• Naturally Occurring Asbestos in Alaska and Experiences and Policy of Other States Regarding its Use

      Perkins, Robert A.; Hargesheimer, John; Winterfeld, Aaron (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2009)
    • Near-Roadway Air Pollution: Evaluation of Fine Particulate Matter (PM2.5) and Ultrafine Particulate Matter (PM0.1) in Interior Alaska

      Aggarwal, Srijan; Kadir, Abdul; Belz, Nathan (2019-01-28)
      This report presents a study of fine (PM2.5) and ultrafine (PM0.1) particles in the Fairbanks North Star Borough (FNSB) in Interior Alaska, with specific emphasis on the relationship of ultrafine particles (UFPs) to vehicular traffic. Chapter 1 provides a summary of published literature on particulates in air from vehicular emissions. Chapter 2 provides a novel and robust GIS-based data analysis approach to PM2.5 data collected by the FNSB. This analysis approach is convenient for identifying hotspots, as well as locations where PM2.5 changes either abruptly or continuously or does not change at all. The results reveal that average on-roadway PM2.5 concentrations are higher in North Pole than in Fairbanks, and mean levels are higher in stationary background monitoring data than in mobile monitoring on-roadway data. Not surprisingly, significant negative correlations were found between temperature and PM2.5. Chapter 3 presents the results from the data collection campaign to measure UFPs at roadside locations in Fairbanks and North Pole and investigate the relationship of UFPs with traffic and meteorological parameters. Multilinear predictive models were developed for estimation of UFPs and PM2.5 based on weather and traffic parameters. Overall, this study improves our understanding of on- and near-roadway particulates in a cold-climate region.
    • Near-roadway air pollution: evaluation of fine particulate matter (PM₂.₅) and ultrafine particulate matter (PM ₀.₁) in Interior Alaska

      Kadir, Abdul; Aggarwal, Srijan; Belz, Nathan; Barnes, David; Mao, Jingqiu (2019-05)
      Particulate air pollution in the form of fine (PM₂.₅) and ultrafine (PM₀.₁) particles has become a global concern, especially in urban areas with high population and vehicular traffic. Considerable research has been carried out to understand the underlying processes that impact particulate pollution, but most studies have been conducted in warmer and urban regions such as in California. The Fairbanks North Star Borough (FNSB), in Interior Alaska, provides an interesting example of a relatively small- to mid-sized northern locality (population ~100,000) with persistent air quality issues and extremely cold climatic conditions for a major part of the year. Since December 2009, the FNSB has been designated a nonattainment region by the U.S. Environmental Protection Agency for the federal PM₂.₅ standard. As part of their remediation efforts, the borough and state have undertaken increased monitoring by using an on-roadway monitoring vehicle (sniffer vehicle) and stationary near-roadway sites for air quality measurements, beyond what is required for regulatory compliance. One of the goals of this project was to develop a novel data investigation and analyses methodology for the geospatial air quality data collected by the borough's mobile monitoring vehicle (years 2012-15), to shed light on the PM₂.₅ issues faced by the FNSB. In addition, this research also undertook measurements of ultrafine particle (UFP) concentration levels at four road weather information system (RWIS) sites in the FNSB region. UFPs, though unregulated, are considered to have significant human health impacts and no known studies have investigated UFPs in FNSB. In addition to UFPs, other parameters such as PM₂.₅, traffic, and weather data were measured at the same locations to investigate any underlying trends/correlations with UFPs. In the first part of the research with mobile monitoring, data were categorized in nine different groups based on their mean and standard deviation values to determine the spatiotemporal distribution of PM₂.₅. This novel way of grouping data allows identification of locations with consistently poor and consistently better air quality, by going beyond the simple analyses of means and accounting for variability and standard deviation in the data. In addition to hotspot identification, analyses found that average on-roadway PM₂.₅ concentrations were higher in North Pole (27.2 μg/m³) than in Fairbanks (12.9 μg/m³), and that average concentrations were higher in the background stationary monitoring data (29.4 μg/m³) than in the mobile monitoring data (20.0 μg/m³) for the study period. Not surprisingly, significant negative correlations (R² = 0.49 for Fairbanks, and R² = 0.31 for North Pole) were found between temperature and PM₂.₅. Temporal distribution of the data suggests that PM₂.₅ levels increase gradually in the months of October and November, peak during the months of December, January, and February, and quickly plummet beginning March. In the latter part of the study, data on UFP measurements were collected at four RWIS sites in the FNSB for four days between March 1 and 18, 2017, for five continuous hours each day. Among other parameters, PM₂.₅ concentrations, temperature, relative humidity, wind speed, and traffic volume data were collected. Data were analyzed to develop correlations between UFPs and other parameters, to compare data from this study with other studies, and to determine current roadside UFP concentration levels in interior Alaska. Fairbanks roadside locations showed higher mean UFP counts (41,700 particles/cm³) than the North Pole (22,100 particles/cm³) locations. Similarly, for the period of study, Fairbanks roadside locations showed higher PM₂.₅ concentrations and traffic counts (6.3 μg/m³; 15 vehicles/min) than the North Pole (4.6 μg/m³; 10 vehicles/min) locations, both being well below the on-roadway and background PM₂.₅ concentrations estimated in the first part of this report. Multilinear predictive models were developed for estimation of UFPs and PM₂.₅ based on weather and traffic parameters. This first study of UFPs in Alaska improves our understanding of near-roadway UFPs in cold regions.
    • Neural-Network Modeling Of Placer Ore Grade Spatial Variability

