• Biosorption of heavy metals by citrus fruit waste materials

      Patil, Santosh Bramhadev (2004-12)
      Conventionally used processes for removing heavy metals from wastewater are usually either expensive, such as ion exchange, or inefficient, such as precipitation. An innovative technique that is both efficient and economical is biosorption, in which living and dead biomass can act as biosorbents through physical-chemical processes like ion exchange and micro-precipitation. Pectin, a structural polysaccharide present in plant cell walls, is similar to alginate, a molecule that is often responsible for the high metal uptake by algae. Based on the structural similarity between alginate and pectin, it was expected that pectin rich bio-wastes may be as good a biosorbent material as brown algae. A comparison between different pectin-rich materials showed high stability and metal binding capacity of citrus peels. Sorption isotherms for citrus peels showed higher metal uptake capacity at pH 5 compared to pH 3. Kinetic studies revealed the time required to reach equilibrium for lemon fruit waste (0.177 mm) was 20 min while for larger particles the time increased to 30 min-60 min. For lemon fruit waste, the content and pKa values of acidic groups were determined by using a pKa spectrum technique. Isotherm modeling was carried out by using Langmuir isotherms and pH sensitive modeling.
    • Biosorption of lead by citrus pectin and peels in aqueous solution

      Balaria, Ankit (2006-05)
      Biosorption of heavy metal ions by different pectin rich materials such as waste citrus peels is emerging as a promising technique for metallic contaminant removal. While binding rate and capacity of citrus peels were previously investigated, there is a lack of mechanistic information about Pb-citrus pectin/peels interaction mechanisms. Present research focused on evaluating this binding mechanism by corroborating macroscopic studies with spectroscopic techniques. Citrus pectins of two different methoxylation degrees and orange peels were characterized using potentiometric titrations and Fourier transform infrared (FTIR) spectroscopy. Binding mechanisms were evaluated using molecular scale FTIR analyses. The effects of particle size, pH, co-ion presence, and background electrolyte concentrations were also investigated for biosorption of Pb by orange peels. Both citrus pectin and orange peels reached their sorption equilibrium within 45 minutes. The maximum uptake capacity for orange peels was found to be 2.32 mmol/g. Citrus peels have very similar FTIR spectra to citrus pectin, suggesting that they have similar functional groups and pectin can be used as a model for citrus peels. Furthermore, carboxylic acid groups were found to be responsible for binding of Pb by citrus pectin and orange peels.
    • Bridge Deck Runoff: Water Quality Analysis and BMP Effectiveness

      Perkins, Robert; Hazirbaba, Yildiz Dak (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2010)
    • Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

      Dong, Yangtao; Song, Ruiqiang; Liu, Helen (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2010)
    • A Builder's Guide to Water and Energy

      Seifert, Richard D.; Dwight, Linda Perry (University of Alaska, Institute of Water Resources, 1980-08)
    • Building a toolset for fuel cell turbine hybrid modeling

      Burbank, Winston S. (2006-12)
      Fuel cell/gas turbine hybrids show promise of high efficiency power generation, with electrical efficiencies of 70% or better shown by modeling, although these efficiency levels have not yet been demonstrated in hardware. Modeling of such systems is important to optimize and control these complex systems. This work describes a modeling tool developed to examine steady-state operation of different hybrid configurations. This model focuses on the area of compressor-turbine modeling, which is a key component of properly controlling fuel cell/gas turbine hybrids. Through side-by-side comparisons, this model has been tested and verified by Dr. Wolf of Brayton Energy [1]. This modeling tool will be used in further work to evaluate various configurations of turbines and fuel cells in hybrid configurations, focusing on both the performance and cost of such systems.
    • Buoyancy Effects On Building Pressurization In Extreme Cold Climates

      Bargar, Harold Edward; Das, Debendra K.; Goering, Douglas J.; Johnson, Ronald A.; Lin, Chuen-Sen; Quang, Pham X. (2003)
      This research investigates building pressurization due to buoyancy effect. The American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) presents an idealized equation to calculate the buoyancy effect. This dissertation compares differential pressure measurements from an actual building exposed to extremely cold temperatures to this idealized model. It also presents new statistical models based on the collected data. These new models should provide engineers with improved tools to properly account for building pressurization for designs in extreme cold climates. Building pressurization, the differential pressure between the interior of a building and its exterior surroundings, is an important design consideration. Pressurization is the driving force in building infiltration/exfiltration. It also affects air flow within building zones. Improper calculation of pressurization can result in under-sizing the building's heating and cooling systems, improper operation of air distribution systems, improper operation of elevators, and freezing and failure of water distribution and circulation systems. Building pressurization is affected by: wind (speed and direction), exterior-to-interior temperature difference, and mechanical equipment operation. In extreme cold climates, the predominant effect is air buoyancy due to temperature differences across the building envelope. The larger the temperature difference, the larger the buoyancy effect. In extreme cold climates, the largest temperature differences often occur at times when wind speed is negligible. This dissertation also demonstrates the use of existing data sources such as building automation systems to collect data for basic research. Modern systems automation provides a tremendous amount of data that, in the past, had to be collected through separate instrumentation and data acquisition systems. Taking advantage of existing automation systems can provide the required data at greatly reduced costs when compared to previous industry practices. The statistical analysis approach taken in this research expands the tools for engineering design. Actual interactions of real world variables are analyzed and used to produce prediction models. These techniques allow the model to incorporate relationships which may not be fully understood at the underlying principle level but are evidenced in the data collected from actual installations.* *This dissertation includes a CD that is compound (contains both a paper copy and CD as part of the dissertation). The CD requires the following applications: Internet Browser; Adobe Acrobat; Microsoft Office; Image Viewer.
    • Calibration of an on-line analyzer using neural network modeling

