• Fatigue behavior of conventional and rubberized asphalt mixes

      Saboundjian, Stephan K.; Raad, Lutfi; Lee, Jonah H.; Hulsey, J. Leroy; Succarieh, Mohamed; Gislason, Gary (1999)
      One of the main distress modes of flexible pavements is the fatigue cracking of the asphalt concrete surface layer. The addition of crumb-rubber modifier (CRM), obtained from scrap tires, to asphalt-aggregate mixtures has shown promise in enhancing their fatigue behavior. In this study, conventional unmodified and CRM modified asphalt-aggregate mixtures are evaluated in terms of their fatigue behavior. Controlled-strain flexural beam fatigue tests are conducted in the laboratory over a wide range of temperatures. Experimental results are compared in terms of flexural, tensile and compressive stiffnesses, phase angle, fatigue life and cumulative dissipated energy. Results showed that CRM mixes are more flexible than unmodified mixes, and that mix fatigue resistance is enhanced by the addition of CRM. Furthermore, a method of converting controlled-strain test data into equivalent controlled-stress behavior is presented. Experimental results revealed the existence of two types of controlled-strain stiffness-ratio variations. For each type of variation, an equivalent controlled-stress stiffness-ratio variation with cycles is derived. Using the predicted variations, fatigue lives for both modes of loading are determined. Predictions showed that, at a given temperature, controlled-stress mode of loading yields, as expected, shorter fatigue lives than its controlled-strain counterpart. An implicit validation of the proposed conversions revealed that fatigue equation parameters K and n for the different mixes fit within the range of values obtained from the literature for controlled-stress conditions. In addition, a fatigue life model, applicable to the haversine pattern of loading used in this study, is presented. The model takes into account the cumulative dissipated energy to failure, mode-of-loading, and initial phase angle, strain and stiffness of the mix. Analogy with the traditional strain-based fatigue equation revealed that K is a temperature-dependent parameter, whereas n and m are independent of mix temperature. A decrease in K is associated with an increase in temperature. The newly developed model is then used to predict fatigue lives of conventional and CRM mixes in typical pavement structures. For this purpose, a finite element-based mechanistic analysis is used. Results revealed the enhanced fatigue resistance of CRM mixes in comparison to unmodified conventional mixes.
    • Feasibility Study of Electric Cars in Cold Regions

      Zhang, Jing; Golub, Michael (Alaska University Transportation Center, 2009)
    • Feasibility study of in-situ heat generation for oil reservoirs underlying the permafrost

      Kargarpour, Mohammad Ali; Ahmadi, Mohabbat; Awoleke, Obadare; Hanks, Catherine (2017-05)
      Development of a heavy oil reservoir is a challenging issue in the oil industry. One of the major issues in heavy oil recovery is its high viscosity; so, using heating methods for producing oil have been developed and employed from the early 1950s. The existing relatively thick permafrost layer which overlays the heavy oil reservoirs of the North Slope of Alaska creates additional complexities for development of these heavy oil reservoirs. Applying any heating oil recovery process in regular way to these heavy oil Alaskan reservoirs would potentially jeopardize the permafrost layer. A down-hole heat generation system has been developed that uses a chemical and a special catalyst to generate heat. The effluent of this system would be steam and nitrogen. The system can be installed in a well string and at the bottom of the injector well. This thesis investigates the feasibility of employing this system for development of the heavy oil reservoirs that underlie the permafrost. The results of this study can be used for any steam injection process which uses any device for down-hole steam generation. The STARS module of the CMG reservoir simulation package is used for this study. In the model, live oil with a viscosity of about 30,000 cp is used. By examining several models with vertical and horizontal wells, a 3-D model with two horizontal injector and producer wells is ultimately constructed for final runs. Different sensitivities are run to find out the optimum operational parameters. Based on the results, a lateral well length of 800 ft in the middle of a reservoir with length of a 1250 ft is selected as a base case. Areal grid block size of 10 ft × 10 ft with the layer thickness of 10 ft in a reservoir with thickness of 50 ft is employed. To minimize the down-hole well bore temperature of the producer, just the last 50 ft (out of 800 ft of lateral length) at the toe of the well is opened to flow. Three different steam injection processes are examined: Steam Assisted Gravity Drainage (SAGD), Cyclic SAGD (CSAGD) and Cyclic Steam Stimulation (CSS). Simulation results reveal that the producer well bore temperature in optimum cases for SAGD, CSAGD and CSS is more than 140 ˚F, 110 ˚F and 100 ˚F, respectively. Also, the 10-year simulation period oil recoveries for optimum cases of SAGD, CSAGD and CSS are about 35%, 18% and 12%, respectively. On the other hand, results show applying any steam injection recovery method (SAGD, CSAGD or CSS) can only be recommended when the thickness of the overlying Sagavanirktok sand formation (which separates the permafrost from the heavy oil reservoir) is equal or more than 300 ft. The results also show that the addition of nitrogen has negative effect on the oil recovery. Based on the results, it is recommended to employ SAGD or CSAGD, but employ a system to cool the producer well-string to avoid melting the permafrost. A simple system of cooling the producer well-string is suggested.
    • Feasibility Study of RFID Technology for Construction Load Tracking

