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Environmental Sciences

2016

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Articles 31 - 60 of 186

Full-Text Articles in Engineering

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/2 - Play 3 - 2016/06/12), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/2 - Play 3 - 2016/06/12), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/3 - Play 1 - 2016/06/08), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/3 - Play 1 - 2016/06/08), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10 - Play 2 - 2016/06/14), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10 - Play 2 - 2016/06/14), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/3 - Play 2 - 2016/06/08), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/3 - Play 2 - 2016/06/08), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10 - Play 1 - 2016/06/10), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10 - Play 1 - 2016/06/10), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/2 - Play 3 - 2016/06/12), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1/2 - Play 3 - 2016/06/12), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1 - Play 1 - 2016/06/07), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 1 - Play 1 - 2016/06/07), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10/11 - Play 4 - 2016/06/21), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10/11 - Play 4 - 2016/06/21), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10/11 - Play 4 - 2016/06/21), David Hanson Aug 2016

University Of New Mexico Bioalgal Energy, Photosynthesis Rates Of Poplar Plants - Measurements With Tdl Machine (Enriched Co2 - Enriched-Exposed - Tray 10/11 - Play 4 - 2016/06/21), David Hanson

Energize New Mexico (NSF EPSCoR Track 1 IV)

Collect the photosynthetic rate of poplar plants under different isotopic compositions of CO2 with the TDL machine and with the Licor equipment.


Nanostructured Thin Film Synthesis By Aerosol Chemical Vapor Deposition For Energy Storage Applications, Tandeep Singh Chadha Aug 2016

Nanostructured Thin Film Synthesis By Aerosol Chemical Vapor Deposition For Energy Storage Applications, Tandeep Singh Chadha

McKelvey School of Engineering Theses & Dissertations

Renewable energy sources offer a viable solution to the growing energy demand while mitigating concerns for greenhouse gas emissions and climate change. This has led to a tremendous momentum towards solar and wind-based energy harvesting technologies driving efficiencies higher and costs lower. However, the intermittent nature of these energy sources necessitates energy storage technologies, which remain the Achilles heel in meeting the renewable energy goals. This dissertation focusses on two approaches for addressing the needs of energy storage: first, targeting direct solar to fuel conversion via photoelectrochemical water-splitting and second, improving the performance of current rechargeable batteries by developing new …


Calcium Carbonate Formation In Energy-Related Subsurface Environments And Engineered Systems, Qingyun Li Aug 2016

Calcium Carbonate Formation In Energy-Related Subsurface Environments And Engineered Systems, Qingyun Li

McKelvey School of Engineering Theses & Dissertations

Geologic CO2 sequestration (GCS) in subsurface saline aquifers is a promising strategy to mitigate climate change caused by increasing anthropogenic CO2 emissions from energy production. At GCS sites, interactions between fluids and geomedia are important because they can affect CO2 trapping efficiency and the safety of CO2 storage. These interactions include the dissolution and precipitation of minerals. One of the most important minerals is calcium carbonate, because it can permanently trap CO2.

In this work, Portland cement was used as a model geomedium to investigate the chemical reactions, mechanical alterations, transport of reactive fluids, and the interplay of all these …


Experimental Testing And Validation Of P-Band Bi-Static Remote Sensing Of Soil Moisture In 137-138mhz Range, Xiangyu Qu, Yao-Cheng Lin, James L. Garrison Aug 2016

Experimental Testing And Validation Of P-Band Bi-Static Remote Sensing Of Soil Moisture In 137-138mhz Range, Xiangyu Qu, Yao-Cheng Lin, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Remote sensing using readily available communication signal transmitted by ORBCOMM satellites at very high frequency (VHF) range (137-138MHz) is a promising method for detecting the root zone soil moisture content. The radio wave reflectivity of soil is strongly correlated to soil moisture content. Therefore, if we were able to measure the reflectivity, we might be able to estimate the soil moisture content. In this preliminary study, we analyze direct signal data from the satellites to investigate and verify communication channels in frequency range of interest and their characteristics (bandwidth, pattern, etc.). The analysis of direct signal data is also used …


