Quantum technological dating of glacier ice from the last millennium and a new self-contained facility for routine measurements

The noble gas radioisotopes 85Kr, 39Ar and 81Kr are of great importance in radiometric dating because their half-lives cover time scales from the last millennium to one million years before present. They are present as inert trace gases in the atmosphere and the exchange with other environmental reservoirs makes them ideal tracers for hydrology, oceanography and glaciology. Their very low isotopic abundance is the huge hindrance for the detection and analysis. Especially in the case of argon with a natural abundance of 8x10^−16, classical decay counting requires tons of water or ice and measurement times of several weeks. To reduce the sample size, techniques from the field of quantum optics are applied to capture the atoms directly rather than rely on their decay signature. Argon Trap Trace Analysis is capable of daily measurements using samples as small as 0.5 mL STP argon and this is demonstrated here for glacier ice. A few kilograms of ice have been taken in artificial glacier caves and the measured argon ages are validated against preexisting constraints. These results and recent pilot studies have arisen a huge demand for small sample radio-argon dating. To meet this development, a second apparatus has been built in a self-sufficient laboratory container. The new machine is optimized for robustness and will increase the sample throughput capacities in the near-future. Furthermore, a setup has been built to characterize and improve the performance of the argon source, a main loss factor concerning efficienc

The Climatic and Hydrostratigraphic Controls on Brine-to-Freshwater Interface Dynamics in Hyperarid Climates: A 2-D Parametric Groundwater Modeling Study

Density dependent flow occurs in areas where high-salinity groundwater interacts with low-salinity groundwater to create a brine-to-freshwater interface that defies common assumptions about groundwater movement. Yet the geologic and hydrologic factors that impact interface dynamics and migration remain poorly defined. With less than 20 mm•yr-1 of precipitation and with an extremely dense (i.e. 1.2 g•cm-3) naturally occurring brine, Chile’s Salar de Atacama (SdA) provides an excellent analog for exploring interface dynamics in other arid regions. Site-specific 2-D models of the interface in the southeastern region of SdA, with interpretations of the hydrostratigraphic framework, provide an analysis for density-driven response rates to climatic change. A separate parametric, equally probable series of distributions of hydraulic conductivity provides a means for expanding analysis to other similar arid salar (i.e. “salt flat”) environments. Comparing the modeled interface’s geometry and response to perturbations in the rates of lateral recharge in each hydrostratigraphic realization yields insight into the dynamics of interface migration to coupled climatic and geologic conditions. Changes in hydrologic conditions, informed by paleoclimatic interpretations and previously modeled climate predictions, are introduced to each hydrostratigraphic realization following the interface reaching an initial dynamic equilibrium, and the interface’s response is assessed subsequent to it reaching a new dynamic equilibrium. Metrics for model evaluation include migration rate, change in the interface’s areal extent, change in interface slope, and the response rate following the introduction to a perturbation in the aquifer’s hydrology. Model analyses suggest that evaporation rates strongly control the interface’s geometry and sensitivity despite climatic and geologic conditions; continuity of high-permeability pathways controls interface slope; increasing continuity also decreases interface stability in terms of time required to reach a new steady state. While these results have implications for interface dynamics in both salars specifically and arid climates in general, they also indicate the importance of considering hydrostatigraphic continuity for saline water intrusion in coastal regions. They also provide a compelling method for assessing interface dynamics in other climatic and geologic conditions

45th Rocky Mountain Conference on Analytical Chemistry

Final program, abstracts, and information about the 45th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 27-31, 2003

Nuclear Power

The world of the twenty first century is an energy consuming society. Due to increasing population and living standards, each year the world requires more energy and new efficient systems for delivering it. Furthermore, the new systems must be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. The goal of the book is to show the current state-of-the-art in the covered technical areas as well as to demonstrate how general engineering principles and methods can be applied to nuclear power systems

Maintaining leachate flow through a leach bed reactor during anaerobic digestion of high-solids cattle manure

