bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joule Heating of Brine Saturated Berea Sandstone: Observations from DC Electric Current
Authors: Smalls P. T. , Villamor-Lora R. , Germaine J. T. , Einstein H. H. 
Published: September 2023

ABSTRACT
High-voltage electrical current can be utilized to increase rock permeability and can be a sustainable alternative to decrease water consumption associated with hydraulic fracturing. During previous applications of this technique, ion carriers, mainly brine water, evaporated as temperature increased during electrical resistive (joule) heating of the reservoir, limiting effectiveness of the technique. Understanding how electrical conductivity evolves as a function of applied electrical current is fundamental for developing methods to overcome previous limitations of the technique. In this study, we developed a first-of-its kind triaxial cell that allows one to apply electrical current, with temperature and pore pressure data collected during the joule heating process of a Berea Sandstone rock specimen. We investigated the relationships between pore fluid composition, pore pressure, and electrical conductivity evolution. The relationships between pore fluid composition, and joule heating evolution under variable electrical energy inputs are important to understand for analyzing the long-term effectiveness of electrical rock fracturing.

INTRODUCTION
Waterless permeability enhancement techniques including mechanical, gaseous, and electrical based methods have been previously investigated to address the environmental concerns associated with hydraulic fracturing (e.g., Gandossi 2013, Kumar et. al, 2017, Wang et. al, 2016). However, widespread adoption of these techniques has stalled due to limitations in stimulated reservoir volume, and environmental safety concerns associated with the exposure of hazardous gases as a fracturing fluid. Alternatively, electrical resistive heating has proven effective at stimulating petroleum reservoirs to increase production (e.g., Elder et. al, 1957, Rehman and Meribout, 2012).
Waterless permeability enhancement techniques including mechanical, gaseous, and electrical based methods have been previously investigated to address the environmental concerns associated with hydraulic fracturing (e.g., Gandossi 2013, Kumar et. al, 2017, Wang et. al, 2016). However, widespread adoption of these techniques has stalled due to limitations in stimulated reservoir volume, and environmental safety concerns associated with the exposure of hazardous gases as a fracturing fluid. Alternatively, electrical resistive heating has proven effective at stimulating petroleum reservoirs to increase production (e.g., Elder et. al, 1957, Rehman and Meribout, 2012).
Production of Ceramic from Sulfidic Mine Tailings and Investigation of Fracture Toughness Under Mode I Loading
Authors: Shabani F. , Asadizadeh M. , Hedayat A. , Tunstall L. , Gorman B. P. , Taboada Neira M. , Vega González J. A. , Verá Alvarado J. W. 
Published: September 2023

ABSTRACT
Mine tailings (MTs) are the waste of mining operations after the valuable metals have been extracted. Given the significant quantities produced globally, the deposition of MTs causes problems including occupation of large areas of land and environmental contamination by toxic leachates. The production of sustainable construction materials from MTs is an environmentally friendly solution to reduce the consumption of natural resources and decrease their adverse impacts on the environment. This study investigates the feasibility of using sulfidic MTs in the production of ceramics. A targeted physical, mineralogical, and chemical characterization of the tailings resulted in the development of a production process that involved grinding the raw tailings, mixing with binders, pressing circular specimens, and then sintering. The properties of sintered ceramics, including crystalline phase, density, water absorption, and compressive strength, were investigated. The mode I fracture toughness of the ceramics was assessed by subjecting a notched semi-circular bending (NSCB) specimen to three-point bending loading. The full-field strains on the surface of the specimens were measured using Digital Image Correlation (DIC) technique, and as a result mode I fracture toughness of ceramics and crack propagation from the existing notch were successfully evaluated.

INTRODUCTION
The disposal of vast amounts of MTs is considered one of the most significant environmental concerns in the mining industry. The presence of contaminated materials after extracting valuable metals such as gold, silver, and copper can lead to harmful environmental consequences. MTs occupy an extensive area of land in the form of mud-like material in tailing ponds or behind storage dams (Barrie et al., 2015; Kossoff et al., 2014). Exposure of sulfide minerals to water and air typically leads to acid mine drainage which is a widespread environmental hazard resulting from seepage and dam failure. This process can impact groundwater and surface water leading to high levels of iron, aluminum, metals, and sulfates (Kinnunen et al., 2018; Nordstrom, 1999). Over the past few years, a number of researchers studied the potential risks to human health and the harm caused by soils that have been contaminated with heavy metal mine tailings (Ngole-Jeme and Fantke, 2017; Ogola et al., 2002; Olobatoke and Mathuthu, 2016).
Investigation of Mode II Fracture Behavior of Alkali-Activated Mine Tailings
Authors: Asadizadeh M. , Hedayat A. , Tunstall L. , Taboada Neira M. , Vega González J. A. , Verá Alvarado J. W. 
Published: September 2023

