Researchers with the Alaska Center for Energy and Power have developed a prototype of a non-invasive tool, the Pump Monitoring Apparatus (PuMA), to monitor the heating fuel consumption of a fuel oil vented heater. The goal of this project is to test the PuMA and develop it into a marketable tool for residential heat load research. As a majority of Alaskans rely on fuel oil to heat their homes, monitoring fuel usage is useful for two reasons. First, if the fuel oil vented heater is the only source of heat in the home, fuel oil consumption can be used as a proxy for residential heat load and thermal characteristics of the home can be deduced. Secondly, knowing heating fuel usage daily and seasonally can help inform researchers and consumers how human behavior and different home efficiency measures affect heat demand. There is currently a lack of a historical record of heating fuel consumption, limited understanding of home heating patterns on a daily, monthly and annual basis, and incomplete documentation of community heat loads. PuMA accuracy in calculating total heating fuel consumption was evaluated to range 3-10% from the actual value during testing. Several deployments of the PuMA have demonstrated its capability to remotely capture and report heating fuel consumption data, but have also highlighted technical challenges that will need to be addressed in future iterations of this tool.

This thesis describes the design, manufacturing, and testing of a high voltage power supply for an electron spectrometer to be used on a small spacecraft. The challenge was reducing complexity, size, and power consumption enough to be useful for a CubeSat or a sounding rocket sub-payload. The power supply has two purposes: i) it produces DC at roughly 2000 V for a microchannel plate detector and ii) it produces exponential voltage sweeps from about +4000 V to below 5 V for an electrostatic analyzer. This power supply uses solid state relays for a charge pump and for producing voltage sweeps with capacitive discharge. The detector power supply is software and hardware regulated to provide tunable output up to 2400 V, with voltage drift and ripple of around ±1%. The power supply is managed by an MSP430 microcontroller. It includes several automatic, hardware-based, closed-loop controls to stabilize performance across a range of temperatures, input voltages, and component parameters. All digital switching, signal changes, measurements, and monitoring are done in a single control loop. The design includes thermal protection, current limiting, a hardware watchdog, transient voltage suppression, and hardware-based overvoltage protection. The circuits survived thermal vacuum testing, operating within specifications for several weeks during many cycles of -40 °C to +70°C. The supply operated a real spectrometer inside an electron beam chamber. The consistent voltage sweeps allowed the spectrometer to accurately distinguish electron beam energies. This power supply is a successful proof of concept for powering a microchannel plate detector and an electrostatic analyzer at over 4000 V using a single 64 mm diameter circuit board, consuming 0.5 W or less from a small spacecraft.

Dust generation is a significant issue in the U.S. mining industry, particularly the underground coal mining industry. It causes health and safety issues for the miners working underground. Prolonged exposure to high concentrations of respirable dust (dust of aerodynamic diameter < 10 μm) causes various diseases, including pneumoconiosis, also known as Black Lung, and silicosis. These diseases lead to an airflow blockage in the lungs, causing lung failure or death. Several techniques have been used to capture respirable dust particles, and a flooded-bed scrubber integrated into a continuous miner is one of them. This research focuses on increasing the efficiency of a flooded-bed scrubber by modifying the geometry of one of its components, known as a demister. A demister consists of a series of sinusoidal plates that separate water droplets from air and contribute to the capture efficiency and pressure drop across the scrubber. The geometry of the demister was modified by adding aerodynamic devices, called Vortex Generators (VG), on its plates. Several computational fluid dynamics (CFD) models of a modified demister were created, and CFD simulations were performed. An analysis of results indicated an improved water droplet capture efficiency for the modified demister. The study also discovered a potential to reduce the size of the demister which will reduce the pressure drop and eventually the energy consumption of the scrubber.