2018 Fall.Includes bibliographical references.To address the accumulation of high-solids cattle manure (HSCM) found at many of the state's Animal Feeding Operations (AFOs), researchers at CSU have developed a Multi-Stage Anaerobic Digester (MSAD). The MSAD system consists of a leach bed reactor (LBR), a compositing tank, and a fixed-film methanogenic reactor. The LBR is a critical part of the MSAD system since hydrolysis can be a rate-limiting step in the anaerobic digestion of HSCM (Hinds 2015; Veeken and Hamelers 1999). To ensure that hydrolysis is occurring properly within the reactor, leachate injection and reactor operation must proceed in a manner that facilitates uniform distribution of leachate through the manure waste bed. Since the leachate must be recirculated through the LBR for the entirety of the batch digestion time, any phenomena that disrupt the duration or uniformity of leachate distribution must be addressed. The overarching goal of this thesis project was to improve the hydraulic performance of the LBR stage of the MSAD. This research included a multi-criterion decision analysis (MCDA) to assess unique design aspects of the MSAD relative to other technologies, construction and operation of a prototype LBR, and the development of an experimentation strategy to assess mechanism of hydraulic failure in the LBR. The MSAD system was compared to four other high-solids anaerobic digester technologies using a MCDA. The purpose of this comparison was to identify unique design features of the MSAD technology compared to other high-solids anaerobic digestion technologies to inform the focus of future design and research activities. The technologies were rated and evaluated for the following criteria: operational requirements, impact of hydraulic failure, capital requirements, operational control, feedstock technology fit, and process efficiency. The scores ranged from 2.9 to 3.7 out of 5 possible points. Under equal criteria weighting, the MSAD system received the highest rating with a score of 3.7. The MSAD system received high ratings due to its strong hydraulic performance, operational control, and process efficiency. Knowledge gained through laboratory and prototype-scale LBR experimentation was used to establish possible improvements to LBR design. The primary improvement to the LBR was the modification from a downflow to an upflow configuration. A prototype LBR was operated in the upflow configuration to facilitate longer durations of undisrupted leachate permeation. In addition, it was determined that leachate injection spacing should be studied further as results from operation of the prototype LBR suggested that higher volatile solids reduction occurred closer to the leachate influent manifold. Column experiments and prototype operation showed some successful operation of LBRs for treating HSCM. However, hydraulic failures due to clogging and preferential pathway formation were observed. Due to the continued risk of hydraulic failure, further research was needed to understand mechanisms for hydraulic failure and to determine approaches to overcome these issues. At commercial scale, hydraulic failure of LBRs would result in decreased energy and agricultural product output and increased operating costs. Since commercial processes rely on reproducible results, a high degree of LBR reliability is required to achieve technical and economic feasibility. Therefore, control over the hydraulic performance of LBRs is critical for commercialization of the MSAD system. To this end, an experimentation strategy was developed, with the goal to elucidate the mechanisms behind hydraulic failures occurring in the LBR. To evaluate these mechanisms, the experimentation strategy recommends the use of electrical resistivity tomography (ERT) to render visualizations of leachate distribution throughout the waste bed. Further characterization of the pore space network geometry at the microscale using either Magnetic Resonance Imaging (MRI) or X-ray Computed Tomography (X-ray CT) is recommended

Characterizing Petrophysical Properties of Carbonate Rocks Using Nuclear Magnetic Resonance and Complex Conductivity

Carbonate rocks are well known for their highly complex petrophysical behaviors due to their intrinsically heterogeneous pore geometry and wide range of pore sizes. As a result, both effective characterization of carbonate pore systems and the prediction of fluid transport in carbonate reservoirs, remains challenging. This thesis focuses on using nuclear magnetic resonance (NMR) and complex conductivity to quantify carbonate pore structure and gain insights into fluid flow and lithology of carbonate reservoir rocks at the core and log scales. In the laboratory study, integrated NMR and complex conductivity data are used to characterize porosity, pore size distribution, and surface area-to-pore volume ratio, in grainstones, packstones, and mudstones from carbonate reservoirs in Kansas. Carbonate samples with varying pore types and depositional texture are characterized according to NMR porosity, log-mean of transverse relaxation time (T2) value T2ML, real conductivity σ', and imaginary conductivity σ". Widely used petrophysical relationships derived from NMR and complex conductivity data also are assessed, and alternative relationships appropriate for carbonate samples at laboratory scale are proposed. Furthermore, to test the proposed petrophysical relationships at a larger spatial scale, and to exploit the potential of borehole NMR data, this study analyzes NMR well log data from Wellington, KS. This study focus on the uses of NMR longitudinal and transverse relaxation time ratio (T1/T2) in electrofacies characterization. Through multivariate analysis of a suite of logs (e.g., sonic slowness, photoelectric factor, etc.), the results show that T1/T2 ratio is uncorrelated with other logs which makes it a potentially independent indicator for rock typing. The data bear on the accuracy of predicted electrofacies using T1/T2 ratio, and how factors such as lithology and fluid could impact the T1/T2 ratio. Extending beyond experimental observations, this work assesses and proposes new electrical and NMR petrophysical models, analyzes the factors controlling the variation within NMR logging data, and harnesses the complete NMR logging information to improve carbonate reservoir characterization. This work demonstrates the potential of combining NMR and electrical methods to advance understandings of fluid distribution and fluid flow in complex carbonate reservoirs

