• Implications of pore-scale distribution of frozen water for the production of hydrocarbon reservoirs located in permafrost

      Venepalli, Kiran Kumar (2011-08)
      Frozen reservoirs are unique with the extra element of ice residing in them along with the conventional components of a reservoir. The sub-zero temperatures of these reservoirs make them complicated to explore. This study investigates reduction in relative permeability to oil with decrease in temperature and proposes a best-production technique for reservoirs occurring in sub zero conditions. Core flood experiments were performed on two clean Berea sandstone cores under permafrost conditions to determine the sensitivity of the relative permeability to oil (kro) over a temperature range of 23°C to -10°C and for connate water salinities ranging from 0 to 6467 ppm. Both cores showed maximum reduction in relative permeability to oil when saturated with deionized water; they showed minimum reduction when saturated with 6467 ppm of saline water. Theoretically, the radius of ice formed in the center of the pore can be determined using the Kozeny-Carman Equation by assuming the pores and pore throats as a cube with 'N' identical parallel pipes embedded in it. With obtained values of kro as input to the Kozeny-Carman Equation at -10°C, the radius of ice dropped from 0.145 [upsilon]rn to 0.069 [upsilon]rn when flooding, water salinity is increased to 6467 ppm. This analysis quantifies the reductions in relative permeability solely due to different formation salinities. Other parameters like fluid saturations and pore structure effects also are discussed. Fluids like deionized water, saline water, and antifreeze (a mixture of 60% ethylene or propylene glycol with 40% water) were tested to find the best flooding agent for frozen reservoirs. At 0°C, 9% greater recovery was observed with antifreeze than with saline water. Antifreeze showed 48% recovery even at -10°C, at which temperature the rest of the fluids failed to increase production.
    • Improved Membrane Filtration For Water And Wastewater Using Air Sparging And Backflushing

      Psoch, Christian (2005)
      The goal of this research was to investigate methods and techniques that enhance mass transfer through the membranes. Two general types of fluids were investigated: synthetic wastewater treated in a membrane bioreactor (MBR) and natural and simulated river water. For both fluids, a wide range of solid concentrations (up to 18 g/L) were tested. The membranes investigated were all tubular modules at pilot scale between 0.75 and 1.20 m length, with tubular diameters of 5.5--6.3 mm, 0.2 mum pore size, and membrane surface areas of 0.036--0.1 m2. For flux enhancement, two techniques were applied: air sparging (AS), and backflushing (BF). Both techniques were compared with the sponge ball cleaning method. The experimental temperature ranged between 10 and 30�C, cross-flow velocities (CFV) ranged between 0.5 and 5.2 m/s, and transmembrane pressure (TMP) ranged between 30 and 350 kPa. Research results showed, that AS was able to enhance the conventional flux over weeks to months up to factor of 4.5 for river water and a factor of 3 for wastewater. At modest CFV of 1.5--2 m/s, AS was as successful as BF. If higher CFV (up to 5.2 m/s) were supplied for BF, this technique could enhance the wastewater flux by factor 4.5. The supply of AS and BF combined was superior to the single application even at moderate CFV. The major finding of this research was that cake thickness on the membrane surface was decreased by AS, contrary to research by other authors. AS can be used as substitute aeration in MBRs, without impairing the degradation performance. The combination of AS and BF generated the least filter cake, but the lowest fouling was observed for AS. An empirical equation was proposed to calculate the viscosity in a sidestream MBR depending on reactor temperature and mixed liquor suspended solids (MLSS).
    • Improvement of the Fairbanks Atmospheric Carbon Monoxide Transport Model -- A Program for Calibration, Verification and Implementation