      Ke, Jinchuan; Bandopadhyay, Sukumar (2002)
      Traditional geostatistical methods have been used in ore reserve estimation for decades. Research in the last two decades or so has added a number of other statistical methodologies for ore reserve estimation procedures. Recent advances in neural networks have provided a new approach to solve this problem. This thesis is focused on the Neural-network modeling for the estimation of placer ore reserve. Due to the spatial variability, multiple dimensional inputs and very noisy drill hole sample data from the selected region, it requires that the neural-network be organized in a multiple-layers to handle the non-linearity and hidden slabs for smoothing the predicted results. Various neural-network architectures are investigated and the Back-propagation is selected for modeling the ore reserve estimation problem. Sensitivity analysis is performed for the following parameters: the type of neural-network architecture, number of hidden layers and hidden neurons, type of activation functions, learning rate and momentum factors, input pattern schedule, weight updated, and so on. The influences of these parameters on the predicted output are analyzed in details and the optimal parameters are determined. To investigate the accuracy and promise of neural network modeling as a tool for ore reserve estimation, the ore grade and tonnage of Neural-network output is compared with those estimated by geostatistical methods under various cut-off grades. In addition, the overall performance is also validated by the analysis of R-squared (R2), Root-Mean-Squared (RMS), and the comparison between predicted values and 'actual' values. As the final part of this study, the optimized Neural Network was used to estimate the distribution of placer gold grade and volume of gold resource in offshore Nome. The predicted results for all the mining blocks in the lease area are validated by checking the values of RMS, R2, and Scatter plots. The estimated gold grades are also presented as contour maps for visualization.
    • New 2012 Precipitation Frequency Estimation Analysis for Alaska: Musings on Data Used and the Final Product

      Kane, Douglas L.; Stuefer, Svetlana (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2013)
    • New microfabrication method for prototyping integrated microfluidic modules with SR-3000 and polydimethylsiloxane (PDMS)

      Gerlach, Thomas Frederick (2012-08)
      This thesis presents the first work on the fabrication of microfluidic modules with SR-3000 Rayzist photoresist paper and polydimethylsiloxane (PDMS). Chapter 1 of the thesis is on the analysis of elemental composition of SR-3000. By using the X-Ray Fluorescence spectrometer we found the SR-3000 sheet is enriched with silicon, the key element for forming covalent bonding to PDMS. Chapters 2, 3,and 4 of the thesis is focused on the characterization of both the hydrophilicity of the plasma-treated SR-3000 surface and the bonding strength between SR-3000 and PDMS. Unfiltered air was used as the process gas for plasma-assisted bonding of SR-3000 to PDMS. Pressure rupture tests were conducted to measure the strength at the bonding interface, which can be as high as 57.7 psi, strong enough to hold the fluid pressure for typical microfluidics applications. The hydrophilicity of SR-3000 is mainly governed by the plasma treatment time. Chapter 5 demonstrates how to use the developed microfabrication method to prototype microfluidic modules for typical microfluidic applications, which include manipulation of laminar flow, mixing of miscible fluids, and production of oil droplets in a stream of water flow.
    • A New Sustainable Additive for Anti-Icing Pavement