Ground hazards are a major safety concern in underground mines, causing deaths, injuries, and lost work time to miners. Although ground hazards such as roof fall accidents have steadily and significantly declined over the last decade, the safety hazards associated with ground hazards still account for a significant portion of the total number of accidents in the underground mining industry. One of the main reasons behind ground hazards in underground mines is abrupt changes in geological conditions that may decrease the competence of the rocks surrounding an excavation, resulting in ground failure. The changes in geological can be detected in a mined-out area, and a possible roof fall accident can be avoided if prompt countermeasures are taken, but changes cannot be easily foreseen in unexcavated areas. An obvious solution to this issue would be to predict strata geological conditions in advance of mining, followed by risk assessment and design of a safe and cost-effective ground support system. The prediction of geological conditions plays a vital role in mine planning and design. It is significantly important for the mine workers' safety and could be economically attractive in terms of increased productivity and reduced production loss. However, predicting changes in geological conditions in unexcavated areas is a complex task, and it requires proper mine strata characterization and mine design. This research aims to address ground control issues in the mining industry by utilizing Artificial intelligence (AI) techniques to predict lithology and RQD based on the location input data ( x, y, and z coordinates). The accurate prediction of lithology and RQD is crucial for effective ground control management in mining operations. The methodology developed in this research involves the creation of a predictive model using various machine learning algorithms. The input dataset is comprised of drill hole x, y, and z coordinates, and the outputs are lithology and the RQD. The model was trained, optimized, and validated using a large set of drill hole data from an underground metal mine. The results show that the random forest (RF) model performed better than other models, with a prediction accuracy of 98%. The trained model was used to build an interactive-user interface. By inputing just any location x,y, and z coordinates within the mine, into the interface, authorized users can get output of lithology and RQD for that location. This research may help improve the accuracy and the efficiency of ground control management practices in the mining industry, as well as economically benefit the industry.

The release of sulfolane from a petroleum refinery to a river flood plain aquifer in a discontinuous permafrost region in North Pole, Alaska has been thoroughly monitored, with the initial site characterizations beginning in 2009. It has been observed that the sulfolane plume advancement is different from typical contaminant plume development in aquifers in the temperate region. This difference relates to the existence of permafrost. Permafrost itself is impermeable but open or lateral taliks provide a connection point of subpermafrost and suprapermafrost groundwater. The redirection of groundwater by these thawed areas in permafrost can produce unpredictable contaminant concentrations at various depths of the aquifers. Groundwater also has the ability to converge and diverge as a result of varying permafrost-table distribution. The contaminant can be channeled and redirected in an area with a deep permafrost-table and be absent or minimal along a shallow permafrost-table. The objective of this study is to examine the relationship between the progression of the sulfolane groundwater plume and the spatial distribution of the discontinuous permafrost and topography in the area between the Tanana and Chena Rivers using the results obtained from 156 monitoring wells, including well logs and sulfolane concentrations. An additional goal of this research is to classify the permafrost features and mechanisms controlling the transport of sulfolane. Spatial maps of the temporal contaminant distribution are produced to aid with the plume delineation, as well as contaminant trend analyses for each monitoring well (shallow/mid/deep) sulfolane concentration over the measured period. A permafrost-table elevation (top of permafrost) map was developed and utilized as a base map under the sulfolane concentration contours to correlate permafrost location and the spatial distribution of sulfolane over a period of six years. This study finds that the variable distribution of permafrost has a great effect on the flow of groundwater, and thus contamination, in the aquifer. The presence of open taliks is the most substantial modifier to the predicted path of the sulfolane groundwater contamination plume. In addition, degradation of permafrost distribution in the future due to thawing would further enhance the preferential movement of the groundwater and sulfolane and continue to move contamination in directions that would not have been predicted by looking at regional groundwater gradients alone. An area thought to be absent of sulfolane contamination may become susceptible, and the well network should be expanded to accommodate extended monitoring of this particular sulfolane plume.

Understanding and modeling the permafrost system, hydrologic cycle, energy balance, and biologic systems in the Arctic are dependent, in part, on snow depth and snow distribution. Point-source snow measurements provide ground-truth observations of snow depth and snow water equivalent, although these measurements may be limited in their spatial and temporal distributions. Satellite-derived remote sensing products and gridded model output provide spatial coverage of snow properties, but their applicability is affected by their balance of resolution, computational speed, and accuracy confidence. The goal of this research is to assess the performance of three snow data products derived from remote sensing techniques as well as model output across the North Slope of Alaska with the International Land Model Benchmarking (ILAMB) Project software. Historic ground-based snow data, collected by agencies, academia, and industry, and dating from 1902 to 2021, was curated to create an ILAMB-compatible benchmark dataset for end-of-winter (EOW) snow depth and snow water equivalent (SWE) for the evaluation of the three snow data products: Canadian Sea Ice and Snow Evolution (CanSISE) network SWE; Arctic Boreal Vulnerability Experiment (ABoVE) snow depth; and Energy Exascale Earth System Model (E3SM) Earth Land Model (ELM) snow depth. The ILAMB evaluation results showed that the ABoVE data product is effective in providing the average EOW snow depth for regions of the North Slope but lacks representation of interannual and spatial variability of snow depth. Comparatively, the CanSISE data product and ELM results are inaccurate in magnitude for applicability across the North Slope of Alaska in addition to lacking representation of snow condition spatial variability. In interpreting ILAMB results, factors to consider were representation bias from inconsistent benchmark site distribution throughout the evaluated time period, the range of dates considered to represent the spring snow data, and uncertainty within the individual benchmark values. Future analysis of the same datasets with ILAMB could include diagnostic tests to understand the sources of error better. Thorough spring snow data collection should continue on the North Slope of Alaska to inform and improve Earth System Models.