      Carlson, Robert F.; Hok, Charlotte (University of Alaska, Institute of Water Resources, 1980-10)
      In the early 70s, state, local and federal officials in Fairbanks, Alaska, became concerned with the rising incidence of high carbon monoxide episodes. Because of that concern, the Alaska Department of Highways (forerunner of the Department of Transportation and Public Facilities) and the Fairbanks North Star Borough requested that the Institute of Water Resources undertake a study to develop a computer model capability for understanding the transport of carbon monoxide and other pollutants within the Fairbanks airshed. The work was completed in June of 1976. Two publications (Carlson and Fox, 1976; Norton and Carlson, 1976) describe the initial development, documentation and implementation of the computer model. The model, ACOSP (Atmospheric Carbon monOxide Simulation Program), describes the two-dimensional behavior of pollutants in the atmosphere via solution of the convection-diffusion equation using the finite element method of numerical analysis.
    • Improving CubeSat downlink capacity with active phased array antennas

      Klein, Jonathan; Hawkins, Joe; Thorsen, Denise; Raskovic, Dejan (2017-08)
      Power budgets on small satellites are restricted by the limited surface area for solar panels. This limits the power available for radio communications, which constrains the downlink budget. The limited transmit power translates to low downlink data rates on small satellites. Antenna gain from directive antennas may be a power efficient way of improving the downlink budget, thereby increasing the downlink rate of small satellites. This project focuses on the design and development of a prototype low-power, electrically-steered S-band phased array RF front-end suitable for a CubeSat that could efficiently increase the EIRP, permitting higher data rates. A prototype of the array has been constructed and tested in an anechoic chamber. The four element array provides a minimum gain of 2.5 dB and average gain of 5 dB compared to a single patch antenna element with a 5W power envelope across a range of up to 60 degrees from broadside of the array.
    • Improving Passing Lane Safety and Efficiency for Alaska’s Rural Non‐divided Highways

      Dyre, Brian P.; Abdel-Rahim, Ahmed (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2014)
    • Improving Performance, Knowledge, and Methods to Provide Quality Service and Products

      Connor, Billy; Bennett, Larry (2015-12)
      The objectives of this study were to educate staff about the impact of research in Alaska, enhance communication and coordination amongst stakeholders, and formulate a long-term research and implementation research plan for pavement and materials. Education begins with an overview of pavement design, construction and maintenance in Alaska since the 1900’s through a series of webinars. Interviews with five state materials engineers were used to explore best practices. Finally, a workshop focused on developing a coordinated research program and improve implementation activities. The workshop provided a series of recommendations to The Alaska Department of Transportation and Public Facilities which will enhance the value of the departments research program.
    • Improving ultimate recovery in the Granite Point field Tyonek C sands

      Nenahlo, Thomas L.; Dandekar, Abhijit; Patil, Shirish; Ning, Samson (2018-12)
      The objective of this research is to determine how the ultimate recovery of the Granite Point field can be improved. An understanding of the depositional setting, structure, stratigraphy, reservoir rock properties, reservoir fluids, aquifer, and development history of the Granite Point field was compiled. This was then leveraged to provide recommendations on how the ultimate recovery can be improved. The Granite Point field Tyonek C sands are located on an anticline structure at 8,000' to 11,000' SSTVD within the offshore Cook Inlet basin. These sands were deposited in a fluvial environment with the source material provided by the Alaska Range to the northwest. Due to uplifting, the Tyonek C sands are of relatively low porosity for their depth. The sands thin, become more numerous, and are of generally lower porosity from southwest to northeast. Oil quality is excellent and displacement efficiency of the reservoir rock with water flood exceeds 50% at breakthrough. Although displacement efficiency is high, the relative permeability to water is extremely low. The fracture gradient of the reservoir rock is on the order of magnitude of 1.0 psi/ft. Many initiatives were undertaken throughout the history of the Granite Point field to improve the rate and resource recovery, all of which were met with negligible success with the exception being the introduction of horizontal wells that were first drilled in the early 1990's. The underlying reason for the lack of success of these other initiatives is the low effective permeability to oil and the extremely low effective permeability to water. Secondary recovery with water injection was successful in the early stage of development, and can be in the future, but only when applied between wells that are connected by a sand of acceptable porosity. The results of this research indicate that to improve the ultimate recovery of the Granite Point field a thorough quantification of aquifer and injection water movement must first be understood, then horizontal wells can be placed in appropriate locations to improve the offtake and leverage the weak aquifer drive to provide pressure support.
    • In-cylinder pressure based combustion performance evaluation of syntroleum synthetic and conventional diesel fuels

