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Articles 1 - 11 of 11

Full-Text Articles in Engineering

The Potential For Co < Inf> 2 -Induced Acidification In Freshwater: A Great Lakes Case Study, Jennifer C. Phillips, Galen A. Mckinley, Val Bennington, Harvey A. Bootsma, Darren J. Pilcher, Robert W. Sterner, Noel Urban Oct 2015

The Potential For Co < Inf> 2 -Induced Acidification In Freshwater: A Great Lakes Case Study, Jennifer C. Phillips, Galen A. Mckinley, Val Bennington, Harvey A. Bootsma, Darren J. Pilcher, Robert W. Sterner, Noel Urban

Michigan Tech Publications

Ocean acidification will likely result in a drop of 0.3–0.4 pH units in the surface ocean by 2100, assuming anthropogenic CO2 emissions continue at the current rate. Impacts of increasing atmospheric pCO2 on pH in freshwater systems have scarcely been addressed. In this study, the Laurentian Great Lakes are used as a case study for the potential for CO2-induced acidification in freshwater systems as well as for assessment of the ability of current water quality monitoring to detect pH trends. If increasing atmospheric pCO2 is the only forcing, pH will decline in the Laurentian Great Lakes at the same rate …


The Impact Of Mpowir A Decade Of Investing In Mentoring Women In Physical Oceanography, Sarah Clem, Sonya Legg, Susan Lozier, Colleen B. Mouw Oct 2015

The Impact Of Mpowir A Decade Of Investing In Mentoring Women In Physical Oceanography, Sarah Clem, Sonya Legg, Susan Lozier, Colleen B. Mouw

Michigan Tech Publications

MPOWIR (Mentoring Physical Oceanography Women to Increase Retention) is a US communityinitiated and community-led mentoring program aimed at improving the retention of women physical oceanographers in academic and/or research positions. This article describes the MPOWIR program elements designed by the US physical oceanography community, quantifies the participation in these programs, describes MPOWIR’s impact to date, and outlines future directions. An examination of surveys to date indicates that MPOWIR, several years after its implementation, is having a positive impact on the retention of junior women in physical oceanography, primarily by giving them a broad professional network and focused mentoring.


Capturing Optically Important Constituents And Properties In A Marine Biogeochemical And Ecosystem Model, S. Dutkiewicz, A. E. Hickman, O. Jahn, W. W. Gregg, C. B. Mouw, M. J. Follows, C. Mouw Jul 2015

Capturing Optically Important Constituents And Properties In A Marine Biogeochemical And Ecosystem Model, S. Dutkiewicz, A. E. Hickman, O. Jahn, W. W. Gregg, C. B. Mouw, M. J. Follows, C. Mouw

Michigan Tech Publications

We present a numerical model of the ocean that couples a three-stream radiative transfer component with a marine biogeochemical-ecosystem component in a dynamic three-dimensional physical framework. The radiative transfer component resolves the penetration of spectral irradiance as it is absorbed and scattered within the water column. We explicitly include the effect of several optically important water constituents (different phytoplankton functional types; detrital particles; and coloured dissolved organic matter, CDOM). The model is evaluated against in situ-observed and satellite-derived products. In particular we compare to concurrently measured biogeochemical, ecosystem, and optical data along a meridional transect of the Atlantic Ocean. The …


Seasonal Variability Of Atmospheric Nitrogen Oxides And Non-Methane Hydrocarbons At The Geosummit Station, Greenland, L. J. Kramer, D. Helmig, J. F. Burkhart, A. Stohl, S. Oltmans, R. E. Honrath Jun 2015

Seasonal Variability Of Atmospheric Nitrogen Oxides And Non-Methane Hydrocarbons At The Geosummit Station, Greenland, L. J. Kramer, D. Helmig, J. F. Burkhart, A. Stohl, S. Oltmans, R. E. Honrath

