1,720,970 research outputs found
Investigation of nanoscale drug particles and their effect on the fluid dynamic properties of the blood
Full text linkMaster's Project (M.S.) University of Alaska Fairbanks, 2020Research has shown that gold nanoparticles increase the efficiency of radiation treatments of cancer by up to 25%. This means patients can be exposed to lower doses of radiation that does more concentrated damage to cancerous cells and less damage to healthy surrounding tissue. Before these nanoparticles can be introduced to the human body, the behavior of these particles in the blood stream must be understood. A model of gold nanoparticle flow through the aortic arch was developed in the present investigation for predicting behavior of these particles in the human body.
A set of initial modeling parameters was developed out of existing data pertaining to blood flow rates and viscosities of a blood-mimicking fluid across a temperature range of 30-40 degrees Celsius. The aorta wall was modeled as a no-slip solid surface. Computational fluid dynamic models using ANSYS Fluent across this temperature range have generated general velocity distributions of blood flow through the aortic arch and identifies several areas of possible recirculation. The current state of the model provides preliminary results, which are valuable in generating an accurate model of gold nanoparticles flowing through the aortic arch
Patterns and potential solutions to coastal geohazards at Golovin, Alaska
Full text linkThesis (M.S.) University of Alaska Fairbanks, 2014The objective of this research is to measure the localized potential for shoreline change and flooding on the Golovin spit, Alaska. Long-term trends of shoreline change have been measured using multi-temporal aerial photography and satellite imagery from 1972-2013, while seasonal and annual changes in shoreline geometry have been measured by re-surveying the beach in July 2012, July 2013, and October 2013. The local bathymetry was updated with data derived from the WorldView-2 satellite to increase the spatial resolution of nearshore topography. These inputs were then integrated to establish an XBeach 1-dimensional numerical model connecting offshore storm water elevations to nearshore dynamics. The spit was found to experience episodic erosion of beach sediments, followed by sediment accretion. This resulted in a dynamic position of the shoreline, with no long-term trend in either the offshore or landward directions. Modeled storms resulted in inundation of low elevations of the spit at a 5- year return interval, with inundation of infrastructure on a 25-year return interval. The modeled results suggest overwash of the entire spit at the 50-100-year return interval. All models were based on the best available forcing data from hindcast modeling. Reinforcing and increasing the elevation of a temporary berm and/or a permanent levee structure, using a 25-year return interval as a design parameter, would help to reduce localized flooding on the spit, and may be considered in the future
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Laboratory investigation of infiltration process of nonnewtonian fluids through porous media in a non-isothermal flow regime for effective remediation of adsorbed contaminants
Full text linkThesis (M.S.) University of Alaska Fairbanks, 2019Contamination of soil and groundwater have serious health implications for man and environment. The overall goal of this research is to study a methodology of using nonNewtonian fluids for effective remediation of adsorbed contaminants in porous media under nonisothermal flow regimes. Non-Newtonian fluids (Guar gum and Xanthan gum solutions) provide a high viscous solution at low concentration and these fluids adjust their viscosities with applied shear rate and change in temperature. Adjustment of viscosity with an applied rate of shear is vital for contaminant remediation because non-Newtonian shear thinning fluids can penetrate to low permeability zones in subsurface by decreasing their viscosities due to high shear rates offered by low permeability zones. The application of non-Newtonian shear thinning fluids for contaminant remediation required the improvement in understanding of rheology and how the factors such as concentration, temperature and change in shear rate impacted the rheology of fluids. In order to study the rheology, we studied the changes in rheological characteristics (viscosity and contact angle) of non-Newtonian fluids of different concentrations (i.e., 0.5g/l, 1g/l, 3g/l, 6g/l and 7g/l) at different temperatures ranging from 0 ºC to 30 ºC. OFITE model 900 viscometer and Tantec contact angle meter were used to record the changes in viscosity of fluids for an applied range of shear rate (i.e., 17.02 s⁻¹ to 1021.38 s⁻¹) and contact angles, respectively, for different concentrations of non-Newtonian fluids. Understanding the flow characteristic