• Development of durable “green” concrete exposed to deicing chemicals via synergistic use of locally available recycled materials and multi-scale modifiers

      Xie, Ning; Cui, Na (Center for Environmentally Sustainable Transportation in Cold Climates, 2018-02)
      From the economic and social perspectives, the use of waste materials would not be attractive until their costs and quality can satisfy the construction requirements. In this study, a pure fly ash paste (PFAP) was developed in place of ordinary Portland cement paste (OPCP). This PFAP was prepared at room temperature and without direct alkali activation. The samples were prepared using only the as-received class C coal fly ash, water, and a very small amount of borax (Na2B4O7). On average, the PFAP featured 28-d compressive strength of about 36 MPa, and micro-nano hardness and elastic modulus 29% and 5%, higher than the OPCP, respectively. These mechanical and other properties of the PFAP make it a viable “green” construction binder suitable for a host of structural and non-structural applications. Advanced characterization of the raw material and PFAP pastes was employed to elucidate the hydration mechanisms of this “green” binder. The obtained knowledge sheds light on the role of class C CFA in the hydration process and may benefit the expanded use of various CFAs in cementitious materials.
    • Development of high spectral resolution iron Boltzmann lidar

      Hou, Tao (2002-12)
      An initial iron (Fe) Boltzmann lidar was developed in winter 2000-2001 at Poker Flat Research Range (PFRR). This resonance lidar system supported Fe concentration measurements. An initial Fe Boltzmann temperature measurement was made in December 2000. This initial system was fundamentally limited by the 1 pm tuning resolution of the laser. During the winter of 2001-2002, a control system was developed to increase the resolution of the laser tuning to 0.09 pm. Fe cooncentration and Fe Boltzmann temperature measurements were made and an experimental analysis of the measurements was developed. This thesis presents lidar observations of the mesospheric Fe layer over these two winters, the principle of Boltzmann Fe lidar, the design and validation of the new laser tuning capability and the new temperature measurements. A complete error analysis is also presented. This full engineering analysis demonstrates that the tuning control system yields significant improvements in both the Fe concentration and temperature measurements.
    • Development Of Resonance Fluorescence Lidar For Studies Of The Aurora

      Su, Liguo; Collins, Richard L. (2007)
      In this thesis I present resonance fluorescence lidar studies of the middle and upper atmosphere. I focus on two specific applications; lidar measurements of heat fluxes in the mesosphere, and lidar measurements of auroral nitrogen ions in the thermosphere. In the heat flux study, I determine the limitations in state-of-the-art sodium Doppler wind-temperature lidar measurements. I conduct statistical analysis of current lidar measurements using analytical and Monte Carlo techniques and extend them to consider future measurements. I find that the expected biases for summertime flux measurements in polar regions will be larger than the geophysical values of the fluxes. In the nitrogen resonance lidar study, I conduct a simulation of the measurements under realistic auroral conditions and found that current lidar systems should be able to make statistically significant measurements of the nitrogen profile at a resolution of 6 km and 300 s. I develop a prototype nitrogen resonance lidar system operating at 390 nm. This lidar system is based on an existing dye laser-based iron resonance lidar system that operates at 372 nm. I designed and implemented a tuning control system that allows 1 pm resolution in the laser tuning. I made a set of field measurements and found that the performance of the prototype lidar was less than expected. I conduct an engineering analysis of the measurements and conclude that the lower than expected performance is due to the lasing characteristics of the dye laser.
    • Diagnostics of magnetospheric electron density and ion composition using whistler mode sounding data from the image satellite