      Kandulapati, Praveen K. (2006-12)
      Synthetic fuels produced from non-petroleum based feedstocks can effectively replace the depleting, petroleum-based conventional fuels while significantly reducing emissions. The zero sulfur content and the near zero percentage of aromatics in the synthetic fuels make them promising clean fuels to meet the upcoming emissions regulations. However, due to their significantly different properties when compared to conventional fuels, existing engines must be tested extensively to study their performance with the new fuels. The current work presents a detailed in-cylinder pressure measurement based comparison of the combustion performance of a natural gas derived synthetic diesel fuel, supplied by Syntroleum Corporation based in Tulsa, OK, and No.1 conventional diesel fuel. These fuels were tested on a Detroit Diesel Series 50 engine with an advanced electronically controlled fuel injection system. The differences observed in various combustion related parameters and their possible effects on engine performance and emissions are documented. The adaptability of the existing ECM to optimize engine performance with the new fuel was also studied.
    • Inclusion of LCCA in Alaska Flexible Pavement Design Software Manual

      Lee, Ming; McHattie, Bob; Liu, Juanyu (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2012)
    • The influence of decomposing salmon on water chemistry

      Brickell, David C.; Goering, John J. (University of Alaska, Institute of Water Resources, 1971)
      To increase our knowledge of the biological and chemical effects of the decomposition of seafood material, we have initiated a study of the decomposition of salmon carcasses in a natural system in southeastern Alaska (i.e. Little Port Walter estuary). The Pacific salmon migrates through this estuary when returning to its natal stream to spawn. Following spawning the fish die and the carcasses are eventually carried to the estuary where they sink to the bottom. During periods of low stream flow, the dead carcasses may remain in the stream itself until higher stream flows transport them to the estuary. In years of large escapements, the density of fish in the spawning stream can be very high. In the system chosen for our work, spawning densities greater than six fish per m2 have been recorded although at the time the current study was conducted the spawning density was slightly more than two fish per m2. Since our system involves primarily pink salmon (O. gorbuscha), the average weight of the fish can be assumed to be 2-3 kilograms. Thus, our study is concerned with the fate and distribution of some 75 metric tons of organic matter in the form of salmon carcasses in one small estuary in Southeastern Alaska. We are particularly interested in determining: (1) the effects of the salmon carcass decomposition on the nitrogen chemistry of the water in which the decomposition occurs; (2) the form and distribution of the organic matter which is returned to the marine system; and (3) the rate at which remineralization occurs. This paper presents the results of our initial investigations.
    • The influence of geomorphic and landscape characteristics on stream temperature and streamwater sensitivity to air temperature in the coastal temperate rainforest of Southeast Alaska

      Winfree, Michael; Stuefer, Svetlana; Hood, Eran; Arp, Christopher; Schindler, Daniel (2017-05)
      Climate warming is projected to increase the regional air temperature in southeast Alaska and alter precipitation patterns and storage, with potentially important implications for the region's aquatic resources. Streamwater temperature is controlled by energy inputs from the atmosphere and surrounding environment that are modified by a watershed's geomorphic and landcover characteristics. The climate-landcover relationships that influence stream temperature have not been comprehensively evaluated in southeast Alaskan watersheds. Thus, improving our understanding of current streamwater thermal regimes is critical to better assess how these regimes may be altered by climate change on a regional scale. In this study, seasonal streamwater thermal regimes in forty-seven watersheds across southeast Alaska were evaluated, and the influence of watershed geomorphic and landscape characteristics on stream temperature and streamwater sensitivity to air temperature was assessed. Stream temperatures were measured during the 2015 water year and analyzed for winter and summer seasons. Mean summer stream temperature ranged from 4.0°C to 17.2°C, while mean winter stream temperature were less variable across the region, ranging from 0.5°C to 3.5°C. Maximum weekly average temperatures (MWAT) ranged from 4.3°C to 21.5°C. Regression and time series analyses revealed that lower latitude, low gradient watersheds with higher lake coverage experienced warmer maximum and average summer stream temperatures and were more sensitive to air temperature fluctuations compared to higher latitude watersheds with high gradients during the summer. Winter mean stream temperature was warmer in higher gradient watersheds with greater forest and lake coverage. Moreover, higher latitude watersheds with steep gradients were less sensitive to changes in air temperature relative to low gradient / low latitude watersheds during the winter. Findings from this study demonstrate thermal regimes and air sensitivity are moderated by watershed geomorphology and landcover to create streamwater thermal heterogeneity across the coastal temperate rainforest of southeast Alaska. Results presented herein demonstrate that streamwater sensitivity to air temperature fluctuations are moderated by watershed geomorphology, and should be considered as a framework for predicting thermal regimes to assess relative watershed thermal response to climate change. This information, in turn, is important for quantifying the likely magnitude and spatial extent of climate-driven thermal impacts on Pacific salmon during their freshwater life history stages in southeast Alaska.
    • Influence of underfill filler settling on the thermomechanical reliability of the flip chip on board package

