copies of electronic and paper records were submitted to the client. All artifacts, including human remains, were returned to the landowner and all copies of project records are permanently curated at the Center for Archaeological Research

Experimental Characterization of the Dimensionless Momentum Length for Submerged Jet Discharges of Air-Steam Mixtures into Stagnant Water

[EN] A very efficient method of condensing the steam in various industrial applications is the steam direct discharge into pools with subcooled water. This kind of condensation is known as Direct Contact Condensation (DCC), by providing high heat transfer and mass exchange capacity, the steam condenses quickly. In the past few decades, many experiments have been carried out on the submerged jets of non-condensable gases and pure steam in pools, supplying much information of interest, but efforts are still being made to obtain more information. In particular, the research of steam and non-condensable gas mixtures is of great interest to the chemical, energy, and nuclear industry. Consequently, this study investigates the discharge behavior of air-steam mixtures in a pool with subcooled water by direct visualization techniques using a high-speed camera. To know the behavior of the dimensionless momentum length, tests were carried out considering several initial discharge conditions such as nozzle diameter, percentage of mixture, and flow rates. After image acquisition, a series of complex processing, filtering, and post-processing procedures are applied using a subroutine in MATLAB. The momentum length of the jet was measured and found to be heavily influenced by the nozzle diameter, the jet velocity, and the mixture percentage. A correlation is obtained for the dimensionless momentum length of the horizontal jet that depends on the Froude and Mach numbers.The authors would like to acknowledge the support provided through the Spanish project EXMOTRANSIN ENE2016-79489-C2-1-P and the Santiago Grisolía Program for the training of research personnel.Y. Córdova; D. Blanco; C. Berna; J. L. Muñoz-Cobo; A. Escrivá; Rivera-Durán, Y. (2022). Experimental Characterization of the Dimensionless Momentum Length for Submerged Jet Discharges of Air-Steam Mixtures into Stagnant Water. International Journal of Computational Methods and Experimental Measurements. 10(3):195-210. https://doi.org/10.2495/CMEM-V10-N3-195-21019521010