Exploring Regional And Telecoupled Land Use Change Impacts From Environmental Shocks, Kevin Hill, Liz Wachs, Brady Hardiman, David Yu, Shweta Singh Aug 2016

Exploring Regional And Telecoupled Land Use Change Impacts From Environmental Shocks, Kevin Hill, Liz Wachs, Brady Hardiman, David Yu, Shweta Singh

The Summer Undergraduate Research Fellowship (SURF) Symposium

Natural disasters or environmental shocks have the potential to disrupt local agricultural systems as well as distant agricultural systems through cascading effects. In this work we selected two distinct environmental shocks and traced their cascading effects on land use change. Quantifying cascading effects is a salient issue because climate change forecasts indicate an increase in frequency and intensity of global environmental shocks. This study incorporated the concept of telecoupled systems involving interrelating ecological, economic and political/social components. A telecoupled framework involving cascading effects was implemented using three approaches. The first approach involved using bilateral agricultural trade matrix data to analyze …


Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood Aug 2016

Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood

Doctoral Dissertations

An estimate of the United States wind potential conducted in 2011 found that the energy available at an altitude of 80 meters is approximately triple the wind energy available 50 meters above ground. In 2012, 43% of all new electricity generation installed in the U.S. (13.1 GW) came from wind power. The majority of this power, 79%, comes from large utility scale turbines that are being manufactured at unprecedented sizes. Existing wind plants operate with a capacity factor of only approximately 30%. Measurements have shown that the turbulent wake of a turbine persists for many rotor diameters, inducing increased vibration …


Lignin-Based Li-Ion Anode Materials Synthesized From Low-Cost Renewable Resources, Nicholas William Mcnutt Aug 2016

Lignin-Based Li-Ion Anode Materials Synthesized From Low-Cost Renewable Resources, Nicholas William Mcnutt

Doctoral Dissertations

In today’s world, the demand for novel methods of energy storage is increasing rapidly, particularly with the rise of portable electronic devices, electric vehicles, and the personal consumption and storage of solar energy. While other technologies have arguably improved at a rate that is exponential in accordance with Moore’s law, battery technology has lagged behind largely due to the difficulty in devising new electric storage systems that are simultaneously high performing, inexpensive, and safe.

In order to tackle these challenges, novel Li-ion battery anodes have been developed at Oak Ridge National Laboratory that are made from lignin, a low-cost, renewable …


Asbestos Cement Pipe Condition Assessment And Remaining Service Life Prediction, Abiy Melles Ghirmay Aug 2016

Asbestos Cement Pipe Condition Assessment And Remaining Service Life Prediction, Abiy Melles Ghirmay

Graduate Theses and Dissertations

This research details a condition assessment of asbestos cement (AC) pipe within in the Bella Vista Village Property Owners Association water distribution system. Bella Vista Village contains appropriately 300 miles of AC pipe with nominal diameters from 6-14 inch. The goal of the research is to determine the current condition of AC pipe within the system and predict future performance of the pipes. AC pipe samples were obtained from 23 locations disturbed across the distribution system with nominal pipe diameters of 6-8 inch. Estimates of current level of degradation were obtained using phenolphthalein staining and hardness measurements of each sample. …


Rational Design Of Cathode Materials For High Performance Lithium-Sulfur Batteries, Xi Chen Aug 2016

Rational Design Of Cathode Materials For High Performance Lithium-Sulfur Batteries, Xi Chen

Theses and Dissertations

Sulfur, one of most promising cathode candidates for next-generation lithium ion batteries, shows a limited cycling performance due to its shuttling effect, low conductivity, self-discharge and volume expansion during lithiation and delithiation process. According to the operation principles, failure mechanism, and recent progress on lithium-sulfur batteries, here we developed several scalable and rational synthesis methods for high performance cathode materials. We dissolved commercial sulfur to anhydrous ethylenediamine (EDA) to form an EDA-S precursor, and then we reduced the sulfur particles size at conductive carbon black substrate. The 70% theoretical capacity of sulfur cathode battery was obtained. We also melted commercial …