      Thammadi, Navin; Chen, Cheng-fu; Lin, Chuen-Sen; Lee, Jonah (2005-08)
      A Flip Chip on Board package (FCOB) is analyzed under thermal cycling loading to study the effect of underfill filler settling on the thermo-mechanical reliability of the package. The Mori-Tanaka method, a micromechanics based formulation, is utilized to model the property gradation caused by filler settling to obtain the effective material model for underfill. The modeling of the underfill material depends on the filler settling assumed. A total of five different underfill material models are used to assess their impact on the reliability. The equivalent underfill material properties calculated are subsequently used in finite element simulations to evaluate the FCOB assembly reliability. The reliability issues investigated in this work are solder joint fatigue and die cracking. This work aims to predict solder joint fatigue lifetime and also determine an acceptable pre-existing flaw size in the die backside to prevent die cracking. The results show that, when the underfill filler settling is gradual (instead of homogeneous), the corresponding solder joint has the minimum fatigue lifetime among the models assessed. However, the filler settling configuration has very little influence on the critical flaw size in the die and the board warpage.
    • Infrared video tracking of UAVs: Guided landing in the absence of GPS signals

      Graves, Logan W.; Hatfield, Michael C.; Lawlor, Orion; Raskovic, Dejan (2019-05)
      Unmanned Aerial Vehicles (UAVs) use Global Positioning System (GPS) signals to determine their position for automated flight. The GPS signals require an unobstructed view of the sky in order to obtain position information. When inside without a clear view of the sky, such as in a building or mine, other methods are necessary to obtain the relative position of the UAV. For obstacle avoidance a LIDAR/SONAR system is sufficient to ensure automated flight, but for precision landing the LIDAR/SONAR system is insufficient for effectively identifying the location of the landing platform and providing flight control inputs to guide the UAV to the landing platform. This project was developed in order to solve this problem by creating a guidance system utilizing an infrared (IR) camera to track an IR LED and blue LEDs mounted on the UAV from a RaspberryPI 3 Model B+. The RaspberryPI, using OpenCV libraries, can effectively track the position of the LED lights mounted on the UAV, determine rotational and lateral corrections based on this tracking, and, using Dronekit-Python libraries, command the UAV to position itself and land on the platform of the Husky UGV (Unmanned Ground Vehicle).
    • Inherent and Maximum Microbiological Activity in Smith Lake : Project Completion Report

      Burton, S. (University of Alaska; Institute of Water Resources, 1968)
      POPULAR ABSTRACT: Bacterial populations were examined in a sub-Arctic lake to augment the understanding of the flow of organic material and other nutrients through these waters. Several micro-organisms were isolated, capable of converting atmospheric nitrogen into biologically available forms. Also organisms capable of removing organic materials at very low temperatures, psychrophiles, were isolated. Enzymes from these unusual organisms were examined to determine what allows these unusual activity at low temperatures. The activities of these enzymes were not found to be unusual.
    • Initial Permafrost Engineering Research In Alaska

