• Copper mineral occurrences in the Wrangell Mountains-Prince William Sound area, Alaska

      Heiner, L.E.; Wolff, E.N.; Grybeck, D.G. (University of Alaska Mineral Industry Research Laboratory, 1971)
      On January 9, 1970, the U.S. Bureau of Mines entered into an agreement with the University of Alaska based upon a proposal submitted by the Mineral Industry Research Laboratory. Under the terms of this agreement, the Laboratory undertook to compile information on copper occurrences in eight quadrangles covering what are loosely known as the Copper River, White River, and Prince William Sound copper provinces. If time permitted four other quadrangles would be added, and this has been possible. Information was to be obtained by searching published and unpublished records of the Bureau of Mines, the U.S. Geological Survey, the State Division of Geological Survey, the University of Alaska, and the recording offices.
    • Cordova Floating Ferry Dock

      Metzger, Andrew T. (2014-12)
      This study began the evaluation of the Cordova floating ferry dock using the ANSYS AQWA software. The AQWA software models the effects of waves, wind and current on floating structures. Floating bodies are modeled as a point-mass with inertial and hydrostatic characteristics. As part of the study, the critical wave characteristic was defined. During the modeling it was found that AQWA can only model rigid bodies and that the Cordova floats experience a wide range of wave periods and directions. Consequently, AQWA requires adaptation to fully model the ferry dock at Cordova.
    • Correcting Oil-Water Relative Permeability Data For Capillary End Effect In Displacement Experiments

      Qadeer, Suhail (1988)
      By neglecting the effect of capillary forces, the relative permeabilities calculated by the method of Johnson, Bossler, and Neumann or Jones and Roszelle from low rate displacement experiments are in error.<p> In this study, steady state and displacement experiments were carried out. A history matching package along with a fully implicit numerical simulator and a Welge type model were developed and the displacement data were analyzed by history matching to quantify these errors. A modified centrifuge drainage bucket was used to obtain drainage and imbibition capillary pressure data.<p> The results show that in the case of drainage the non-wetting phase end point relative permeabilities and saturation exponents increase with an increase in rate. However the saturation exponent for the wetting phase decreases with rate. The wetting phase end point relative permeability stayed more or less constant with rate. In the case of imbibition these parameters did not indicate any meaningful rate dependent trend. <p>
    • Correlation of microstructure and thermo-mechanical properties of a novel hydrogen transport membrane

      Zhang, Yongjun; 张咏君; Bandopadhyay, Sukumar; Trainor, Tom; Balachandran, Uthamalingam; Nag, Nagendra (2014-05)
      A key part of the FutureGen concept is to support the production of hydrogen to fuel a 'hydrogen economy,' with the use of clean burning hydrogen in power-producing fuel cells, as well as for use as a transportation fuel. One of the key technical barriers to FutureGen deployment is reliable and efficient hydrogen separation technology. Most Hydrogen Transport Membrane (HTM) research currently focuses on separation technology and hydrogen flux characterization. No significant work has been performed on thermo-mechanical properties of HTMs. The objective of the thesis is to understand the structure-property correlation of HTM and to characterize (1) thermo mechanical properties under different reducing environments and thermal cycles (thermal shock), and (2) evaluate the stability of the novel HTM material. A novel HTM cermet bulk sample was characterized for its physical and mechanical properties at both room temperature and at elevated temperature up to 1000°C. Microstructural properties and residual stresses were evaluated in order to understand the changing mechanism of the microstructure and its effects on the mechanical properties of materials. A correlation of the microstructural and thermo mechanical properties of the HTM system was established for both HTM and the substrate material. Mechanical properties of both selected structural ceramics and the novel HTM cermet bulk sample are affected mainly by porosity and microstructural features, such as grain size and pore size-distribution. The Young's Modulus (E-value) is positively correlated to the flexural strength for materials with similar crystallographic structure. However, for different crystallographic materials, physical properties are independent of mechanical properties. Microstructural properties, particularly, grain size and crystallographic structure, and thermodynamic properties are the main factors affecting the mechanical properties at both room and high temperatures. The HTM cermet behaves more like an elastic material at room temperature and as a ductile material at temperature above 850°C. The oxidation and the plasticity of Pd phase mainly affected the mechanical properties of HTM cermet at high temperature, also as a result of thermal cycling. Residual stress induced in the HTM by thermo cycles also plays a very critical role in defining the thermo-mechanical properties.
    • Corrosion behavior and residual stress of microarc oxidation coated AZ31 magnesium alloy for biomedical applications