      Henrie, Morgan; Ronchetti, Mike (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2010)
    • Ferric chloride leaching of the Delta sulfide ores and gold extraction from the leaching residue

      Lin, H.K.; Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1988)
      Conventional differential and bulk flotation processes have difficulties in achieving high recoveries with acceptable grades far zinc, lead and copper from the complex sulfide ores found at Tok, Alaska. Furthermore, gold and silver, which account for a significant fraction of total value of the ores, are distributed evenly in the flotation tailings and concentrate. Therefore, processing both flotation tailings and concentrate would be necessary to obtain high recoveries of gold and silver. A mineralogical study revealed that the economic sulfide minerals are interstitially associated with a large preponderance of pyrite. The economic sulfide minerals are 10 to 40 microns in size. These mineralogical facts explain the difficulties encountered in the flotation process. A hydrometallurgical method involving ferric chloride leaching and subsequent steps to recover lead, zinc, silver and copper from the leach liquor has been studied at the Mineral Industry Research Laboratory, University of Alaska Fairbanks for the treatment of Delta ores. This alternative is attractive for processing complex sulfide ores which conventional flotation and smelting cannot handle. In addition, the liberation of sulfur in the environmentally acceptable elemental form, rather than as sulfur dioxide, may prove a major advantage of this hydrometallurgical method because of stringent environmental regulations.
    • Fifth annual conference on Alaskan placer mining

      Campbell, B.W.; Madonna, J.A.; Husted, S.M. (University of Alaska Mineral Industry Research Laboratory, 1983)
      An abridged format of papers, presentations and addresses given during the 1983 conference held on March 30-31, 1983 compiled and edited by Bruce W. Campbell, Jim Madonna, and M. Susan Husted.
    • Final report - mineral resources of northern Alaska

      Heiner, L.E.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1968)
      PURPOSE. This is the final report on the work authorized on July 29, 1967, by the NORTH Commission. The purpose is to inventory mineral resources in northern Alaska and to delineate favorable mineral areas, insofar as possible. Later, a mineral policy study was added and a survey of available airborne geophysics. The Alaska Railroad made possible the large scale dredging at Fairbanks and became a feeder to all interior districts. It allowed the building of military bases during and after World War II. Freight moves predominantly north.
    • Financial Impact of Fines in the Unbound Pavement Layers

      Liu, Jenny; Zhang, Xiong; Chamberlain, Andrew; Li, Lin (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2014)
    • Finite element analysis of yield functions of Kelvin foams with open cells

      Huang, Beiqing (2001-12)
      Proper design of foams requires an understanding of the response of the materials to stress. This thesis, based on finite element analysis, provides numerical solutions in modeling the yield behavior of Kelvin foams. The FEA model, representing a complicated unit cell, was calculated and meshed. C++ programs were designed and implemented to generate meshes for unit cells. Finite element analyses were performed for many cases. Multiple methods were employed for the determination of yield points which form yield surfaces. Comparisons between several results have been made. Our FEA results, Zhang's function and Gibson's theory show good agreements except some differences under hydrostatic loading. A conclusion can be made: besides the void fraction and the yield strength of the wall material, the structure of foams also has a significant effect on the yield behavior of foams. Yield surfaces normalized by the uniaxial tensile strength of foams are more reasonable.
    • Flood Frequency Design in Sparse-data Regions

      Carlson, Robert F.; Fox, Patricia M. (University of Alaska, Institute of Water Resources, 1978-06)
      This report summarizes work conducted with funds received from the Office of Water Research and Technology (OWRT), Project B-030-ALAS, Flood Frequency in Sparse-Data Regions. The study was conducted from July 1, 1974, to June 30, 1976, plus a one-year extension to June 30, 1977. The technical results are given in a number of publications which are referenced and abstracted here along with a presentation of the overall philosophy of the project and a coherent summary of the work. Alaska may be characterized, as can most northern areas, by a very sparse data collection network of hydrologic variables. In combination with several physical characteristics of northern hydrology, the sparse data network leads to a very difficult design circumstance. The most well known physical aspect of northern hydrology is permafrost. Other factors of importance are large elevation differences, regional inhomogeneity, high latitude, low temperatures, and the very dynamic nature of the spring breakup. These factors, in combination with the short data base in northern regions, cause hydrologic design to have a large degree of uncertainty.
    • Flood Frequency Estimation in Northern Sparse Data Regions: Completion Report