      Zhang, Yan; Shi, Xianming (2019-08-30)
      Based on a review and synthesis of the state-of-the-art literature on asphalt pavement with anti-icing additives, this laboratory study developed an anti-icing asphalt pavement that incorporates innovative salt-storage additives with a sustained salt-release rate. These additives were prepared through a surface treatment approach, in which zeolite containing CaCl2 was coated by a porous epoxy layer. The anti-icing performances and mechanical properties of asphalt mixture with the obtained additives were investigated. The experimental results indicated that the anti-icing capability of asphalt mixture at both -3.9 °C (25°F) and -9.4 °C (15°F) was significantly improved by the addition of the additives, and the friction coefficient of the pavement at 60 min after moisture spray was 0.75 at -3.9 °C to 0.55 at -9.4 °C. Reducing the size of additives resulted in a further improved anti-icing capability. Under simulated conditions, the estimated effective anti-icing period of asphalt pavement with additives #8, #16, and #30 were 5.8 years, 9.9 years and 15.3 years, respectively. The incorporation of the additives exhibited negligible effect on the moisture damage resistance of asphalt mixture, and almost all the mixtures passed the WSDOT specification as well as the Wisconsin and Iowa specifications. The rutting resistance, mid-temperature (fatigue) cracking resistance, and low-temperature (thermal) cracking resistance of asphalt mixture improved due to the addition of these anti-icing additives to various extents.
    • North Slope Borough water study: a background for planning

      Johnson, Ronald A.; Dreyer, Linda Dwight (University of Alaska, Institute of Water Resources, 1977-06-15)
      The Planning and Research Section of Alaska Dept. of Natural Resources initiated this pilot water study with the North Slope Borough and the University of Alaska's Arctic Environmental Information and Data Center and Institute of Water Resources. Traditional and present water uses in the eight North Slope Borough villages are examined to assist in evaluating and planning for present and future water use, treatment, and disposal requirements.
    • A Northern Snowmelt Model

      McDougall, James; Carlson, Robert F. (University of Alaska, Institute of Water Resources, 1974-08)
      In early 1968, a large petroleum discovery was made in the Prudhoe Bay area of Alaska's Arctic Coastal Plain. This discovery has led Alaska into a period of development of unprecedented speed and magnitude. This development will require the construction of many engineering facilities which are affected by the water resources. The design of each of these requires an understanding of the hydrologic system, a system which is dominated in Alaska by low temperatures, high latitudes, large elevation differences and sparse data. The latter factor is unique to Alaska and makes application of common design techniques virtually impossible.
    • A novel low-cost autonomous 3D LIDAR system

      Dial, Ryker L.; Bogosyan, Seta; Hatfield, Michael; Lawlor, Orion (2018-05)
      To aid in humanity's efforts to colonize alien worlds, NASA's Robotic Mining Competition pits universities against one another to design autonomous mining robots that can extract the materials necessary for producing oxygen, water, fuel, and infrastructure. To mine autonomously on the uneven terrain, the robot must be able to produce a 3D map of its surroundings and navigate around obstacles. However, sensors that can be used for 3D mapping are typically expensive, have high computational requirements, and/or are designed primarily for indoor use. This thesis describes the creation of a novel low-cost 3D mapping system utilizing a pair of rotating LIDAR sensors, attached to a mobile testing platform. Also, the use of this system for 3D obstacle detection and navigation is shown. Finally, the use of deep learning to improve the scanning efficiency of the sensors is investigated.
    • A Novel Systematic Strategy Towards Air-Purifying, Corrosion Resistant and Self-Healing Concrete Infrastructure