      Yu, Shaohai (2003-08)
      The goal of the project was to predict the ash content of raw coal in real time using the Americium-137 and Cesium-241 scintillation counts from an on-line analyzer. Rather than regression methods (that are current industrial practice), neural networks were used to map the scintillation counts to percentage ash. Quick stop training was used to prevent overfitting The noise and sparseness of the data required that the training, calibration and prediction subsets are statistically similar to each other. Therefore, Kohonen networks were first used to detect the features present in the data set. Three subsets were then built such that they had representative members from each feature. Neural network models were developed for the screened coal, the unscreened coal and the combined data respectively. The results show that the performance of the combined model was comparable to the performance with two different models for the screened and unscreened data. Due to the variance in the sample data, the neural networks (screened, unscreened and combined) did not predict individual samples well. The network predictions were, however, accurate on the average. Compared to the common regression approach, neural network modeling demonstrated much better performance in ash prediction based on certain criteria.
    • Calibration of microbolometer infrared cameras for measuring volcanic ash mass loading

      Carroll, Russell C.; Hawkins, Joseph; Thorsen, Denise; Raskovic, Dejan; Hatfield, Michael (2014-08)
      Small spacecraft with thermal infrared (TIR) imaging capabilities are needed to detect dangerous levels of volcanic ash that can severely damage jet aircraft engines and must be avoided. Grounding aircraft after a volcanic eruption may cost the airlines millions of dollars per day, while accurate knowledge of volcanic ash density might allow for safely routing aircraft around dangerous levels of volcanic ash. There are currently limited numbers of satellites with TIR imaging capabilities so the elapsed time between revisits can be large, and these instruments can only resolve total mass loading along the line-of-sight. Multiple small satellites could allow for decreased revisit times as well as multiple viewing angles to reveal the three-dimensional structure of the ash cloud through stereoscopic techniques. This paper presents the design and laboratory evaluation of a TIR imaging system that is designed to fit within the resource constraints of a multi-unit CubeSat to detect volcanic ash mass loading. The laboratory prototype of this TIR imaging system uses a commercial off-theshelf (COTS) camera with an uncooled microbolometer sensor, two narrowband filters, a black body source and a custom filter wheel. The infrared imaging system detects the difference in attenuation of volcanic ash at 11 μm and 12 μm by measuring the brightness temperature at each band. The brightness temperature difference method is used to measure the column mass loading. Multi-aspect images and stereoscopic techniques are needed to estimate the mass density from the mass loading, which is the measured mass per unit area. Laboratory measurements are used to characterize the noise level and thermal stability of the sensor. A calibration technique is developed to compensate for sensor temperature drift. The detection threshold of volcanic ash density of this TIR imaging system is found to be from 0.35 mg/m3 to 26 mg/m3 for ash clouds that have thickness of 1 km, while ash cloud densities greater than 2.0 mg/m3 are considered dangerous to aircraft. This analysis demonstrates that a TIR imaging system for determining whether the volcanic ash density is dangerous for aircraft is feasible for multi-unit Cubesat platforms.
    • Carbon Monoxide Exposure and Human Health

      Joy, Richard W.; Tilsworth, Timothy; Williams, Darrell D. (University of Alaska, Institute of Water Resources, 1975-02)
    • A case/control analysis and comparison of indoor air quality in Alaskan homes

      Dinakaran, Satish; Johnson, Ron; Naidu, Sathy; Lin, Chuen-Sen; Seifert, Rich (2005-08)
      Indoor Air Quality (IAQ) parameters such as CO, CO₂, relative humidity, temperature, radon, particulate matter, formaldehyde, benzene, toluene, hexane, Total Volatile Organic Compounds (TVOC) and microbial matter were monitored before and after remediation in 36 low-income homes in Alaska (Hooper Bay and Fairbanks). The objective was to see if there was any improvement in IAQ with remediation. Hooper Bay homes had significantly higher levels of CO₂ and relative humidity compared to Fairbanks homes both before and after remediation. There was a general reduction in CO₂ with remediation, although it was not statistically significant. When IAQ in two moderate-income homes in Fairbanks was compared with that in the remediated low-income homes, it was observed that indoor CO₂ levels were affected by ventilation rates and per capita floor area. A single zone model to predict concentration of indoor pollutants was constructed, using steady state and transient mass conservation, to predict, metabolically produced CO₂, and particulate matter when no indoor sources were present. The cost of energy to reduce indoor CO₂ levels in one of the homes by increasing ventilation by either using an exhaust-only system or a Heat Recovery Ventilator (HRV) is discussed.
    • A Catalog of Hydroclimatological Data for Alaska's Coastal Zone