      Cysewski, Margaret Hope; Shur, Yuri (2013)
      Past permafrost engineering research and projects can aid modern permafrost engineering. The knowledge base of lessons learned among engineers is important, especially between generations of engineers, so history does not repeat itself Uncovering the history of permafrost engineering, and its compilation, summarization, and analysis, is beneficial for the Alaskan engineering community. This master's thesis is devoted to the early years of permafrost engineering in Alaska with projects carried out from the Gold Rush era to shortly after WWII. The projects include: thawing technology developed by gold miners, Alaska Highway road design and construction with its influence, and early comprehensive research by the Permafrost Division of the U.S. Army Corps of Engineers' St. Paul District, particularly the development of the test site, the Fairbanks Research Area, along Farmers Loop Road. Each of these projects has been successfully adapted to modern practices, laying the foundation of permafrost engineering.
    • Institute of Northern Engineering 2006 Annual Report

      University of Alaska Fairbanks, Institute of Northern Engineering; Rohr, Melanie (INE Publications, University of Alaska Fairbanks, 2006)
    • Integrated experimental and computer modeling approach to understand permafrost thaw subsidence induced oil well instability for Alaska North Slope oil wells

      Suryawanshi, Saurabh Sheshrao; Patil, Shirish; Dandekar, Abhijit; Bray, Matthew; Khataniar, Santanu (2016-05)
      Hydrocarbon reservoirs in the Arctic region of Alaska have been developed by various oil and gas producers for several years. Most of them are overlain by massive layers of permafrost soils which extend to a thickness of up to 2300 feet. Production and injection wells in such regions have experienced design and operational challenges due to heat loss from the wellbore and subsequent thawing of the permafrost soils. Thawing is a phase change of ice to water resulting in volumetric reduction of the frozen soil due to pore space contraction and segregated ice thaw, causing a major problem of thaw subsidence. Thaw subsidence affects the stability of the well, causing buckling and structural distress along the length of the wellbore within the thaw susceptible permafrost zones, thus damaging the well casing. Two different experimental approaches, one-dimensional consolidation and three-dimensional physical scale test, were employed to study thaw subsidence mechanisms in three different types of soils; namely, clay, silt and sand. The main objective of these experiments was to understand the well-soil system and the changes occurring within it with time, which will further increase knowledge of the interaction between the wellbore and the soil in Arctic regions during progressive thaw. Due to a lack of data and information, several areas were selected for multiple experimental approaches, including lateral pressure development, soil strain and strain within well casing, to study the frictional effects along the wellbore and pore-pressure response within the soil. Along with the experimental work, two different models were built in COMSOL Multiphysics™. The first model focused on thermal analysis of the thawing and refreezing behavior of ice-rich permafrost for drilling and production operations, while the second model focused on mechanical analysis, to study and understand the generation of the vertical and horizontal loads and stress-strain characteristics of the ice-rich permafrost. Simulations focused mainly on obtaining data for lateral pressure development, well stress-strain and temperature.
    • The integrated hydrologic and societal impacts of a warming climate in Interior Alaska