      Yang, Zhengxian (2019-09-15)
      Transportation causes major emissions of harmful gases (NOx, CO, VOCs). These pollutants also travel long distances to produce secondary pollution such as acid rain. The most popularly used photocatalytic cementitious composites based on TiO2 achieve the air purification function under ultraviolet sunlight, significantly impeding a broader application of photocatalytic cementitious composites. This study focused on developing an environmentally friendly and durable cementitious system based on the multifunctional photocatalytic Graphitic carbon nitride (g-C3N4). The photocatalytic cementitious composites (PCC) were prepared in three manners: (1) incorporating g-C3N4 nanosheets (CNNs) in cement at three mixing dosages (0.5%, 1% and 2% by weight of cement), (2) applying CNNs at various concentration levels as the coating on recycled asphalt pavement aggregate, (3) applying CCNs s with vinyl chloride/vinyl ester/ethylene copolymer (as a binder) as the coating on cement mortar. The photocatalytic performance and durability of the newly developed cementitious composites were evaluated systematically and the results showed that the PCC hold marked efficiency in terms of NOx removal and self-cleaning when the CNNs were applied in a proper way. The obtained knowledge sheds light on a future perspective of developing a novel systematic strategy towards air-purifying, corrosion resistant, and self-healing concrete infrastructure.
    • A novel virtual reality-based system for remote environmental monitoring and control using an activity modulated wireless sensor network

      Montz, Benjamin; Raskovic, Dejan; Mayer, Charles E.; Thorsen, Denise (2019-08)
      The ability to monitor and control a home environment remotely has improved considerably in recent years due to improvements in the computational power, reduction in physical size, reduced implementation cost, and widespread use of both wireless sensor networks and smart home systems. This thesis presents a remote environment management system that integrated a custom wireless sensor network that monitored environmental factors in multiple locations, a smart system that controlled those factors, and a virtual reality system that functioned as a remote interface with the environment. The resulting system enabled a user to efficiently interact with a distant environment using an immersive virtual reality experience. The user was able to interact with the remote environments by issuing voice commands, performing hand gestures, and interacting with virtual objects. This type of system has applications in many fields ranging from healthcare to the industrial sector. The case study system that was designed in this thesis monitored and controlled the environments of several rooms in a home. A novel approach to modulating the activity of the wireless sensor network was implemented in this system. The rate at which the sensor nodes collected and transmitted data was modulated based on the visibility of the virtual objects called VSNs. These virtual sensor nodes displayed the sensor node measurements in virtual reality. This method was expanded upon using a motion prediction algorithm that was used to predict if the virtual sensor nodes were going to be visible to the user. This prediction was then used to modulate the activity of the wireless sensor network. These activity modulation algorithms were used to reduce the power consumption of the wireless sensor network and thus increasing its operational lifespan, while simultaneously reducing unnecessary RF signals in the environment that can interfere with the operation of other wireless systems. These algorithms would be crucial for systems monitoring complex sensor-rich environments where reducing the data transmitted and extending the system's lifespan was paramount, such as managing the environments of many rooms in a large industrial park or controlling the environments of spacecraft from Mission Control on Earth.
    • Numerical analysis of structural behavior of welded wire reinforcement in reinforced concrete beams

      Balasubramanian, Radhakrishnan; பாலசுப்ரமணியன், ராதாகிருஷ்ணன்; Hulsey, J. Leroy; Ahn, Il-Sang; Perreault, Paul V.; Lin, Chuen-Sen (2016-05)
      Modernization and industrialization have paved the way for the construction industry of India to expand. On the other hand the Indian construction industry is set to face an acute workforce shortage. The shortage of construction workers has in fact slowed down the growth of this industry in major cities across the country and escalated its cost by 40 percent. An alternative way to replace the labor force is by automation techniques. This study is a numerical analysis to evaluate structural behavior of simply supported concrete beams reinforced with welded wires in comparison with mild steel reinforced concrete beams. Welding conventional steel bars (60 ksi) reduces their shear strength by 50 percent. Welded Wire Reinforcement (80 ksi), with its greater strength, higher durability, significantly lower placing and overall cost, provides an alternative and perhaps a better substitution for mild steel bars. The commercial finite element analysis program, ABAQUS, was used to model the non-linear behavior of reinforced concrete beams. In order to evaluate the structural behavior of welded wire reinforced concrete beams, different configurations of longitudinal and transverse wires have been considered. First, different types of stirrup configurations in a rectangular reinforced concrete beam are compared with a conventional reinforced beam. Second, a structurally performing welded wire configuration is compared with a Mexican chair styled reinforcement configuration. This part of the analysis is evaluated for a T–beam, used for building roof applications.
    • Numerical analysis of the stability of a column laterally restrained by a flexible brace