      Gu, Yanhong; Bandopadhyay, Sukumar; Severin, Kenneth P.; Chen, Cheng-fu; Kim, Sunwoo (2012-08)
      Mg alloys are potentially new biomaterials for bone repair or replacement. Appropriate coating is, however, needed to make the Mg alloy more resistant to corrosion. In this research, protective microarc oxidation (MAO) coatings were produced on AZ31 Mg alloys in sodium phosphate electrolyte. The coatings were produced under varying pulse frequency, applied voltage, oxidation time and electrolyte concentrations. This research analyzed the effects of the above four MAO process control parameters on the residual stresses and the corrosion behavior. Optimization of the MAO control parameters would allow production of AZ31 Mg alloy with high corrosion resistance. It is well accepted that residual stress and corrosion behavior are two significant factors in the development of AZ31 Mg alloys. The residual stresses in the MAO coatings were evaluated by the X-ray diffraction (XRD)-sin²ψ method. A predictive model of the residual stresses is proposed and a principal components analysis (PCA) was conducted to determine the contribution of the MAO control parameter on the residual stresses. Long-term corrosion behavior of MAO-coated Mg alloys was evaluated by the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. The porosity of the samples after various immersion durations was evaluated by the potentiodynamic polarization method. The pre- and post- corrosion microstructures and the phase composition of MAO-coated samples were studied. Post-corrosion phase identification showed that hydroxyapatite (HA) was formed on the surface of the samples. The ratio of Ca/P in HA was determined by the X-Ray Fluorescence (XRF) technique. The degradation of the MAO-coated AZ31 alloys is reduced due to the MAO coating and the formation of a corrosion product layer. A predictive model of the corrosion current density is proposed and a PCA was conducted to determine the contributions of the individual MAO control parameter on the corrosion rate. The corrosion process and mechanism of MAO-coated AZ31 alloys in SBF were modeled based on the electrochemical corrosion results and the pre- and post-corrosion surface analysis. It is believed that under optimized control parameters, the MAO-coated AZ31 Mg alloy is superior implant material for biomedical applications.
    • Corrosion behavior of microarc oxidation and polycaprolactone coatings applied to AZ31 magnesium alloy evaluated in simulated body fluid and balanced salt solution

      Wilke, Benjamin M.; Zhang, Lei; Peterson, Rorik; Zhang, Junqing; Chen, Cheng-fu (2015-08)
      Recent research in orthopedic implant materials has focused on the use of magnesium alloys as a base material due to its mechanical properties similar to that of human bone. Rapid corrosion of magnesium materials in aqueous environments poses a significant hurdle to their application as a biomedical implant. A variety of coatings have been shown to improve the corrosion resistance of magnesium based materials in simulated body fluid environments including microarc oxidation and polymer coatings. However, formulation and corrosion rates vary significantly between solution types. Furthermore, in vivo results have shown that many common in vitro solutions over estimate corrosion rates. In addition to variations between solutions needing to be resolved, there has been little work performed to characterize large sample corrosion under stress. This is an essential step in evaluating concept performance at a macro scale, for application as a human implant. The experiments performed and presented in this thesis primarily involve the comparison of conventional simulated body fluid (c-SBF) and Earle's balanced salt solution (EBSS). Samples evaluated in these environments are microarc oxidation (MAO) coated AZ31 magnesium alloy and polycaprolactone dip-coated AZ31. MAO coated samples were created for a range of process settings to observe the effect of processing on corrosion performance. A dependence of MAO coating thickness on process voltage was found which augmented the initial corrosion resistance values observed via electrochemical testing. Both MAO and PCL coatings were found to improve the corrosion resistance of the samples as compared to uncoated AZ31. It was found that all variations (MAO, PCL, and uncoated) showed a reduced corrosion rate in EBSS as compared to c-SBF. This corrosion reduction was apparent through potentiodynamic scanning, electrochemical impedance spectroscopy, and visual inspection. Preliminary mechanical corrosion results, in the form of constant extension testing, showed no dependence of corrosion on stress level. Future work may be aimed towards expanding modes of mechanical testing and further refining simulated body fluids to fit with in vivo test results.
    • Corrosion behavior of titanium dioxide (TiO₂)-coated Al alloy in saline environment