Addressing Instability Issues In Microgrids Caused By Constant Power Loads Using Energy Storage Systems, Eklas Hossain Aug 2016

Addressing Instability Issues In Microgrids Caused By Constant Power Loads Using Energy Storage Systems, Eklas Hossain

Theses and Dissertations

Renewable energy sources, the most reasonable fuel-shift taken over the naturally limited conventional fuels, necessarily deal with the self-functional microgrid system rather than the traditional grid distribution system. The study shows that the microgrid system, a comparatively low-powered system, experiences the challenge of instability due to the constant power load (CPL) from many electronic devices such as inverter-based systems. In this dissertation, as a methodical approach to mitigate the instability complication, AC microgrid stability is thoroughly investigated for each and every considerable parameter of the system. Furthermore, a specific loading limit is depicted by evaluating the stability margin from the …


Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey Aug 2016

Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey

Open Access Theses

Accurate geometric representation of the river channel is required for accurate hydraulic modeling of rivers. These are generally obtained through remote sensing techniques such as Light Detection and Ranging (LIDAR). However, these techniques lack the ability to model the submerged channel bed effectively and need to be complemented with surveyed bathymetric data for complete representation of the channel bathymetry, which can be time and cost prohibitive. An alternative to address this issue is to develop conceptual models that can estimate bathymetry.

This study aims to evaluate the potential of a conceptual model, the River Channel Morphology Model (RCMM) which estimates …


Enabling A Sustainable Economy Through Energy Systems Modeling: Solar-Centric, Efficient, Integrated And Continuous Process Synthesis And Optimization, Emre Gencer Aug 2016

Enabling A Sustainable Economy Through Energy Systems Modeling: Solar-Centric, Efficient, Integrated And Continuous Process Synthesis And Optimization, Emre Gencer

Open Access Dissertations

The expected increase in food, energy and water demand due to increase in population and change in consumption habits in conjunction with diminishing fossil fuel reserves and increasing greenhouse gas emissions urge the development and implementation of alternative energy conversion techniques using renewable energy for a sustainable economy. Among renewable energy sources, solar energy is prominent due to its abundance. A sustainable economy can be created by producing building blocks foundational to meeting all basic human needs of daily existence. However, intermittencies and limitations on land area dedicated to harness solar energy are the major obstacles on widespread implementation of …


Enhancing Silymarin Fractionation Via Molecular Modeling Using The Conductor-Like Screening Model For Real Solvents, Emma C. Brace Aug 2016

Enhancing Silymarin Fractionation Via Molecular Modeling Using The Conductor-Like Screening Model For Real Solvents, Emma C. Brace

Open Access Theses

The market for bio-based products from plant sources is on the rise. There is a global challenge to implement environmentally clean practices for the production of fuels and pharmaceuticals from sustainable resources. A significant hurdle for discovery of comparable plant-derived products is the extensive volume of trial-and-error experimentation required. To alleviate the experimental burden, a quantum mechanics based molecular modeling approach known as the COnductor-like Screening Model for Real Solvents (COSMO-RS) was used to predict the best biphasic solvent system to purify silymarins from an aqueous mixture. Silymarins are a class of flavonolignans present in milk thistle ( Silybum marianum …


Transient Control Of Synchronous Machine Active And Reactive Power In Micro-Grid Power Systems, Luke Gerard Weber Aug 2016

Transient Control Of Synchronous Machine Active And Reactive Power In Micro-Grid Power Systems, Luke Gerard Weber

Theses and Dissertations

There are two main topics associated with this dissertation. The first is to investigate

phase–to–neutral fault current magnitude occurring in generators with multiple zero–sequence

current sources. The second is to design, model, and tune a linear control system for oper-

ating a micro–grid in the event of a separation from the electric power system.