      Carlson, Robert F.; Fox, Patricia (University of Alaska, Institute of Water Resources, 1974-07)
      The primary objective of this project was to complete development of an arctic hydrologic model and to evaluate its usefulness in generating information useful for a design tool in estimation of peak flow discharges. The peak flow discharges studied were those generally analyzed and evaluated in the design of facilities for stream crossings.
    • Flood hazard hydrology: interdisciplinary geospatial preparedness and policy

      Petty, Timothy R.; Schnabel, William; Prakash, Anupma; Folger, Peter; Djokie, Dean (2017-05)
      Floods rank as the deadliest and most frequently occurring natural hazard worldwide, and in 2013 floods in the United States ranked second only to wind storms in accounting for loss of life and damage to property. While flood disasters remain difficult to accurately predict, more precise forecasts and better understanding of the frequency, magnitude and timing of floods can help reduce the loss of life and costs associated with the impact of flood events. There is a common perception that 1) local-to-national-level decision makers do not have accurate, reliable and actionable data and knowledge they need in order to make informed flood-related decisions, and 2) because of science--policy disconnects, critical flood and scientific analyses and insights are failing to influence policymakers in national water resource and flood-related decisions that have significant local impact. This dissertation explores these perceived information gaps and disconnects, and seeks to answer the question of whether flood data can be accurately generated, transformed into useful actionable knowledge for local flood event decision makers, and then effectively communicated to influence policy. Utilizing an interdisciplinary mixed-methods research design approach, this thesis develops a methodological framework and interpretative lens for each of three distinct stages of flood-related information interaction: 1) data generation—using machine learning to estimate streamflow flood data for forecasting and response; 2) knowledge development and sharing—creating a geoanalytic visualization decision support system for flood events; and 3) knowledge actualization—using heuristic toolsets for translating scientific knowledge into policy action. Each stage is elaborated on in three distinct research papers, incorporated as chapters in this dissertation, that focus on developing practical data and methodologies that are useful to scientists, local flood event decision makers, and policymakers. Data and analytical results of this research indicate that, if certain conditions are met, it is possible to provide local decision makers and policy makers with the useful actionable knowledge they need to make timely and informed decisions.
    • Floodplain assessment for the Teklanika and Toklat River project reaches in Denali National Park and Preserve, Alaska

      Schalk, Brian N. (2005-05)
      The National Park Service (NPS) is required to assess risks of flooding to existing and proposed structures within the boundaries of the NPS system. Within Denali National Park and Preserve (DNP & P), there are several large, braided rivers that require floodplain management. The objective of this investigation is to provide DNP & P with guidelines and methods that apply fluvial geomorphic, hydrologic, and hydraulic analysis in order to delineate flood hazard zones on this type of stream. Data collected from Teklanika and Toklat Rivers were used to develop a return period versus flood depth/bankfull depth curve and assess potential streambank erosion. Site specific data combined with this curve will enable NPS personnel to easily approximate flood hazard zones for the project reaches. The method can be applied to assess other flood hazard zones associated with other braided rivers with similar characteristics.
    • Fluid flow in oscillating cavities

      Ragunathan, Srivathsan (2003-12)
      Oscillatory flows have gained considerable research attention in the recent decades following an interest in transport enhancement in micro-electronic devices. Heat transfer enhancement due to flow modulation has an inherent advantage over conventional mechanical heat transfer components in terms of reduction in weight and space. The present work is aimed at studying fluid flow in oscillating square cavities as a first step towards heat transfer enhancement. A commercial CFD code, Fluent, was used to model a test case consisting of Stokes' second problem, with a source code written in the C programming language. The simulated results were in good agreement with the analytical results found in the literature. Since the description of an oscillatory boundary condition in complex geometries would prove to be a difficult exercise because of the presence of spanwise walls, Newton's second law of motion for accelerating reference frames was used. This method proved to be an effective one computationally and the results agreed well with the analytical results. The cavity problem was analyzed using Fluent with the Non-Newtonian formulation described above. Fluid dynamic characteristics were studied with respect to dimensionless parameters and they exhibited an explicit dependence on these parameters.
    • Focus on Alaska's coal '75, proceedings of the conference