      Rabbey, Md Fazlay; Zhang, Lei; Zhang, Junqing; Huang, Daisy; Peterson, Rorik (2018-08)
      Al alloys have been used in many applications, however, they are susceptible to corrosion when exposed in saline environment. In this work, TiO₂ nanoellipsoids with aspect ratios (AR) of 1, 2, 4 and 6 were synthesized, TiO₂ coatings of AR 1, AR2, AR4, and AR6 were fabricated on AA2024-T3 Al alloy substrate, and their corrosion behaviors in the saline environment were investigated by analyzing the scanning electron microscope (SEM) imaging, potentiodynamic polarization scans and electrochemical impedance spectroscopy. TiO₂-coated Al samples showed better corrosion performance compared to the bare Al sample. Among the coated samples, TiO₂ AR6 coated samples showed lower corrosion rate compared to other samples. Although TiO₂ nanoellipsoids coatings show good corrosion resistance, it is noted that TiO₂ coatings are porous, which allows the penetration of corrosive media through the pores to reach the surface of the substrate. A polystyrene (PS)-TiO₂ AR6 nanocomposite coating was fabricated, where the pores of the coatings were sealed by polystyrene, which is expected to further improve the corrosion resistance of TiO₂ coatings.
    • A Corrosion Monitoring System for Existing Reinforced Concrete Structure

      Shi, Xianming; Ye, Zhirui; Muthumani, Anburaj; Fang, Yida; Zhang, Yan; Yu, Hui (Alaska University Transportation Center, Oregon Department of Transportation, 2013)
    • Corrosion of Steel in Calcium-Magnesium-Acetate (CMA) Deicier

      Venkatesh, Eswarahalli S.; Kutterer, Stephanie (1985-01)
      The corrosiveness of a new road deicer, Calcium Magnesium Acetate (CMA), was determined under various conditions of temperature, pH, and concentration. The corrosion rates of steel in CMA solutions were generally found to be of the order of 2 mils per year (mpy). In comparison, for the currently used chloride salt deicers the corrosion rates can range from 25-80 mpy. CMA is generally found to be a non-corrosive medium compared to sodium and calcium chloride. Although this preliminary corrosion research indicates that CMA is less corrosive to steels than salts, further work is necessary to confirm the corrosion characteristics of CMA on other materials. Additional studies should be performed on environmental and aesthetic aspects before widespread application of CMA as a road deicier.
    • Cost of exploration for metallic minerals in Alaska

      Grybeck, D; Peek, B.C.; Robinson, M.S. (University of Alaska Mineral Industry Research Laboratory, 1976)
      The high cost of exploration for metallic minerals in Alaska not only reflects a 20-50% increase in the cost of supplies, food and salaries over those "outside" but also some additional costs that are characteristic of most Alaskan exploration efforts. Transportation in particular often represents half of the exploration budget and is a major cost of almost all programs. Helicopters commonly are used as the basic mode of field transportation; their cost is high (about $125 to $300 per hour) and increasing, and their availability is becoming less certain with the accelerating demand for them. Salaries for field personnel are also considerably higher than those paid to personnel "outside". And the demand, both from within and without the mining industry, for those with Alaskan experience is so great as to drive those salaries even higher. Fuel and communication costs not only show the usual Alaskan mark-up but are also subject to local scarcity and almost unavoidable problems. Fuel will probably continue to be available in the major population centers but there have always been difficulties in providing or obtaining fuel in the bush; these will undoubtedly be magnified with the booming development of Alaska's petroleum resources and national scarcity. Communications with the field will undoubtedly continue to be uncertain at times and will frequently present major problems that money along cannot solve and result in much frustration and delay. Contract services such as drilling, geophysical work, and geochemical analyses are available within the state in varying degree or can be obtained "outside" at rates that do not seem to be unduly expensive. However, the cost of transportation, mobilization, and demobilization of the personnel and equipment used in performing these services may result in unusually high costs for projects of short duration. Early logistical planning has always been considered wise in Alaskan field work and it will undoubtedly continue to be important, if not essential. The lack of it may be alleviated in some cases with copious applications of money but with Alaska's present booming development, the lack of planning may lead to an uncertain ability to work in the field at all. The cost of Alaskan exploration programs vary greatly. Many of the reconnaissance geologic and geochemical programs are strikingly expensive chiefly because of the need for helicopter support. Other types of programs such as prospect evaluations are not nearly so expensive and Alaskan costs for projects of limited area or duration are nor necessarily prohibitive. In almost all cases, experience, imagination, and prior planning can reduce costs significantly.
    • Cost of exploration for metallic minerals in Alaska - 1982