The Long-Range Airborne Snow and Sea Ice Thickness Observing System (LASSITOS) is an airborne electromagnetic (AEM) system, currently under development, which uses a customdesigned instrument mounted on an Unmanned Aerial System (UAS) to measure Arctic sea ice and snow thickness. This project requires specialized instruments that are both low-power and lightweight. This thesis describes a design and implementation of a prototype data logging system based on an ultra-low power microcontroller, for the LASSITOS instrument. Three 32-bit Analog-toDigital Converter (ADC) integrated circuits (IC) are used to sample and convert the receiving EM signal at a rate of 19200 SPS. The system is capable of writing the sampled data and diagnostic data to the SD card at a combined rate of up to 307200 B/s. A 30 KB circular buffer is used to avoid data loss during SD card busy periods. Three DMA channels are used to optimize the communication between the ADCs and the SD card over SPI to achieve these data rates.

Heat recovery ventilation systems have become increasingly popular in modern residential buildings, particularly in cold climates. This has led to the research and development of supporting technologies, such as combined intake/exhaust vents. Conventionally, the intake and exhaust airflows of a heat recovery ventilation system use separate vents and penetrations in a building's envelope; combined intake/exhaust vents package these airflows together and use only one penetration. This simplifies heat recovery ventilation system installation and can lead to higher operating efficiencies; the implications are reduced up-front and operating costs as well as broadened access to heat recovery ventilation. Unfortunately, in cold climates, existing combined intake/exhaust vent designs are susceptible to frost accumulation, a mode of failure. The aim of this work was to develop a combined intake/exhaust vent more suitable for cold climate use: the Arctic Dual Hood. The design was developed in iterations informed by experimentation. These experiments included climate chamber evaluations and field performance comparisons. This design process produced a functional prototype with favorable frost mitigation characteristics compared to an existing combined intake/exhaust vent design, as determined through the field performance comparisons. Additionally, this prototype observed the constraints and met the performance requirements imposed by the American Society of Heating, Refrigeration, and Air-Conditioning Engineer's Standard 62.2: Ventilation and Acceptable Indoor Air Quality in Residential Buildings.

Exploitation of viscous and heavy oils on Alaska North Slope (ANS) requires nonthermal enhanced oil recovery (EOR) techniques. Currently, three nonthermal EOR methods, including solvent injection, low salinity water (LSW) flooding, and low salinity polymer (LSP) injection, have been proved to be useful on ANS. ANS viscous and heavy oils can be developed effectively by combining those three nonthermal EOR techniques. In this dissertation, lab experiments have been conducted to investigate the potential of the proposed hybrid nonthermal EOR techniques, including HSW (high salinity water)-LSW-softened LSW flooding, HSW-LSW-LSP flooding, CO₂-enriched LHS (light hydrocarbon solvent)-alternating-LSW flooding, LHS-alternating-LSW flooding, CO₂-enriched LHS (light hydrocarbon solvent)-alternating-LSP flooding, and LHS-alternating-LSP flooding, to improve ANS viscous oil recovery. Besides, the effect of essential clay minerals, including sodium-based montmorillonite (Na-Mt), calcium-based montmorillonite (Ca-Mt), illite, and kaolinite, on LSW flooding has been examined. In addition, the CO₂ influence on solvent-alternating-LSP flooding in enhancing ANS viscous oil recovery has been investigated. Furthermore, the blockage issue during CO₂-enriched LHS-alternating-LSP flooding has been investigated, and its solution has been proposed and analyzed. The EOR potential of the proposed hybrid EOR techniques has been evaluated by conducting coreflooding experiments. Additionally, relative permeability, swelling property, zeta potential, interfacial tension (IFT), and pressure-volume-temperature (PVT) tests have been conducted to reveal the EOR mechanisms of the proposed hybrid EOR techniques. Moreover, water ion analysis of DI-water/natural-sand and DI-water/natural-sand/CO₂ systems has been carried out to reveal the complex reaction between CO₂, sand, and LSP solution. It was found that, compared to conventional waterflooding, all the proposed hybrid EOR techniques could result in better oil recovery potential. It was noticed that the presence of CO₂ in LHS could be more beneficial to the solvent-alternating-LSW/LSP flooding processes during the 1st cycle due to the greater effectiveness of oil viscosity reduction. In particular, severe blockage issue occurred when conducting CO₂-enriched LHS-alternating-LSP flooding using sand pack due to the polymer precipitation. Additionally, the calculated water relative permeabilities are much lower than the typical values, implying more complex interactions between the reservoir rock, heavy oil, and injected water. Moreover, comparing to HSW, LSW could further swell Na-Mt significantly, which may benefit LSW flooding by improving sweep efficiency since in-situ swelling of Na-Mt has the potential to block the higher permeable water-flooded zone and divert the injected brine to lower permeable and unswept area. Comparing to Na-Mt, LSW couldn't swell Ca-Mt and illite further, whereas kaolinite was incapable of swelling in both HSW and LSW. Furthermore, about 60 mole% of solvent could be dissolved into the ANS viscous oil at target reservoir condition, resulting in oil swelling and viscosity reduction effects, which provided better microscopic displacement efficiency. Although the presence of CO₂ in LHS had a negative impact on the oil swelling effect, the influence on the oil viscosity reduction was positive. In addition, reducing the salinity of water could generate more negative zeta potential values on the surface of clay minerals and sand, making it more water wet. Besides, IFT of oil/LSW system is higher than that of oil/HSW system, indicating that IFT reduction is not an EOR mechanism of LSW flooding in our proposed hybrid EOR techniques. Additionally, after introducing CO₂ to the DIwater/natural-sand system, the concentration of multivalent cations was increased, which may be responsible for the polymer precipitation. The blockage issue could be solved by injecting LSW as a spacer between CO₂-enriched LHS injection and LSP injection.