      Proddaturi, Radha Krishna (2007-08)
      This thesis reports the observations of the Magnetospherically Reflected (MR) Whistler Mode (WM) echoes on the IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) satellite. These observations and interpretations were first reported in Sonwalkar et at. [2006]. MR-WM echoes were observed when RPI (Radio Plasma Imager) onboard the IMAGE satellite transmitted 3.2 ms pulses in the 6 kHz to 63 kHz frequency band. These echoes occurred at frequencies less than ~12 kHz with time delays ranging from 40 ms to 130 ms. MR-WM echoes were recorded when the satellite was at altitudes ranging from 700 km to 4000 km, geomagnetic latitudes from -30° to 50°, and magnetic local times 3 to 17. Ray tracing simulations confirmed that MR- WM echoes are a result of WM waves propagating along the geomagnetic field line and reflecting at an altitude where local flh [almost equal] f, where flh is the lower hybrid frequency and f is the wave frequency. In this interpretation, the lower and upper cutoff frequencies of the MR- WM echoes are equal to the flh at the satellite and the maximum flh along the geomagnetic field line passing through the satellite, respectively. These echoes were frequently accompanied by discrete WM echoes at frequencies greater than the maximum frequency of the MR- WM echoes. By matching the measured dispersions of the MR- WM and discrete WM echoes with that calculated from ray tracing simulations, remote estimates of electron density and ion effective mass were obtained along the geomagnetic field line passing through the satellite.
    • Diesel Fuel Additives: Use and Efficacy for Alaska's Diesel Generators

      Kemp, Chandler; Williams, Frank; Holdmann, Gwen; Witmer, Dennis (2013-05)
    • Digital Dissemination Platform of Transportation Engineering Education Materials Founded in Adoption Research

      Perkins, Robert A. (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2014)
    • Direct Satellite Communications

      Hills, Alex (1985-06)
      Mobile radio communications in Alaska are not always effective along our highways, marine system, and remote field sites. This ineffective mobile radio communications coverage is due in part to the lack of repeaters in appropriate locations and an excess of users on certain frequencies. Lower frequencies can propogate over hilly areas whereas higher frequencies tend to travel in straight lines and are shielded by hills, ridges, and tall buildings. A new communications system called Mobile Satellite Service (MSS) may be available for use in the State in three or four years. The MSS system utilizes a satellite link between the transmitting station to the receiving station. The system is best suited for areas with few path obstructions therefore use in remote, rural areas where other forms of communication are unavailable or unreliable is very appropriate. This interim report identifies candidate applications in the state and determines coverage which will be provided in Alaska by each of the proposed satellites. The final report will give specific recommendations for feasible applications and include a technical and economical analysis of mobile satellite operations in Alaska, specifying technical requirements and defining potential operating difficulties.
    • Disinfection by-product experiences in Alaskan village drinking water systems and the Caribou-Poker Creek watershed

      Narr, Jasprit (2001-08)
      The purpose of this research was to study the disinfection by-product formation potential (DBPFP) in small drinking water systems in Alaska. As per the US. E.P.A's disinfectants/disinfection by-products (D/DBP) rule, the maximum contaminant limit (MCL) for the two major DBPs namely, total trihalomethanes (TTHMs) is 80 micrograms (ug) per liter (L) and 60 micrograms/liter for the five 5 halloacetic acids (HAA5). It was decided to conduct research on the total trihalomethane formation potential (TTHMFP) and the 5- haloacetic acid formation potential (HAA5PF) of the 17 Alaskan village drinking water systems with reportedly high TTHM and HAA5 values. It was found that specific UV absorbance (SUVA) had excellent correlations with TTHM/DOC and HAA5/DOC. These correlations were used to aid in drinking water source selection in a sub-arctic watershed named the Caribou-Poker Creek Research Watershed (CPCRW).
    • Distribution of certain minor elements in Alaskan coals

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1968)
      Seventy-five samples of coal from Northern Alaska, Jarvis Creek, Nenana, Matanuska, Kenai and Bering River Coal Fields were analyzed by quantitative spectrochemical procedures f o r lead, gallium, copper, barium, beryllium, nickel, titanium, vanadium, zirconium, cobalt, chromium, germanium, and tin. Other elements, of significance, identified from the spectrograms were, gold and silver identified in certain Nenana coals and silver in coals from Chickaloon in the Matanuska field, in concentrations up to several parts per million of coal ash. Forty-one of the above samples were sink-floated to study the distribution of minor elements between the organic and inorganic phases of the coals. Relative affinities of the minor of the minor elements to the organic matter in the coal is discussed.
    • Distribution of Organics from Salmon Decomposition: Completion Report