of non-Newtonian fluids under low temperature conditions could help in developing methods to effectively remediate contaminants from soils. Results of rheological tests manifested an increase in the viscosity of both polymers with concentration and decrease in temperature. Mid (i.e., 3g/l) to high (i.e., 6g/l and 7g/l) concentrations of polymers manifested higher viscosities compared to 0.5g/l for both polymers. Flow of high viscous solutions required more force to pass through a glass-tube-bundle setup which represented a synthetic porous media to study the flow characteristic and effectiveness of Newtonian and non-Newtonian fluids for contaminant remediation. Low concentrations of 0.5g/l were selected for flow and remediation experiments because this concentration can flow through porous media easily without application of force. The 0.5g/l of Xanthan gum and de-ionized water were used to conduct the infiltration experiments to study the flow characteristics of Newtonian and non-Newtonian fluids at 0.6°C, 5°C and 19°C in synthetic porous media. Infiltration depth of both Newtonian and non-Newtonian fluids would decrease with the decrease in temperature because of the change in their properties like dynamic viscosity, density and angle of contact. The result of comparison of Newtonian and non-Newtonian fluids showed water to be more effective in remediating a surrogate adsorbent contaminant (Dichlobenil) from the synthetic porous media at 19°C. This result was counter-intuitive to what we began with as our hypothesis. However, it was also observed later that 0.5 g/l concentration of Guar gum behaved more like a Newtonian fluid and 0.5 g/l concentration of Xanthan gum had not shown strong non-Newtonian behavior compared to higher concentrations of Xanthan gum. Hence more analysis needs to be done to determine what concentration of non-Newtonian fluid should be more effective for remediation.USGS-National Institute of Water Resources (NIWR), National Institute of Food and Agriculture (NIFA) USDA Hatch program, University of Alaska Fairbanks Clarence Berry fellowship and Alaskan Section of American Water Resources Association scholarshipChapter 1: Introduction -- Chapter 2: Effect of temperature on rheological properties of Guar gum and Xanthan gum of different concentrations -- Chapter 3: Porous media flow characteristics of Newtonian and non-Newtonian Fluids under different thermal regimes -- Chapter 4: Comparison of Newtonian and non-Newtonian fluid for remediation of adsorbent contaminant -- Chapter 5: Conclusion
A Low-cost alternative to mitigate heavy metal and phosphorous contamination in water
Full text linkMaster's Project (M.S.) University of Alaska Fairbanks, 2021Heavy metals and phosphorous are contaminants that may enter surface waters through mining and
agricultural activities. As these activities occur in Alaska, it is important to analyze locally available
biosorption materials that may be available in Alaska and may reduce costs to current treatment methods.
The adsorption of lead (Pb), cadmium (Cd), and phosphorous (P), by sodium hydroxide-treated, Alaskasourced spruce sawdust at 6.5°C, 15°C and 22.5°C was analyzed. Three kinetic models (zero-order, pseudo
first-order, and pseudo second-order) were used to analyze the adsorption kinetics and mechanism. The
pseudo second-order kinetic model best described the adsorption of Pb, Cd, and P at all three temperatures,
and the adsorption mechanism was determined to be driven by chemisorption. Optimal contact time for
adsorption was determined for all three temperatures. At 22.5OC, adsorption equilibrium was reached at 3
hr, 1 hr, and 1.5 hr for Pb, Cd, and P, respectively. Adsorption equilibrium at 15OC was reached at 9 hr, 7
hr, and 9 hr for Pb, Cd, and P, respectively. At the lowest temperature, 6.5 OC, adsorption equilibrium was
reached at 11 hr, 14 hr, and 12 hr for Pb, Cd, and P, respectively. Adsorption behavior was further evaluated
by fitting the Langmuir and Freundlich isotherm models to the adsorption isotherm data. The adsorption
behavior of Pb, Cd, and P were found to vary greatly from each other at each analyzed temperature. Pb
adsorption favored the Langmuir isotherm, while Cd and P favored the Freundlich isotherm. Further,
adsorption of Cd was found to be unfavorable to the spruce sawdust adsorbent. Apart from elucidating the
adsorption properties ofspruce sawdust for locally relevant contaminants, the adsorption data trends in this
work suggested that the temperature effects on the adsorption of Pb, Cd, and P vary. The effects of
decreasing temperature are not equal for the adsorption of these different sorbates, indicating adsorption
limitations at decreased temperatures, that may vary with respect to sorbates analyzed in adsorption studies.National Institute of Water Resources 2018AK138
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Engineering economic analysis of a rail extension from Dunbar siding to Livengood, Alaska