      Metz, P.A.; Campbell, B.W. (University of Alaska Mineral Industry Research Laboratory, 1982)
      This report prepared by the professional staff of the Mineral Industry Research Laboratory (M.I.R.L.), is a contemporary and detailed source of information relating to the costs of conducting mineral exploration for metallics in Alaska with commentary on the availability of essential services. As such it will serve the needs of established mining companies engaged in exploration ventures as well as newcomers to the Alaskan scene.
    • Cost-Effective Use of Sustainable Cementitious Materials as Reactive Filter Media (Phase I)

      Li, Wenbing; Shi, Xianming (2019-08-31)
      This report presents a laboratory study on the use of nano SiO2 as modifier in crushed fines recycled concrete (CFRCs), coupled with thermal treatment, with the goal of fabricating a sustainable reactive medium to capture the chloride anions in deicer-laden stormwater runoff. A uniform design (UD) scheme was employed for the statistical design of experiments. Predictive models were developed based on the experimental data to quantify the influence of each design parameter on the effectiveness of removing Cl- ions from simulated stormwater. The models were verified, and then employed for predictions. Finally, the samples of different CFRCs modified by nano SiO2 and heating regimes were prepared under the optimal parameters identified via the Response Surface Methodology (RSM). The optimal processing of CRFCs include the use of admixing nano SiO2 at 0.3% (by mass), then heating the material at 525oC for 3h. The structure and properties of these CFRCs materials were characterized by XRD, FTIR, BET, SEM and EDS. These advanced characterization tools revealed that the modified CFRCs achieved great potential to chemically bind chloride anions. This work is expected to produce substantial benefits for highway agencies and other stakeholders of deicer stormwater runoff, through enhanced understanding of the efficacy and appropriateness of cementitious filter media in passive reactive systems for decreasing contaminant loading in stormwater runoff. The use of CRFCs as a low-cost sorbent will be economically attractive and environmentally sustainable, diverting them from waste stream and landfill and towards sustainable stormwater management.
    • Creep Behavior of Shallow Anchors in Ice-rich Silt

      Zhang, Xiong; Chen, Liangbiao; Lin, Chuang; McHattie, Robert (2013-07)
      Grouted anchors have become a common technique in the application of earth retention systems, slope stability problems and tie-down structures in unfrozen soils due to its cost and time efficiency. However, within much of Alaska area, permafrost is a common type of soil and might contain large amount of visible ice. The highly time and temperature dependent properties of ice-rich soil make it a challenge for the application of anchors in permafrost area. This project valuates the effect of water content and temperature on the creep behavior of shallow anchors in cold room lab. Also, field test was conducted to determine effectiveness of three types of grouting materials, including Bentonite clay, Microsil Anchor Grout and special cement formula. The temperature along the anchor was monitored to evaluate the degradation of the surrounding frozen soil. Research results may be applicable in the design of shallow anchors in ice-rich permafrost at various ice content and temperature range. Also, the load distribution and the pullout test results could give a general guidance for the shallow anchor design in permafrost area.
    • Creep of grouted anchors in ice-rich silt