In the former case, detailed generator, AC8B excitation system, and four–wire electric

power system models are constructed. Where available, manufacturers data is used to

validate the generator and exciter models. A gain–delay with frequency droop control

is used to model an internal combustion engine and governor. …


Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile Aug 2016

Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile

Graduate Theses and Dissertations

This study investigated the effects of source water quality in Beaver Lake on the amount of chlorine (Cl) needed to develop decision support system to help guide chlorination practices in pre-treatment of source water. Chlorine demand assays were performed on water samples from Beaver Lake collected from the intake structure at Beaver Water District from March 2014 through August 2015, and using data from these assays, the two points of interest in this study were the Cl dose at which Cl residuals began to accumulate and the mean Cl demand occurring after that dose. Three methods of analysis were used …


Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson Aug 2016

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …


Assessing The Remanufacturability Of Office Furiniture: A Multi-Criteria Decision Making Approach, Po-Hsun Chen Aug 2016

Assessing The Remanufacturability Of Office Furiniture: A Multi-Criteria Decision Making Approach, Po-Hsun Chen

Theses and Dissertations

While the average life cycle of consumer goods is continuously decreasing, the amount of used product at their end-of-life (EOL) is accumulating fast at and at the same pace. Most EOL products end up in landfills, and many of which are not biodegradable. These two challenges have necessitated renewed global interest in product EOL management strategies by manufacturers, third party companies, consumers and governments. Remanufacturing is one of the EOL strategies which is highly environmental-friendly. Additionally, remanufacturing is seen as one of the highly profitable re-use business strategies. The selling price of remanufactured products is usually about 50—80% of a …


Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise Aug 2016

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …


Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau Aug 2016

Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau

Boise State University Theses and Dissertations

Thermoelectric half-Heusler compounds have potential to convert the heat wasted from industrial and transportation processes to useful electricity. Among the highest performing half-Heusler compounds are nano-structured bulk materials which have been arc-melted, pulverized into a nano-powder, and sintered by DC-hot press. High performing n- and p-type half-Heusler compounds with nominal composition of Hf0.25Zr0.75NiSn0.99Sb0.01 and Nb0.75Ti0.25FeSb, respectively, have been provided to us in both dense and powder form by our collaborators at the University of Houston. We consolidate these powders by SPS, refine these powders to improve both particle size …


The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii Aug 2016

The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii

Graduate Theses and Dissertations

Organic matter (OM) in the environment acts as a nutrient, but may also act as a transport vector for harmful chemical compounds and bacteria. Acetate is a labile form of OM produced during fermentation in anaerobic lagoons used to store animal fecal-waste from concentrated animal feeding operations (CAFOs). Dry and liquid fertilizers from CAFOs pose a threat to groundwater by introducing excessive amounts of nutrients (e.g. OM, nitrate and ammonia), metals, and antibiotic compounds. In the epikarst of Northern Arkansas in the Buffalo River watershed additional input of labile dissolved organic carbon (DOC) from liquid CAFO waste-fertilizers was hypothesized to …


The Use Of Sodium Persulfate In Hydraulic Fracturing Fluids: A Degradation Study Based On Furfural, Katherine Elizabeth Manz Aug 2016

The Use Of Sodium Persulfate In Hydraulic Fracturing Fluids: A Degradation Study Based On Furfural, Katherine Elizabeth Manz

Masters Theses

Hydraulic fracturing has allowed natural gas to become a viable energy source via extraction of unconventional shale reserves, but this process requires an enormous amount of water. To ensure a productive fracture, a proprietary blend of chemical additives is added to the water. In this research, a hydraulic fracturing chemical additive – an enzyme breaking agent – is analyzed for organic components using gas chromatography mass spectrometry. The chemical changes that occur over the course of a fracture are also investigated using one model chemical found in the additive, furfural, in order to help assess the environmental risk that hydraulic …


Miss Lonesome: Old Boats Past Their Prime, Garth Woodruff Aug 2016

Miss Lonesome: Old Boats Past Their Prime, Garth Woodruff

Faculty Publications

No abstract provided.