      Kulchitskaya, Natalia; Кульчицкая, Наталья Борисовна; Hulsey, Leroy; Yang, Liao; Metzger, Andrew; Shur, Yuri (2014-08)
      The paper analyses the behavior of a structure which includes a classically restrained steel column under an axial load and a single flexible brace attached at an arbitrary point along the column to restrict its lateral deformation. The column is assumed to have an initial imperfection limited according to the current code requirements. Focusing on lateral deformations only, the paper studies the maximum load the system can resist before failure, as well as a brace force arisen at this load. Due to the complexity of the problem when it is extended from the elastic region to the plastic domain, a numerical solution is utilized. In the current work, a student version of AbaqusTM provides results of finite-element analysis implemented for a variety of ASTM A992 steel W-Shaped columns. The results confirm that the failure load and brace force highly depend on brace location and its stiffness. It is also shown that the current code provision of a brace load is not always conservative for braces shifted from the center of the column.
    • Numerical modelling of electromagnetic wave propagation in a hallway

      Venkatasubramanian, Arun (2003-08)
      This research involves the numerical modelling of electromagnetic wave propagation, (1) to calculate the electric and magnetic fields at any point in a hallway for a known transmitter and receiver antenna pattern and orientation and (2) to determine the wave normal direction of the electromagnetic wave using the electric fields calculated in (1). The results of the numerical simulation are compared with measurements for two hallways. Both the transmitter and receiver employ vertically oriented /4 dipoles operating at 2.4 GHz. Our work has led to the following new results: (1) The calculated signal power varies as 1/r² whereas the measured data varies as 1/r¹·⁴, where r is the transmitter receiver separation distance, (2) The temporal clustering of calculated multipath arrival times qualitatively agrees with the Saleh-Valenzuela model [1987], (3) For an SNR of 0 dB, the standard deviation of the error in the DOA estimate for the direct path signal is 2̃° and 4̃ ̊for the azimuth and elevation angles respectively. (4) In the presence of multi path, the DOA estimate shows an error of 50 ̊in the elevation and 125 ̊in the azimuth.
    • Numerical Simulation Of Single Phase And Boiling Microjet Impingement

      Ragunathan, Srivathsan (2008)
      This work presents results from the numerical simulation of single phase and boiling microjets primarily for high density electronics cooling. For the single phase microjets, numerical simulation results for the flow fields and heat transfer characteristics in a laminar, confined microjet (76 mum in diameter) impingement arrangement are presented. The parameters varied included the jet Reynolds Number, the fluid Prandtl Number and the ratio of the nozzle-to-plate distance to the jet diameter. Primary and secondary recirculation zones were observed in the stagnation region and the radial outflow region which had a significant impact on the local Nusselt Number distribution on the heated surface. The location and the displacement of the primary and secondary recirculation zones are of particular importance and are associated with secondary peaks in the Nusselt Number similar to those observed for turbulent jet impingement in larger conventional jets. Numerical simulation results are presented for boiling microjet impingement in a confined arrangement. The Rensselaer Polytechnic Institute (RPI) model was modified for laminar flow boiling for simulating these types of flows. The model primarily proposes three different heat transfer components, the single phase heat transfer, the quenching heat transfer and the evaporative heat transfer. The model was first validated with experimental results from the literature and then extended to study the effects of liquid subcooling, microjet Reynolds Number based on the nozzle inlet, and heat flux levels. The simulation results were in good agreement with results from comparable experiments in the literature. The average wall temperature increases as the applied wall heat flux is increased. The slopes of the temperature curves in the radial direction flatten out at higher heat fluxes and lower levels of subcooling indicating the effectiveness of boiling heat transfer. For the cases considered in this study, the single phase heat transfer component dominates the other two modes of heat transfer The liquid velocity profile has a considerable impact on the vapor bubble nucleation, vapor drag and the bubble departure diameter. Lower levels of subcooling are associated with boiling inception and more vigorous boiling in the vicinity of the stagnation zone rather than those with higher levels of subcooling. The degree of subcooling emerged as the single largest factor controlling the lateral temperature rise in an electronic chip cooled by a single, confined impinging microjet. Increases in the jet inlet Reynolds Number for the same heat flux and subcooling levels increased the dominance of forced convection heat transfer over the boiling heat transfer. Lower Reynolds Number flows are marked by partial nucleate boiling in contrast to higher Reynolds Number flows marked by forced convection boiling. For all the cases considered in this work, the single phase heat transfer component dominated the other two modes of heat transfer. The evaporative mode dominates the quenching heat transfer mode, an observation that is markedly different from those observed for turbulent evaporative jets found in the literature.
    • Numerical Simulation of Snow Deposition Around living Snow Fences