      Chen, Liangbiao (2011-05)
      Creep is a critical consideration for designing anchors in ice-rich silt. In this study, creep was evaluated for grouted anchors in ice-rich silt by laboratory tests. A total of nineteen staged-load pullout tests were conducted on smooth grouted anchors. The anchors were loaded until either a tertiary creep stage or the capacity of the load system was reached. Soil temperatures evaluated in this study ranged from 32 °F to 26.6 °F. It was found that the onset of tertiary creep for smooth anchors was around 0.03 inches, which was much smaller than that suggested in the literature for rough anchors (1.0 inch). Given the same shear stress and soil temperature, the observed creep displacement rates for smooth anchors were greater than those given by the existing design guidelines for rough anchors. A new creep model was proposed in which soil temperature was included as an additional variable. Model parameters were developed as a function of soil temperature and moisture contents by using the test data. The model predictions were compared with the laboratory tests. It was found that the creep displacement rates decreased with the decreasing of soil moisture contents and temperature. Based on the analysis of laboratory test data, design charts were provided to give the allowable pullout capacity for smooth anchors in ice-rich silt.
    • Creosote Treated Timber in the Alaskan Marine Environment

      Perkins, Robert (Alaska University Transportation Center, 2009-08)
      Creosote is a wood preservative that is used in marine structures in Alaska, such as piles, docks, and floating structures. Some of the PAH chemicals in creosote are toxic to marine organisms, and resources agencies and environmental groups question its use. Mesoscale testing of creosoted wood has not indicated significant negative effects of wood treated with Best Management Practices (BMP), which is now standard practice. The EPA pesticide recertification of creosote required only the use of BMP or a risk assessment. The National Marine Fisheries Service issued draft guidelines for wood preservatives, which does not preclude use of creosote, but suggest a risk assessment if the qualities of treated wood are large or they are installed in sensitive areas. This report recommends consideration of the risks of creosote and presents an algorithm for analyzing the risks. Many applications require only an overview risk assessment. Applications of large quantities of preserved wood or in sensitive areas should have a more formal risk assessment. The report and the EPA recertification suggest a screening assessment published by the Western Wood Preservers Institute. If the screening indicates further assessment is needed, the report points to more detailed assessments.
    • Crude oil bioremediation in Arctic seashore sediments

      Sharma, Priyamvada; Schiewer, Silke; Trainor, Thomas; Schnabel, William (2015-08)
      Oil is an important energy source but also an environment pollutant. Crude oil spills along Arctic shorelines might occur due to the expected increase in offshore oil production. To reduce adverse effects on the environment in the case of a spill, it is important to develop approaches to remove spilled oil. Bioremediation with addition of nutrients has shown promising results in enhancing oil degradation rates. This research focuses on determining the effect of different environmental conditions on the rate of crude oil biodegradation in laboratory experiments, as a proxy for oil spills at Arctic seashores. Laboratory microcosms were set up containing beach sediments collected from Barrow, spiked with North Slope Crude. These microcosms were incubated at varying temperatures (3°C vs. 20°C), salinities (30 vs. 35 g/L) and crude oil concentrations (1 vs. 5 mL/kg), all with a standard concentration of nutrients. Measurements of respiration rates (breakdown of hydrocarbons to CO₂), hydrocarbons remaining in the sediment (GC/FID), and hydrocarbons volatilized and sorbed to activated carbon (GC/MS) were performed. In all microcosms, higher respiration rates by naturally occurring microorganisms were observed at 20ºC compared to 3°C. Surprisingly, volatile organic compounds (VOC) release was similar at both temperatures, for different crude oil concentration and salinities. High total petroleum hydrocarbon (TPH) levels remained at 3°C for microcosms with high initial crude oil concentration. Regardless of temperature, increased salinity had a positive impact on the rate of crude oil removal, i.e. high CO₂ release, high VOC production and low amount of TPH in sediments. At higher crude oil dosages, a larger amount of volatiles was released, however CO₂ production did not significantly increase with the contaminant concentration. The results of this study will assist decision-makers in choosing effective spill response strategies for future crude oil spills in Arctic shorelines.
    • Cubesat Attitude Control Utilizing Low-Power Magnetic Torquers & A Magnetometer