Full text linkThesis (M.S.) University of Alaska Fairbanks, 2011The Dunbar Siding to Livengood rail extension study is an economic prefeasibility investigation, and is conducted from two perspectives as a cost benefit analysis. The first perspective is, that of the Alaska Railroad Corporation (ARRC) in which the capital and operating costs of the proposed extension are recovered through the revenue stream resulting from the out-bound mineral freight loads, the in-bound re-supply freight loads, and the potential commuter passenger service to mining projects and communities in the Livengood area. The second perspective is that of the private sector in which a shipping sensitivity and employee transport analysis with respect to mining project developments. The large mineral resource base within the Dunbar-Livengood Corridor indicates an excellent freight potential with generous benefits for Alaska's economy of greater than $2 billion annually in gross revenues; whereas, resource and rail development are synergistic.Alaska Department of Transportation/Public Facilities1.0. Introduction -- 1.1. Opening -- 1.2. Foreground -- 2.0. Location and geologic hazards -- 2.1. General route setting -- 2.2. Bedrock geology -- 2.3. Surficial geology -- 2.4. Seismicity -- 2.5. Aufies/Icings -- 2.6. Frozen ground -- 3.0 History -- 3.1. Brief history of the Alaska Railroad -- 3.2. History of mining in Livengood -- 4.0. Methods and models -- 4.1. Freight modeling summary -- 4.2. ARRC model -- 4.3. Initial rail operation cost estimates -- 4.4. Final rail operation cost estimates -- 4.5. Freight sources -- 4.5.1. ITH, money knob project freight model -- 4.5.2. Shorty Creek project -- 4.5.3. Globe Creek limestone project -- 4.5.4. Probable prospects -- 4.5.5. Ore prospect tonnage model -- 4.5.6. Timber resources -- 4.5.7. Tourism -- 4.5.8. Truck freight -- 4.6. Rail freight model results -- 5.0. Livengood money knob project mine model -- 5.1. Introduction to Money Knob project model -- 5.2. Pit costs -- 5.3. Heap leach costs -- 5.4. Mill (floatation) costs -- 5.5. Gravity recovery circuit cost -- 5.6. Cyanide agitated leach costs -- 5.7. Carbon in pulp costs -- 5.8. Electric power -- 5.9. Trolley assisted haul summary -- 5.10. Mine model cash flow analysis -- 5.11. Mine modeling results, at specific tonnages -- 6.0. Economic benefits -- 7.0. Cost benefit analysis -- 7.1. ARRC perspective -- 7.2. Public perspective 7.3. Cost benefit results -- 8.0. Discussion -- 9.0. Conclusions and recommendations 9.1. Conclusions -- 9.2. Recommendations -- 10.0. References -- Appendix
Using the generalized interpolation material point method for fluid-solid interactions induced by surface tension
Full text linkDissertation (Ph.D.) University of Alaska Fairbanks, 2013.This thesis is devoted to the development of new, Generalized Interpolation Material Point Method (GIMP)-based algorithms for handling surface tension and contact (wetting) in fluid-solid interaction (FSI) problems at small scales. In these problems, surface tension becomes so dominant that its influence on both fluids and solids must be considered. Since analytical solutions for most engineering problems are usually unavailable, numerical methods are needed to describe and predict complicated time-dependent states in the solid and fluid involved due to surface tension effects. Traditional computational methods for handling fluid-solid interactions may not be effective due to their weakness in solving large-deformation problems and the complicated coupling of two different types of computational frameworks: one for solid, and the other for fluid. On the contrary, GIMP, a mesh-free algorithm for solid mechanics problems, is numerically effective in handling problems involving large deformations and fracture. Here we extend the capability of GIMP to handle fluid dynamics problems with surface tension, and to develop a new contact algorithm to deal with the wetting boundary conditions that include the modeling of contact angle and slip near the triple points where the three phases -- fluid, solid, and vapor -- meet. The error of the new GIMP algorithm for FSI problems at small scales, as verified by various benchmark problems, generally falls within the 5% range. In this thesis, we have successfully extended the capability of GIMP for handling FSI problems under surface tension in a one-solver numerical framework, a unique and innovative approach.Chapter 1. Introduction -- Chapter 2. Using the generalized interpolation material point method for fluid dynamics at low reynolds numbers -- Chapter 3. On the modeling of surface tension and its applications by the generalized interpolation material point method -- Chapter 4. Using the generalized interpolation material point method for fluid-solid interactions induced by surface tension -- Chapter 5. Conclusions
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