Michigan Tech Publications

Measurements of atmospheric nitrogen oxides NOx (NOx = NO + NO2), peroxyacetyl nitrate (PAN), NOy, and non-methane hydrocarbons (NMHC) were taken at the Greenland Environmental Observatory at Summit (GEOSummit) station, Greenland (72.34° N, 38.29° W; 3212 m a.s.l.), from July 2008 to July 2010. The data set represents the first year-round concurrent record of these compounds sampled at a high latitude Arctic site. Here, the study focused on the seasonal variability of these important ozone (O3) precursors in the Arctic troposphere and the impact from transported anthropogenic and biomass burning emissions. Our analysis shows that PAN is the dominant NOy …


Spatial Analysis Of Mount St. Helens Tephra Leachate Compositions: Implications For Future Sampling Strategies, P. M. Ayris, P. Delmelle, B. Pereira, E. C. Maters, D. E. Damby, A. J. Durant, D. B. Dingwell Jun 2015

Spatial Analysis Of Mount St. Helens Tephra Leachate Compositions: Implications For Future Sampling Strategies, P. M. Ayris, P. Delmelle, B. Pereira, E. C. Maters, D. E. Damby, A. J. Durant, D. B. Dingwell

Michigan Tech Publications

Tephra particles in physically and chemically evolving volcanic plumes and clouds carry soluble sulphate and halide salts to the Earth’s surface, ultimately depositing volcanogenic compounds into terrestrial or aquatic environments. Upon leaching of tephra in water, these salts dissolve rapidly. Previous studies have investigated the spatial and temporal variability of tephra leachate compositions during an eruption in order to gain insight into the mechanisms of gas-tephra interaction which emplace those salts. However, the leachate datasets analysed are typically small and may poorly represent the natural variability and complexity of tephra deposits. Here, we have conducted a retrospective analysis of published …


Sensing Based On Fano-Type Resonance Response Of All-Dielectric Metamaterials, Elena Semouchkina, Ran Duan, George Semouchkin, Ravindra Pandey Apr 2015

Sensing Based On Fano-Type Resonance Response Of All-Dielectric Metamaterials, Elena Semouchkina, Ran Duan, George Semouchkin, Ravindra Pandey

Michigan Tech Publications

A new sensing approach utilizing Mie resonances in metamaterial arrays composed of dielectric resonators is proposed. These arrays were found to exhibit specific, extremely high-Q factor (up to 15,000) resonances at frequencies corresponding to the lower edge of the array second transmission band. The observed resonances possessed with features typical for Fano resonances (FRs), which were initially revealed in atomic processes and recently detected in macro-structures, where they resulted from interference between local resonances and a continuum of background waves. Our studies demonstrate that frequencies and strength of Fano-type resonances in all-dielectric arrays are defined by interaction between local Mie …


The Application Of Biomedical Engineering Techniques To The Diagnosis And Management Of Tropical Diseases: A Review, Fatimah Ibrahim, Tzer Hwai Gilbert Thio, Tarig Faisal, Michael Neuman Mar 2015

The Application Of Biomedical Engineering Techniques To The Diagnosis And Management Of Tropical Diseases: A Review, Fatimah Ibrahim, Tzer Hwai Gilbert Thio, Tarig Faisal, Michael Neuman

Michigan Tech Publications

This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications.


Railroad Capacity Tools And Methodologies In The U.S. And Europe, Hamed Pouryousef, Pasi Lautala, Thomas White Mar 2015

Railroad Capacity Tools And Methodologies In The U.S. And Europe, Hamed Pouryousef, Pasi Lautala, Thomas White

Michigan Tech Publications

A growing demand for passenger and freight transportation, combined with limited capital to expand the United States (U.S.) rail infrastructure, is creating pressure for a more efficient use of the current line capacity. This is further exacerbated by the fact that most passenger rail services operate on corridors that are shared with freight traffic. A capacity analysis is one alternative to address the situation and there are various approaches, tools, and methodologies available for application. As the U.S. continues to develop higher speed passenger services with similar characteristics to those in European shared-use lines, understanding the common methods and tools …