Exploration of Villarrica Geothermal System using Geophysical and Geochemical Techniques [Finale Version]

Für den globalen, zukünftigen Energiemix prognostiziert die internationale Energieagentur (IEA) einen erheblichen Beitrag aus geothermischer Energie. Dabei soll die grundlastfähige, dezentrale und permanent verfügbare Energiequelle helfen, fossile Energieträger zu ersetzen. Aktuell konzentriert sich die Erschließung geothermischer Lagerstätten vor allem auf konventionelle High-Enthalpy Ressourcen, die oftmals in Zusammenhang mit Vulkanismus oder Magmatismus an aktiven Kontinentalrändern oder Rifting-Prozessen auftreten. Die aktiven Kontinentalränder, die den Pazifik umspannen (auch "pazifischer Feuerring" genannt), werden von vielen Anrainern geothermisch genutzt. Lediglich in der Andenregion konnten bislang keine nennenswerten geothermischen Ressourcen erschlossen werden. Chile hat, nach Inbetriebnahme des ersten geothermischen Kraftwerks, begonnen das geothermische Potential systematisch zu entwickeln. Dabei sollen, um eine nachhaltige Energieversorgung zu gewährleisten, neben der Erschließung von High-Enthalpy Lagerstätten auch Low/Medium-Enthalpy Reservoire genutzt werden. Global gesehen sind Low/Medium-Enthalpy Reservoire oft an große Störungssysteme oder geothermische geeignete Gesteinsformationen gebunden. Zur Auffindung und Charakterisierung der Lagerstätten bedarf es einer angepassten Explorationsstrategie, da klassische geothermische Exploration auf High-Enthalpy Ressourcen ausgelegt ist. Im Rahmen dieser Doktorarbeit soll eine Explorationsstrategie für Low/Medium Enthalpy Geothermierreservoire in Chile entwickelt werden. Als Forschungsstandort wurde das Geothermalsystem am Vulkan Villarrica gewählt, da der Erfolg der Explorationsstrategie zur Charakterisierung des komplexen Störungszonensystems und eines markanten Lithologie Wechsel getestet werden kann. Um sowohl die Reservoirgeometrie als auch Reservoirprozesse quantifizieren zu können, wurde ein interdisziplinarer Ansatz gewählt, der geochemische und geophysikalische Methoden koppelt. Störungszonensysteme besitzen eine übergeordnete Bedeutung zur Ausbildung des geothermischen Zirkulationssystems und somit zur Bildung der Lagerstätte. Der Forschungsstandort ist gekennzeichnet durch das Schneiden zweier überregionaler Störungszonen, der Liquiñe-Ofqui Störungssystem (LOFS) und der Mocha-Villarrica Störungszone (MVFZ), die mit geophysikalischen Methoden untersucht werden. Mit Hilfe hoch aufgelöster magnetotellurischer Messungen können beide Störungszonen durch verminderte elektrische Widerstände identifiziert werden. Diese Widerstandsreduktion wird durch das Auftreten von leitfähigen geothermischen Tiefenwässern und/oder hydrothermalen Alterationsprodukten hervorgerufen werden. Für die MVFZ zeigen die Untersuchungen eine nordwärts einfallende Störungszone, die mit einer Zone erhöhter elektrischer Leitfähigkeit in der mittleren Kruste verbunden ist. Der Ausbiss der Störungszone fällt mit der Lage der Villarrica-Quetrupillán- Lanín Vulkankette zusammen. Die LOFS zeigt sich als vertikale Zone erhöhter Leitfähigkeit, die sich von der Erdoberfläche bis zum Spröd-Duktilen Übergang erstreckt. Ein mögliches Eindringen in den duktilen Bereich mit potentieller Verbindung zu einer vorhandenen Zone erhöhter Leitfähigkeit in der mittleren Kruste wird durch erhöhte Leitfähigkeiten der duktilen Kruste maskiert. Parallel zu den MT Profilen werden gravimetrische Messungen durchgeführt. Die LOFS zeichnet sich durch eine markante negative Bouguer Anomalie aus, die räumlich mit den erhöhten Leitfähigkeiten übereinstimmt. Die Anwendung von