      Jones, Charles E.; Kielland, Knut; Hinzman, Larry; Kane, Douglas; Prakash, Anupma; Schneider, William (2014-12)
      In this dissertation, interdisciplinary research methods were used to examine how changes in hydrology associated with climate affect Alaskans. Partnerships were established with residents of Fairbanks and Tanana to develop scientific investigations relevant to rural Alaskans. In chapter 2, local knowledge was incorporated into scientific models to identify a socialecological threshold used to model potential driftwood harvest from the Yukon River. Anecdotal evidence and subsistence calendar records were combined with scientific data to model the harvest rates of driftwood. Modeling results estimate that between 1980 and 2010 hydrologic factors alone were responsible for a 29% decrease in the annual wood harvest, which approximately balanced a 23% reduction in wood demand due to a decline in number of households. The community's installation of wood-fired boilers in 2007 created a threshold increase (76%) in wood demand that is not met by driftwood harvest. Modeling of climatic scenarios illustrates that increased hydrologic variability decreases driftwood harvest and increases the financial or temporal costs for subsistence users. In chapter 3, increased groundwater flow related to permafrost degradation was hypothesized to be affect river ice thickness in sloughs of the Tanana River. A physically-based, numerical model was developed to examine the importance of permafrost degradation in explaining unfrozen river conditions in the winter. Results indicated that ice melt is amplified by increasing groundwater upwelling rates, groundwater temperatures, and snowfall. Modeling results also suggest that permafrost degradation could be a valid explanation of the phenomenon, but does not address the potential drivers (e.g. warming climate, forest fire, etc.) of the permafrost warming. In chapter 4, remote sensing techniques were hypothesized to be useful for mapping dangerous ice conditions on the Tanana River in interior Alaska. Unsupervised classification of high-resolution satellite imagery was used to identify and map open water and degraded ice conditions on the Tanana River. Ninety-five percent of the total river channel surface was classified as "safe" for river travel, while 4% of the channel was mapped as having degraded ice and 0.6% of the channel was classified as open water (overall accuracy of 73%). This research demonstrates that the classification of high-resolution satellite images can be useful for mapping hazardous ice for recreational, transportation, or industrial applications in northern climates. These results are applicable to communities throughout the North. For people that rely upon subsistence activities, increased variability in climate cycles can have substantial financial, cultural, recreational, or even mortal consequences. This research demonstrates how collaborations between scientists and local stakeholders can create tools that help to assess the impacts of increased environmental variability (such as flooding) or to detect or predict unsafe conditions (such as thin or unpredictable ice cover). Based upon this research, I conclude that regional-scale adaptations and technological advances (such as modeling and remote sensing tools) may help to alleviate the effects of environmental variability associated by climate.
    • Intelligent platform management interface protocol security

      Clayton, Syler W.; Hay, Brian; Nance, Kara; Genetti, Jon (2014-04)
      The Intelligent Platform Management Interface (IPMI) is a protocol that allows administrators to manage servers remotely. Hardware vendors including Dell, HP, Supermicro, IBM, Lenovo, Fujitsu and Oracle support IPMI though a Baseboard Management Controller (BMC) which can either be integrated into the motherboard or purchased as a pluggable module. The BMC runs silently alongside other components of the server and provides a lower level of hardware access than the Operating System (OS). This allows support for features like power cycling the server, mounting virtual media and accessing a remote console. The failure of BMC vendors to produce a more secure product, along with the inherent flaws of the IPMI protocol, increases the need for these systems' security capabilities to be evaluated. The IPMI protocol and various vendor implementations of the BMC has been the subject of recent scrutiny, and initial investigation has raised concerns about the security properties of these components. This project focuses on evaluating specific IPMI supported hardware and software setup in an environment modeled to simulate real use, for the explicit purpose of evaluating the security of the system. This project presents: several methods by which unprivileged users can gain remote access to the system, a list of best practices for proper configuration, a guide to clearing configuration settings before decommission, and a basic Metasploit module to scan for BMC related services.
    • Intelligent traffic monitoring and control system

      Ch, Nabil Al Nahin; Raskovic, Dejan; Thorsen, Denise; Hatfield, Michael (2019-08)
      This thesis presents an intelligent system for monitoring and controlling traffic by sensing vehicles' attributes and using communication between vehicles and roadside infrastructures. The goal of this system is to improve the safety of the commuters and help the drivers in making better decisions by providing them with additional information about the traffic conditions. A prototype system consisting of a roadside unit (RSU) and an on-board unit (OBU) was developed to test the functionalities of the proposed system. The RSU consists of sensors for detecting vehicles and estimating their attributes and a radio for communicating with the OBU. The OBU also has a radio for communication purpose. Afterward, a vehicle was used to test the functionalities of the system and the communication between OBU and RSU was evaluated by emulating the presence of a vehicle. A protocol for exchanging messages between the RSU and the OBU was developed to support effective communication. The efficiency of the communication process was further improved by varying the transmission range of different messages. A format for the message was proposed to convey all the necessary information efficiently. The process of collecting vehicle data, processing them and extracting useful information from the data was discussed here along with some limitations of the proposed system.