      Petrie, John; Zhang, Kun; Shehata, Mahmoud (2019-09-13)
      In this study, computational fluid dynamics (CFD) was used to investigate the air flow around porous snow fences to gain insight into snow transport and deposition in the vicinity of fences. Numerical simulations were performed to validate the CFD approach using experimental data from a wind tunnel study. Subsequent simulations were used to test the use of a porosity model to represent fence geometry and determine the effect of fence spacing for fences comprised of multiple rows. The results demonstrate that CFD simulations can reproduce the aerodynamics around porous fences. Additionally, the flow field generated with a porosity model is in close agreement with that from a model with explicit representation of fence porosity. Simulations of fences comprised of two rows spaced at various distances demonstrate that when the row spacing is small the fence behaves as a single row.
    • Numerical simulation of thermo-mechanical behavior of gypsum board wall assembly

      Quan, Zhili; Hulsey, J. Leroy; Ahn, Il Sang; Chen, Cheng-fu; Xiang, Yujiang (2019-05)
      Fire safety has become a significant concern to public safety; especially in the aftermath of 9/11 attack where, according to official reports, three World Trade Center buildings collapsed because of fire. Therefore, the level of thermal insulation required from building material and structural elements has increased. In recent years, gypsum board wall assemblies have been increasingly used as compartmentation for high-rise residential and commercial buildings. The increasing popularity of gypsum board wall assemblies is due to their relatively high strength-to-weight ratio, ease of prefabrication, fast erection and good thermal insulation. Before implementation of any building material or structural element, its Fire Resistance Rating must be determined by subjecting the material or element to a standard furnace fire test. Over the years, a large database has been collected for the Fire Resistance Rating of building materials and structural elements. However, due to the expensive and time-consuming nature of the standard fire tests, determining an accurate Fire Resistance Rating can be a difficult task. In this study, the author numerically evaluated the Fire Resistance Rating of a new gypsum board wall assembly. Composite steel-EPS (Expanded Polystyrene) insulation is added to a traditional gypsum board wall assembly. The author first did numerical simulation of an experiment on the thermal response of a non-load-bearing gypsum board wall assembly to verify the thermal modeling methodology. The author then did numerical simulation of an experiment on the mechanical response of a load-bearing gypsum board wall assembly to verify the mechanical modeling methodology. Finally, the author used the verified thermal and structural modeling methodology to simulate the new composite steel-EPS gypsum board wall assembly and obtained its numerical Fire Resistance Rating. This Fire Resistance Rating should be compared with future experimental results of the new wall assembly. All modeling was done with ABAQUS V6.14.
    • Numerical simulation study to evaluate recovery performance of miscible displacement and WAG process

      Wu, Xingru (2002-08)
      Several factors including gravity segregation, solvent types, injection methods, and production/injection well constraints are known to impact the performance of Water-Alternate-Gas (WAG) process and miscible displacement. This thesis studies well completions to optimize the miscible displacement and WAG processes through numerical simulation of a pattern model with stochastic permeability distribution. To study the impact of well placement and completions on miscible performance in heterogeneous media, we injected various solvents and examined the effect of gravity segregation, permeability distribution and anisotropy, horizontal well lengths, orientation of vertical and horizontal wells on oil recovery. Also, we conducted simulations with various WAG ratios and cycle lengths to understand the WAG processes. Performance of miscible gas flooding and WAG process are compared to that of waterflooding.