      Goering, J.; Brickell, D. (University of Alaska, Institute of Water Resources, 1972-12)
      In the fall of 1969, an OWRR-supported study of salmon carcass decomposition was initiated with the intent of collecting information on the biological and chemical dynamics of the decomposition and deposition of salmon wastes in Alaskan estuaries. The study aim was to elucidate the rates and mechanisms of the chemical transformations that accompany breakdown of fish flesh and to reveal the capacity of the Alaskan estuaries to handle quantities of organic seafood waste without presenting a pollution problem. This study has been in progress for several years, and the results have markedly increased our understanding of the decomposition of such organic materials in coastal streams and estuaries.
    • Distribution, analysis, and recovery of fine gold from alluvial deposits

      Cook, D.J.; Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1973)
      The United States Bureau of Mines, in its Heavy Metals Program, desired to have research performed to determine the size-frequency distribution and possible economic value of gold particles in the fine size ranges of Alaskan placer deposits. Primary interest was involved in obtaining evidence of the occurrence of fine gold and to determine the ameanability of standard sampling and production methods in the evaluation and recovery processes. A research contract between the United States Bureau of Mines and the University of Alaska was initiated in June, 1968 as the first phase of this investigation, but was subsequently modified in June, 1969 to include beneficiation processes amenable to recovery as well as evaluation methods for fine and flakey gold. In searching the literature relative to fine gold in Alaskan placer deposits, it was found that virtually no research has been devoted to determining the extent of fine gold distribution and its effect on evaluation and subsequent recovery methods. Standard evaluation techniques have relied on gravity methods of concentration and recovery of the visible gold from the concentrate. In general, this has proved satisfactory in that operational recovery methods used were probably not conducive to retaining gold particles of less than 100 mesh in size. Operators have made no attempt to obtain a size analysis of gold in a head sample, but many have kept records of the size distribution of the gold as actually recovered. A review of these records, from selected areas, indicates that the -100 mesh gold represents from 0 to 5% of the total gold recovered. Although figures of this type may point to a probably fine gold loss, the difficulties inherent in evaluating the tailng material or modifying the recovery system have usually discouraged efforts in this direction.
    • DOCUMENTING THE CHARACTERISTICS OF TRAFFIC CRASHES FOR RITI COMMUNITIES IN IDAHO

      Abdel-Rahim, Ahmed; Swoboda-Colberg, Skye; Mohamed, Mohamed; Gonzalez, Angel (2020-08)
      This project documents the characteristics of traffic crashes in rural, isolated, tribal, and indigenous (RITI) communities in Idaho and establishes an in-depth understanding of the baseline traffic safety conditions in RITI communities. Different sources of crash data for RITI communities in Idaho was used to conduct an in-depth ten-year crash analysis (2007-2016) to document the characteristics of traffic crashes in rural roads that serve RITI communities in Idaho. The results of analysis of fatal and severe injury crashes on unpaved roads clearly shows that ATVs and pickup trucks and the two most common vehicle types involved in crashes in these roads. The results also showed that the majority of fatal and severe injury crashes on unpaved roads involved male drivers and occupants 24 years or younger with considerable number involving occupants younger than 14 years old. A comparative safety analysis was conducted to identify and document the differences in characteristics between crashes that occurred on unpaved and paved rural roads in Idaho. The results of the analysis show that the percent of fatal and severe injury crashes where no restraining device was used is much higher in unpaved roads (50.4% and 38.3% in unpaved roads compared to 37.9 and 22.8 on paved roads). The same trend also exists in helmet use which shows the critical need for a much more aggressive seat belt and helmet use enforcement among communities who use rural unpaved roads in Idaho. The results also show a substantial difference in ATV crashes on unpaved versus paved. Teenagers or children that are 14 years or younger are more susceptible to fatal and severe injuries on unpaved roads compared to paved roads. Crash injuries for age groups from 15 to 44 are also higher on unpaved roadways. The results also clearly highlight the fact that unpaved roads have higher percentages of crashes where alcohol impairment was a major contributing circumstance. The same is true for speeding and inattention related crashes. A proportion statistical test results show that many of these results have a calculated p-value less than 0.05, indicating that these results are statistically significant at the 95% confidence level.
    • DRONES FOR IMPROVING TRAFFIC SAFETY IN RITI COMMUNITIES IN WASHINGTON STATE