ABSTRACT
Reuse of mine tailings (MTs) rich in aluminum oxide and silicon dioxide to produce a geopolymer using an alkali activator is a sustainable approach to reduce the MTs’ environmental hazard. The fracturing behavior of mine tailing-based alkali activated materials under mode II loading has been largely unexplored. In this study, the mode II fracture tests have been adopted to examine the double-edge notched Brazilian disk (DNBD) geopolymer specimens under diametral loading. A mixture of MTS (85% wt.), class F fly ash (FA) (15% wt.), and 10 M NaOH solution with solid/liquid ratio of 14% was prepared, and using a cylindrical mold, specimens were cast and then cured at 70 °C. Mode II fracture toughness, the evolution of the crack tip opening and sliding displacement and the shear and minimum principal strain behavior were examined through strain mapping using the Digital Image Correlation (DIC) technique. The results showed that although DNBD is intended to provide pure mode II loading, mixed mode fracturing was observed, as there was still some crack surface opening. The study highlights the need for further investigation to fully understand the nature of mixed-mode fracture behavior in DNBD specimens and its implications for material characterization.
With the rise in demand for mineral excavation and processing, significant quantities of mine tailings (MTs) are produced annually around the world. MTs are the waste rocks that are left over after the extraction of valuable metals has been completed during the mineral processing. As a result, there is a growing concern on how to manage the increasing amounts of MTs that are generated, and how to utilize them effectively. Based on the different phases, MTs can be stored either in impounding lakes for slurries or waste piles for solids (Kiventerä et al., 2018). Given their abundance and potential impact on the environment, it is important to explore ways to reuse these materials. MTs that contain sufficient quantities of aluminosilicates can be efficiently transformed into sustainable building materials by subjecting them to the process of alkaline activation and geopolymerization. The geopolymerization process creates a strong and durable material that can be used in various construction applications, including the manufacturing of bricks, tiles, and concrete (Davidovits, 2020; Muñoz Velasco et al., 2014; Provis & Van Deventer, 2009). Therefore, the utilization of MTs as a resource for construction materials can offer economic and environmental advantages (Singh et al., 2015; Zhang, Hedayat, Bolaños Sosa, Huamani Bernal, et al., 2021; Zhang, Hedayat, Han, et al., 2022; Zhang, Hedayat, Perera-Mercado, et al., 2022).
An Optimized Deep Neural Network for Rockburst Damage Potential Modelling
Authors: Toksanbayev N. K. , Adoko A. C. 
Published: September 2023

ABSTRACT
Managing ground prone to rockburst is challenging, especially in seismically active underground mines. Over the past few decades, numerous studies have been conducted on predicting rockburst damage potential. However, in most cases, only fair model performance was achieved due to the complex nature of rockburst as a seismic event and the non-linearity of data. To overcome these limitations, this paper presents a more reliable model for predicting rockburst damage potential (RDP). An Artificial Neural Network was established, and its parameters were optimized using the Adam optimizer. Rockburst data consisting of 254 case histories were compiled and used to model the RDP scale. The dataset was divided into two parts: a training set, which accounted for 80% of the dataset, and a separate test set, which accounted for the remaining 20%. Cross-validation technique was applied to the training set to avoid overfitting. The input parameters for the model included the capacity of the ground support system, stress conditions, presence of geological structure, excavation span, and peak particle velocity. Several performance indices were used to evaluate the model, and the overall results indicate good performance. In conclusion, this study could help engineers adequately assess rockburst damage in seismically active mines.

INTRODUCTION
Rockburst refers to the damage that occurs on rock excavation surfaces as a result of a seismic event (Ortlepp and Stacey, 1994). It is characterized by a sudden release of strain energy stored within a specific volume of rock (Kaiser and Cai, 2012). Rockbursts are known for their unpredictable and violent nature, representing a significant threat to workers’ safety, mining productivity, and operational costs. Rockbursts and mine seismicity are responsible for a large number of accidents and casualties in many parts of the world every year, as reported in Europe (Ptáček, 2017; Heib, 2018), China (Cai, 2016; Jian-Po Liu, 2018; Linming Dou, 2018; Xia-Ting Feng, 2018), India (Panthi, 2018), South Africa (Aswegen, 2018), and Canada (Leveille et al., 2017; Simser, 2019). Furthermore, with the depletion of near-surface mineral resources caused by the rising demand for minerals, there is a shift towards exploiting deeper deposits, often in high-stress and unfavorable geo-engineering conditions. This results in an increased likelihood of rockburst incidents and makes mining-induced seismic activity a significant concern for the mining sector. It is, thus, evident that the ability to forecast and manage rockburst occurrences is becoming increasingly important.
Alternation Injection Induced Thermal Performance of a Heterogeneous Fracture in Geothermal Reservoirs
Authors: Chen Yuedu , Liang Weiguo 
Published: September 2023