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1975)
      Interest in Alaska's coals has increased greatly in the last few years partly as a II result of the public's realization that we are in a real energy shortage and partly because the building of the Alaska pipe line has demonstrated that transportation for Alaska's raw materials can be supplied if needed. Both President Ford and Secretary of Interior Kleppe have pointedly stated that Alaska must furnish much of the nation's energy needs in the next few decades. During the years 1974 and 1975, industry also showed greater interest as indicated by the large scale exploration activities in the Nenana, Beluga and Susitna coal fields. As a result of all of this interest it was decided that the time was right for an exchange of information on Alaska's coal; to bring people together and bring them up to date, and this conference was the result. Focus on Alaska's Coal, the first conference of its kind, attracted wide participation and apparently an enthusiastic response. The papers and the audience questions showed an overriding concern for the nation's energy needs and the possibility that Alaska can help alleviate those needs with its enormous solid fuel resources along with its oil and gas resources. As a result of the conference, the following points were brought into focus: Alaska's coal deposits are much more extensive than hitherto known. The development of a coal industry in Alaska to supply west coast markets is no longer a dream, and will in fact be a reality before long. Additional research on characterization and upgrading of coals is needed to further evaluate the potential of the enormous reserves. Alaska's coals are low in sulfur and thus are environmentally more acceptable. It is hoped that this conference brought into focus the opportunities Alaska offers to the nation and as a result, that work will be stimulated leading to the further development and utilization of its coal resources.
    • Focus on Alaska's coal '80, proceedings of the conference

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1980)
      The principal objectives of the conference were to bring together current knowledge on Alaska's coal resources, mining methods, utilization and marketing, and every interested party to share this knowledge. The excellent papers presented and the large number of participants indicates that the objectives were accomplished.
    • Focus on Alaska's coal '86 - proceedings of the conference

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1987)
      This volume contains 35 papers presented at the two-day conference, "Focus on Alaska's Coal '86," held in Anchorage at the Hotel Captain Cook on October 28 and 29, 1986.
    • Focus on Alaska's coal '93 - proceedings of the conference

      Rao, P.D.; Walsh, D.E. (University of Alaska Mineral Industry Research Laboratory, 1994)
      This volume contains 20 of the 28 papers presented at the two-day conference, "Focus on Alaska's Coal '93," held in Anchorage at the Hotel Captain Cook on May 5-7; 1993. "Focus on Alaska's Coal '93" is the fourth in a series of conferences. "Focus on Alaska's Coal 1975" and "Focus on Alaska's Coal 1980" were held in Fairbanks, and "Focus on Alaska's Coal '86" was held in Anchorage. Their proceedings have been published.
    • The formation of pore ice in coarse grained soils

      Fourie, Walter (2005-12)
      Understanding the formation of pore ice in coarse grained soils is important to geotechnical and geo-environmental projects such as the construction of roads, airstrips and gravel foundations as well as the treatment of contaminated soils in the arctic, sub-arctic, alpine and northern regions. The amount of pore ice present controls the strength characteristics of the soils as well as the flow of fluid through the soil. Tests have been conducted to qualify the impact of gradation, temperature, compaction and initial moisture content on the formation of pore ice in coarse grained soils. The purpose of this study was to prepare a conceptual model of the freezing mechanism in coarse grained soils and to qualify the parameters that influence the ice formation. Results from this study indicate that the presence of fine grained particles in a coarse grained soil greatly impact the depth at which the pore space initially becomes saturated with ice. A conceptual model was developed and its application is shown with regards to the process of thaw weakening in roads and the creation of preferential flow paths in permeable reactive barriers.
    • Fortran IV program for processing geochemical sediment data, 34 p.

      Heiner, L.E. (University of Alaska Mineral Industry Research Laboratory, 1970)
      A general computer program has been written to process geochemical data resulting from the analysis of up to 34 trace elements per sample. This program will: 1. Produce a table for direct inclusion in formalreports. The table contains the map number and field number of the geochemical samples, the corresponding elemental values and a table giving descriptive data about the sample. Prior to printing, the samples are arranged according to map number for easy correspondence between the table of values and to the geochemical map. 2. Compute the average value for each element, normally and lognormally. 3. Compute the standard deviation for each element, normally and lognormally. 4. Compute the threshold value for each element, normally and lognormally. 5. Compute the anomalous concentrations for each element, normally and lognormally. 6. Draw lognormal, or standard histograms for each element. All geochemical samples taken by the Alaska Division of Mines and Geology during the summer of 1968 and 1969 were processed by this program or a modification of the program. The program can be modified to enable production of automatic maps and tables of anomalous samples.