      Carlson, Robert F.; Weller, Gunter (University of Alaska, Institute of Water Resources, 1972-05)
      In order to perceive a better understanding of the interrelationships of the coastal zone water we proposed a research project which was to sort out many of the complex variables. The project was not begun due to the lack of sufficient funds. We did, however, begin a limited literature search and listing of hydroclimatological data sources of Alaska's coastal zone. We felt this would be a modest but useful start towards the larger study. It should also have some practical usefulness to others. This data catalog is a result of this initial study. Because of the wide variety of types of agency which collect data and the literally hundreds of sources through which they are reported, it is often quite bewildering for even experienced investigators to sort out what can be found and where. Although we are sure that the catalog is far from complete, we feel that it is a useful beginning towards an attempt to better understand the hydroclimatological processes in Alaska's coastal zone. We wish to invite contributions and criticisms which could lead to an improved and more comprehensive version at some future date.
    • The Characteristics and Ultimate Disposal of Waste Septic Tank Sludge

      Tilsworth, Timothy (University of Alaska, Institute of Water Resources, 1974-11)
    • Characteristics and utilization of fly ash

      Lu, F.C.; Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1971)
      Fly ash produced by four power plants in Fairbanks and vicinity was collected and analyzed. Current fly ash specification and potential users of fly ash in general and in the Fairbanks area in particular were evaluated. A detailed bibliography on utilization of fly ash is appended for reference by producers and potential users of fly ash.
    • Characterization and evaluation of washability of Alaskan coals

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1980)
      This report is a result of the second part of a continuing study to obtain washability data for Alaskan coals to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals.
    • Characterization and evaluation of washability of Alaskan coals - fifty selected seams from various coal fields

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1986)
      FINAL TECHNICAL REPORT: September 30,1976 to February 28,1986
    • Characterization and evaluation of washability of Alaskan coals - phase i - selected seams from Nenana, Jarvis Creek and Matanuska coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1979)
      This report covers the results of a study conducted to obtain washability data for Alaskan coals to supplement the efforts of the U.S. Department of Energy (formerly U.S. Bureau of Mines) in its ongoing studies on washability of U.S. coals.
    • Characterization and evaluation of washability of Alaskan coals - phase iii, selected seams from the northern Alaska, Nulato, Eagle, Nenana, Broad Pass, Kenai, Beluga, and Chignik coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1982)
      This report is a result of the third part of a continuing study to obtain washability date for Alaskan coals, to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals. Washability characteristics were determined for fifteen coal samples from the Northern Alaska, Nulato, Eagle, Nenana, Broad Pass, Kenai, Beluga and Chignik coal fields. The raw coals were crushed to 1-1/2 inches, 2/8 inch and 14 mesh topsizes, and float-sink separations were made at 1.30, 1.40 and 1.70 specific gravities.
    • Characterization and evaluation of washability of Alaskan Coals - phase iv, selected seams from the northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna, and Herendeen Bay coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1982)
      This report is a result of the fourth and final part of a study to obtain washability data for Alaskan coals, to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals. Washability characteristics were determined for fifteen coal samples from the Northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna and Herendeen Bay coal fields. The raw coal was crushed to 1 1/2 inches, 3/8 inch and 14 mesh top sizes, and float-sink separations were made at 1.30, 1.40 and 1.60 specific gravities.
    • Characterization and fluid flow properties of frozen rock systems of Umiat Oil Field, Alaska

      Godabrelidze, Vasil (2010-12)
      The Umiat field, located in northwestern Alaska between the Brooks Range and the Arctic Ocean, potentially contains the largest accumulation of oil in Naval Petroleum Reserve No.4. Most of the oil is found within the permafrost zone. The main oil-producing zones in the Umiat field are marine sandstones in the Grandstand Formation of the Cretaceous Nanushuk group. Although the temperatures are close to freezing, the oil in the Umiat field remains unfrozen due to its very high API gravity. However, this results in a very unique pore space containing frozen water and oil, posing a particular challenge to characterization and measurement of fluid flow properties necessary for production. The unsteady-state gas-oil relative permeability measurement experiments were conducted in order to obtain critical information about the properties of two-phase fluid flow through the Umiat porous medium. Fluid flow experiments at 22°C and -10°C on representative core samples from the Umiat field showed 61% average decline in oil relative permeability as a result of freezing irreducible water. Capillary pressure measurement experiments were also carried out on selected core samples with an intention of characterizing their pore size distribution. Subsequently obtained data indicates fairly wide range of pore size for Umiat cores.