The Arctic and its permafrost terrain are inherently dynamic, complex, and sensitive environments. Understanding the past and current changes occurring in these systems is key in predicting future variations, including the response of permafrost to climate change, and to terrain modifications resulting from natural processes or anthropogenic activities. This study contributes to advance our understanding of permafrost dynamics in varying permafrost environments of northern Alaska and northwestern Canada using a terrain-cryofacies approach. This unique approach helps to increase our understanding of permafrost dynamics from the site-specific scale to over extended areas by recognizing linkages between terrain and subsurface properties, and by identifying similar terrain units in remote sensing analysis. In the Colville River Delta (Alaska), our terrain-cryofacies study integrated data from 79 boreholes with a remote sensing analysis to evaluate the temporal changes in the Nigliq channel positions from 1948 to 2013 and the related permafrost dynamics. Most land cover changes occurred as land exposition (64%), whereas about 36% of the total changes were classified as eroded. The erosion of the older terrain units from the floodplain toposequence, such as the inactive-floodplain cover deposits, implied ground loss volumes of about one-fifth of soil solids and four-fifths of ground ice. Along this channel, we also identified the typical configuration and properties of taliks and cryopegs, as well as subsequent epigenetic permafrost growth. We found that the active channel was underlain by closed taliks, rather than through taliks and thus did not penetrate the entire layer of permafrost connecting supra- and sub-permafrost groundwater. A cryopeg connected to the active channel talik was identified from borehole data in the adjacent terrain units that developed following channel migration. We estimated the likelihood of encountering such taliks and cryopegs over extended areas. The terrain-cryofacies approach was also applied to understand permafrost dynamics of hillslope thermokarst located in multiple ecoregions of northern Alaska and northwestern Canada, including areas affected by interactions with infrastructure. Six features were studied through the combination of field-based and remote sensing methods, whereas 150 others were assessed solely by remote sensing. Studies along a pipeline indicated that embankment construction led to an increase in the active layer thickness, reaching the underlying ice-rich intermediate layer, and causing thaw settlement. This formed a thermokarst-ditch that facilitated channelization of cross-drainage water, and thermal erosion of the ice-rich permafrost that became affected by thermal denudation and caused a retrogressive thaw slump (RTS). The RTS later selfstabilized mainly due to the lateral discontinuity of massive ice (i.e., ice wedge) and the low-relief terrain. We suggested approaches to develop adaptation strategies for infrastructure at risk of RTS based on: these findings and conditions that favor or limit RTS growth by local feedbacks; considering the interaction patterns that we identified between RTS and infrastructure; and the main destabilization processes that we highlighted by terrain units. Further research is necessary, however, and must include testing potential mitigation techniques at multiple sites with monitoring programs to assess the variability in performance with respect to site-specific conditions.