ABSTRACT
The continuous and alternation injection-production operation modes through three injection wells and three production wells towards the single fracture was considered numerically to evaluate its effect on flow patterns and thermal performance, including aperture evolution, flow rates, production temperature. The anisotropic fracture aperture distributions studied were generated follow a log-normal distribution. The results show that, when fluid is injected into a fracture zone, the local fracture permeability will be enhanced, which in turn promotes the migration of fluid along the fracture. Initial heterogeneous fracture aperture attracts more fluid and promotes directional development of the fracture aperture during the thermal extraction process. The continuous injection is associated with a more pronounced directional aperture increase within the heterogeneous fracture, which generally exacerbates flow channeling and causes decreases in production temperature with the injection time. By contrast, the alternation operation avoiding the formation of concentrated channeling flow and effectively promote fluid migration across the entire fracture surface and achieve a larger heat exchange area compared to continuous operation. The average of the temperature and production heat of the three production wells during alternation operation is found to be overall larger than that of the continuous operation. The results of this study suggest that alternation operation through multi-wells is helpful to result in favorable thermal performance.

INTRODUCTION
Geothermal energy is widely regarded as a sustainable and fully renewable energy(Tester et al. 2006). The efficient extraction of thermal energy from subsurface geothermal reservoirs necessitates the creation or access of an interconnected fracture system, often achieved through hydraulic fracturing or shearing(Park et al. 2020). The fluid circulation within the fractures or faults, which is heated upon contact with hot rocks, carries the heat to the surface(Detournay et al. 2022). The flow pattern and evolution of the fluid within individual fractures and the resulting heat exchange between the fluid and the surrounding rock are key factors in heat production(Guo et al. 2016). Understanding and optimizing these processes are crucial for efficient and sustainable geothermal energy production.
Innovative Approach for Monitoring Underground Excavations at San Xavier Underground Mine Laboratory
Authors: Akbulut Nilufer B. , Anani Angelina , Brown Leonard D. , Wellman Edward C. 
Published: September 2023

ABSTRACT
Assessing and making decisions in underground mines is crucial and is difficult due to the harsh environment and the limitation of accessibility. Monitoring plays an important role in assessing ground conditions to ensure safety and efficiency. Through consistent monitoring, a safe interoperable underground mine can be achieved, but to ensure coherent and valid monitoring, there are factors that need to be considered. The approach taken for monitoring with technologies used in it can highly impact the safety, productivity, and understanding of ground conditions. Visualizations designed with principles of Human-Computer Interaction (HCI), can improve knowledge, and aid situational awareness. Focusing on monitoring systems and interfaces that are user-friendly and reliable can help improve overall underground conditions. This paper proposes a monitoring framework that uses desktop and Virtual Reality (VR) to display rock movement in the San Xavier (SX) Underground Mine Laboratory through a digital twin.

INTRODUCTION
Continuous monitoring is required to enhance assessment and situational awareness (SA) in engineering projects such as mining. Monitoring creates a safer workplace, ensuring efficient and continuous production that meets production and profit goals. An optimal monitoring system for large-scale projects would be a system understood by different subject matter experts with varying levels of expertise. Continuous and efficient monitoring plays a foundational role in harsh and uncertain underground mine conditions. The data obtained from monitoring the rock mass in underground mine operations improves decision-making process, enhances the understanding of the current state of the mine, and helps make predictions. With the overwhelming flow of data, there is a higher possibility of having false positives and uninformative data representation, leading to serious cognitive burden (Zhou et al., 2017). The display of data and information and monitoring network design is crucial to overcoming cognitive burden. A monitoring system that emphasizes user-friendly methods, such as visual analytics (VA), would help engineers and workers gain insight from large and complex data sets resulting in enhanced overall SA (Zhou et al., 2017). Having a monitoring system that considers the display of information at an underground mine could secure the safety of the workers and minimize risks, help to plan better designs, and evaluate current designs, and improve the advancement at the mine.
Numerical Modelling of the Influence of Tidal Stresses on Qualitative Fracture Patterns on the Surface of Europa
Authors: Walding J. C. , Paluszny A. , Zimmerman R. W. 
Published: September 2023