      Ban, Xuegang (Jeff); Abramson, Daniel; Zhang, Yiran (2020-04-04)
      Transportation and traffic safety is a primary concern in Rural, Isolated, Tribal, or Indigenous (RITI) communities in Washington (WA) State. Parallel to this, while emerging technologies (e.g., connected/autonomous vehicles, drones) have been developed and tested in addressing traffic safety issues, they are often not widely shared in RITI communities for various reasons. Compared with other technological advances, drone technologies have been rapidly improved and can be flexibly applied to multiple fields, including engineering, agriculture and disaster managements. The goal of this study is to explore and synthesize the opportunities, challenges and scenarios that drone technologies can assist to resolve traffic safety related issues and concerns in RITI communities. Through the outreach activities with the outer Pacific Coast in WA state, it is found that the principal concern within these communities are disaster management and mitigation since they are facing the threat of coastal erosion, earthquake and tsunami. Thus, the emergency management and hazard mitigation becomes the major way to further explore drone applications in the selected communities. To achieve this, we reviewed the current state of the drone technologies, conducted surveys from National Guard and coastal communities in WA, including City of Westport, South Beach Region, Grays Harbor County, Shoalwater Bay Tribe, and Quinault Indian Nation, to better understand their current needs, challenges and issues. Ultimately, recommendations of drone applications under specific scenarios are provided based upon the integration of drone technologies with community safety needs.
    • Durability and Smart Condition Assessment of Ultra-High Performance Concrete in Cold Climates

      Qiao, Pizhong; Zhou, Zhidong; Allena, Srinivas (Center for Environmentally Sustainable Transportation in Cold Climates, 2016-12-31)
      The goals of this study were to develop ecological ultra-high performance concrete (UHPC) with local materials and supplementary cementitious materials and to evaluate the long-term performance of UHPC in cold climates using effective mechanical test methods, such as “smart aggregate” technology and microstructure imaging analysis. The optimal UHPC mixture approximately exhibited compressive strength of 15 ksi, elastic modulus of 5,000 ksi, direct tensile strength of 1.27 ksi, and shrinkage of 630  at 28 days, which are characteristics comparable to those of commercial products and other studies. The tensile strength and modulus of elasticity in tension, dynamic modulus, and wave modulus show slight increases from the original values after 300 freeze-thaw (F-T) cycles, indicating that UHPC has excellent frost resistance in cold climates. Although porosity deterioration was observed in the F-T cyclic conditioning process, no internal damage (cracks or fractures) was found during imaging analysis up to 300 cycles. Since structures for which UHPC would be used are expected to have a longer service life, more F-T cycles are recommended to condition UHPC and investigate its mechanical performance over time. Moreover, continuum damage mechanic-based models have the potential to evaluate damage accumulation in UHPC and its failure mechanism under frost attack and to predict long-term material deterioration and service life.
    • DUST PALLIATIVE MEAN PARTICLE RESIDENCE TIME CALCULATOR

      Metzgar, Jonathan (2020-12-31)
      Previous research efforts at UAF have established that dust palliative performance may be compared using a calculation called the mean particle residence time (tau, or MPRT). The MPRT value is computed using linear regression techniques to determine the time when the dust palliative loses its effectiveness. A technician tests the palliative using a dustfall column and a nephelometer to measure the concentration of PM10 over time. The technician needs to manually process this raw data with an Excel spreadsheet making dust palliative MPRT reports time-consuming and prone to error. Finally, the certifying technician prints and files the report for future reference which limits future dissemination. We developed a web-based calculator, called UAFDUST, to automate the process of producing the MPRT report. UAFDUST combines a web app front end using Google's Angular library with a PHP and SQL database backend. This database enables a laboratory to record metadata about the dust palliative including the dustfall column testing date and technician, certification date, and certifying technician. The app calculates the MPRT and produces accompanying linear regression plots. The UAFDUST app stores dust palliative MPRT tests in a public database and trained laboratory technicians may contribute new data.
    • Dying intestate or with a will on toxic estate? an evaluation of petroleum fiscal systems and the economic and policy implications for decommissioning of onshore crude oil fields in Nigeria