Ring-Opening Polymerization Of Ε-Caprolactone Initiated By Ganciclovir (Gcv) For The Preparation Of Gcv-Tagged Polymeric Micelles, Alicia J. Sawdon, Ching-An Peng Feb 2015

Ring-Opening Polymerization Of Ε-Caprolactone Initiated By Ganciclovir (Gcv) For The Preparation Of Gcv-Tagged Polymeric Micelles, Alicia J. Sawdon, Ching-An Peng

Michigan Tech Publications

Ganciclovir (GCV) is a nucleoside analogue with antiviral activity against herpes viral infections, and the most widely used antiviral to treat cytomegalovirus infections. However, the low bioavailability and short half-life of GCV necessitate the development of a carrier for sustained delivery. In this study, guanosine-based GCV was used as the initiator directly in ring-opening polymerization of ε-caprolactone (ε-CL) to form hydrophobic GCV-poly(caprolactone) (GCV-PCL) which was then grafted with hydrophilic chitosan to form amphiphilic copolymers for the preparation of stable micellar nanoparticles. Successful synthesis of GCV-PCL and GCV-PCL-chitosan were verified by 1H-NMR analysis. Self-assembled micellar nanoparticles were characterized by dynamic …


Stratospheric Volcanic Ash Emissions From The 13 February 2014 Kelut Eruption, N. I. Kristiansen, A. J. Prata, A. Stohl, S. A. Carn Jan 2015

Stratospheric Volcanic Ash Emissions From The 13 February 2014 Kelut Eruption, N. I. Kristiansen, A. J. Prata, A. Stohl, S. A. Carn

Michigan Tech Publications

Mount Kelut (Indonesia) erupted explosively around 15:50 UT on 13 February 2014 sending ash and gases into the stratosphere. Satellite ash retrievals and dispersion transport modeling are combined within an inversion framework to estimate the volcanic ash source term and to study ash transport. The estimated source term suggests that most of the ash was injected to altitudes of 16-17km, in agreement with space-based lidar data. Modeled ash concentrations along the flight track of a commercial aircraft that encountered the ash cloud indicate that it flew under the main ash cloud and encountered maximum ash concentrations of 9±3mgm-3, mean concentrations …


Reviews And Syntheses: Ocean Acidification And Its Potential Impacts On Marine Ecosystems, K. M.G. Mostofa, C. Q. Liu, W. D. Zhai, M. Minella, D. Vione, K. Gao, D. Minakata, T. Arakaki, T. Yoshioka, K. Hayakawa, E. Konohira, E. Tanoue, A. Akhand, A. Chanda, B. Wang, H. Sakugawa Jan 2015

Reviews And Syntheses: Ocean Acidification And Its Potential Impacts On Marine Ecosystems, K. M.G. Mostofa, C. Q. Liu, W. D. Zhai, M. Minella, D. Vione, K. Gao, D. Minakata, T. Arakaki, T. Yoshioka, K. Hayakawa, E. Konohira, E. Tanoue, A. Akhand, A. Chanda, B. Wang, H. Sakugawa

Michigan Tech Publications

Ocean acidification, a complex phenomenon that lowers seawater pH, is the net outcome of several contributions. They include the dissolution of increasing atmospheric CO2 that adds up with dissolved inorganic carbon (dissolved CO2, H2CO3, HCO3-, and CO32-) generated upon mineralization of primary producers (PP) and dissolved organic matter (DOM). The aquatic processes leading to inorganic carbon are substantially affected by increased DOM and nutrients via terrestrial runoff, acidic rainfall, increased PP and algal blooms, nitrification, denitrification, sulfate reduction, global warming (GW), and by atmospheric CO2 itself through enhanced photosynthesis. They are consecutively associated with enhanced ocean acidification, hypoxia in acidified …