Butterworth Filtern in Kombination mit gravimetrischer Modellierung ermöglicht die Bestimmung der Störungszonengeometrie und die Quantifizierung des Dichtekontrasts. In einer gemeinsamen Interpretation magnetotellurischer und gravimetrischer Daten können die Eigenschaften der LOFS in Bezug auf Tonmineralgehalt und Porosität berechnet werden um die Permeabilität der Störungszone abzuschätzen. Mit Hilfe geochemischer Methoden sollen die Reservoirprozesse charakterisiert werden. Dazu werden die Thermalwasseraustritte als Fenster zum Untergrund genutzt um den Ursprung und die Genese der Thermalwässer zu bestimmen. Es kann gezeigt werden, dass die Thermalwässer meteorische Ursprungs sind und durch intensive Reaktion mit Kristallin Gestein entstehen. Obwohl räumliche Nähe zu aktiven Vulkanen besteht, kann kein substantieller Einfluss magmatischer Fluide oder Gase festgestellt werden. Nachfolgend werden die Gesteins-Wasser Wechselwirkungen durch eine vergleichende Studie der Thermalwässer und möglicher Reservoirgesteine untersucht. Dabei wird der markante Lithologie Kontrast, zwischen plutonischen Gesteinen des Nord Patagonischen Batholiths (NPB) und vulkano-klastischen Gesteinen der Cura-Mallín Formation, durch die Analyse von Strontium Isotopen nachgezeichnet. Durch Analyse von FCKW Spezies und Sauerstoff Isotopen des SO4-H2O Systems kann gezeigt werden, dass in beiden Formationen unterschiedliche Fluidzirkulationssysteme auftreten. Im NPB kommt es zu einer Konzentration der Thermalwasserzirkulation auf Hauptstörungszonen, wohingegen für die Cura-Mallín Formation eine verzweigtere Fluidzirkulation nachgewiesen werden kann. Die Analyse der verschiedenen FCKW Spezies ermöglicht die Quantifizierung der Vermischungsprozesse im Untergrund und kann so genutzt werden um die in-situ Thermalwasserzusammensetzung zu ermitteln. Erst diese ermöglicht eine genaue Bestimmung der Reservoirbedingungen und des geothermischen Potentials. Der Villarrica Geothermalsystem besitzt ein erhöhtes geothermisches Potential. Durch Thermalwasseraufstieg entlang der Hauptstörungszonen bilden sich Reservoire in erschließbarer Tiefe. Als unterirdischer Wärmetauscher eignet sich vor allem die Cura-Mallín Formation durch das verzweigte Fließfeld. Maximale Reservoirtemperaturen 140–180°C eignen sich beispielsweise zur Wärmeversorgung der Stadt Pucón durch eine Fernwärmesystem

SURE 2022 Undergraduate Science Conference Booklet

The SURE 2022 Conference was the fifth series of Science Undergraduate Research Experience (SURE) Conferences. The conference took place on Friday, 14th October, 2022, co-hosted by SETU – Carlow campus and TU Dublin as a live Face2Face event running simultaneously in both venues on the same day. Students from throughout Ireland completing their Final Year Project in a science discipline in 2021-22 presented their undergraduate research work to this conference. The aims of each of the SURE conferences are to: Provide current students with an opportunity to gain an understanding of the work which has been undertaken by recent graduates, and the career opportunities that exist for graduates in Scientific disciplines. Provide recent graduates with an opportunity to gain a reviewed publication based on the scientific research undertaken by them during their undergraduate studies in SURE-J, Irelands first and only undergraduate expert reveiwed research journal. Celebrate the academic achievements of recent graduates in the scientific disciplines. Provide a multi-disciplinary scientific forum through which undergraduate research outputs can be disseminated to students, researchers, academic professionals and industry