      Afieroho, Erovie-Oghene Uyoyou-karo; Patil, Shirish L.; Dandekar, Abhijit; Reynolds, Douglas B.; Perkins, Robert (2018-05)
      Many giant fields in the world like the onshore fields in Nigeria which were initially discovered over half a century ago, have begun to see consistent decline in production and profit, and are gradually entering into the economic end of field life or decommissioning phase. Characteristically, in most regions with mature fields, the large multinational oil companies have begun to sell their oil fields to small indigenous companies who may not be financially robust enough to complete the decommissioning, when it occurs. Because of the pervasive societal impact of the oil industry, if an investor fails to properly decommissioning the infrastructure, a responsible government will have to pay for the proper decommissioning, else society will suffer the socioeconomic, political, health and environmental impact. Therefore, society needs to be effectively engaged in the development of a sustainable decommissioning policy framework, which is hindered if society is uninformed and lacks access to pertinent information. Currently, there is abysmal information in the public space on the cost of decommissioning liabilities of oil fields, especially in developing countries like Nigeria. The public also need simple interpretative ways to determine the vulnerability of a county or entity to decommissioning default risk and the imminence of a default risk. Furthermore, there is currently, no way to benchmark the level of maturity or level of preparedness for decommissioning phase such that countries and entities can identify their gaps to a sustainable decommissioning policy framework and define a roadmap to close the gaps. These are important challenges to vigorous public participation, which is an essential requirement for development and implementation of any sustainable public policy for a public issue like decommissioning of crude oil fields. This study adopted several research methods to develop and introduce a new cost estimating methodology that uses publicly declared cost of asset retirement obligations (ARO) to determine a plausible cost estimate range for decommissioning liabilities. It was demonstrated with Nigeria onshore crude oil fields, which it determined to have a rough order of magnitude cost estimate for decommissioning liabilities that could be as high as $3 billion. Secondly, it also introduced decommissioning coverage ratio (DCR) and decommissioning coverage ratio vector (DCRV) as new metrics to evaluate the vulnerability to and imminence of decommissioning default risk. In demonstrating these new metrics, this study determined that the imminence of and vulnerability to decommissioning default risk for the onshore crude oil fields in Nigeria, with respect to any of the available revenue streams, is high. Thirdly, it developed a graded scale maturity model for sustainable decommissioning of petroleum fields. The model described as Fairbanks maturity model for sustainable decommissioning in the petroleum industry, has five progressive levels of maturity. It leveraged the methodology used for similar maturity models developed in other industries and for business management, and a comparative analysis of level of progress in decommissioning frameworks between some countries with leading decommissioning experience in the petroleum industry, to develop the Fairbanks maturity model. Based on the Fairbanks maturity model, frameworks for sustainable decommissioning of Nigeria onshore crude oil fields were evaluated to be at Level 1, Ad hoc maturity level, which is the lowest maturity level. Recommendations to close the identified gaps were also were made. These methodologies can be applied to any petroleum producing region or entity in the world and are advancements to the frontier of knowledge in the management of decommissioning phase for petroleum fields in general and Nigeria onshore fields in particular.
    • Dynamic Modeling Of The Hydrologic Processes In Areas Of Discontinuous Permafrost