ABSTRACT
The ice crust of Jupiter's Galilean satellite Europa exhibits a number of large-scale lineae features, as well as numerous regions with smaller scale lineae patterns. In this work, a three-dimensional finite-element simulator is used to model lineae as fractures in the crust that nucleate, grow, and interact. The medium is assumed to be isotropic and linearly elastic. Fractures are assumed to grow primarily in tension due to tidal stresses in the ice crust, and a damage criterion is used to model the weakening of the ice matrix that occurs concurrently with fracturing. The growth of multiple fractures is modelled geometrically as a function of multi-modal stress intensity factors computed at the fracture tips. The tidal forces that drive this fracturing process are computed according to the model of Wahr et al. (2009), and fracturing is evaluated over multi-scale periods from days to millions of years. Fracture nucleation and growth are modelled within the span of the satellite, with emphasis on characterizing the fracture patterns in the equatorial region. Multiple three-dimensional non-planar fractures are seen to grow and interact within each region. The simulated patterns are qualitatively compared against images obtained by NASA's Galileo mission.

INTRODUCTION
Europa is the fourth largest Galilean moon of Jupiter; with a radius of 1560 km (Nimmo et al., 2007), and is the sixth closest to its parent planet. It has a rocky core that is entirely surrounded by an ice shell, which is estimated to be between 1 and 30 km thick (Billings and Kattenhorn, 2005), where the lower estimates arise from mechanical flexure analysis (Figueredo et al., 2002; Nimmo et al., 2007), and the higher estimates arise from thermodynamic analysis (Hussmann et al., 2002; McKinnon, 1999; Ojakangas and Stevenson, 1989). Estimates based on impact cratering tend to lie between these two bounds (Greeley et al., 1998; Moore et al., 1998; Schenk, 2002). Encased between the silicate core and the ice shell is thought to be a vast liquid water ocean, approximately 100 km thick (Pappalardo et al., 1999). This ocean, and therefore Europa as a whole, is the object of great scientific curiosity, due to its viability as a habitat for extra-terrestrial life (Schulze-Makuch and Irwin, 2000; Kargel et al., 2000).
In-Situ X-Ray Measurements of Grain Stress and Strain During Uniaxial Compaction of Miniature Sandstone Samples
Authors: Hurley R. C. , Shahin G. 
Published: September 2023

ABSTRACT
Laboratory rock deformation has been extensively studied using in-situ optical and X-ray imaging and acoustic emissions (AE) measurements. These measurements have revealed rich kinematics across scales during sandstone compaction, from grain-scale breakage to sample-scale shear and compaction bands. Nevertheless, much progress remains in understanding the connection between rock deformation and grain-scale stress evolution before and after yielding and during the onset and progression of sample-scale strain localization. Such an understanding may offer opportunities for new mechanism-based constitutive models and estimation of grain-scale properties such as intra- and inter-granular bond strength. In this work, we describe the first-known simultaneous application of in-situ X-ray tomography and 3D X-ray diffraction to make strain and stress measurements in miniature samples of Nugget and Berea sandstones. This data provides a first quantification of grain-scale stress heterogeneity, grain-scale and inter-granular bond strength, and larger-scale stress heterogeneity during sandstone compaction. We discuss challenges in X- ray tomography and diffraction analyses for sandstones, which are related to challenges in identification of individual grains in tomographic images featuring minimal contrast at grain boundaries and challenges in performing diffraction microscopy from non-ideal diffraction spots generated by natural quartz crystals. We propose methods for examining the strength of inter-granular bonds and relating AE activity to stress fluctuations using our experimental data.

INTRODUCTION
Sandstone accommodates macroscopic deformation by a combination of microscopic mechanisms including cement bridge breakage, Hertzian particle fractures, particle crushing and pore collapse, and grain rearrangements (Paterson & Wong, 2005; Wong & Baud, 2012). Heterogeneous structures emerge at all length scales during sandstone compaction – from the contact-scale through cement-bridge breakage and chipping, to the grain-scale through breakage and pulverization, to the bulk-scale through shear and compaction band development. The evolution of these structures as a function of microscopic and macroscopic stress states and evolution is a key pursuit of rock mechanics. Success in this pursuit may enable development of robust mechanism-based constitutive models and progress in evaluating long standing questions related to associativity and other aspects of plasticity laws for rocks (Menéndez et al., 1996; Tengattini et al., 2014; Wong et al., 1997).