      Mentch, Donald B.; Thorsen, Denise (2011)
      The CubeSat Project has lowered development time and costs associated with university satellite missions that conform to their 10 centimeter cube design specification. Providing attitude control to a spacecraft, of such small volume, with a very limited power budget has been a challenge around the world. This work describes the development of an attitude control system based on a very low-power magnetic torquer used in conjunction with a magnetometer. This will be the first flight use of this torquer which is composed of a hard magnetic material wrapped inside of a solenoid. By discharging a capacitor through the solenoid, the magnetic dipole moment of this permanent magnet can be reversed. The completed attitude control system will make the first use of the low-power magnetic torquer to arrest satellite tip-off rates. It will then make the first known use of a dual axis magnetic dipole moment bias algorithm to achieve three-axis attitude alignment. The complete system is standalone for high inclination orbits, and will align the spacecraft to within 5 degrees of ram, nadir, and local vertical, without any requirement for attitude determination. The system arrests tip-off rates of up to 5� per second (in all 3 axes) for a satellite in a 600 kilometer polar orbit expending 0.56 milliwatts of power. Once in the proper alignment, it utilizes 0.028 milliwatts to maintain it. The system will function for low inclination orbits with the addition of a gravity boom. The system utilizes the magnetometer to calculate spacecraft body rates. This is the only known use of a magnetometer to directly measure spacecraft body rates without prior knowledge of spacecraft attitude.
    • Current state-of-the-art in drying low-rank coals

      Rao, P.D. and Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1976)
      Research on drying of low-rank coals, such as lignites and subbituminous coals, has been conducted for nearly half a century. Although partial drying of Dakota lignite is practiced for freeze-proofing by mixing partially dried coal with run-of-mine coal, full scale drying of low rank coals has never been practiced commercially in this country. The reasons are: ( 1 ) drying of low rank coals by conventional methods results in severe degradation of coal particles; (2) dried coals are thus dusty and difficult to handle; (3) reabsorption of moisture in storage and transit defeats the drying process. In addition the dry coal particles will react with ambient oxygen, and heat up enough to ignite. It appears that large-scale development of Alaskan coals may have to await solutions to these problems. Our Mineral Industry Research Laboratory at the University of Alaska is making a comprehensive literature search seeking solutions to these problems and identifying areas of research that should be undertaken.
    • Current thermal state of permafrost and potential impact on the El Niño Southern Oscillation (ENSO) in the Southern Peruvian Andes

      Yoshikawa, Kenji; Úbeda, Jose; Masías, Pablo; Pari, Walter; Vásquez, Pool; Apaza, Fredy; Callata, Betto; Luna, Gonzalo; Concha, Ronald; Iparraguirre, Joshua; et al. (2018)
      Tropical, high-mountain permafrost has a unique thermal regime due to its exposure to strong solar radiation and to the rougher surface snow morphology (due to an increased occurrence of penitentes -- that is, snow spikes and ridges ranging from centimeters to meters in height) which reduce convective sensible heat transfer from the surface. Latent heat transfer and higher albedo occurring during the wet season contributes to positive feedback that supports the presence of permafrost. This preliminary study reports on the thermal state of Peruvian permafrost. It evaluates the potential combined impact of the El Niño Southern Oscillation (ENSO), along with the eleven-year solar cycles of Coropuna (15°32′S; 72°39′W; 6,377 m a.s.l.), and the Chachani volcanic complexes (16°11′S; 71°31′W; 6,057m a.s.l.); both mountains are located in the western Central Andes (e.g., west edge of the Altiplano). Temperature monitoring boreholes were established at 5217m on Coropuna and 5331m at Chachani, and electric resistivity was surveyed to better understand permafrost spatial distribution in these locations. This seven-year record of permafrost temperature data encompasses historically extreme El Niño and La Niña events. Our results show that the current lower-altitude permafrost boundary (ca. 5100m) is critically influenced by the balance of wet and dry seasons: permafrost tends to deplete during drought years. Typical permafrost thickness was 10-20 m and contained ice-rich pore spaces. The presence of permafrost and its thermal resistance depends on ice content and on higher albedo, usually due to pyroclastic materials (especially pumice) which are ideal materials for supporting permafrost resilience.