      Bolton, William Robert; Hinzman, Larry (2006)
      The overarching hypothesis of this dissertation is "in the sub-arctic environment, the presence or absence of permafrost is dominant influence on hydrologic processes." The presence or absence of permafrost is the defining hydrologic characteristic in the sub-arctic environment. Discontinuous permafrost introduces very distinct changes in soil hydraulic properties, which introduce sharp discontinuities in hydrologic processes and ecosystem characteristics. Hydraulic properties vary over short and long time scales as the active layer thaws over the course of a summer or with changes in permafrost extent. The influence of permafrost distribution, active layer thaw depth, and wildfire on the soil moisture regime and stream flow were explored through a combination of field-based observations and computer simulations. Ice-rich conditions at the permafrost table do not allow significant percolation of surface waters, which result in saturated soils near the ground surface and limited subsurface storage capacity, compared to well-drained non-permafrost sites. The removal of vegetation by wildfire results in short-term (<10 years) increases in moisture content through reduced evapotranspiration. Long-term (>10 years) drying of soils in moderate to severe wildfire sites is the result of an increased active layer depth and storage capacity. A spatially-distributed, process-based hydrologic model, TopoFlow, was modified to allow spatial and temporal variation in the hydraulic conductivity and porosity of soils. By continual variation of the hydraulic conductivity (proxy for permafrost distribution and active layer thaw depth) and porosity (proxy for storage capacity), the dynamic soil properties found in the sub-arctic environment are adequately represented. The sensitivity of TopoFlow to changes in permafrost condition, vegetation regime, and evapotranspiration is analyzed. The net result of the field observations and computer simulations conducted in this research suggest the presence or absence of permafrost is the dominant influence on soil moisture dynamics and has an important, but secondary role in the stream flow processes.
    • Dynamic simulator for a grinding circuit

      Srivastava, Vaibhav; Ganguli, Rajive; Ghosh, Tathagata; Akdogan, Guven; Darrow, Margaret (2017-08)
      The grinding circuit is a primary and indispensable unit of a mineral processing plant. The product from a grinding circuit affects the recovery rate of minerals in subsequent downstream processes and governs the amount of concentrate produced. Because of the huge amount of energy required during the grinding operation, they contribute to a major portion of the concentrator cost. This makes grinding a crucial process to be considered for optimization and control. There are numerous process variables that are monitored and controlled during a grinding operation. The variables in a grinding circuit are highly inter-related and the intricate interaction among them makes the process difficult to understand from an operational viewpoint. Modeling and simulation of grinding circuits have been used by past researchers for circuit design and pre-flowsheet optimization in terms of processing capacity, recovery rate, and product size distribution. However, these models were solved under steady approximation and did not provide any information on the system in real time. Hence, they cannot be used for real time optimization and control purposes. Therefore, this research focuses on developing a dynamic simulator for a grinding circuit. The Matlab/Simulink environment was used to program the models of the process units that were interlinked to produce the flowsheet of a grinding circuit of a local gold mine operating in Alaska. The flowsheet was simulated under different operating conditions to understand the behavior of the circuit. The explanation for such changes has also been discussed. The dynamic simulator was then used in designing a neural network based controller for the semi-autogenous mill (SAG). A two-layer non-linear autoregressive (NARX) neural network with feed to the mill as exogenous input was designed using data generated by the simulator for a range of operating conditions. Levenberg-Marquardt (LM) and Bayesian Regularization (BR) training algorithms were used to train the network. Comparison of both algorithms showed LM performed better provided the number of parameters in the network were chosen in a prudent manner. Finally, the implementation of the controller for maintaining SAG mill power to a reference point is discussed.
    • Dynamics simulation of human box delivering task

      Owens, Paul Davis; Xiang, Yujiang; Peterson, Rorik; Chen, Cheng-fu (2018-05)
      The dynamic optimization of a box delivery motion is a complex task. The key component is to achieve an optimized motion associated with the box weight, delivering speed, and location. This thesis addresses one solution for determining the optimal delivery of a box. The delivering task is divided into five subtasks: lifting, transition step, carrying, transition step, and unloading. Each task is simulated independently with appropriate boundary conditions so that they can be stitched together to render a complete delivering task. Each task is formulated as an optimization problem. The design variables are joint angle profiles. For lifting and carrying task, the objective function is the dynamic effort. The unloading task is a byproduct of the lifting task, but done in reverse, starting with holding the box and ending with it at its final position. In contrast, for transition task, the objective function is the combination of dynamic effort and joint discomfort. The various joint parameters are analyzed consisting of joint torque, joint angles, and ground reactive forces. A viable optimization motion is generated from the simulation results. It is also empirically validated. This research holds significance for professions containing heavy box lifting and delivering tasks and would like to reduce the chance of injury.